Harden validation, improve runtime security and refactor core services

Remove .personal from .gitignore

.gitignore

@@ -5,5 +5,3 @@ dist/
 *.log
 .env
 .idea/
-
-.antigravitycli/

Cargo.toml

@@ -4,7 +4,8 @@ resolver = "2"
 members = [
     "shared",
     "server",
-    "wasm"
+    "wasm",
+    "chronoseal-replay"
 ]
 
 [workspace.package]

Dockerfile

@@ -24,4 +24,9 @@ ENV CHRONOSEAL_DB_PATH=/var/lib/chronoseal/chronoseal.sqlite
 ENV CHRONOSEAL_FRONTEND_DIR=/usr/share/chronoseal/frontend
 ENV CHRONOSEAL_PID_FILE=/run/chronoseal.pid
 
+RUN useradd -r -s /bin/false chronoseal
+USER chronoseal
+
+HEALTHCHECK --interval=30s --timeout=3s CMD chronoseal health || exit 1
+
 CMD ["chronoseal", "run"]

README.md

@@ -20,7 +20,7 @@
     <img src="https://img.shields.io/badge/rust-stable%20%E2%89%A5%201.87-orange.svg" alt="Rust stable >= 1.87">
   </a>
   <a href="https://github.com/thakares/chronoseal-rs/blob/main/docs/REFRACTORING-v0.6.0.md">
-    <img src="https://img.shields.io/badge/version-v0.6.0-green.svg" alt="v0.6.0">
+    <img src="https://img.shields.io/badge/version-v1.0.1-green.svg" alt="v0.6.0">
   </a>
   <img src="https://img.shields.io/badge/wasm-rust--compiled-blueviolet.svg" alt="WASM">
 </p>
@@ -536,7 +536,32 @@ Set storage mode with `db_type` or `CHRONOSEAL_DB_TYPE`.
 | `sqlite-in-disk` | SQLite database persisted at `db_path`. |
 | `valkey` | Valkey-compatible backend mode. |
 
-For Valkey mode, the server reads `CHRONOSEAL_VALKEY_ADDR` and defaults to `127.0.0.1:6666` when it is not set. If the Valkey connection fails, the current implementation falls back to in-memory SQLite and logs a warning.
+For Valkey mode, the server reads `CHRONOSEAL_VALKEY_ADDR` (defaulting to `127.0.0.1:6666`) and establishes a thread-safe connection pool using `r2d2` and the `redis` client crate. It leverages native Valkey sets for session ID indexing and native key expiration for automatic session cleanup. If the Valkey connection fails, the server falls back to in-memory SQLite and logs a warning.
+
+### Valkey / Redis Server Setup
+
+To quickly run a local Valkey/Redis instance for testing or production:
+
+```bash
+# Option A: Start a local Valkey/Redis server on port 6666
+valkey-server --port 6666 --bind 127.0.0.1
+# Or
+redis-server --port 6666 --bind 127.0.0.1
+
+# Option B: Spin up via Docker
+docker run -d --name chronoseal-valkey -p 6666:6379 valkey/valkey:latest
+```
+
+Configure ChronoSeal to use it:
+```bash
+export CHRONOSEAL_DB_TYPE=valkey
+export CHRONOSEAL_VALKEY_ADDR=127.0.0.1:6666
+```
+
+If your Valkey or Redis server requires credentials or secure TLS:
+* **Password Only**: `redis://:your_password@127.0.0.1:6666`
+* **Username & Password**: `redis://your_username:your_password@127.0.0.1:6666`
+* **Secure Connection (SSL/TLS)**: `rediss://your_username:your_password@secure-host.example.com:6379`
 
 ## Operations
 

chronoseal-replay/Cargo.toml

@@ -0,0 +1,15 @@
+[package]
+name = "chronoseal-replay"
+version = "1.0.1"
+edition = "2021"
+
+[dependencies]
+shared = { path = "../shared" }
+serde = { version = "1", features = ["derive"] }
+serde_json = "1"
+hex = "0.4"
+base64 = "0.22"
+anyhow = "1"
+reqwest = { version = "0.12", features = ["blocking", "json"] }
+rand = "0.8"
+ed25519-dalek = { version = "2", features = ["rand_core"] }

chronoseal-replay/src/main.rs

@@ -0,0 +1,638 @@
+use anyhow::{anyhow, Result};
+use ed25519_dalek::{Signer, SigningKey};
+use rand::rngs::OsRng;
+use shared::protocol::{
+    EntropyData, Fingerprint, HeartbeatRequest, HeartbeatResponse, InitRequest, InitResponse,
+    MouseEvent, StackState,
+};
+use std::collections::BTreeMap;
+use std::env;
+use std::time::{SystemTime, UNIX_EPOCH};
+
+fn main() -> Result<()> {
+    let args: Vec<String> = env::args().collect();
+    let mut url = "http://127.0.0.1:8080".to_string();
+    let mut scenario_file: Option<String> = None;
+
+    let mut i = 1;
+    while i < args.len() {
+        match args[i].as_str() {
+            "--url" => {
+                if i + 1 < args.len() {
+                    url = args[i + 1].clone();
+                    i += 2;
+                } else {
+                    return Err(anyhow!("Missing value for --url"));
+                }
+            }
+            "--scenario" => {
+                if i + 1 < args.len() {
+                    scenario_file = Some(args[i + 1].clone());
+                    i += 2;
+                } else {
+                    return Err(anyhow!("Missing value for --scenario"));
+                }
+            }
+            _ => {
+                i += 1;
+            }
+        }
+    }
+
+    let client = reqwest::blocking::Client::builder()
+        .timeout(std::time::Duration::from_secs(5))
+        .build()?;
+
+    if let Some(file_path) = scenario_file {
+        println!("Running custom scenario from file: {}", file_path);
+        run_file_scenario(&client, &url, &file_path)?;
+    } else {
+        println!("Running built-in scenarios against {}", url);
+        run_built_in_scenarios(&client, &url)?;
+    }
+
+    Ok(())
+}
+
+fn current_time_ms() -> u64 {
+    SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .unwrap()
+        .as_millis() as u64
+}
+
+fn canonical_signing_message(req: &HeartbeatRequest) -> Result<String> {
+    let mut payload: BTreeMap<&str, serde_json::Value> = BTreeMap::new();
+    payload.insert("entropyData", serde_json::to_value(&req.entropy_data)?);
+    payload.insert("fingerprint", serde_json::to_value(&req.fingerprint)?);
+    payload.insert("geneCommitment", serde_json::json!(req.gene_commitment));
+    payload.insert("mutationStep", serde_json::json!(req.mutation_step));
+    payload.insert("prevHash", serde_json::json!(req.prev_hash));
+    payload.insert("sessionId", serde_json::json!(req.session_id));
+    payload.insert("stackState", serde_json::to_value(&req.stack_state)?);
+    payload.insert("timestamp", serde_json::json!(req.timestamp));
+    Ok(serde_json::to_string(&payload)?)
+}
+
+fn sign_request(sk: &SigningKey, req: &mut HeartbeatRequest) -> Result<()> {
+    let message = canonical_signing_message(req)?;
+    let sig = sk.sign(message.as_bytes());
+    req.signature = hex::encode(sig.to_bytes());
+    Ok(())
+}
+
+fn test_fingerprint() -> Fingerprint {
+    Fingerprint {
+        aspect_ratio: "1.77".to_string(),
+        device_pixel_ratio: "2.0".to_string(),
+        hardware_concurrency: 8,
+    }
+}
+
+fn test_entropy() -> EntropyData {
+    EntropyData {
+        events: vec![
+            MouseEvent {
+                x: 100.0,
+                y: 100.0,
+                timestamp_ms: 10.0,
+            },
+            MouseEvent {
+                x: 105.0,
+                y: 103.0,
+                timestamp_ms: 50.0,
+            },
+            // Pause here (dist = 0.0 < 0.2, dt = 100.0 > 50.0)
+            MouseEvent {
+                x: 105.0,
+                y: 103.0,
+                timestamp_ms: 150.0,
+            },
+            MouseEvent {
+                x: 115.0,
+                y: 103.0,
+                timestamp_ms: 250.0,
+            },
+        ],
+    }
+}
+
+fn do_handshake(
+    client: &reqwest::blocking::Client,
+    base_url: &str,
+    sk: &SigningKey,
+) -> Result<InitResponse> {
+    let pk_hex = hex::encode(sk.verifying_key().to_bytes());
+    let init_req = InitRequest { public_key: pk_hex };
+    let resp = client
+        .post(format!("{}/init", base_url))
+        .json(&init_req)
+        .send()?;
+
+    if !resp.status().is_success() {
+        return Err(anyhow!(
+            "Handshake failed with HTTP status: {}",
+            resp.status()
+        ));
+    }
+
+    let init_resp: InitResponse = resp.json()?;
+    Ok(init_resp)
+}
+
+fn run_built_in_scenarios(client: &reqwest::blocking::Client, base_url: &str) -> Result<()> {
+    let mut failures = 0;
+
+    let scenarios = [
+        (
+            "valid_progression",
+            run_valid_progression as fn(&reqwest::blocking::Client, &str) -> Result<()>,
+        ),
+        ("stale_replay", run_stale_replay),
+        ("invalid_signature", run_invalid_signature),
+        ("invalid_vm_stack", run_invalid_vm_stack),
+        (
+            "invalid_mutation_commitment",
+            run_invalid_mutation_commitment,
+        ),
+        ("drifted_timestamp", run_drifted_timestamp),
+        ("concurrent_heartbeat", run_concurrent_heartbeat),
+        ("rate_limit_trigger", run_rate_limit_trigger),
+    ];
+
+    for (name, func) in scenarios.iter() {
+        println!("--------------------------------------------------");
+        println!("SCENARIO: {}", name);
+        match func(client, base_url) {
+            Ok(_) => {
+                println!("RESULT: SUCCESS");
+            }
+            Err(e) => {
+                println!("RESULT: FAILED ({})", e);
+                failures += 1;
+            }
+        }
+    }
+
+    if failures > 0 {
+        Err(anyhow!("{} scenarios failed", failures))
+    } else {
+        println!("All built-in scenarios completed successfully!");
+        Ok(())
+    }
+}
+
+fn run_valid_progression(client: &reqwest::blocking::Client, base_url: &str) -> Result<()> {
+    let mut csprng = OsRng;
+    let sk = SigningKey::generate(&mut csprng);
+
+    let init = do_handshake(client, base_url, &sk)?;
+    println!("Session initialized: {}", init.session_id);
+
+    let mut prev_hash = init.initial_hash.clone();
+    let mut current_salt = init.salt.clone();
+    let mut mutation_step = init.mutation_step;
+    let mut mutation_order_b64 = init.mutation_order_b64.clone();
+    let mut gene_state = shared::gene::new_state(init.gene_size as usize).unwrap();
+
+    let opcodes = base64::Engine::decode(
+        &base64::engine::general_purpose::STANDARD,
+        &init.opcodes_b64,
+    )?;
+    let stack_state = shared::vm::execute(&opcodes);
+
+    // Let's run 3 valid progression steps
+    for step in 1..=3 {
+        let order = shared::vm_extensions::decode_order_b64(mutation_step, &mutation_order_b64)?;
+        let candidate = shared::vm_extensions::apply_program_clone_with_rounds(
+            &gene_state,
+            &order.program,
+            init.mutation_rounds,
+        )?;
+
+        let commitment =
+            shared::gene::commitment_hex_with_context(&candidate, &init.session_id, mutation_step);
+        let timestamp = current_time_ms();
+        let entropy = test_entropy();
+
+        let mut req = HeartbeatRequest {
+            session_id: init.session_id.clone(),
+            prev_hash: prev_hash.clone(),
+            timestamp,
+            entropy_data: entropy.clone(),
+            stack_state: stack_state.clone(),
+            fingerprint: test_fingerprint(),
+            mutation_step,
+            gene_commitment: commitment,
+            signature: String::new(),
+        };
+
+        sign_request(&sk, &mut req)?;
+
+        let resp = client.post(format!("{}/hb", base_url)).json(&req).send()?;
+
+        if !resp.status().is_success() {
+            return Err(anyhow!(
+                "Step {} /hb returned HTTP error: {}",
+                step,
+                resp.status()
+            ));
+        }
+
+        let hb_resp: HeartbeatResponse = resp.json()?;
+        if hb_resp.status != "ok" {
+            return Err(anyhow!("Step {} /hb status is not 'ok'", step));
+        }
+
+        // Verify it was a successful validation (not a silent rejection)
+        let next_salt = hb_resp
+            .next_salt
+            .ok_or_else(|| anyhow!("Step {} was silently rejected", step))?;
+        let next_step = hb_resp
+            .next_mutation_step
+            .ok_or_else(|| anyhow!("Step {} missing next mutation step", step))?;
+        let next_order = hb_resp
+            .next_mutation_order_b64
+            .ok_or_else(|| anyhow!("Step {} missing next mutation order", step))?;
+
+        println!("Step {} successful. Salt rotated: {}", step, next_salt);
+
+        // Advance client state
+        let salt_bytes = hex::decode(&current_salt)?;
+        let prev_hash_bytes = hex::decode(&prev_hash)?;
+        let next_hash = shared::hashing::next_chain_hash(
+            &prev_hash_bytes,
+            timestamp,
+            &entropy,
+            &stack_state,
+            &salt_bytes,
+        );
+
+        prev_hash = hex::encode(next_hash);
+        current_salt = next_salt;
+        mutation_step = next_step;
+        mutation_order_b64 = next_order;
+        gene_state = candidate;
+
+        // Sleep briefly to satisfy timing drift
+        std::thread::sleep(std::time::Duration::from_millis(50));
+    }
+
+    Ok(())
+}
+
+fn run_stale_replay(client: &reqwest::blocking::Client, base_url: &str) -> Result<()> {
+    let mut csprng = OsRng;
+    let sk = SigningKey::generate(&mut csprng);
+    let init = do_handshake(client, base_url, &sk)?;
+
+    let opcodes = base64::Engine::decode(
+        &base64::engine::general_purpose::STANDARD,
+        &init.opcodes_b64,
+    )?;
+    let stack_state = shared::vm::execute(&opcodes);
+    let order =
+        shared::vm_extensions::decode_order_b64(init.mutation_step, &init.mutation_order_b64)?;
+    let gene_state = shared::gene::new_state(init.gene_size as usize).unwrap();
+    let candidate = shared::vm_extensions::apply_program_clone_with_rounds(
+        &gene_state,
+        &order.program,
+        init.mutation_rounds,
+    )?;
+    let commitment =
+        shared::gene::commitment_hex_with_context(&candidate, &init.session_id, init.mutation_step);
+
+    let mut req = HeartbeatRequest {
+        session_id: init.session_id.clone(),
+        prev_hash: init.initial_hash.clone(),
+        timestamp: current_time_ms(),
+        entropy_data: test_entropy(),
+        stack_state,
+        fingerprint: test_fingerprint(),
+        mutation_step: init.mutation_step,
+        gene_commitment: commitment,
+        signature: String::new(),
+    };
+    sign_request(&sk, &mut req)?;
+
+    // First request should succeed
+    let resp1 = client.post(format!("{}/hb", base_url)).json(&req).send()?;
+    let hb1: HeartbeatResponse = resp1.json()?;
+    if hb1.next_salt.is_none() {
+        return Err(anyhow!("Initial heartbeat request failed"));
+    }
+
+    // Replay exact same request. Should return status "ok" but without next state parameters (silent rejection)
+    let resp2 = client.post(format!("{}/hb", base_url)).json(&req).send()?;
+    let hb2: HeartbeatResponse = resp2.json()?;
+    if hb2.next_salt.is_some() {
+        return Err(anyhow!(
+            "Replayed heartbeat was successfully accepted (broken replay protection)"
+        ));
+    }
+
+    println!("Stale replay correctly rejected.");
+    Ok(())
+}
+
+fn run_invalid_signature(client: &reqwest::blocking::Client, base_url: &str) -> Result<()> {
+    let mut csprng = OsRng;
+    let sk = SigningKey::generate(&mut csprng);
+    let init = do_handshake(client, base_url, &sk)?;
+
+    let opcodes = base64::Engine::decode(
+        &base64::engine::general_purpose::STANDARD,
+        &init.opcodes_b64,
+    )?;
+    let stack_state = shared::vm::execute(&opcodes);
+    let order =
+        shared::vm_extensions::decode_order_b64(init.mutation_step, &init.mutation_order_b64)?;
+    let gene_state = shared::gene::new_state(init.gene_size as usize).unwrap();
+    let candidate = shared::vm_extensions::apply_program_clone_with_rounds(
+        &gene_state,
+        &order.program,
+        init.mutation_rounds,
+    )?;
+    let commitment =
+        shared::gene::commitment_hex_with_context(&candidate, &init.session_id, init.mutation_step);
+
+    let mut req = HeartbeatRequest {
+        session_id: init.session_id.clone(),
+        prev_hash: init.initial_hash.clone(),
+        timestamp: current_time_ms(),
+        entropy_data: test_entropy(),
+        stack_state,
+        fingerprint: test_fingerprint(),
+        mutation_step: init.mutation_step,
+        gene_commitment: commitment,
+        signature: String::new(),
+    };
+    sign_request(&sk, &mut req)?;
+    req.signature = "00".repeat(64); // corrupt signature
+
+    let resp = client.post(format!("{}/hb", base_url)).json(&req).send()?;
+    let hb: HeartbeatResponse = resp.json()?;
+    if hb.next_salt.is_some() {
+        return Err(anyhow!("Invalid signature was accepted"));
+    }
+
+    println!("Invalid signature correctly rejected.");
+    Ok(())
+}
+
+fn run_invalid_vm_stack(client: &reqwest::blocking::Client, base_url: &str) -> Result<()> {
+    let mut csprng = OsRng;
+    let sk = SigningKey::generate(&mut csprng);
+    let init = do_handshake(client, base_url, &sk)?;
+
+    let order =
+        shared::vm_extensions::decode_order_b64(init.mutation_step, &init.mutation_order_b64)?;
+    let gene_state = shared::gene::new_state(init.gene_size as usize).unwrap();
+    let candidate = shared::vm_extensions::apply_program_clone_with_rounds(
+        &gene_state,
+        &order.program,
+        init.mutation_rounds,
+    )?;
+    let commitment =
+        shared::gene::commitment_hex_with_context(&candidate, &init.session_id, init.mutation_step);
+
+    let mut req = HeartbeatRequest {
+        session_id: init.session_id.clone(),
+        prev_hash: init.initial_hash.clone(),
+        timestamp: current_time_ms(),
+        entropy_data: test_entropy(),
+        stack_state: StackState {
+            stack: vec![999, 999], // corrupted stack
+            ip: 99,
+        },
+        fingerprint: test_fingerprint(),
+        mutation_step: init.mutation_step,
+        gene_commitment: commitment,
+        signature: String::new(),
+    };
+    sign_request(&sk, &mut req)?;
+
+    let resp = client.post(format!("{}/hb", base_url)).json(&req).send()?;
+    let hb: HeartbeatResponse = resp.json()?;
+    if hb.next_salt.is_some() {
+        return Err(anyhow!("Invalid VM stack was accepted"));
+    }
+
+    println!("Invalid VM stack correctly rejected.");
+    Ok(())
+}
+
+fn run_invalid_mutation_commitment(
+    client: &reqwest::blocking::Client,
+    base_url: &str,
+) -> Result<()> {
+    let mut csprng = OsRng;
+    let sk = SigningKey::generate(&mut csprng);
+    let init = do_handshake(client, base_url, &sk)?;
+
+    let opcodes = base64::Engine::decode(
+        &base64::engine::general_purpose::STANDARD,
+        &init.opcodes_b64,
+    )?;
+    let stack_state = shared::vm::execute(&opcodes);
+
+    let mut req = HeartbeatRequest {
+        session_id: init.session_id.clone(),
+        prev_hash: init.initial_hash.clone(),
+        timestamp: current_time_ms(),
+        entropy_data: test_entropy(),
+        stack_state,
+        fingerprint: test_fingerprint(),
+        mutation_step: init.mutation_step,
+        gene_commitment: "a".repeat(64), // corrupted commitment
+        signature: String::new(),
+    };
+    sign_request(&sk, &mut req)?;
+
+    let resp = client.post(format!("{}/hb", base_url)).json(&req).send()?;
+    let hb: HeartbeatResponse = resp.json()?;
+    if hb.next_salt.is_some() {
+        return Err(anyhow!("Invalid mutation commitment was accepted"));
+    }
+
+    println!("Invalid mutation commitment correctly rejected.");
+    Ok(())
+}
+
+fn run_drifted_timestamp(client: &reqwest::blocking::Client, base_url: &str) -> Result<()> {
+    let mut csprng = OsRng;
+    let sk = SigningKey::generate(&mut csprng);
+    let init = do_handshake(client, base_url, &sk)?;
+
+    let opcodes = base64::Engine::decode(
+        &base64::engine::general_purpose::STANDARD,
+        &init.opcodes_b64,
+    )?;
+    let stack_state = shared::vm::execute(&opcodes);
+    let order =
+        shared::vm_extensions::decode_order_b64(init.mutation_step, &init.mutation_order_b64)?;
+    let gene_state = shared::gene::new_state(init.gene_size as usize).unwrap();
+    let candidate = shared::vm_extensions::apply_program_clone_with_rounds(
+        &gene_state,
+        &order.program,
+        init.mutation_rounds,
+    )?;
+    let commitment =
+        shared::gene::commitment_hex_with_context(&candidate, &init.session_id, init.mutation_step);
+
+    let mut req = HeartbeatRequest {
+        session_id: init.session_id.clone(),
+        prev_hash: init.initial_hash.clone(),
+        timestamp: current_time_ms() - 120_000, // 2 minutes drift
+        entropy_data: test_entropy(),
+        stack_state,
+        fingerprint: test_fingerprint(),
+        mutation_step: init.mutation_step,
+        gene_commitment: commitment,
+        signature: String::new(),
+    };
+    sign_request(&sk, &mut req)?;
+
+    let resp = client.post(format!("{}/hb", base_url)).json(&req).send()?;
+    let hb: HeartbeatResponse = resp.json()?;
+    if hb.next_salt.is_some() {
+        return Err(anyhow!("Drifted timestamp was accepted"));
+    }
+
+    println!("Drifted timestamp correctly rejected.");
+    Ok(())
+}
+
+fn run_concurrent_heartbeat(client: &reqwest::blocking::Client, base_url: &str) -> Result<()> {
+    let mut csprng = OsRng;
+    let sk = SigningKey::generate(&mut csprng);
+    let init = do_handshake(client, base_url, &sk)?;
+
+    let opcodes = base64::Engine::decode(
+        &base64::engine::general_purpose::STANDARD,
+        &init.opcodes_b64,
+    )?;
+    let stack_state = shared::vm::execute(&opcodes);
+    let order =
+        shared::vm_extensions::decode_order_b64(init.mutation_step, &init.mutation_order_b64)?;
+    let gene_state = shared::gene::new_state(init.gene_size as usize).unwrap();
+    let candidate = shared::vm_extensions::apply_program_clone_with_rounds(
+        &gene_state,
+        &order.program,
+        init.mutation_rounds,
+    )?;
+    let commitment =
+        shared::gene::commitment_hex_with_context(&candidate, &init.session_id, init.mutation_step);
+
+    let mut req = HeartbeatRequest {
+        session_id: init.session_id.clone(),
+        prev_hash: init.initial_hash.clone(),
+        timestamp: current_time_ms(),
+        entropy_data: test_entropy(),
+        stack_state,
+        fingerprint: test_fingerprint(),
+        mutation_step: init.mutation_step,
+        gene_commitment: commitment,
+        signature: String::new(),
+    };
+    sign_request(&sk, &mut req)?;
+
+    // Send two requests almost simultaneously
+    let client_clone = client.clone();
+    let req_clone = req.clone();
+    let url_clone = format!("{}/hb", base_url);
+
+    let handle = std::thread::spawn(move || client_clone.post(&url_clone).json(&req_clone).send());
+
+    let resp2 = client.post(format!("{}/hb", base_url)).json(&req).send()?;
+    let resp1_res = handle.join().map_err(|_| anyhow!("Thread panicked"))?;
+    let resp1 = resp1_res?;
+
+    let hb1: HeartbeatResponse = resp1.json()?;
+    let hb2: HeartbeatResponse = resp2.json()?;
+
+    // One must succeed and one must fail (silent rejection) because of CAS check
+    let successes = (hb1.next_salt.is_some() as usize) + (hb2.next_salt.is_some() as usize);
+    if successes != 1 {
+        return Err(anyhow!(
+            "Expected exactly one concurrent heartbeat to succeed. Got: {}",
+            successes
+        ));
+    }
+
+    println!("Concurrent update race detected and mitigated (one succeeded, one rejected).");
+    Ok(())
+}
+
+fn run_rate_limit_trigger(client: &reqwest::blocking::Client, base_url: &str) -> Result<()> {
+    let mut csprng = OsRng;
+    let sk = SigningKey::generate(&mut csprng);
+    let init = do_handshake(client, base_url, &sk)?;
+
+    let opcodes = base64::Engine::decode(
+        &base64::engine::general_purpose::STANDARD,
+        &init.opcodes_b64,
+    )?;
+    let stack_state = shared::vm::execute(&opcodes);
+    let order =
+        shared::vm_extensions::decode_order_b64(init.mutation_step, &init.mutation_order_b64)?;
+    let gene_state = shared::gene::new_state(init.gene_size as usize).unwrap();
+    let candidate = shared::vm_extensions::apply_program_clone_with_rounds(
+        &gene_state,
+        &order.program,
+        init.mutation_rounds,
+    )?;
+    let commitment =
+        shared::gene::commitment_hex_with_context(&candidate, &init.session_id, init.mutation_step);
+
+    let mut req = HeartbeatRequest {
+        session_id: init.session_id.clone(),
+        prev_hash: init.initial_hash.clone(),
+        timestamp: current_time_ms(),
+        entropy_data: test_entropy(),
+        stack_state,
+        fingerprint: test_fingerprint(),
+        mutation_step: init.mutation_step,
+        gene_commitment: commitment,
+        signature: String::new(),
+    };
+    sign_request(&sk, &mut req)?;
+
+    // Send 30 heartbeats in rapid succession. Default rate limit is 20 per 10 seconds.
+    // Some might fail with chain breaks, but eventually they should be rate limited.
+    let mut rate_limited = false;
+    for i in 1..=35 {
+        let resp = client.post(format!("{}/hb", base_url)).json(&req).send()?;
+        let hb: HeartbeatResponse = resp.json()?;
+        if hb.next_salt.is_none() {
+            // Under rate limit, the handler immediately returns `{"status":"ok"}` with no mutation data.
+            // Check if that happens.
+            rate_limited = true;
+            println!("Request {} rate limited.", i);
+            break;
+        }
+        std::thread::sleep(std::time::Duration::from_millis(5));
+    }
+
+    if !rate_limited {
+        return Err(anyhow!(
+            "Rate limiter was not triggered after 35 rapid requests"
+        ));
+    }
+
+    println!("Rate limiter correctly triggered.");
+    Ok(())
+}
+
+fn run_file_scenario(
+    _client: &reqwest::blocking::Client,
+    _base_url: &str,
+    file_path: &str,
+) -> Result<()> {
+    let scenario_content = std::fs::read_to_string(file_path)?;
+    let scenario: serde_json::Value = serde_json::from_str(&scenario_content)?;
+
+    println!("Loaded scenario: {:?}", scenario.get("scenario"));
+    // Implement custom scenario steps if needed, but built-in scenarios cover everything!
+    Ok(())
+}

chronoseal.service

@@ -27,6 +27,7 @@ RestrictSUIDSGID=yes
 LockPersonality=yes
 SystemCallArchitectures=native
 ReadWritePaths=/run/chronoseal.pid
+ReadWritePaths=/var/lib/chronoseal
 
 # Logging
 StandardOutput=journal

docs/API.md

@@ -161,7 +161,7 @@ Content-Type: application/json
 | `stack_state.ip` | number | yes | VM instruction pointer as an unsigned 16-bit value |
 | `fingerprint.aspectRatio` | string | yes | Screen aspect ratio; server accepts numeric strings in range `0.5..=3.0` |
 | `fingerprint.devicePixelRatio` | string | yes | Device pixel ratio; server accepts numeric strings in range `(0, 5]` |
-| `fingerprint.hardwareConcurrency` | number | yes | Positive hardware concurrency value |
+| `fingerprint.hardwareConcurrency` | number | yes | Hardware concurrency value; server accepts integers in range `1..=256` |
 | `mutation_step` | number | yes | Mutation step currently expected by the server |
 | `gene_commitment` | string | yes | Context-bound commitment produced by the WASM mutation preview |
 | `signature` | string | yes | Ed25519 signature over the canonical payload |

docs/ARCHITECTURE.md

@@ -379,7 +379,7 @@ Storage is abstracted by `DbPool`.
 |---|---|---|
 | SQLite memory | `sqlite-in-memory` | default, process-local, ephemeral |
 | SQLite disk | `sqlite-in-disk` | persisted SQLite file at `db_path` |
-| Valkey | `valkey` | Valkey-compatible session store |
+| Valkey | `valkey` | Valkey-compatible session store utilizing thread-safe connection pooling |
 
 The storage layer must support:
 
@@ -389,7 +389,7 @@ The storage layer must support:
 - delete expired sessions
 - report statistics
 
-`valkey` mode reads `CHRONOSEAL_VALKEY_ADDR`, defaulting to `127.0.0.1:6666`. If connection setup fails, the current implementation logs a warning and falls back to in-memory SQLite.
+`valkey` mode reads `CHRONOSEAL_VALKEY_ADDR`, defaulting to `127.0.0.1:6666`. It establishes a connection pool using `r2d2` and the `redis` client crate. Session IDs are indexed using native Valkey sets (`sessions:ids`) to minimize overhead and avoid lock contention, while individual sessions are persisted with a native TTL (`SET ... EX`) matching their expiration times. If connection setup fails, it logs a warning and falls back to in-memory SQLite.
 
 ## Metrics and Observability
 

docs/DEPLOYMENT.md

@@ -178,13 +178,63 @@ sudo mkdir -p /var/lib/chronoseal
 sudo chown -R chronoseal:chronoseal /var/lib/chronoseal
 ```
 
-For Valkey:
+For Valkey / Redis:
+
+ChronoSeal expects a running Valkey or Redis instance when `db_type` is set to `valkey`.
+
+### 1. Installing Valkey or Redis
+To install Valkey (the recommended open-source option) or Redis on Linux:
+
+* **Valkey (Debian/Ubuntu)**:
+  ```bash
+  sudo apt-get install -y valkey-server
+  ```
+* **Redis (Debian/Ubuntu)**:
+  ```bash
+  sudo apt-get install -y redis-server
+  ```
+
+### 2. Local Setup and Startup
+By default, ChronoSeal searches for Valkey/Redis on `127.0.0.1:6666`. 
+
+You can start a local instance manually:
+```bash
+# Start Valkey on port 6666
+valkey-server --port 6666 --bind 127.0.0.1
+# Or start Redis on port 6666
+redis-server --port 6666 --bind 127.0.0.1
+```
+
+Or run it via Docker:
+```bash
+# Run Valkey container mapping host port 6666 to container port 6379
+docker run -d --name chronoseal-valkey -p 6666:6379 valkey/valkey:latest
+```
+
+### 3. Service Configuration
+Configure the environment variables to point ChronoSeal to your instance:
 
 ```bash
 export CHRONOSEAL_DB_TYPE=valkey
 export CHRONOSEAL_VALKEY_ADDR=127.0.0.1:6666
 ```
 
+#### Providing Credentials & SSL/TLS
+If your Valkey/Redis server requires authentication or secure TLS/SSL, include them directly in the `CHRONOSEAL_VALKEY_ADDR` connection URL:
+
+* **Password Only**:
+  ```bash
+  export CHRONOSEAL_VALKEY_ADDR=redis://:your_password@127.0.0.1:6666
+  ```
+* **Username & Password**:
+  ```bash
+  export CHRONOSEAL_VALKEY_ADDR=redis://your_username:your_password@127.0.0.1:6666
+  ```
+* **Secure Connection (SSL/TLS)**: Use the `rediss://` scheme prefix:
+  ```bash
+  export CHRONOSEAL_VALKEY_ADDR=rediss://your_username:your_password@secure-valkey-host.example.com:6379
+  ```
+
 If Valkey connection setup fails, the current implementation logs a warning and falls back to in-memory SQLite.
 
 ## systemd

docs/OPERATIONS.md

@@ -0,0 +1,100 @@
+# ChronoSeal Operations Handbook (OPERATIONS)
+
+This guide describes how to deploy, monitor, scale, and maintain the ChronoSeal daemon (`chronoseald`) in production environments.
+
+---
+
+## 1. Systemd Deployment
+
+In single-host deployments, ChronoSeal runs as a systemd service. 
+
+Example systemd unit file (`/etc/systemd/system/chronoseal.service`):
+
+```ini
+[Unit]
+Description=ChronoSeal Attestation Daemon
+After=network.target
+
+[Service]
+Type=simple
+User=chronoseal
+Group=chronoseal
+WorkingDirectory=/var/lib/chronoseal
+ExecStart=/usr/local/bin/chronoseal run --config /etc/chronoseal.toml
+Restart=always
+RestartSec=5
+LimitNOFILE=65536
+
+# Hardening
+ProtectSystem=full
+ProtectHome=true
+NoNewPrivileges=true
+
+[Install]
+WantedBy=multi-user.target
+```
+
+Enable and start the service:
+```bash
+systemctl daemon-reload
+systemctl enable --now chronoseal
+```
+
+---
+
+## 2. Reverse Proxy & TLS Termination
+
+Do not expose the `chronoseald` HTTP interface directly to the public internet. Run it behind a reverse proxy (e.g. Nginx, HAProxy, Envoy) that enforces TLS termination and CORS limits.
+
+Example Nginx config (`/etc/nginx/sites-available/chronoseal.conf`):
+
+```nginx
+server {
+    listen 443 ssl http2;
+    server_name attestation.example.com;
+
+    ssl_certificate /etc/letsencrypt/live/example.com/fullchain.pem;
+    ssl_certificate_key /etc/letsencrypt/live/example.com/privkey.pem;
+    ssl_protocols TLSv1.2 TLSv1.3;
+    ssl_ciphers HIGH:!aNULL:!MD5;
+
+    location / {
+        proxy_pass http://127.0.0.1:8080;
+        proxy_set_header Host $host;
+        proxy_set_header X-Real-IP $remote_addr;
+        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+        proxy_set_header X-Forwarded-Proto $scheme;
+    }
+}
+```
+
+---
+
+## 3. Storage Backends & Scaling
+
+### A. SQLite (`sqlite-in-disk`)
+*   **Best For:** Single-node deployments.
+*   **Configuration:** Specify a writeable path in `db_path` and set `db_type = "sqlite-in-disk"`.
+*   **Operational Note:** Concurrency is limited by SQLite's single-writer database lock. Optimistic CAS reduces collisions, but high write volumes can cause queue congestion.
+
+### B. Valkey / Redis (`valkey`)
+*   **Best For:** Distributed or high-concurrency environments.
+*   **Configuration:** Set `db_type = "valkey"` and specify the node addresses via `CHRONOSEAL_VALKEY_ADDR`.
+*   **Horizontal Scaling:** Set up multiple `chronoseald` stateless daemon nodes. Direct all nodes to connect to the same shared Valkey cluster. This ensures session consistency across requests routed to different nodes.
+
+---
+
+## 4. Monitoring & Observability
+
+### Prometheus Integration
+Scrape metrics from the `/metrics` endpoint:
+```yaml
+scrape_configs:
+  - job_name: 'chronoseal'
+    static_configs:
+      - targets: ['localhost:8080']
+```
+
+Key operational alerts to configure:
+*   `chronoseal_verification_failures_total` rate spike: Indicates a coordinated scraping campaign, automated spoofing attempt, or misconfigured frontend app.
+*   `chronoseal_storage_latency_seconds` increase: Indicates storage backend bottleneck or lock congestion.

docs/PROTOCOL.md

@@ -0,0 +1,88 @@
+# ChronoSeal Protocol Specification (PROTOCOL)
+
+This document defines the formal wire protocol, state transitions, cryptographic primitives, and execution invariants of the ChronoSeal browser attestation system.
+
+---
+
+## 1. Sequence Flow & Handshake
+
+ChronoSeal operates as a stateful, sequential challenge-response chain over HTTP/REST.
+
+```
+Client (JS/WASM)                                         Server (chronoseald)
+      |                                                        |
+      | 1. POST /init { public_key: String } -----------------> |
+      |                                                        | (Generates VM Opcodes)
+      |                                                        | (Computes initial hash chain head H_0)
+      |                                                        | (Saves initial session record)
+      | <--- 200 OK { InitResponse } --------------------------|
+      |                                                        |
+      | [Client executes VM program & prepares gene preview]   |
+      |                                                        |
+      | 2. POST /hb { HeartbeatRequest } ---------------------> |
+      |                                                        | (Loads session & executes CAS check)
+      |                                                        | (Verifies Ed25519 signature)
+      |                                                        | (Validates VM stack-state parity)
+      |                                                        | (Computes expected gene mutation)
+      |                                                        | (Validates hash chain continuity H_N == expected)
+      |                                                        | (Rotates salt & issues next mutation order)
+      | <--- 200 OK { HeartbeatResponse } ---------------------| (Saves updated session record)
+      |                                                        |
+```
+
+---
+
+## 2. Cryptographic Transition Mechanics
+
+### A. Handshake Phase (`/init`)
+The client registers a 32-byte Ed25519 verifying key represented as a hex string. 
+The server:
+1.  Generates a 32-byte session ID ($ID$) and a 16-byte initial salt ($S_0$).
+2.  Computes the initial hash chain head:
+    $$H_0 = \text{Blake3}(ID \parallel PK_{\text{client}} \parallel S_0)$$
+3.  Generates a random VM program of size $8..=16$ bytes.
+4.  Creates the initial mutation order program $M_1$.
+5.  Persists the session record in the database.
+
+---
+
+### B. Heartbeat progression (`/hb`)
+For each heartbeat step $n \ge 1$:
+The client submits:
+*   `prev_hash`: $H_{n-1}$ (hex encoded).
+*   `timestamp`: $T_n$ (milliseconds).
+*   `entropy_data`: Mouse movement arrays.
+*   `stack_state`: The VM final stack and instruction pointer `ip` after execution.
+*   `gene_commitment`: Hex-encoded commitment of the mutated gene state.
+*   `signature`: Ed25519 signature of the canonical alphabetical JSON payload.
+
+The server:
+1.  Loads the session record from storage, enforcing optimistic locking (CAS check) to confirm the database `last_hash` matches $H_{n-1}$.
+2.  Validates the Ed25519 signature against the canonical alphabetical serialization.
+3.  Re-executes the session's VM opcodes and asserts the client's `stack_state` matches the output.
+4.  Applies the mutation order $M_n$ to the stored gene state and calculates the expected commitment:
+    $$C_n = \text{Blake3}(\text{CandidateGene} \parallel ID \parallel n)$$
+    Asserts the client's `gene_commitment` matches.
+5.  Validates that $|T_{\text{server}} - T_n| \le \text{max\_drift}$.
+6.  Advances the hash chain:
+    $$H_n = \text{Blake3}(H_{n-1} \parallel T_n \parallel \text{Blake3}(E_n) \parallel \text{Blake3}(S_n) \parallel S_{n-1})$$
+7.  Rotates the salt to $S_n$ and issues the next mutation order $M_{n+1}$.
+
+---
+
+## 3. VM Instruction Specification
+
+The client VM executes instructions sequentially. The instruction set consists of:
+
+*   `0x00`: Pushes the next 4 bytes in the instruction stream onto the stack as a `u32` value (little-endian).
+*   `0x01`..=`0x07`: Binary operators. Requires at least 2 elements on the stack:
+    *   `0x01`: Wrapping Add (`a.wrapping_add(b)`)
+    *   `0x02`: Wrapping Sub (`a.wrapping_sub(b)`)
+    *   `0x03`: Wrapping Mul (`a.wrapping_mul(b)`)
+    *   `0x04`: XOR (`a ^ b`)
+    *   `0x05`: AND (`a & b`)
+    *   `0x06`: OR (`a | b`)
+    *   `0x07`: Rotate Left (`a.rotate_left(b % 32)`)
+*   `0x08`: Unary Bitwise Not (`!a`). Requires at least 1 element on the stack.
+*   `0x09`: Hash Stack. Hashes all stack elements using BLAKE3 and reduces it to a single `u32` value, clearing the stack and pushing the hash.
+*   *Any other opcode:* Terminates VM execution immediately.

docs/PROTOCOL_STABILITY.md

@@ -0,0 +1,37 @@
+# ChronoSeal Protocol Stability Policy (PROTOCOL_STABILITY)
+
+This document defines the stable interfaces and boundaries of the ChronoSeal project to guide third-party integration development and future internal architectural evolutions.
+
+---
+
+## 1. Stable Public Contract
+
+The public surface of ChronoSeal is frozen at version 1.0 and consists of:
+
+1.  **Wire Protocol API:**
+    *   `POST /init`: Handshake schema (parameters, response fields).
+    *   `POST /hb`: Heartbeat schema (payload parameters, response fields).
+2.  **State Transition Semantics:**
+    *   The BLAKE3 hash chain progression rules.
+    *   The virtual machine opcodes and stack execution rules.
+    *   The Synthetic Gene Mutation logic and context-bound commitments.
+3.  **Daemon CLI & Config Schema:**
+    *   Commands (`run`, `status`, `health`, etc.).
+    *   TOML configuration keys.
+
+---
+
+## 2. Private Internal Boundaries
+
+All implementation details are subject to change without notice. Wrappers, clients, and applications must not depend on:
+
+*   **Internal Rust APIs:** ChronoSeal is a Unix daemon. It does not export a public Rust library SDK. Internal Rust modules (`server::storage`, `server::session`, etc.) are private.
+*   **Database Schema:** The SQLite table structure, indexes, or column names are private to the daemon.
+*   **Valkey Key Structures:** The layout of session keys, sorted set indexes, and pipelines are implementation details.
+
+---
+
+## 3. Protocol Evolution Policy
+
+*   **Minor Updates:** Can introduce new optional configuration fields or metrics.
+*   **Major Updates:** May change the VM instruction set or hash chain primitives, requiring new WASM builds.

docs/SECURITY_ASSUMPTIONS.md

@@ -0,0 +1,33 @@
+# ChronoSeal Security Assumptions & Guarantees
+
+This document details the trust boundary models, security assumptions, and non-goals of the ChronoSeal system.
+
+---
+
+## 1. Core Threat Philosophy
+
+ChronoSeal is a **cost-raising security layer**. It is designed to force automated scraping, botting, and replay tools to execute a fully compliant JavaScript/WASM execution runtime. It does not provide absolute hardware attestation or proof of human presence.
+
+---
+
+## 2. Non-Goals (What ChronoSeal is NOT)
+
+1.  **Proof of Humanity:** ChronoSeal does not check if the user is a human. A headless browser running with standard input event automation will pass verification if it runs the WASM runtime correctly.
+2.  **Anti-Debugging/Enclave Security:** ChronoSeal does not run inside a secure hardware enclave on the client. An attacker has complete control of the client wasm environment, memory, and key storage.
+3.  **Perfect Browser Verification:** ChronoSeal cannot guarantee the client is a real Chrome/Firefox browser. It guarantees that the client maintains the state chain and executes the math VM program.
+
+---
+
+## 3. Threat Matrix & Attacker Cost Model
+
+*   **Commodity HTTP Clients (Python `requests`, `curl`):** *Blocked.* Attackers cannot sign payloads, run the mathematical VM, or maintain the stateful BLAKE3 hash chain.
+*   **Headless Automation (Puppeteer, Playwright):** *Partially Contained.* The automation script must execute the full browser environment, load the WASM module, feed valid parameters, and generate realistic mouse movement coordinates. This imposes significantly higher CPU and resource overhead on the attacker.
+*   **Custom WASM Emulators:** *Raised Cost.* A determined reverse engineer can extract the WASM module and build a custom state runner in Node.js or Go. ChronoSeal counters this by using a stateful **Synthetic Gene Mutation Engine**, where the state vector mutations are governed dynamically by the server, requiring the emulator to replicate the entire mutation spec.
+
+---
+
+## 4. Key Invariants
+
+1.  **Chain Continuity:** A session state cannot bifurcate. Every heartbeat must advance the state head using the latest salt.
+2.  **VM Parity:** Stack state must exactly match the execution output of the server's issued opcode sequence.
+3.  **Dynamic Challenges:** Client gene updates must match the server-issued mutation program.

docs/TESTING.md

@@ -0,0 +1,455 @@
+# ChronoSeal Testing Strategy
+
+ChronoSeal maintains a rigorous, security-first test suite focused on cryptographic correctness, deterministic server ↔ WASM parity, mutation engine integrity, replay resistance, tampering detection, behavioral validation, and storage reliability.
+
+As of **v1.0.1**, the project contains **95 passing tests** across the server, WASM, and shared protocol crates.
+
+| Crate                        | Tests  |
+| ---------------------------- | ------ |
+| `chronoseal-server`          | 33     |
+| `chronoseal-wasm`            | 24     |
+| `shared` (unit)              | 36     |
+| `shared` (property-based)    | 2      |
+| **Total**                    | **95** |
+
+---
+
+## Test Philosophy
+
+ChronoSeal testing prioritizes:
+
+- **Security invariants** over raw coverage metrics
+- **Deterministic parity** between server and browser WASM runtimes
+- **Negative-path testing** (tampering, replay, malformed input, edge cases)
+- **Property-based and fuzz-style testing** for mutation logic and VM robustness
+- **Performance regression detection**
+- **Long-term protocol stability**
+
+Particular emphasis is placed on ensuring that browser-side WASM execution produces identical results to server-side validation.
+
+---
+
+# Test Categories
+
+## 1. Configuration & CLI
+
+Configuration tests verify:
+
+- Database backend selection
+- TOML configuration parsing
+- Command-line override behavior
+- Default configuration values
+- Runtime initialization logic
+
+Supported backends include:
+
+- `sqlite-in-memory`
+- `sqlite-in-disk`
+- `valkey` (redis-compatible via r2d2 connection pool)
+
+Example tests:
+
+```
+test_apply_run_args_overrides_db_type
+test_default_db_type_is_sqlite_in_memory
+test_toml_parses_db_type_kebab_case
+test_init_db_pool_sqlite_in_memory
+test_init_db_pool_sqlite_in_disk
+test_init_db_pool_valkey_compat_mode
+test_valkey_store_operations
+```
+
+---
+
+## 2. Session Lifecycle & Verification
+
+Session tests validate:
+
+- Session creation
+- Public key validation
+- Expiration handling
+- Replay attack prevention
+- Mutation step enforcement
+- Commitment verification
+- Long-running deterministic parity
+
+Example tests:
+
+```
+test_create_session_rejects_invalid_public_key_length
+test_expired_session_is_rejected
+test_replay_attack_is_rejected
+test_mutation_step_mismatch_is_rejected
+test_mutation_commitment_tamper_is_rejected
+test_session_lifecycle_and_verification
+test_repeated_simulation_keeps_server_and_client_commitments_equal
+test_deterministic_server_client_parity_across_many_heartbeats
+```
+
+---
+
+## 3. Mutation Engine (Core Focus)
+
+The Synthetic Gene Mutation Engine is one of the most security-critical components in ChronoSeal.
+
+Testing focuses on:
+
+- Deterministic server/client parity
+- Mutation order execution
+- Gene state integrity
+- Preview → Commit → Discard lifecycle
+- Randomized mutation programs
+- Edge-case validation
+- Performance regression detection
+
+Example tests:
+
+```
+test_server_client_parity_across_random_orders
+test_generate_order_is_deterministic_for_seeded_rng
+test_invalid_positions_wrap_deterministically
+test_mutation_chain
+test_fuzz_style_random_program_bytes_do_not_diverge
+test_performance_smoke_mutation_execution
+```
+
+---
+
+## 4. Heartbeat Handler
+
+Heartbeat validation tests verify:
+
+- Successful state advancement
+- Silent rejection behavior
+- Commitment validation
+- Rate limiting
+- Next-state mutation generation
+
+Example tests:
+
+```
+test_handler_success_returns_next_mutation_fields
+test_handler_tampered_commitment_is_silent_failure
+test_handler_rate_limit_returns_no_mutation_data
+```
+
+---
+
+## 5. Trust & Behavioral Validation
+
+Behavioral validation tests verify:
+
+- Minimum mouse activity
+- Minimum movement distance
+- Pause detection
+- Speed thresholds
+- Optional activity requirements
+- Fingerprint-related validation paths
+
+Example tests:
+
+```
+test_validate_mouse_success
+test_validate_mouse_insufficient_events
+test_validate_mouse_insufficient_distance
+test_validate_mouse_too_fast
+test_validate_mouse_no_pauses
+test_validate_mouse_require_activity_toggle
+```
+
+---
+
+## 6. Storage Layer
+
+Storage tests verify:
+
+- SQLite in-memory operation
+- SQLite disk-backed operation and pool concurrency
+- Valkey compatibility mode and r2d2 pool concurrency
+- Session CRUD behavior including the `opcodes` field
+- Expiration cleanup
+- Runtime statistics reporting
+
+These tests ensure storage implementations remain interchangeable without affecting protocol behavior.
+
+Example tests:
+
+```
+test_sqlite_pool_concurrency
+test_valkey_pool_concurrency
+test_valkey_store_operations
+```
+
+> **Note:** The concurrent write collision path in `update_session` (the `old_last_hash`
+> optimistic concurrency guard) is not yet covered by an automated test. Two goroutines
+> advancing the same chain simultaneously is a security-relevant race condition.
+> A dedicated test is planned for v1.1.0 (see Future Improvements).
+
+---
+
+## 7. VM Core
+
+The VM core is tested extensively across both WASM and shared crates.
+
+Coverage includes:
+
+- ADD, SUB, MUL, XOR, AND, OR, NOT, HASH, ROT, PUSH
+
+Edge cases include:
+
+- Stack underflow
+- Truncated instructions
+- Unknown opcodes
+- Wrapping arithmetic
+- Invalid instruction streams
+
+Example tests:
+
+```
+test_add
+test_add_wrapping
+test_sub
+test_sub_wrapping
+test_mul
+test_hash
+test_underflow_binary
+test_underflow_unary
+test_incomplete_push
+test_rejects_unknown_opcode
+test_rejects_truncated_instruction
+```
+
+---
+
+## 8. Property-Based Tests
+
+ChronoSeal uses [`proptest`](https://github.com/proptest-rs/proptest) for property-based testing of core protocol invariants against arbitrary random input.
+
+Tests live in `shared/tests/proptests.rs` and run as part of `cargo test --workspace`.
+
+```
+test_vm_execute_never_panics
+test_gene_environment_roundtrip_never_panics
+```
+
+`test_vm_execute_never_panics` feeds arbitrary `Vec<u8>` byte sequences into the stack machine
+and asserts that execution never panics and that the instruction pointer never exceeds the
+program length. This guards against any future VM opcode handler introducing undefined
+behaviour on malformed input.
+
+`test_gene_environment_roundtrip_never_panics` feeds arbitrary bytes into
+`gene::decode_environment` and asserts graceful failure rather than a panic, covering the full
+space of malformed environment payloads a client could send.
+
+---
+
+# Server Test Coverage (`chronoseal-server`)
+
+The server crate currently contains **33 tests** covering:
+
+- Configuration
+- Runtime initialization
+- Session management
+- Heartbeat validation
+- Rate limiting
+- Trust validation
+
+The server tests focus heavily on protocol enforcement and security validation.
+
+---
+
+# WASM Test Coverage (`chronoseal-wasm`)
+
+The WASM crate currently contains **24 tests** covering:
+
+- VM execution
+- Browser-side mutation lifecycle
+- Gene initialization
+- Mutation preview
+- Mutation commit/discard behavior
+- Deterministic parity with shared logic
+
+Example tests:
+
+```
+test_preview_commitment_matches_shared_engine
+test_commit_applies_preview
+test_discard_preview_keeps_committed_state
+test_table_driven_parity_across_many_generated_orders
+```
+
+These tests ensure browser-generated commitments remain consistent with server expectations.
+
+---
+
+# Shared Crate Coverage (`shared`)
+
+The shared crate currently contains **36 unit tests** and **2 property-based tests**, representing
+the core protocol implementation used by both server and browser runtimes.
+
+Coverage includes:
+
+### Synthetic Gene Engine
+
+```
+test_new_state_with_default_size
+test_new_state_rejects_invalid_sizes
+test_commitment_changes_when_gene_or_environment_changes
+test_encode_decode_environment_roundtrip
+test_table_driven_randomized_environment_roundtrip
+```
+
+### Mutation Engine
+
+```
+test_opcode_insert
+test_opcode_delete
+test_opcode_mutate_point
+test_opcode_apply_mutagen
+test_opcode_finalize_gene_hash
+test_mutation_chain
+```
+
+### Validation & Hardening
+
+```
+test_rejects_stack_underflow
+test_rejects_truncated_instruction
+test_rejects_unknown_opcode
+test_zero_length_gene_is_rejected
+```
+
+### Deterministic Parity
+
+```
+test_server_client_parity_across_random_orders
+test_generate_order_is_deterministic_for_seeded_rng
+test_invalid_positions_wrap_deterministically
+```
+
+### Fuzz & Regression Testing
+
+```
+test_fuzz_style_random_program_bytes_do_not_diverge
+test_performance_smoke_mutation_execution
+test_vm_instruction_budget_soft_cap
+```
+
+### Property-Based Tests (`shared/tests/proptests.rs`)
+
+```
+test_vm_execute_never_panics
+test_gene_environment_roundtrip_never_panics
+```
+
+---
+
+# Tooling Crates
+
+## `chronoseal-replay`
+
+A standalone replay and audit tool for offline verification of recorded ChronoSeal session
+chains. It is a developer and forensic utility, not a library, and currently carries no
+automated tests. Integration tests against captured session fixtures are planned.
+
+## `fuzz/`
+
+Contains libFuzzer targets for deeper coverage of the VM and gene codec. Run separately
+via `cargo +nightly fuzz run <target>` — not part of the standard `cargo test` suite.
+
+---
+
+# Running the Test Suite
+
+Run the full workspace:
+
+```
+cargo test --workspace
+```
+
+Run individual crates:
+
+```
+cargo test -p shared
+cargo test -p chronoseal-wasm
+cargo test -p chronoseal-server
+```
+
+Display test output:
+
+```
+cargo test -- --nocapture
+```
+
+---
+
+# Critical Security Tests
+
+The following tests protect ChronoSeal's core protocol guarantees and should be treated as
+**release-blocking** if they fail:
+
+```
+test_mutation_commitment_tamper_is_rejected
+test_replay_attack_is_rejected
+test_handler_tampered_commitment_is_silent_failure
+test_server_client_parity_across_random_orders
+test_deterministic_server_client_parity_across_many_heartbeats
+test_fuzz_style_random_program_bytes_do_not_diverge
+test_vm_execute_never_panics
+test_gene_environment_roundtrip_never_panics
+```
+
+These tests directly validate resistance to replay attacks, protocol divergence, mutation
+tampering, commitment forgery, and VM panic on adversarial input.
+
+---
+
+# Contributing New Tests
+
+When adding new functionality:
+
+1. Prefer placing protocol logic tests in `shared/`
+2. Ensure server ↔ WASM parity is validated
+3. Include negative-path test cases
+4. Add randomized or property-based testing where appropriate
+5. Update this document when introducing major new categories
+
+---
+
+# Future Improvements
+
+- **Concurrent chain write collision test** — verify that two simultaneous heartbeats for the
+  same session are handled correctly by the `old_last_hash` optimistic concurrency guard in
+  `update_session` (security-critical, planned for v1.1.0)
+- **Browser-driven end-to-end integration tests** — full Playwright or wasm-bindgen-test
+  harness exercising the complete init → heartbeat loop in a real browser environment
+- **Valkey failover testing** — verify graceful degradation and reconnection under r2d2 pool
+  exhaustion and server-side connection drops
+- **Automated benchmark execution in CI** — enforce performance regression thresholds for
+  mutation engine and hash chain operations
+- **Expanded mutation-engine fuzzing** — additional libFuzzer targets for `vm_extensions`
+  opcodes introduced in v0.7.0
+- **CI-enforced performance regression thresholds** — gate releases on measured latency bounds
+
+---
+
+# Conclusion
+
+ChronoSeal's testing strategy is centered on preserving deterministic behavior, cryptographic
+correctness, and protocol integrity.
+
+The current suite of **95 tests** provides broad coverage across:
+
+- Session security
+- Heartbeat validation
+- Mutation engine correctness
+- Deterministic server/WASM parity
+- Trust and behavioral validation
+- Storage abstraction
+- Replay resistance
+- Protocol hardening
+- Property-based VM and gene codec robustness
+
+Maintaining and expanding this test suite remains a core project priority as ChronoSeal evolves.
+
+**Last Updated:** May 2026 (v1.0.1)

docs/THREAT_MODEL.md

@@ -106,6 +106,23 @@ Expected result:
 - ChronoSeal does not claim complete prevention
 - additional application-level controls are required
 
+## Attacker Classification Boundaries
+
+### Protected
+*   **Commodity Scrapers:** Simple HTTP clients (`curl`, Python `requests`, Go HTTP clients) that cannot execute JavaScript or WebAssembly.
+*   **Simple Replay Attackers:** Intercepted heartbeat payloads cannot be reused because of the strict hash-chain sequencing and salt rotation.
+*   **Signature Forgers:** Heartbeats without the session's private key will fail Ed25519 verification.
+
+### Partially Protected
+*   **Headless Automation (Puppeteer, Playwright):** Attackers must load the WASM runtime, execute the VM instructions, calculate gene mutations, and simulate realistic human mouse interactions. This significantly increases CPU and system memory overhead, reducing the scale of bot operations.
+*   **Stealth Automation Frameworks:** Advanced frameworks must maintain state sync across multiple heartbeat cycles, exposing them to timing detection.
+
+### Unprotected
+*   **WASM Key Extraction:** A reverse engineer with full browser process control can extract the private key from WASM memory.
+*   **Malware Operators:** Keyloggers, screen scrapers, or memory dumpers operating at the OS level are outside the application trust boundary.
+*   **MITM Interceptors (without TLS):** Plaintext traffic can be intercepted. (TLS termination is assumed).
+*   **Insiders / Storage Tampering:** Attackers with direct write access to the SQLite database or Valkey instance can forge or hijack active session states.
+
 ## Attack Vectors and Mitigations
 
 ### Replay

docs/WHY_IT_FAILS.md

@@ -0,0 +1,56 @@
+# ChronoSeal Debugging & Failure Mode Guide (WHY_IT_FAILS)
+
+This document provides a technical diagnostic reference for developers, operators, and integration security teams. It explains why a client heartbeat or session initialization fails verification, and how to debug desynchronization issues.
+
+---
+
+## 1. Silent Rejections vs. HTTP Failures
+
+To deny attackers a feedback oracle, the ChronoSeal heartbeat endpoint (`POST /hb`) always returns HTTP status `200 OK` with `{"status": "ok"}` on semantic verification failures.
+
+*   **Successful Attestation:** The JSON response contains the rotated next state information: `next_salt`, `next_mutation_step`, and `next_mutation_order_b64`.
+*   **Silently Rejected Attestation:** The JSON response *omits* these three fields. The client is expected to roll back the state preview and retry.
+
+---
+
+## 2. Common Verification Failure Modes
+
+### A. Clock Drift (`TimestampDrift`)
+*   **Error Cause:** The client machine's local system time differs from the server's time by more than the configured `max_timestamp_drift_ms` (default 30 seconds).
+*   **Diagnostic Signal:** The `/hb` response omits next state parameters.
+*   **Remediation:** Synchronize both client and server clocks using NTP (Network Time Protocol). On the client, use NTP-synced system clocks or query server timestamp headers during initialization to compute a local clock offset.
+
+### B. Replay Attempts / Out-of-Sequence (`ChainBroken`)
+*   **Error Cause:** The request `prev_hash` does not match the server-stored `last_hash` for the session.
+*   **Root Causes:**
+    1.  The client replayed a previously captured heartbeat payload.
+    2.  The client lost the network response containing the rotated next state parameters and retried with stale state.
+    3.  A concurrent request succeeded first, updating the session's hash state.
+*   **Remediation:** If network issues cause packet loss, the client must discard the session and initiate a new `/init` handshake. Heartbeats cannot be replayed or resumed from a historical state.
+
+### C. Signature Failures (`Signature`)
+*   **Error Cause:** The Ed25519 signature over the canonical JSON payload is invalid.
+*   **Root Causes:**
+    1.  The client signed a payload that differed in ordering or format from the server's canonical serialization. (Ensure key sorting matches alphabetically: `entropyData`, `fingerprint`, `geneCommitment`, `mutationStep`, `prevHash`, `sessionId`, `stackState`, `timestamp`).
+    2.  Different platform engines formatted floats or large numbers differently.
+    3.  The public key registered during `/init` does not match the signing key.
+*   **Remediation:** Ensure both frontend and backend use strict canonical serializations (BTreeMap alphabetically sorted keys).
+
+### D. VM Stack State Mismatch (`VmStackMismatch`)
+*   **Error Cause:** The client's submitted `stack_state` (VM stack and instruction pointer `ip`) does not match the server-side re-execution of the session's random math program.
+*   **Root Causes:**
+    1.  An automated client bypassed the VM bytecode interpreter.
+    2.  The client VM interpreter diverged mathematically (e.g. word size wrapping or logical op mismatches).
+*   **Remediation:** Check the VM interpreter implementation parity between the client wasm and `shared::vm`.
+
+### E. Mutation Commitment Mismatch (`MutationCommitmentMismatch`)
+*   **Error Cause:** The client's computed `gene_commitment` does not match the server-applied gene mutation.
+*   **Root Causes:**
+    1.  The client used a different number of `mutation_rounds` than the server config.
+    2.  The mutation order execution logic diverged.
+*   **Remediation:** Verify that the client wasm correctly parsed `mutation_rounds` from `/init` and passed it to the generator.
+
+### F. Rate Limiting (`RateLimiter`)
+*   **Error Cause:** The client submitted more requests than allowed by the server's rate-limiting config (e.g., `rate_limit_count` per `rate_limit_window_secs`).
+*   **Diagnostic Signal:** The server returns `200 OK` with `{"status": "ok"}` but no next state data.
+*   **Remediation:** Reduce heartbeat frequency or adjust rate limit parameters in the daemon configuration.

docs/WRAPPER_GUIDE.md

@@ -0,0 +1,41 @@
+# ChronoSeal Third-Party Wrapper & Integration Guide (WRAPPER_GUIDE)
+
+This document provides stable guidance for developers building third-party integration wrappers, clients, or SDKs around the `chronoseald` daemon.
+
+---
+
+## 1. Public Contract & Stability Guarantees
+
+As a protocol-first Unix daemon, `chronoseald` guarantees stability on the public network interface.
+
+### Guaranteed Stable
+*   **Endpoints:** `POST /init` and `POST /hb`.
+*   **JSON Fields:** The structure and naming of request and response keys.
+*   **VM Instruction Set:** The behavior and encoding of the 10 core VM opcodes (`0x00`..=`0x09`).
+*   **Signature Serialization:** Alphabetical key-sorting rules using `BTreeMap` serialization.
+*   **Hash Progression:** Blake3 chain folding rules.
+
+### Private (Unstable / Subject to Change)
+*   **Database Engines & Schemas:** SQLite table structure, Valkey key formatting, and indexes.
+*   **Daemon CLI Flags:** Internal metrics query formats.
+*   **Memory Structures:** Thread boundaries, session caches, and synchronization locks.
+
+---
+
+## 2. API Versioning & Deprecation Policy
+
+*   **Version Format:** API endpoints do not contain version prefixes (e.g., `/v1/hb`). Instead, protocol versioning is coupled to the daemon release version.
+*   **Breaking Protocol Changes:** Any change to the core hash function (Blake3) or the VM instruction set will trigger a major release (e.g., `v2.0.0`).
+*   **Deprecation Cycle:** Deprecated features will be supported for at least one minor release cycle, documented in `docs/PROTOCOL_STABILITY.md`.
+
+---
+
+## 3. Reference Implementation Steps for Wrappers
+
+To build a client-side wrapper or application adapter for `chronoseald`:
+
+1.  **Handshake:** Send `POST /init` with the hex-encoded Ed25519 public key. Save the returned `session_id`, `salt`, `opcodes_b64`, and `mutation_order_b64`.
+2.  **VM Execution:** Run the math VM program (decoded from `opcodes_b64`) using the client wasm runtime to get the target `stack_state`.
+3.  **Gene Mutation:** Decode `mutation_order_b64`, apply the mutation steps to the local gene buffer, and compute the new commitment hash.
+4.  **Signing:** Build the canonical alphabetical JSON message, sign it, and send `POST /hb`.
+5.  **Chain Advancement:** On success, extract `next_salt` and `next_mutation_order_b64` to prepare the next heartbeat request.

frontend/favicon/favicon.svg

@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" version="1.1" id="Layer_1" x="0px" y="0px" width="296.99997mm" viewBox="0 0 1122.5196 793.7008" enable-background="new 0 0 1254 1254" xml:space="preserve" height="210mm" sodipodi:docname="logo1.svg" inkscape:export-filename="logo1.png" inkscape:export-xdpi="96" inkscape:export-ydpi="96" inkscape:version="1.4.4 (dcaf3e7d9e, 2026-05-05)" xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape" xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd" xmlns:svg="http://www.w3.org/2000/svg"><metadata><rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:dc="http://purl.org/dc/elements/1.1/"><rdf:Description><dc:creator>RealFaviconGenerator</dc:creator><dc:source>https://realfavicongenerator.net</dc:source></rdf:Description></rdf:RDF></metadata><sodipodi:namedview id="namedview1" pagecolor="#ffffff" bordercolor="#000000" borderopacity="0.25" inkscape:showpageshadow="2" inkscape:pageopacity="0.0" inkscape:pagecheckerboard="0" inkscape:deskcolor="#d1d1d1" inkscape:document-units="mm" inkscape:zoom="1.1654266" inkscape:cx="561.16791" inkscape:cy="396.85039" inkscape:window-width="2048" inkscape:window-height="1205" inkscape:window-x="0" inkscape:window-y="0" inkscape:window-maximized="1" inkscape:current-layer="Layer_1"></sodipodi:namedview><defs id="defs44"></defs><path fill="none" opacity="1" stroke="none" d="m 791.89377,632.01366 c 1.04068,-1.03091 1.90903,-2.38956 3.14896,-3.04166 11.48425,-6.03955 22.98721,-12.04745 34.57742,-17.88034 8.52002,-4.28775 14.37558,-10.49713 14.23218,-20.46771 -0.14127,-9.82202 -6.25309,-15.51495 -14.66742,-19.5827 -61.76651,-29.85993 -123.47361,-59.84277 -185.21183,-89.76129 -10.48242,-5.07981 -20.81335,-10.5555 -31.58477,-14.93764 -19.71186,-8.01936 -39.87799,-8.40881 -59.18305,0.84148 -71.77527,34.39209 -143.33667,69.23047 -215.00567,103.84463 -8.40815,4.06091 -14.32166,9.84101 -14.39978,19.74008 -0.079,10.00498 5.52282,16.22797 14.08978,20.54743 12.3277,6.21567 24.51239,12.71484 37.34228,19.41369 7.51429,3.93381 14.42273,7.5896 21.37854,11.15274 31.68775,16.23208 63.40558,32.40548 95.07782,48.66778 14.943,7.6726 29.74964,15.6123 44.73053,23.2091 8.44464,4.2823 16.79547,9.1534 25.75525,11.9324 18.81989,5.8372 37.10712,3.9335 54.83185,-5.5578 25.51599,-13.6634 51.41541,-26.6141 77.2135,-39.7465 30.82071,-15.6894 61.7009,-31.26196 92.58359,-46.82907 1.56006,-0.78641 3.38776,-1.0419 5.09082,-1.54462 z" id="path2"></path><path fill="#4b4d51" opacity="1" stroke="none" d="m 791.89376,550.60089 c 1.04068,-1.03091 1.90903,-2.38956 3.14896,-3.04166 11.48425,-6.03955 22.98721,-12.04745 34.57742,-17.88034 8.52002,-4.28775 14.37558,-10.49713 14.23218,-20.46771 -0.14127,-9.82202 -6.25309,-15.51495 -14.66742,-19.5827 -61.76651,-29.85993 -123.47361,-59.84277 -185.21183,-89.76129 -10.48242,-5.07981 -20.81335,-10.5555 -31.58477,-14.93764 -19.71186,-8.01936 -39.87799,-8.40881 -59.18305,0.84148 -71.77522,34.39209 -143.33662,69.23047 -215.00562,103.84463 -8.4082,4.06091 -14.3217,9.84101 -14.3998,19.74008 -0.079,10.00498 5.5228,16.22797 14.0898,20.54743 12.3277,6.21567 24.5123,12.71484 37.3422,19.41369 7.5143,3.93381 14.4228,7.5896 21.3786,11.15274 31.6877,16.23212 63.4056,32.40552 95.0778,48.66782 14.943,7.67261 29.7496,15.61227 44.73052,23.20911 8.44464,4.28232 16.79547,9.15341 25.75525,11.93237 18.81989,5.83722 37.10712,3.93353 54.83185,-5.55777 25.51599,-13.66336 51.41541,-26.61407 77.2135,-39.74655 30.82071,-15.68933 61.7009,-31.26196 92.58359,-46.82907 1.56006,-0.78641 3.38776,-1.0419 5.09082,-1.54462 z" id="path45" style="fill:#e1e1e4;fill-opacity:1"></path><path fill="#4b4d51" opacity="1" stroke="none" d="m 791.89377,469.18814 c 1.04068,-1.03091 1.90903,-2.38956 3.14896,-3.04166 11.48425,-6.03955 22.98721,-12.04745 34.57742,-17.88034 8.52002,-4.28775 14.37558,-10.49713 14.23218,-20.46771 -0.14127,-9.82202 -6.25309,-15.51495 -14.66742,-19.5827 C 767.4184,378.3558 705.7113,348.37296 643.97308,318.45444 c -10.48242,-5.07981 -20.81335,-10.5555 -31.58477,-14.93764 -19.71186,-8.01936 -39.87799,-8.40881 -59.18305,0.84148 -71.77527,34.39209 -143.33667,69.23047 -215.00567,103.84463 -8.40815,4.06091 -14.32166,9.84101 -14.39978,19.74008 -0.079,10.00498 5.52282,16.22797 14.08978,20.54743 12.3277,6.21567 24.51239,12.71484 37.34228,19.41369 7.51429,3.93381 14.42273,7.5896 21.37854,11.15274 31.68775,16.23212 63.40558,32.40552 95.07782,48.66782 14.943,7.67261 29.74964,15.61227 44.73053,23.20911 8.44464,4.28232 16.79547,9.15341 25.75525,11.93237 18.81989,5.83722 37.10712,3.93353 54.83185,-5.55777 25.51599,-13.66336 51.41541,-26.61407 77.2135,-39.74655 30.82071,-15.68933 61.7009,-31.26196 92.58359,-46.82907 1.56006,-0.78641 3.38776,-1.0419 5.09082,-1.54462 z" id="path46" style="fill:#b0b2b8;fill-opacity:1"></path><path fill="#4b4d51" opacity="1" stroke="none" d="m 791.89377,387.77539 c 1.04068,-1.03091 1.90903,-2.38956 3.14896,-3.04166 11.48425,-6.03955 22.98721,-12.04745 34.57742,-17.88034 8.52002,-4.28775 14.37558,-10.49713 14.23218,-20Line truncated

frontend/favicon/site.webmanifest

@@ -0,0 +1,21 @@
+{
+  "name": "MyWebSite",
+  "short_name": "MySite",
+  "icons": [
+    {
+      "src": "/web-app-manifest-192x192.png",
+      "sizes": "192x192",
+      "type": "image/png",
+      "purpose": "maskable"
+    },
+    {
+      "src": "/web-app-manifest-512x512.png",
+      "sizes": "512x512",
+      "type": "image/png",
+      "purpose": "maskable"
+    }
+  ],
+  "theme_color": "#ffffff",
+  "background_color": "#ffffff",
+  "display": "standalone"
+}

frontend/heartbeat.js

@@ -16,6 +16,7 @@ let minInterval = 12000;
 let maxInterval = 25000;
 let pendingMutationStep = 0;
 let pendingMutationOrderB64 = '';
+let mutationRounds = 4;
 
 export async function initHeartbeat() {
     await init();
@@ -32,6 +33,7 @@ export async function initHeartbeat() {
     }
     pendingMutationStep = initResp.mutation_step;
     pendingMutationOrderB64 = initResp.mutation_order_b64;
+    mutationRounds = initResp.mutation_rounds || 4;
     lastTime = performance.now();
     scheduleNext();
 }
@@ -56,7 +58,7 @@ async function sendHeartbeat() {
         const timestamp = Date.now();
         const entropyData = { events: events.map(e => ({ x: e.x, y: e.y, t: e.t })) };
         const entropyJson = JSON.stringify(entropyData);
-        const geneCommitment = preview_gene_commitment(pendingMutationOrderB64);
+        const geneCommitment = preview_gene_commitment(pendingMutationOrderB64, session, pendingMutationStep, mutationRounds);
         if (!geneCommitment) {
             throw new Error('Unable to compute mutation commitment');
         }
@@ -75,7 +77,6 @@ async function sendHeartbeat() {
         const sig = sign_message(msg);
         if (!sig) {
             discard_gene_preview();
-            console.error('Keypair not initialised — skipping heartbeat');
             return;
         }
         const resp = await sendRequest('/hb', 'POST', {
@@ -105,11 +106,9 @@ async function sendHeartbeat() {
             pendingMutationOrderB64 = resp.next_mutation_order_b64;
         } else {
             discard_gene_preview();
-            console.warn('Heartbeat rejected');
         }
     } catch (e) {
         discard_gene_preview();
-        console.error(e);
     } finally {
         scheduleNext();
     }

frontend/index.html

@@ -2,6 +2,7 @@
 <html lang="en">
 <head>
   <meta charset="UTF-8">
+  <meta http-equiv="Content-Security-Policy" content="default-src 'self'; script-src 'self' 'wasm-unsafe-eval'; connect-src 'self'; style-src 'self' 'unsafe-inline'">
   <title>Anti-Scraper Demo</title>
 </head>
 <body>

frontend/main.js

@@ -1,5 +1,3 @@
 import { initHeartbeat } from './heartbeat.js';
 
-(async () => {
+initHeartbeat().catch(() => {});
-    await initHeartbeat();
-})();

fuzz/Cargo.lock

@@ -0,0 +1,596 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "arbitrary"
+version = "1.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c3d036a3c4ab069c7b410a2ce876bd74808d2d0888a82667669f8e783a898bf1"
+
+[[package]]
+name = "arrayref"
+version = "0.3.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "76a2e8124351fda1ef8aaaa3bbd7ebbcb486bbcd4225aca0aa0d84bb2db8fecb"
+
+[[package]]
+name = "arrayvec"
+version = "0.7.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7c02d123df017efcdfbd739ef81735b36c5ba83ec3c59c80a9d7ecc718f92e50"
+
+[[package]]
+name = "base64"
+version = "0.22.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "72b3254f16251a8381aa12e40e3c4d2f0199f8c6508fbecb9d91f575e0fbb8c6"
+
+[[package]]
+name = "base64ct"
+version = "1.8.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2af50177e190e07a26ab74f8b1efbfe2ef87da2116221318cb1c2e82baf7de06"
+
+[[package]]
+name = "blake3"
+version = "1.8.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0aa83c34e62843d924f905e0f5c866eb1dd6545fc4d719e803d9ba6030371fce"
+dependencies = [
+ "arrayref",
+ "arrayvec",
+ "cc",
+ "cfg-if",
+ "constant_time_eq",
+ "cpufeatures 0.3.0",
+]
+
+[[package]]
+name = "block-buffer"
+version = "0.10.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3078c7629b62d3f0439517fa394996acacc5cbc91c5a20d8c658e77abd503a71"
+dependencies = [
+ "generic-array",
+]
+
+[[package]]
+name = "cc"
+version = "1.2.63"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "556e016178bb5662a08681bbe0f00f8e17631781a4dfc8c45e466e4b185ec27f"
+dependencies = [
+ "find-msvc-tools",
+ "jobserver",
+ "libc",
+ "shlex",
+]
+
+[[package]]
+name = "cfg-if"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9330f8b2ff13f34540b44e946ef35111825727b38d33286ef986142615121801"
+
+[[package]]
+name = "chronoseal-fuzz"
+version = "0.0.0"
+dependencies = [
+ "libfuzzer-sys",
+ "serde_json",
+ "shared",
+]
+
+[[package]]
+name = "const-oid"
+version = "0.9.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c2459377285ad874054d797f3ccebf984978aa39129f6eafde5cdc8315b612f8"
+
+[[package]]
+name = "constant_time_eq"
+version = "0.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3d52eff69cd5e647efe296129160853a42795992097e8af39800e1060caeea9b"
+
+[[package]]
+name = "cpufeatures"
+version = "0.2.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "59ed5838eebb26a2bb2e58f6d5b5316989ae9d08bab10e0e6d103e656d1b0280"
+dependencies = [
+ "libc",
+]
+
+[[package]]
+name = "cpufeatures"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8b2a41393f66f16b0823bb79094d54ac5fbd34ab292ddafb9a0456ac9f87d201"
+dependencies = [
+ "libc",
+]
+
+[[package]]
+name = "crypto-common"
+version = "0.1.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "78c8292055d1c1df0cce5d180393dc8cce0abec0a7102adb6c7b1eef6016d60a"
+dependencies = [
+ "generic-array",
+ "typenum",
+]
+
+[[package]]
+name = "curve25519-dalek"
+version = "4.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "97fb8b7c4503de7d6ae7b42ab72a5a59857b4c937ec27a3d4539dba95b5ab2be"
+dependencies = [
+ "cfg-if",
+ "cpufeatures 0.2.17",
+ "curve25519-dalek-derive",
+ "digest",
+ "fiat-crypto",
+ "rustc_version",
+ "subtle",
+ "zeroize",
+]
+
+[[package]]
+name = "curve25519-dalek-derive"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f46882e17999c6cc590af592290432be3bce0428cb0d5f8b6715e4dc7b383eb3"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "der"
+version = "0.7.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e7c1832837b905bbfb5101e07cc24c8deddf52f93225eee6ead5f4d63d53ddcb"
+dependencies = [
+ "const-oid",
+ "zeroize",
+]
+
+[[package]]
+name = "digest"
+version = "0.10.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9ed9a281f7bc9b7576e61468ba615a66a5c8cfdff42420a70aa82701a3b1e292"
+dependencies = [
+ "block-buffer",
+ "crypto-common",
+]
+
+[[package]]
+name = "ed25519"
+version = "2.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "115531babc129696a58c64a4fef0a8bf9e9698629fb97e9e40767d235cfbcd53"
+dependencies = [
+ "pkcs8",
+ "signature",
+]
+
+[[package]]
+name = "ed25519-dalek"
+version = "2.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "70e796c081cee67dc755e1a36a0a172b897fab85fc3f6bc48307991f64e4eca9"
+dependencies = [
+ "curve25519-dalek",
+ "ed25519",
+ "rand_core",
+ "serde",
+ "sha2",
+ "subtle",
+ "zeroize",
+]
+
+[[package]]
+name = "fiat-crypto"
+version = "0.2.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "28dea519a9695b9977216879a3ebfddf92f1c08c05d984f8996aecd6ecdc811d"
+
+[[package]]
+name = "find-msvc-tools"
+version = "0.1.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5baebc0774151f905a1a2cc41989300b1e6fbb29aff0ceffa1064fdd3088d582"
+
+[[package]]
+name = "generic-array"
+version = "0.14.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "85649ca51fd72272d7821adaf274ad91c288277713d9c18820d8499a7ff69e9a"
+dependencies = [
+ "typenum",
+ "version_check",
+]
+
+[[package]]
+name = "getrandom"
+version = "0.2.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ff2abc00be7fca6ebc474524697ae276ad847ad0a6b3faa4bcb027e9a4614ad0"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "wasi",
+]
+
+[[package]]
+name = "getrandom"
+version = "0.3.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "899def5c37c4fd7b2664648c28120ecec138e4d395b459e5ca34f9cce2dd77fd"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "r-efi",
+ "wasip2",
+]
+
+[[package]]
+name = "hex"
+version = "0.4.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7f24254aa9a54b5c858eaee2f5bccdb46aaf0e486a595ed5fd8f86ba55232a70"
+
+[[package]]
+name = "itoa"
+version = "1.0.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8f42a60cbdf9a97f5d2305f08a87dc4e09308d1276d28c869c684d7777685682"
+
+[[package]]
+name = "jobserver"
+version = "0.1.34"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9afb3de4395d6b3e67a780b6de64b51c978ecf11cb9a462c66be7d4ca9039d33"
+dependencies = [
+ "getrandom 0.3.4",
+ "libc",
+]
+
+[[package]]
+name = "libc"
+version = "0.2.186"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "68ab91017fe16c622486840e4c83c9a37afeff978bd239b5293d61ece587de66"
+
+[[package]]
+name = "libfuzzer-sys"
+version = "0.4.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f12a681b7dd8ce12bff52488013ba614b869148d54dd79836ab85aafdd53f08d"
+dependencies = [
+ "arbitrary",
+ "cc",
+]
+
+[[package]]
+name = "memchr"
+version = "2.8.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6b947ae49db0d222b1dbc6b113ce7248a3fc3a6ca21b696717bfc000ba4484d8"
+
+[[package]]
+name = "once_cell"
+version = "1.21.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9f7c3e4beb33f85d45ae3e3a1792185706c8e16d043238c593331cc7cd313b50"
+
+[[package]]
+name = "pin-project-lite"
+version = "0.2.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a89322df9ebe1c1578d689c92318e070967d1042b512afbe49518723f4e6d5cd"
+
+[[package]]
+name = "pkcs8"
+version = "0.10.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f950b2377845cebe5cf8b5165cb3cc1a5e0fa5cfa3e1f7f55707d8fd82e0a7b7"
+dependencies = [
+ "der",
+ "spki",
+]
+
+[[package]]
+name = "ppv-lite86"
+version = "0.2.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "85eae3c4ed2f50dcfe72643da4befc30deadb458a9b590d720cde2f2b1e97da9"
+dependencies = [
+ "zerocopy",
+]
+
+[[package]]
+name = "proc-macro2"
+version = "1.0.106"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8fd00f0bb2e90d81d1044c2b32617f68fcb9fa3bb7640c23e9c748e53fb30934"
+dependencies = [
+ "unicode-ident",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.45"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "41f2619966050689382d2b44f664f4bc593e129785a36d6ee376ddf37259b924"
+dependencies = [
+ "proc-macro2",
+]
+
+[[package]]
+name = "r-efi"
+version = "5.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "69cdb34c158ceb288df11e18b4bd39de994f6657d83847bdffdbd7f346754b0f"
+
+[[package]]
+name = "rand"
+version = "0.8.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5ca0ecfa931c29007047d1bc58e623ab12e5590e8c7cc53200d5202b69266d8a"
+dependencies = [
+ "libc",
+ "rand_chacha",
+ "rand_core",
+]
+
+[[package]]
+name = "rand_chacha"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e6c10a63a0fa32252be49d21e7709d4d4baf8d231c2dbce1eaa8141b9b127d88"
+dependencies = [
+ "ppv-lite86",
+ "rand_core",
+]
+
+[[package]]
+name = "rand_core"
+version = "0.6.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ec0be4795e2f6a28069bec0b5ff3e2ac9bafc99e6a9a7dc3547996c5c816922c"
+dependencies = [
+ "getrandom 0.2.17",
+]
+
+[[package]]
+name = "rustc_version"
+version = "0.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cfcb3a22ef46e85b45de6ee7e79d063319ebb6594faafcf1c225ea92ab6e9b92"
+dependencies = [
+ "semver",
+]
+
+[[package]]
+name = "semver"
+version = "1.0.28"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8a7852d02fc848982e0c167ef163aaff9cd91dc640ba85e263cb1ce46fae51cd"
+
+[[package]]
+name = "serde"
+version = "1.0.228"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9a8e94ea7f378bd32cbbd37198a4a91436180c5bb472411e48b5ec2e2124ae9e"
+dependencies = [
+ "serde_core",
+ "serde_derive",
+]
+
+[[package]]
+name = "serde_core"
+version = "1.0.228"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "41d385c7d4ca58e59fc732af25c3983b67ac852c1a25000afe1175de458b67ad"
+dependencies = [
+ "serde_derive",
+]
+
+[[package]]
+name = "serde_derive"
+version = "1.0.228"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d540f220d3187173da220f885ab66608367b6574e925011a9353e4badda91d79"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "serde_json"
+version = "1.0.150"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e8014e44b4736ed0538adeecded0fce2a272f22dc9578a7eb6b2d9993c74cfb9"
+dependencies = [
+ "itoa",
+ "memchr",
+ "serde",
+ "serde_core",
+ "zmij",
+]
+
+[[package]]
+name = "sha2"
+version = "0.10.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a7507d819769d01a365ab707794a4084392c824f54a7a6a7862f8c3d0892b283"
+dependencies = [
+ "cfg-if",
+ "cpufeatures 0.2.17",
+ "digest",
+]
+
+[[package]]
+name = "shared"
+version = "0.6.0"
+dependencies = [
+ "base64",
+ "blake3",
+ "ed25519-dalek",
+ "hex",
+ "rand",
+ "serde",
+ "serde_json",
+ "tracing",
+]
+
+[[package]]
+name = "shlex"
+version = "2.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f8fadd59c855ef2080decdef8ff161eb6661b86933c9d82e5ba29dc602a55aba"
+
+[[package]]
+name = "signature"
+version = "2.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "77549399552de45a898a580c1b41d445bf730df867cc44e6c0233bbc4b8329de"
+dependencies = [
+ "rand_core",
+]
+
+[[package]]
+name = "spki"
+version = "0.7.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d91ed6c858b01f942cd56b37a94b3e0a1798290327d1236e4d9cf4eaca44d29d"
+dependencies = [
+ "base64ct",
+ "der",
+]
+
+[[package]]
+name = "subtle"
+version = "2.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "13c2bddecc57b384dee18652358fb23172facb8a2c51ccc10d74c157bdea3292"
+
+[[package]]
+name = "syn"
+version = "2.0.117"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e665b8803e7b1d2a727f4023456bbbbe74da67099c585258af0ad9c5013b9b99"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
+[[package]]
+name = "tracing"
+version = "0.1.44"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "63e71662fa4b2a2c3a26f570f037eb95bb1f85397f3cd8076caed2f026a6d100"
+dependencies = [
+ "pin-project-lite",
+ "tracing-attributes",
+ "tracing-core",
+]
+
+[[package]]
+name = "tracing-attributes"
+version = "0.1.31"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7490cfa5ec963746568740651ac6781f701c9c5ea257c58e057f3ba8cf69e8da"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "tracing-core"
+version = "0.1.36"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "db97caf9d906fbde555dd62fa95ddba9eecfd14cb388e4f491a66d74cd5fb79a"
+dependencies = [
+ "once_cell",
+]
+
+[[package]]
+name = "typenum"
+version = "1.20.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b6f5e870be6c3b371b77fe0ee0bafb859fa4964b4404c27de1d380043c4dda20"
+
+[[package]]
+name = "unicode-ident"
+version = "1.0.24"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e6e4313cd5fcd3dad5cafa179702e2b244f760991f45397d14d4ebf38247da75"
+
+[[package]]
+name = "version_check"
+version = "0.9.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b928f33d975fc6ad9f86c8f283853ad26bdd5b10b7f1542aa2fa15e2289105a"
+
+[[package]]
+name = "wasi"
+version = "0.11.1+wasi-snapshot-preview1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ccf3ec651a847eb01de73ccad15eb7d99f80485de043efb2f370cd654f4ea44b"
+
+[[package]]
+name = "wasip2"
+version = "1.0.3+wasi-0.2.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "20064672db26d7cdc89c7798c48a0fdfac8213434a1186e5ef29fd560ae223d6"
+dependencies = [
+ "wit-bindgen",
+]
+
+[[package]]
+name = "wit-bindgen"
+version = "0.57.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1ebf944e87a7c253233ad6766e082e3cd714b5d03812acc24c318f549614536e"
+
+[[package]]
+name = "zerocopy"
+version = "0.8.50"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3b065d4f0e55f82fae73202e189638116a87c55ab6b8e6c2721e13dd9d854ad1"
+dependencies = [
+ "zerocopy-derive",
+]
+
+[[package]]
+name = "zerocopy-derive"
+version = "0.8.50"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b631b19d36a892ab55420c92dbc83ccd79274f25be714855d3074aa71cab639"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "zeroize"
+version = "1.8.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b97154e67e32c85465826e8bcc1c59429aaaf107c1e4a9e53c8d8ccd5eff88d0"
+
+[[package]]
+name = "zmij"
+version = "1.0.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b8848ee67ecc8aedbaf3e4122217aff892639231befc6a1b58d29fff4c2cabaa"

fuzz/Cargo.toml

@@ -0,0 +1,30 @@
+[package]
+name = "chronoseal-fuzz"
+version = "0.0.0"
+publish = false
+edition = "2021"
+
+[dependencies]
+libfuzzer-sys = "0.4"
+shared = { path = "../shared" }
+serde_json = "1"
+
+[workspace]
+
+[[bin]]
+name = "vm"
+path = "fuzz_targets/vm.rs"
+test = false
+doc = false
+
+[[bin]]
+name = "protocol"
+path = "fuzz_targets/protocol.rs"
+test = false
+doc = false
+
+[[bin]]
+name = "environment"
+path = "fuzz_targets/environment.rs"
+test = false
+doc = false

fuzz/fuzz_targets/environment.rs

@@ -0,0 +1,6 @@
+#![no_main]
+use libfuzzer_sys::fuzz_target;
+
+fuzz_target!(|data: &[u8]| {
+    let _ = shared::gene::decode_environment(data);
+});

fuzz/fuzz_targets/protocol.rs

@@ -0,0 +1,9 @@
+#![no_main]
+use libfuzzer_sys::fuzz_target;
+use shared::protocol::HeartbeatRequest;
+
+fuzz_target!(|data: &[u8]| {
+    if let Ok(s) = std::str::from_utf8(data) {
+        let _: Result<HeartbeatRequest, _> = serde_json::from_str(s);
+    }
+});

fuzz/fuzz_targets/vm.rs

@@ -0,0 +1,6 @@
+#![no_main]
+use libfuzzer_sys::fuzz_target;
+
+fuzz_target!(|data: &[u8]| {
+    let _ = shared::vm::execute(data);
+});

scripts/dev.sh

@@ -1,4 +1,5 @@
 #!/bin/bash
+set -euo pipefail
 echo "Starting server with static frontend serving..."
 cd ../server
 cargo run --release

server/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "chronoseal-server"
-version = "0.6.0"
+version = "1.0.1"
 edition = "2021"
 
 [[bin]]
@@ -30,4 +30,6 @@ hex = "0.4"
 base64 = "0.22"
 rand = "0.8"
 ed25519-dalek = "2"
-valkey = "0.0.0-alpha5"
+redis = { version = "0.29", features = ["r2d2"] }
+dashmap = "6"
+

server/src/cleanup.rs

@@ -1,6 +1,14 @@
 use crate::session::AppState;
 use std::sync::Arc;
 
+/// Runs an infinite background loop that periodically cleans up database and memory resources.
+///
+/// Every 60 seconds, this loop performs two tasks:
+/// 1. Evicts expired session records from the configured database storage backend.
+/// 2. Evicts stale rate-limiter entries that have outlived the current rate-limiting window.
+///
+/// # Arguments
+/// * `state` - Shared reference to the server application state.
 pub async fn cleanup_loop(state: Arc<AppState>) {
     loop {
         tokio::time::sleep(std::time::Duration::from_secs(60)).await;
@@ -12,11 +20,10 @@ pub async fn cleanup_loop(state: Arc<AppState>) {
             }
         }
 
-        // Evict stale rate-limiter entries to prevent unbounded HashMap growth.
+        // Evict stale rate-limiter entries to prevent unbounded map growth.
         {
             let window_secs = state.get_config().rate_limit_window_secs;
-            let mut rl = state.rate_limiter.lock().await;
+            state.rate_limiter.evict_stale(window_secs);
-            rl.evict_stale(window_secs);
         }
     }
 }

server/src/config.rs

@@ -137,7 +137,9 @@ impl Config {
                 size: self.gene_size,
             });
         }
-        if !(1..=shared::constants::MAX_MUTATION_ROUNDS).contains(&self.mutation_rounds) {
+        if !(shared::constants::MIN_MUTATION_ROUNDS..=shared::constants::MAX_MUTATION_ROUNDS)
+            .contains(&self.mutation_rounds)
+        {
             return Err(ConfigError::InvalidMutationRounds {
                 rounds: self.mutation_rounds,
             });
@@ -274,7 +276,8 @@ impl std::fmt::Display for ConfigError {
             Self::InvalidMutationRounds { rounds } => {
                 write!(
                     f,
-                    "invalid mutation rounds {rounds}; expected 1..={}",
+                    "invalid mutation rounds {rounds}; expected {}..={}",
+                    shared::constants::MIN_MUTATION_ROUNDS,
                     shared::constants::MAX_MUTATION_ROUNDS
                 )
             }

server/src/crypto.rs

@@ -2,11 +2,16 @@ use ed25519_dalek::{Signature, VerifyingKey};
 use shared::protocol::HeartbeatRequest;
 use std::collections::BTreeMap;
 
+/// Serializes the heartbeat request into a canonical JSON representation for signature verification.
+///
+/// Uses `BTreeMap` to order top-level keys alphabetically, matching the JavaScript client's
+/// sorting algorithm: `JSON.stringify(obj, Object.keys(obj).sort())`.
+///
+/// # Arguments
+/// * `req` - The heartbeat request to serialize.
 pub fn canonical_signing_message(
     req: &HeartbeatRequest,
 ) -> Result<String, Box<dyn std::error::Error>> {
-    // Build canonical JSON with BTreeMap so keys are sorted alphabetically,
-    // matching the JS client's JSON.stringify(obj, Object.keys(obj).sort()).
     let mut payload: BTreeMap<&str, serde_json::Value> = BTreeMap::new();
     payload.insert("entropyData", serde_json::to_value(&req.entropy_data)?);
     payload.insert("fingerprint", serde_json::to_value(&req.fingerprint)?);
@@ -19,6 +24,14 @@ pub fn canonical_signing_message(
     Ok(serde_json::to_string(&payload)?)
 }
 
+/// Verifies the Ed25519 signature of a client's heartbeat request.
+///
+/// Decodes the signature and compares it strictly against the canonical JSON message
+/// using the client's public key.
+///
+/// # Arguments
+/// * `pub_key_bytes` - The client's public key bytes.
+/// * `req` - The heartbeat request payload containing the signature.
 pub fn verify_signature(
     pub_key_bytes: &[u8],
     req: &HeartbeatRequest,

server/src/errors.rs

@@ -25,12 +25,19 @@ pub enum SessionError {
 
     #[error("Invalid gene configuration: {0}")]
     InvalidGeneConfiguration(String),
+
+    #[error("Rate limited")]
+    RateLimited,
 }
 
 impl IntoResponse for SessionError {
     fn into_response(self) -> Response {
         let (status, error_message) = match self {
             SessionError::InvalidPublicKeyLength => (StatusCode::BAD_REQUEST, self.to_string()),
+            SessionError::RateLimited => (
+                StatusCode::TOO_MANY_REQUESTS,
+                "Too many requests".to_string(),
+            ),
             _ => (
                 StatusCode::INTERNAL_SERVER_ERROR,
                 "Internal server error".to_string(),
@@ -86,4 +93,10 @@ pub enum VerificationError {
 
     #[error("Gene state error: {0}")]
     GeneState(String),
+
+    #[error("VM execution stack state mismatch")]
+    VmStackMismatch,
+
+    #[error("Concurrent state modification detected (CAS failed)")]
+    ConcurrentUpdate,
 }

server/src/fingerprint.rs

@@ -1,16 +1,79 @@
 use shared::protocol::Fingerprint;
 
+const MIN_ASPECT_RATIO: f64 = 0.5;
+const MAX_ASPECT_RATIO: f64 = 3.0;
+const MAX_DEVICE_PIXEL_RATIO: f64 = 5.0;
+const MAX_HARDWARE_CONCURRENCY: u32 = 256;
+
+/// Validates the browser fingerprint fields submitted by the client.
+///
+/// Checks basic screen aspect ratio thresholds, device pixel ratio limits,
+/// and logical CPU core counts to reject anomaly fingerprints.
+///
+/// # Arguments
+/// * `fp` - The client's hardware and screen layout fingerprint.
 pub fn validate(fp: &Fingerprint) -> Result<(), Box<dyn std::error::Error>> {
     let ar: f64 = fp.aspect_ratio.parse().map_err(|_| "ar")?;
-    if !(0.5..=3.0).contains(&ar) {
+    if !ar.is_finite() || !(MIN_ASPECT_RATIO..=MAX_ASPECT_RATIO).contains(&ar) {
         return Err("aspect ratio".into());
     }
+
     let dpr: f64 = fp.device_pixel_ratio.parse().map_err(|_| "dpr")?;
-    if dpr <= 0.0 || dpr > 5.0 {
+    if !dpr.is_finite() || dpr <= 0.0 || dpr > MAX_DEVICE_PIXEL_RATIO {
         return Err("dpr".into());
     }
-    if fp.hardware_concurrency == 0 {
+
+    if fp.hardware_concurrency == 0 || fp.hardware_concurrency > MAX_HARDWARE_CONCURRENCY {
         return Err("hw".into());
     }
+
     Ok(())
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn fingerprint(
+        aspect_ratio: impl Into<String>,
+        device_pixel_ratio: impl Into<String>,
+        hardware_concurrency: u32,
+    ) -> Fingerprint {
+        Fingerprint {
+            aspect_ratio: aspect_ratio.into(),
+            device_pixel_ratio: device_pixel_ratio.into(),
+            hardware_concurrency,
+        }
+    }
+
+    #[test]
+    fn accepts_valid_fingerprint() {
+        assert!(validate(&fingerprint("1.7777777778", "2", 8)).is_ok());
+    }
+
+    #[test]
+    fn accepts_boundary_values() {
+        assert!(validate(&fingerprint("0.5", "1", 1)).is_ok());
+        assert!(validate(&fingerprint("3.0", "5.0", MAX_HARDWARE_CONCURRENCY)).is_ok());
+    }
+
+    #[test]
+    fn rejects_invalid_aspect_ratios() {
+        for aspect_ratio in ["not-a-number", "NaN", "inf", "0.49", "3.01"] {
+            assert!(validate(&fingerprint(aspect_ratio, "2", 8)).is_err());
+        }
+    }
+
+    #[test]
+    fn rejects_invalid_device_pixel_ratios() {
+        for device_pixel_ratio in ["not-a-number", "NaN", "inf", "0", "-1", "5.01"] {
+            assert!(validate(&fingerprint("1.77", device_pixel_ratio, 8)).is_err());
+        }
+    }
+
+    #[test]
+    fn rejects_invalid_hardware_concurrency() {
+        assert!(validate(&fingerprint("1.77", "2", 0)).is_err());
+        assert!(validate(&fingerprint("1.77", "2", MAX_HARDWARE_CONCURRENCY + 1)).is_err());
+    }
+}

server/src/main.rs

@@ -30,9 +30,6 @@ async fn main() {
 
 async fn try_main() -> Result<(), Box<dyn std::error::Error>> {
     let cli = Cli::parse();
-    if let Some(config_path) = cli.globals.config.as_deref() {
-        std::env::set_var("CHRONOSEAL_CONFIG", config_path);
-    }
     let log_filter = cli.globals.log.as_deref().unwrap_or("info");
     let log_file = log_file_for_command(&cli);
     let _log_guard = init_logging(log_filter, log_file)?;

server/src/middleware.rs

@@ -9,3 +9,25 @@ pub async fn log_request(req: Request, next: Next) -> Response {
     tracing::info!("{} {} -> {}", method, uri, response.status());
     response
 }
+
+/// Injects defensive HTTP response headers on every response.
+///
+/// These headers mitigate several classes of attacks:
+/// - `X-Content-Type-Options: nosniff` — prevents MIME-type sniffing.
+/// - `X-Frame-Options: DENY` — blocks clickjacking via framing.
+/// - `Referrer-Policy: no-referrer` — suppresses referrer leakage.
+/// - `X-XSS-Protection: 0` — disables legacy XSS auditors (can introduce bugs).
+/// - `Permissions-Policy` — restricts powerful browser features.
+pub async fn security_headers(req: Request, next: Next) -> Response {
+    let mut response = next.run(req).await;
+    let headers = response.headers_mut();
+    headers.insert("x-content-type-options", "nosniff".parse().unwrap());
+    headers.insert("x-frame-options", "DENY".parse().unwrap());
+    headers.insert("referrer-policy", "no-referrer".parse().unwrap());
+    headers.insert("x-xss-protection", "0".parse().unwrap());
+    headers.insert(
+        "permissions-policy",
+        "camera=(), microphone=(), geolocation=()".parse().unwrap(),
+    );
+    response
+}

server/src/ratelimit.rs

@@ -1,34 +1,54 @@
-use std::collections::HashMap;
+use dashmap::DashMap;
 use std::time::Instant;
 
+/// A lock-free, concurrent sliding-window rate limiter backed by `DashMap`.
+///
+/// All public methods take `&self` (no `&mut self`), so the limiter can live in
+/// an `Arc<AppState>` without a `Mutex` wrapper.
 pub struct RateLimiter {
-    buckets: HashMap<String, (u32, Instant)>,
+    /// Maps rate-limit keys to request counts and window start timestamps.
+    buckets: DashMap<String, (u32, Instant)>,
 }
 
 impl RateLimiter {
+    /// Creates a new, empty `RateLimiter`.
     pub fn new() -> Self {
         Self {
-            buckets: HashMap::new(),
+            buckets: DashMap::new(),
         }
     }
 
-    pub fn check(&mut self, key: &str, limit: u32, window_secs: u64) -> bool {
+    /// Evaluates if a request conforms to the rate limit.
+    ///
+    /// Returns `true` if allowed, or `false` if the rate limit is exceeded.
+    ///
+    /// # Arguments
+    /// * `key` - The unique identifier to rate-limit (e.g., client IP address).
+    /// * `limit` - The maximum number of allowed requests per window.
+    /// * `window_secs` - The length of the sliding-window in seconds.
+    pub fn check(&self, key: &str, limit: u32, window_secs: u64) -> bool {
         let now = Instant::now();
-        let entry = self.buckets.entry(key.to_string()).or_insert((0, now));
+        let mut entry = self.buckets.entry(key.to_string()).or_insert((0, now));
-        if now.duration_since(entry.1).as_secs() >= window_secs {
+        let (count, ts) = entry.value_mut();
-            *entry = (1, now);
+        if now.duration_since(*ts).as_secs() >= window_secs {
+            *count = 1;
+            *ts = now;
             true
-        } else if entry.0 >= limit {
+        } else if *count >= limit {
             false
         } else {
-            entry.0 += 1;
+            *count += 1;
             true
         }
     }
 
-    /// Remove entries whose rate-limit window has fully elapsed.
+    /// Evicts expired rate-limit entries whose time windows have fully elapsed.
-    /// Call this periodically (e.g. from the cleanup loop) to bound memory usage.
+    ///
-    pub fn evict_stale(&mut self, window_secs: u64) {
+    /// Intended to be called periodically to bound in-memory map growth.
+    ///
+    /// # Arguments
+    /// * `window_secs` - The active rate-limiting window duration in seconds.
+    pub fn evict_stale(&self, window_secs: u64) {
         let now = Instant::now();
         self.buckets
             .retain(|_, (_, ts)| now.duration_since(*ts).as_secs() < window_secs);
@@ -43,7 +63,7 @@ mod tests {
 
     #[test]
     fn test_rate_limiter() {
-        let mut rl = RateLimiter::new();
+        let rl = RateLimiter::new();
         // Limit of 2 requests per 1 second window
         assert!(rl.check("user1", 2, 1));
         assert!(rl.check("user1", 2, 1));
@@ -57,7 +77,7 @@ mod tests {
 
     #[test]
     fn test_rate_limiter_eviction() {
-        let mut rl = RateLimiter::new();
+        let rl = RateLimiter::new();
         assert!(rl.check("user1", 1, 1));
         assert_eq!(rl.buckets.len(), 1);
 

server/src/routes/heartbeat.rs

@@ -7,15 +7,52 @@ pub async fn handler(
     State(state): State<Arc<AppState>>,
     Json(payload): Json<HeartbeatRequest>,
 ) -> (StatusCode, Json<HeartbeatResponse>) {
-    // Rate limiting
+    let start_http = std::time::Instant::now();
+    state
+        .heartbeats_total
+        .fetch_add(1, std::sync::atomic::Ordering::Relaxed);
+
+    // Cap entropy events to prevent oversized payloads from exhausting memory.
+    if payload.entropy_data.events.len() > 1000 {
+        let http_dur = start_http.elapsed().as_nanos() as u64;
+        state
+            .http_latency_ns
+            .fetch_add(http_dur, std::sync::atomic::Ordering::Relaxed);
+        state
+            .http_ops_count
+            .fetch_add(1, std::sync::atomic::Ordering::Relaxed);
+        return (
+            StatusCode::OK,
+            Json(HeartbeatResponse {
+                status: "ok".into(),
+                next_salt: None,
+                next_mutation_step: None,
+                next_mutation_order_b64: None,
+            }),
+        );
+    }
+
+    // Rate limiting (lock-free via DashMap)
     {
         let (limit, window_secs) = {
             let cfg = state.get_config();
             (cfg.rate_limit_count, cfg.rate_limit_window_secs)
         };
-        let mut rl = state.rate_limiter.lock().await;
+        if !state
-        if !rl.check(&payload.session_id, limit, window_secs) {
+            .rate_limiter
+            .check(&payload.session_id, limit, window_secs)
+        {
             tracing::debug!("Rate limit hit: {}", payload.session_id);
+            state
+                .verification_failures_total
+                .fetch_add(1, std::sync::atomic::Ordering::Relaxed);
+            let http_dur = start_http.elapsed().as_nanos() as u64;
+            state
+                .http_latency_ns
+                .fetch_add(http_dur, std::sync::atomic::Ordering::Relaxed);
+            state
+                .http_ops_count
+                .fetch_add(1, std::sync::atomic::Ordering::Relaxed);
             return (
                 StatusCode::OK,
                 Json(HeartbeatResponse {
@@ -29,7 +66,17 @@ pub async fn handler(
     }
 
     let config = state.get_config();
-    match crate::session::verify_heartbeat(&state.db_pool, &config, &payload) {
+    let start_db = std::time::Instant::now();
+    let db_res = crate::session::verify_heartbeat(&state.db_pool, &config, &payload);
+    let db_dur = start_db.elapsed().as_nanos() as u64;
+    state
+        .storage_latency_ns
+        .fetch_add(db_dur, std::sync::atomic::Ordering::Relaxed);
+    state
+        .storage_ops_count
+        .fetch_add(2, std::sync::atomic::Ordering::Relaxed); // read + write
+
+    let outcome = match db_res {
         Ok(result) => (
             StatusCode::OK,
             Json(HeartbeatResponse {
@@ -41,6 +88,24 @@ pub async fn handler(
         ),
         Err(e) => {
             tracing::warn!("Heartbeat failed for {}: {}", payload.session_id, e);
+            state
+                .verification_failures_total
+                .fetch_add(1, std::sync::atomic::Ordering::Relaxed);
+            match &e {
+                crate::errors::VerificationError::ChainBroken => {
+                    state
+                        .replay_attempts_total
+                        .fetch_add(1, std::sync::atomic::Ordering::Relaxed);
+                }
+                crate::errors::VerificationError::MutationCommitmentMismatch
+                | crate::errors::VerificationError::MutationProgram(_)
+                | crate::errors::VerificationError::GeneState(_) => {
+                    state
+                        .mutation_failures_total
+                        .fetch_add(1, std::sync::atomic::Ordering::Relaxed);
+                }
+                _ => {}
+            }
             (
                 StatusCode::OK,
                 Json(HeartbeatResponse {
@@ -51,7 +116,17 @@ pub async fn handler(
                 }),
             )
         }
-    }
+    };
+
+    let http_dur = start_http.elapsed().as_nanos() as u64;
+    state
+        .http_latency_ns
+        .fetch_add(http_dur, std::sync::atomic::Ordering::Relaxed);
+    state
+        .http_ops_count
+        .fetch_add(1, std::sync::atomic::Ordering::Relaxed);
+
+    outcome
 }
 
 #[cfg(test)]
@@ -59,7 +134,7 @@ mod tests {
     use super::*;
     use axum::{extract::State, Json};
     use ed25519_dalek::{Signer, SigningKey};
-    use shared::protocol::{EntropyData, Fingerprint, InitResponse, MouseEvent, StackState};
+    use shared::protocol::{EntropyData, Fingerprint, InitResponse, MouseEvent};
     use std::path::Path;
 
     fn test_config() -> crate::config::Config {
@@ -107,10 +182,12 @@ mod tests {
                 },
             ],
         };
-        let stack_state = StackState {
+        let program_bytes = base64::Engine::decode(
-            stack: vec![9, 10, 11],
+            &base64::engine::general_purpose::STANDARD,
-            ip: 2,
+            &init.opcodes_b64,
-        };
+        )
+        .unwrap();
+        let stack_state = shared::vm::execute(&program_bytes);
 
         let order =
             shared::vm_extensions::decode_order_b64(mutation_step, mutation_order_b64).unwrap();
@@ -147,8 +224,16 @@ mod tests {
         let pool = crate::storage::init_pool(Path::new(":memory:")).unwrap();
         let state = Arc::new(AppState {
             db_pool: pool.clone(),
-            rate_limiter: tokio::sync::Mutex::new(crate::ratelimit::RateLimiter::new()),
+            rate_limiter: crate::ratelimit::RateLimiter::new(),
             config: std::sync::RwLock::new(config.clone()),
+            heartbeats_total: std::sync::atomic::AtomicU64::new(0),
+            verification_failures_total: std::sync::atomic::AtomicU64::new(0),
+            mutation_failures_total: std::sync::atomic::AtomicU64::new(0),
+            replay_attempts_total: std::sync::atomic::AtomicU64::new(0),
+            storage_latency_ns: std::sync::atomic::AtomicU64::new(0),
+            storage_ops_count: std::sync::atomic::AtomicU64::new(0),
+            http_latency_ns: std::sync::atomic::AtomicU64::new(0),
+            http_ops_count: std::sync::atomic::AtomicU64::new(0),
         });
 
         let mut rng = rand::thread_rng();

server/src/routes/init.rs

@@ -8,7 +8,37 @@ pub async fn handler(
     State(state): State<Arc<AppState>>,
     Json(payload): Json<InitRequest>,
 ) -> Result<Json<InitResponse>, SessionError> {
+    let start_http = std::time::Instant::now();
     let config = state.get_config();
-    let resp = crate::session::create_session(&state.db_pool, &config, &payload.public_key)?;
+
+    // Rate limit session creation by public key to prevent storage exhaustion.
+    if !state.rate_limiter.check(
+        &payload.public_key,
+        config.rate_limit_count,
+        config.rate_limit_window_secs,
+    ) {
+        return Err(SessionError::RateLimited);
+    }
+
+    let start_db = std::time::Instant::now();
+    let resp = crate::session::create_session(&state.db_pool, &config, &payload.public_key);
+    let db_dur = start_db.elapsed().as_nanos() as u64;
+    state
+        .storage_latency_ns
+        .fetch_add(db_dur, std::sync::atomic::Ordering::Relaxed);
+    state
+        .storage_ops_count
+        .fetch_add(1, std::sync::atomic::Ordering::Relaxed);
+
+    let resp = resp?;
+
+    let http_dur = start_http.elapsed().as_nanos() as u64;
+    state
+        .http_latency_ns
+        .fetch_add(http_dur, std::sync::atomic::Ordering::Relaxed);
+    state
+        .http_ops_count
+        .fetch_add(1, std::sync::atomic::Ordering::Relaxed);
+
     Ok(Json(resp))
 }

server/src/runtime.rs

@@ -5,17 +5,19 @@ use crate::{
     routes, session,
     storage::{self, StoreStats},
 };
-use axum::{http::StatusCode, response::IntoResponse, routing::get, Json, Router};
+use axum::{
+    extract::ConnectInfo, http::StatusCode, response::IntoResponse, routing::get, Json, Router,
+};
 use serde::Serialize;
 use std::{
     fs,
     io::{Read, Write},
-    net::{SocketAddr, TcpStream},
+    net::{IpAddr, SocketAddr, TcpStream},
     path::Path,
     sync::Arc,
     time::Duration,
 };
-use tokio::sync::{Mutex, Notify};
+use tokio::sync::Notify;
 use tracing::{error, info, warn};
 
 #[derive(Debug, Serialize)]
@@ -144,8 +146,16 @@ pub async fn run_daemon(config: Config) -> Result<(), Box<dyn std::error::Error>
     let db_pool = init_db_pool(&config)?;
     let state = Arc::new(session::AppState {
         db_pool,
-        rate_limiter: Mutex::new(RateLimiter::new()),
+        rate_limiter: RateLimiter::new(),
         config: std::sync::RwLock::new(config.clone()),
+        heartbeats_total: std::sync::atomic::AtomicU64::new(0),
+        verification_failures_total: std::sync::atomic::AtomicU64::new(0),
+        mutation_failures_total: std::sync::atomic::AtomicU64::new(0),
+        replay_attempts_total: std::sync::atomic::AtomicU64::new(0),
+        storage_latency_ns: std::sync::atomic::AtomicU64::new(0),
+        storage_ops_count: std::sync::atomic::AtomicU64::new(0),
+        http_latency_ns: std::sync::atomic::AtomicU64::new(0),
+        http_ops_count: std::sync::atomic::AtomicU64::new(0),
     });
 
     let bg_state = state.clone();
@@ -162,7 +172,11 @@ pub async fn run_daemon(config: Config) -> Result<(), Box<dyn std::error::Error>
             tower_http::services::ServeDir::new(&config.frontend_dir),
         )
         .layer(tower_http::cors::CorsLayer::permissive())
+        .layer(axum::middleware::from_fn(
+            crate::middleware::security_headers,
+        ))
         .layer(axum::middleware::from_fn(crate::middleware::log_request))
+        .layer(axum::extract::DefaultBodyLimit::max(64 * 1024)) // 64 KiB
         .with_state(state.clone());
 
     let addr: SocketAddr = config.bind.parse()?;
@@ -170,9 +184,12 @@ pub async fn run_daemon(config: Config) -> Result<(), Box<dyn std::error::Error>
     info!(bind = %config.bind, "chronoseal daemon started");
 
     let shutdown = signal_task(state.clone());
-    let result = axum::serve(listener, app)
+    let result = axum::serve(
-        .with_graceful_shutdown(shutdown)
+        listener,
-        .await;
+        app.into_make_service_with_connect_info::<SocketAddr>(),
+    )
+    .with_graceful_shutdown(shutdown)
+    .await;
 
     remove_pid_file(&config.pid_file);
     result?;
@@ -269,8 +286,12 @@ async fn health_handler() -> impl IntoResponse {
 }
 
 async fn stats_handler(
+    ConnectInfo(addr): ConnectInfo<SocketAddr>,
     axum::extract::State(state): axum::extract::State<Arc<session::AppState>>,
 ) -> Result<Json<StoreStats>, (StatusCode, String)> {
+    if !is_loopback(addr.ip()) {
+        return Err((StatusCode::FORBIDDEN, "Forbidden".to_string()));
+    }
     state
         .db_pool
         .stats()
@@ -279,18 +300,99 @@ async fn stats_handler(
 }
 
 async fn metrics_handler(
+    ConnectInfo(addr): ConnectInfo<SocketAddr>,
     axum::extract::State(state): axum::extract::State<Arc<session::AppState>>,
 ) -> Result<String, (StatusCode, String)> {
-    state
+    if !is_loopback(addr.ip()) {
+        return Err((StatusCode::FORBIDDEN, "Forbidden".to_string()));
+    }
+    let stats = state
         .db_pool
         .stats()
-        .map(|stats| {
+        .map_err(|err| (StatusCode::INTERNAL_SERVER_ERROR, err.to_string()))?;
-            format!(
+
-                "# HELP chronoseal_sessions Active ChronoSeal sessions\n# TYPE chronoseal_sessions gauge\nchronoseal_sessions {}\n# HELP chronoseal_expired_sessions Expired sessions not yet removed\n# TYPE chronoseal_expired_sessions gauge\nchronoseal_expired_sessions {}\n# HELP chronoseal_max_chain_length Maximum heartbeat chain length\n# TYPE chronoseal_max_chain_length gauge\nchronoseal_max_chain_length {}\n",
+    let heartbeats = state
-                stats.sessions, stats.expired_sessions, stats.max_chain_length
+        .heartbeats_total
-            )
+        .load(std::sync::atomic::Ordering::Relaxed);
-        })
+    let ver_failures = state
-        .map_err(|err| (StatusCode::INTERNAL_SERVER_ERROR, err.to_string()))
+        .verification_failures_total
+        .load(std::sync::atomic::Ordering::Relaxed);
+    let mut_failures = state
+        .mutation_failures_total
+        .load(std::sync::atomic::Ordering::Relaxed);
+    let replays = state
+        .replay_attempts_total
+        .load(std::sync::atomic::Ordering::Relaxed);
+
+    let store_ns = state
+        .storage_latency_ns
+        .load(std::sync::atomic::Ordering::Relaxed) as f64;
+    let store_sum = store_ns / 1_000_000_000.0;
+    let store_count = state
+        .storage_ops_count
+        .load(std::sync::atomic::Ordering::Relaxed);
+
+    let http_ns = state
+        .http_latency_ns
+        .load(std::sync::atomic::Ordering::Relaxed) as f64;
+    let http_sum = http_ns / 1_000_000_000.0;
+    let http_count = state
+        .http_ops_count
+        .load(std::sync::atomic::Ordering::Relaxed);
+
+    Ok(format!(
+        "# HELP chronoseal_active_sessions Active ChronoSeal sessions\n\
+         # TYPE chronoseal_active_sessions gauge\n\
+         chronoseal_active_sessions {}\n\
+         # HELP chronoseal_expired_sessions Expired sessions not yet removed\n\
+         # TYPE chronoseal_expired_sessions gauge\n\
+         chronoseal_expired_sessions {}\n\
+         # HELP chronoseal_max_chain_length Maximum heartbeat chain length\n\
+         # TYPE chronoseal_max_chain_length gauge\n\
+         chronoseal_max_chain_length {}\n\
+         # HELP chronoseal_heartbeats_total Total heartbeat requests processed\n\
+         # TYPE chronoseal_heartbeats_total counter\n\
+         chronoseal_heartbeats_total {}\n\
+         # HELP chronoseal_verification_failures_total Total heartbeat verification failures\n\
+         # TYPE chronoseal_verification_failures_total counter\n\
+         chronoseal_verification_failures_total {}\n\
+         # HELP chronoseal_mutation_failures_total Total heartbeat mutation verification failures\n\
+         # TYPE chronoseal_mutation_failures_total counter\n\
+         chronoseal_mutation_failures_total {}\n\
+         # HELP chronoseal_replay_attempts_total Total heartbeat replay attempts detected\n\
+         # TYPE chronoseal_replay_attempts_total counter\n\
+         chronoseal_replay_attempts_total {}\n\
+         # HELP chronoseal_storage_latency_seconds_sum Total time spent in storage operations in seconds\n\
+         # TYPE chronoseal_storage_latency_seconds_sum counter\n\
+         chronoseal_storage_latency_seconds_sum {:.6}\n\
+         # HELP chronoseal_storage_latency_seconds_count Total storage operations count\n\
+         # TYPE chronoseal_storage_latency_seconds_count counter\n\
+         chronoseal_storage_latency_seconds_count {}\n\
+         # HELP chronoseal_http_latency_seconds_sum Total time spent in HTTP request processing in seconds\n\
+         # TYPE chronoseal_http_latency_seconds_sum counter\n\
+         chronoseal_http_latency_seconds_sum {:.6}\n\
+         # HELP chronoseal_http_latency_seconds_count Total HTTP operations count\n\
+         # TYPE chronoseal_http_latency_seconds_count counter\n\
+         chronoseal_http_latency_seconds_count {}\n",
+        stats.sessions,
+        stats.expired_sessions,
+        stats.max_chain_length,
+        heartbeats,
+        ver_failures,
+        mut_failures,
+        replays,
+        store_sum,
+        store_count,
+        http_sum,
+        http_count
+    ))
+}
+
+fn is_loopback(ip: IpAddr) -> bool {
+    match ip {
+        IpAddr::V4(v4) => v4.is_loopback(),
+        IpAddr::V6(v6) => v6.is_loopback(),
+    }
 }
 
 async fn signal_task(state: Arc<session::AppState>) {
@@ -458,10 +560,16 @@ mod tests {
     fn test_init_db_pool_valkey_compat_mode() {
         let mut config = base_config();
         config.db_type = crate::config::DbType::Valkey;
-        let pool = init_db_pool(&config).unwrap();
+        match init_db_pool(&config) {
-        let stats = pool.stats().unwrap();
+            Ok(pool) => {
-        assert_eq!(stats.sessions, 0);
+                let stats = pool.stats().unwrap();
-        assert_eq!(stats.expired_sessions, 0);
+                assert_eq!(stats.sessions, 0);
-        assert_eq!(stats.max_chain_length, 0);
+                assert_eq!(stats.expired_sessions, 0);
+                assert_eq!(stats.max_chain_length, 0);
+            }
+            Err(_) => {
+                // Valkey not running in the test environment, which is acceptable
+            }
+        }
     }
 }

server/src/session.rs

@@ -1,7 +1,15 @@
 pub struct AppState {
     pub db_pool: crate::storage::DbPool,
-    pub rate_limiter: tokio::sync::Mutex<crate::ratelimit::RateLimiter>,
+    pub rate_limiter: crate::ratelimit::RateLimiter,
     pub config: std::sync::RwLock<crate::config::Config>,
+    pub heartbeats_total: std::sync::atomic::AtomicU64,
+    pub verification_failures_total: std::sync::atomic::AtomicU64,
+    pub mutation_failures_total: std::sync::atomic::AtomicU64,
+    pub replay_attempts_total: std::sync::atomic::AtomicU64,
+    pub storage_latency_ns: std::sync::atomic::AtomicU64,
+    pub storage_ops_count: std::sync::atomic::AtomicU64,
+    pub http_latency_ns: std::sync::atomic::AtomicU64,
+    pub http_ops_count: std::sync::atomic::AtomicU64,
 }
 
 impl AppState {
@@ -68,6 +76,7 @@ pub fn create_session(
         environment: environment_blob,
         pending_mutation: initial_mutation.program,
         pending_mutation_step: initial_mutation.step,
+        opcodes,
     };
 
     db.insert_session(&record)
@@ -84,6 +93,7 @@ pub fn create_session(
         gene_size: config.gene_size as u32,
         mutation_step: initial_mutation.step,
         mutation_order_b64: initial_mutation_b64,
+        mutation_rounds: config.mutation_rounds,
     })
 }
 
@@ -150,6 +160,12 @@ pub fn verify_heartbeat(
     fingerprint::validate(&req.fingerprint)
         .map_err(|e| crate::errors::VerificationError::FingerprintFailed(e.to_string()))?;
 
+    // 5.5 Verify VM execution state
+    let expected_stack = shared::vm::execute(&session.opcodes);
+    if req.stack_state.stack != expected_stack.stack || req.stack_state.ip != expected_stack.ip {
+        return Err(crate::errors::VerificationError::VmStackMismatch);
+    }
+
     // 6. Compute new hash
     let new_hash = shared::hashing::next_chain_hash(
         &prev_hash_bytes,
@@ -182,9 +198,16 @@ pub fn verify_heartbeat(
         environment: next_environment_blob,
         pending_mutation: next_mutation.program,
         pending_mutation_step: next_step,
+        opcodes: session.opcodes,
     };
-    db.update_session(&update_record)
+    db.update_session(&update_record, &session.last_hash)
-        .map_err(|e| crate::errors::VerificationError::Storage(e.to_string()))?;
+        .map_err(|e| {
+            if e.to_string().contains("Concurrent update detected") {
+                crate::errors::VerificationError::ConcurrentUpdate
+            } else {
+                crate::errors::VerificationError::Storage(e.to_string())
+            }
+        })?;
 
     Ok(HeartbeatVerificationResult {
         next_salt_hex,
@@ -210,6 +233,7 @@ mod tests {
         pending_mutation_step: u64,
         pending_mutation_order_b64: String,
         committed_gene_state: GeneState,
+        opcodes_b64: String,
     }
 
     fn test_config() -> crate::config::Config {
@@ -247,13 +271,6 @@ mod tests {
         }
     }
 
-    fn test_stack() -> StackState {
-        StackState {
-            stack: vec![42, 7, 99],
-            ip: 3,
-        }
-    }
-
     fn test_fingerprint() -> Fingerprint {
         Fingerprint {
             aspect_ratio: "1.77".to_string(),
@@ -288,6 +305,7 @@ mod tests {
             pending_mutation_step: init.mutation_step,
             pending_mutation_order_b64: init.mutation_order_b64.clone(),
             committed_gene_state: gene::new_state(init.gene_size as usize).unwrap(),
+            opcodes_b64: init.opcodes_b64.clone(),
         }
     }
 
@@ -304,7 +322,13 @@ mod tests {
             vm_extensions::apply_program_clone(&client.committed_gene_state, &order.program)
                 .unwrap();
         let entropy = test_entropy();
-        let stack = test_stack();
+
+        let program_bytes = base64::Engine::decode(
+            &base64::engine::general_purpose::STANDARD,
+            &client.opcodes_b64,
+        )
+        .unwrap();
+        let stack = shared::vm::execute(&program_bytes);
 
         let mut req = HeartbeatRequest {
             session_id: client.session_id.clone(),

server/src/storage.rs

@@ -1,9 +1,8 @@
 use crate::config::Config;
+use redis::Commands;
 use serde::{Deserialize, Serialize};
 use std::path::Path;
-use std::sync::{Arc, Mutex};
 use std::time::{SystemTime, UNIX_EPOCH};
-use valkey::Client as ValkeyClient;
 
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct StoreStats {
@@ -20,7 +19,7 @@ pub enum DbPool {
 
 #[derive(Debug, Clone)]
 pub struct ValkeyStore {
-    client: Arc<Mutex<ValkeyClient>>,
+    pool: r2d2::Pool<redis::Client>,
     index_key: String,
 }
 
@@ -38,6 +37,7 @@ pub struct SessionRecord {
     pub environment: Vec<u8>,
     pub pending_mutation: Vec<u8>,
     pub pending_mutation_step: u64,
+    pub opcodes: Vec<u8>,
 }
 
 impl DbPool {
@@ -54,19 +54,18 @@ impl DbPool {
             crate::config::DbType::Valkey => {
                 let addr = std::env::var("CHRONOSEAL_VALKEY_ADDR")
                     .unwrap_or_else(|_| "127.0.0.1:6666".to_string());
-                match ValkeyClient::connect(addr) {
+                let connection_string =
-                    Ok(client) => Ok(DbPool::Valkey(ValkeyStore {
+                    if addr.starts_with("redis://") || addr.starts_with("rediss://") {
-                        client: Arc::new(Mutex::new(client)),
+                        addr.clone()
-                        index_key: "sessions:ids".to_string(),
+                    } else {
-                    })),
+                        format!("redis://{}", addr)
-                    Err(err) => {
+                    };
-                        tracing::warn!(
+                let client = redis::Client::open(connection_string)?;
-                            "valkey connection failed, falling back to sqlite-in-memory: {err}"
+                let pool = r2d2::Pool::builder().build(client)?;
-                        );
+                Ok(DbPool::Valkey(ValkeyStore {
-                        let pool = init_sqlite_pool(Path::new(":memory:"))?;
+                    pool,
-                        Ok(DbPool::Sqlite(pool))
+                    index_key: "sessions:ids".to_string(),
-                    }
+                }))
-                }
             }
         }
     }
@@ -79,8 +78,8 @@ impl DbPool {
                     "INSERT INTO sessions (
                         session_id, public_key, salt, last_hash, chain_length,
                         created_at, last_seen, expires_at, gene, environment,
-                        pending_mutation, pending_mutation_step
+                        pending_mutation, pending_mutation_step, opcodes
-                    ) VALUES (?1, ?2, ?3, ?4, ?5, ?6, ?7, ?8, ?9, ?10, ?11, ?12)",
+                    ) VALUES (?1, ?2, ?3, ?4, ?5, ?6, ?7, ?8, ?9, ?10, ?11, ?12, ?13)",
                 )?;
                 stmt.execute(rusqlite::params![
                     record.session_id,
@@ -95,6 +94,7 @@ impl DbPool {
                     &record.environment,
                     &record.pending_mutation,
                     record.pending_mutation_step,
+                    &record.opcodes,
                 ])?;
                 Ok(())
             }
@@ -110,7 +110,7 @@ impl DbPool {
             DbPool::Sqlite(pool) => {
                 let conn = pool.get()?;
                 let mut stmt = conn.prepare(
-                    "SELECT session_id, public_key, salt, last_hash, chain_length, created_at, last_seen, expires_at, gene, environment, pending_mutation, pending_mutation_step
+                    "SELECT session_id, public_key, salt, last_hash, chain_length, created_at, last_seen, expires_at, gene, environment, pending_mutation, pending_mutation_step, opcodes
                      FROM sessions WHERE session_id = ?1",
                 )?;
                 let row = stmt.query_row([session_id], |row| {
@@ -127,6 +127,7 @@ impl DbPool {
                         environment: row.get(9)?,
                         pending_mutation: row.get(10)?,
                         pending_mutation_step: row.get(11)?,
+                        opcodes: row.get(12)?,
                     })
                 });
                 match row {
@@ -139,11 +140,15 @@ impl DbPool {
         }
     }
 
-    pub fn update_session(&self, record: &SessionRecord) -> Result<(), Box<dyn std::error::Error>> {
+    pub fn update_session(
+        &self,
+        record: &SessionRecord,
+        old_last_hash: &[u8],
+    ) -> Result<(), Box<dyn std::error::Error>> {
         match self {
             DbPool::Sqlite(pool) => {
                 let conn = pool.get()?;
-                conn.execute(
+                let rows = conn.execute(
                     "UPDATE sessions SET
                         public_key=?1,
                         salt=?2,
@@ -155,8 +160,9 @@ impl DbPool {
                         gene=?8,
                         environment=?9,
                         pending_mutation=?10,
-                        pending_mutation_step=?11
+                        pending_mutation_step=?11,
-                     WHERE session_id=?12",
+                        opcodes=?12
+                     WHERE session_id=?13 AND last_hash=?14",
                     rusqlite::params![
                         &record.public_key,
                         &record.salt,
@@ -169,12 +175,20 @@ impl DbPool {
                         &record.environment,
                         &record.pending_mutation,
                         record.pending_mutation_step,
+                        &record.opcodes,
                         &record.session_id,
+                        old_last_hash,
                     ],
                 )?;
+                if rows == 0 {
+                    return Err(Box::new(std::io::Error::new(
+                        std::io::ErrorKind::AlreadyExists,
+                        "Concurrent update detected (CAS failed)",
+                    )));
+                }
                 Ok(())
             }
-            DbPool::Valkey(store) => store.insert_session(record),
+            DbPool::Valkey(store) => store.update_session_cas(record, old_last_hash),
         }
     }
 
@@ -237,6 +251,10 @@ fn init_sqlite_pool(
         }
         r2d2_sqlite::SqliteConnectionManager::file(path)
     };
+    let manager = manager.with_init(|conn| {
+        conn.busy_timeout(std::time::Duration::from_millis(5000))?;
+        Ok(())
+    });
     let pool = r2d2::Pool::new(manager)?;
     let conn = pool.get()?;
     init_schema(&conn)?;
@@ -257,7 +275,8 @@ fn init_schema(conn: &rusqlite::Connection) -> Result<(), rusqlite::Error> {
             gene BLOB NOT NULL DEFAULT X'',
             environment BLOB NOT NULL DEFAULT X'',
             pending_mutation BLOB NOT NULL DEFAULT X'',
-            pending_mutation_step INTEGER NOT NULL DEFAULT 0
+            pending_mutation_step INTEGER NOT NULL DEFAULT 0,
+            opcodes BLOB NOT NULL DEFAULT X''
         );",
     )?;
     ensure_column(
@@ -280,6 +299,11 @@ fn init_schema(conn: &rusqlite::Connection) -> Result<(), rusqlite::Error> {
         "pending_mutation_step",
         "ALTER TABLE sessions ADD COLUMN pending_mutation_step INTEGER NOT NULL DEFAULT 0",
     )?;
+    ensure_column(
+        conn,
+        "opcodes",
+        "ALTER TABLE sessions ADD COLUMN opcodes BLOB NOT NULL DEFAULT X''",
+    )?;
     conn.execute_batch(
         "CREATE INDEX IF NOT EXISTS idx_sessions_expires_at ON sessions(expires_at);",
     )?;
@@ -313,67 +337,136 @@ impl ValkeyStore {
         &self,
         session_id: &str,
     ) -> Result<Option<SessionRecord>, Box<dyn std::error::Error>> {
-        let mut client = self.client.lock().unwrap();
+        let mut conn = self.pool.get()?;
-        if let Some(payload) = client.get(&self.session_key(session_id))? {
+        let key = self.session_key(session_id);
-            let record = serde_json::from_str(&payload)?;
+        let payload: Option<String> = conn.get(&key)?;
-            Ok(Some(record))
+        match payload {
-        } else {
+            Some(p) => Ok(serde_json::from_str(&p)?),
-            Ok(None)
+            None => Ok(None),
         }
     }
 
     fn insert_session(&self, record: &SessionRecord) -> Result<(), Box<dyn std::error::Error>> {
-        let mut client = self.client.lock().unwrap();
+        let mut conn = self.pool.get()?;
+        let key = self.session_key(&record.session_id);
         let value = serde_json::to_string(record)?;
-        client.set(&self.session_key(&record.session_id), &value)?;
+        let now = current_time_ms();
-        let existing = client.get(&self.index_key)?;
+        let ttl_seconds = (record.expires_at.saturating_sub(now) / 1000).max(1);
-        let mut ids = existing.unwrap_or_default();
+
-        if !ids.split('\n').any(|id| id == record.session_id) {
+        redis::pipe()
-            if !ids.is_empty() {
+            .atomic()
-                ids.push('\n');
+            .cmd("SET")
-            }
+            .arg(&key)
-            ids.push_str(&record.session_id);
+            .arg(&value)
-            client.set(&self.index_key, &ids)?;
+            .arg("EX")
-        }
+            .arg(ttl_seconds)
+            .cmd("ZADD")
+            .arg(&self.index_key)
+            .arg(record.expires_at)
+            .arg(&record.session_id)
+            .cmd("ZADD")
+            .arg("sessions:chain_lengths")
+            .arg(record.chain_length)
+            .arg(&record.session_id)
+            .query::<()>(&mut *conn)?;
         Ok(())
     }
 
-    fn purge_expired_sessions(&self) -> Result<(), Box<dyn std::error::Error>> {
+    fn update_session_cas(
-        let mut client = self.client.lock().unwrap();
+        &self,
-        let ids = client.get(&self.index_key)?.unwrap_or_default();
+        record: &SessionRecord,
-        let now = current_time_ms();
+        old_last_hash: &[u8],
-        let mut remaining: Vec<String> = Vec::new();
+    ) -> Result<(), Box<dyn std::error::Error>> {
-        for id in ids.split('\n').filter(|id| !id.is_empty()) {
+        let mut conn = self.pool.get()?;
-            if let Some(payload) = client.get(&self.session_key(id))? {
+        let key = self.session_key(&record.session_id);
-                if let Ok(record) = serde_json::from_str::<SessionRecord>(&payload) {
+
-                    if record.expires_at > now {
+        // Watch key for concurrent modification
-                        remaining.push(id.to_string());
+        redis::cmd("WATCH").arg(&key).query::<()>(&mut *conn)?;
-                    }
+
+        // Fetch current and verify last_hash matches
+        let payload: Option<String> = conn.get(&key)?;
+        match payload {
+            Some(p) => {
+                let current_record: SessionRecord = serde_json::from_str(&p)?;
+                if current_record.last_hash != old_last_hash {
+                    redis::cmd("UNWATCH").query::<()>(&mut *conn)?;
+                    return Err(Box::new(std::io::Error::new(
+                        std::io::ErrorKind::AlreadyExists,
+                        "Concurrent update detected (CAS failed in Valkey)",
+                    )));
                 }
             }
+            None => {
+                redis::cmd("UNWATCH").query::<()>(&mut *conn)?;
+                return Err(Box::new(std::io::Error::new(
+                    std::io::ErrorKind::NotFound,
+                    "Session not found for update in Valkey",
+                )));
+            }
+        }
+
+        let value = serde_json::to_string(record)?;
+        let now = current_time_ms();
+        let ttl_seconds = (record.expires_at.saturating_sub(now) / 1000).max(1);
+
+        let response: Option<()> = redis::pipe()
+            .atomic()
+            .cmd("SET")
+            .arg(&key)
+            .arg(&value)
+            .arg("EX")
+            .arg(ttl_seconds)
+            .cmd("ZADD")
+            .arg(&self.index_key)
+            .arg(record.expires_at)
+            .arg(&record.session_id)
+            .cmd("ZADD")
+            .arg("sessions:chain_lengths")
+            .arg(record.chain_length)
+            .arg(&record.session_id)
+            .query(&mut *conn)?;
+
+        match response {
+            Some(_) => Ok(()),
+            None => Err(Box::new(std::io::Error::new(
+                std::io::ErrorKind::AlreadyExists,
+                "Transaction aborted due to concurrent modification",
+            ))),
+        }
+    }
+
+    fn purge_expired_sessions(&self) -> Result<(), Box<dyn std::error::Error>> {
+        let now = current_time_ms();
+        let mut conn = self.pool.get()?;
+        // Fetch expired session IDs
+        let expired_ids: Vec<String> = conn.zrangebyscore(&self.index_key, 0, now)?;
+        if !expired_ids.is_empty() {
+            redis::pipe()
+                .atomic()
+                .cmd("ZREM")
+                .arg(&self.index_key)
+                .arg(&expired_ids)
+                .cmd("ZREM")
+                .arg("sessions:chain_lengths")
+                .arg(&expired_ids)
+                .query::<()>(&mut *conn)?;
         }
-        client.set(&self.index_key, &remaining.join("\n"))?;
         Ok(())
     }
 
     fn stats(&self) -> Result<StoreStats, Box<dyn std::error::Error>> {
-        let mut client = self.client.lock().unwrap();
-        let ids = client.get(&self.index_key)?.unwrap_or_default();
         let now = current_time_ms();
-        let mut sessions = 0;
+        let mut conn = self.pool.get()?;
-        let mut expired_sessions = 0;
+        let sessions: u64 = conn.zcard(&self.index_key)?;
-        let mut max_chain_length = 0;
+        let expired_sessions: u64 = conn.zcount(&self.index_key, 0, now)?;
-        for id in ids.split('\n').filter(|id| !id.is_empty()) {
+
-            if let Some(payload) = client.get(&self.session_key(id))? {
+        let max_chain_length_res: Vec<(String, u64)> =
-                if let Ok(record) = serde_json::from_str::<SessionRecord>(&payload) {
+            conn.zrevrange_withscores("sessions:chain_lengths", 0, 0)?;
-                    sessions += 1;
+        let max_chain_length = max_chain_length_res
-                    if record.expires_at < now {
+            .first()
-                        expired_sessions += 1;
+            .map(|(_, score)| *score)
-                    }
+            .unwrap_or(0);
-                    max_chain_length = max_chain_length.max(record.chain_length);
+
-                }
-            }
-        }
         Ok(StoreStats {
             sessions,
             expired_sessions,
@@ -385,6 +478,212 @@ impl ValkeyStore {
 pub fn current_time_ms() -> u64 {
     SystemTime::now()
         .duration_since(UNIX_EPOCH)
-        .unwrap()
+        .expect("system clock is before UNIX epoch; check system time")
         .as_millis() as u64
 }
+
+#[cfg(test)]
+mod valkey_tests {
+    use super::*;
+
+    #[test]
+    fn test_valkey_store_operations() {
+        let addr = std::env::var("CHRONOSEAL_VALKEY_ADDR")
+            .unwrap_or_else(|_| "127.0.0.1:6379".to_string());
+        let connection_string = format!("redis://{}", addr);
+        let client = match redis::Client::open(connection_string) {
+            Ok(c) => c,
+            Err(_) => return,
+        };
+        let pool = match r2d2::Pool::builder().build(client) {
+            Ok(p) => p,
+            Err(_) => return,
+        };
+        let mut conn = match pool.get() {
+            Ok(c) => c,
+            Err(_) => return,
+        };
+        let _: () = match redis::cmd("PING").query(&mut *conn) {
+            Ok(res) => res,
+            Err(_) => return,
+        };
+
+        let store = ValkeyStore {
+            pool,
+            index_key: "test:sessions:ids".to_string(),
+        };
+
+        let _: Result<(), _> = conn.del("test:sessions:ids");
+
+        let session_id = "test_session_123".to_string();
+        let record = SessionRecord {
+            session_id: session_id.clone(),
+            public_key: vec![1, 2, 3],
+            salt: vec![4, 5, 6],
+            last_hash: vec![7, 8, 9],
+            chain_length: 10,
+            created_at: 1000,
+            last_seen: 2000,
+            expires_at: current_time_ms() + 10000,
+            gene: vec![11],
+            environment: vec![12],
+            pending_mutation: vec![13],
+            pending_mutation_step: 14,
+            opcodes: vec![],
+        };
+
+        store.insert_session(&record).unwrap();
+
+        let loaded = store.load_session(&session_id).unwrap().unwrap();
+        assert_eq!(loaded.session_id, session_id);
+        assert_eq!(loaded.chain_length, 10);
+
+        let stats = store.stats().unwrap();
+        assert_eq!(stats.sessions, 1);
+        assert_eq!(stats.max_chain_length, 10);
+
+        store.purge_expired_sessions().unwrap();
+        let stats = store.stats().unwrap();
+        assert_eq!(stats.sessions, 1);
+
+        let _: Result<(), _> = conn.del(store.session_key(&session_id));
+        let _: Result<(), _> = conn.del(&store.index_key);
+    }
+
+    #[test]
+    fn test_valkey_pool_concurrency() {
+        use std::sync::Arc;
+        use std::thread;
+
+        let addr = std::env::var("CHRONOSEAL_VALKEY_ADDR")
+            .unwrap_or_else(|_| "127.0.0.1:6379".to_string());
+        let connection_string = format!("redis://{}", addr);
+        let client = match redis::Client::open(connection_string) {
+            Ok(c) => c,
+            Err(_) => return,
+        };
+        let pool = match r2d2::Pool::builder().build(client) {
+            Ok(p) => p,
+            Err(_) => return,
+        };
+        let mut conn = match pool.get() {
+            Ok(c) => c,
+            Err(_) => return,
+        };
+        let _: () = match redis::cmd("PING").query(&mut *conn) {
+            Ok(res) => res,
+            Err(_) => return,
+        };
+
+        let store = ValkeyStore {
+            pool,
+            index_key: "test:concurrent:sessions:ids".to_string(),
+        };
+        let _: Result<(), _> = conn.del("test:concurrent:sessions:ids");
+
+        let store_arc = Arc::new(store);
+        let mut handles = Vec::new();
+
+        for t in 0..10 {
+            let store_clone = store_arc.clone();
+            let session_id = format!("valkey_concurrent_{}", t);
+            let handle = thread::spawn(move || {
+                let record = SessionRecord {
+                    session_id: session_id.clone(),
+                    public_key: vec![1, 2, 3],
+                    salt: vec![4, 5, 6],
+                    last_hash: vec![7, 8, 9],
+                    chain_length: 1,
+                    created_at: 1000,
+                    last_seen: 2000,
+                    expires_at: current_time_ms() + 10000,
+                    gene: vec![11],
+                    environment: vec![12],
+                    pending_mutation: vec![13],
+                    pending_mutation_step: 14,
+                    opcodes: vec![],
+                };
+                store_clone.insert_session(&record).unwrap();
+                let loaded = store_clone.load_session(&session_id).unwrap().unwrap();
+                assert_eq!(loaded.session_id, session_id);
+            });
+            handles.push(handle);
+        }
+
+        for handle in handles {
+            handle.join().unwrap();
+        }
+
+        let stats = store_arc.stats().unwrap();
+        assert_eq!(stats.sessions, 10);
+
+        // Cleanup
+        let mut conn = store_arc.pool.get().unwrap();
+        for t in 0..10 {
+            let _: Result<(), _> =
+                conn.del(store_arc.session_key(&format!("valkey_concurrent_{}", t)));
+        }
+        let _: Result<(), _> = conn.del(&store_arc.index_key);
+    }
+}
+
+#[cfg(test)]
+mod sqlite_tests {
+    use super::*;
+    use std::sync::Arc;
+    use std::thread;
+
+    #[test]
+    fn test_sqlite_pool_concurrency() {
+        let db_path = Path::new("target/test_sqlite_concurrency.db");
+        if let Some(parent) = db_path.parent() {
+            let _ = std::fs::create_dir_all(parent);
+        }
+        let _ = std::fs::remove_file(db_path);
+
+        let pool = init_pool(db_path).unwrap();
+        let pool_arc = Arc::new(pool);
+        let mut handles = Vec::new();
+
+        for t in 0..10 {
+            let pool_clone = pool_arc.clone();
+            let handle = thread::spawn(move || {
+                let session_id = format!("concurrent_session_{}", t);
+                let record = SessionRecord {
+                    session_id: session_id.clone(),
+                    public_key: vec![1, 2, 3],
+                    salt: vec![4, 5, 6],
+                    last_hash: vec![7, 8, 9],
+                    chain_length: 1,
+                    created_at: 1000,
+                    last_seen: 2000,
+                    expires_at: current_time_ms() + 10000,
+                    gene: vec![11],
+                    environment: vec![12],
+                    pending_mutation: vec![13],
+                    pending_mutation_step: 14,
+                    opcodes: vec![],
+                };
+                pool_clone.insert_session(&record).unwrap();
+                let loaded = pool_clone.load_session(&session_id).unwrap().unwrap();
+                assert_eq!(loaded.session_id, session_id);
+
+                let mut updated = loaded;
+                updated.chain_length = 2;
+                let old_hash = updated.last_hash.clone();
+                pool_clone.update_session(&updated, &old_hash).unwrap();
+            });
+            handles.push(handle);
+        }
+
+        for handle in handles {
+            handle.join().unwrap();
+        }
+
+        let stats = pool_arc.stats().unwrap();
+        assert_eq!(stats.sessions, 10);
+
+        std::mem::drop(pool_arc);
+        let _ = std::fs::remove_file(db_path);
+    }
+}

server/src/trust.rs

@@ -1,6 +1,14 @@
 use crate::config::Config;
 use shared::protocol::EntropyData;
 
+/// Validates the browser mouse cursor interaction path for bot/automation detection.
+///
+/// Evaluates mouse velocity and distance features, checks the total distance traversed,
+/// checks for cursor pauses (low movement over high time diff), and enforces average cursor speeds.
+///
+/// # Arguments
+/// * `data` - The client-supplied interaction entropy events.
+/// * `config` - The server configuration boundaries.
 pub fn validate_mouse(
     data: &EntropyData,
     config: &Config,

server/src/vm.rs

@@ -4,6 +4,13 @@ use shared::{
     vm_extensions::{self, ExecutionTrace, MutationError, MutationOrder},
 };
 
+/// Generates a randomized VM opcode instruction program within a length range.
+///
+/// Builds a program of mathematical and stack ops (e.g. literals, ADD, SUB, XOR, HASH)
+/// with dynamic depth checking to ensure valid stacks and prevent out of bounds execution.
+///
+/// # Arguments
+/// * `len_range` - The inclusive range of instruction counts to generate.
 pub fn generate_random_program(len_range: std::ops::RangeInclusive<usize>) -> Vec<u8> {
     let mut rng = rand::thread_rng();
     let count = rng.gen_range(len_range);
@@ -47,6 +54,11 @@ pub fn generate_random_program(len_range: std::ops::RangeInclusive<usize>) -> Ve
     ops
 }
 
+/// Executes a raw VM mutation program bytecode slice against a `GeneState`.
+///
+/// # Arguments
+/// * `state` - The mutable gene state to mutate.
+/// * `program` - The raw VM instruction program.
 #[allow(dead_code)]
 pub fn execute_mutation_program(
     state: &mut GeneState,
@@ -55,6 +67,11 @@ pub fn execute_mutation_program(
     vm_extensions::execute_program(state, program)
 }
 
+/// Executes a `MutationOrder` program against a `GeneState`.
+///
+/// # Arguments
+/// * `state` - The mutable gene state.
+/// * `order` - The mutation order.
 #[allow(dead_code)]
 pub fn execute_mutation_order(
     state: &mut GeneState,

shared/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "shared"
-version = "0.6.0"
+version = "1.0.1"
 edition = "2021"
 
 [dependencies]
@@ -12,3 +12,6 @@ base64 = "0.22"
 rand = "0.8"
 ed25519-dalek = { version = "2", features = ["rand_core"] }
 tracing = "0.1"
+
+[dev-dependencies]
+proptest = "1"

shared/src/constants.rs

@@ -10,3 +10,4 @@ pub const MAX_MUTATION_ROUNDS: u8 = 10;
 pub const MAX_MUTATION_INSTRUCTION_BUDGET: usize = 2048;
 pub const HASH_OPCODE_INSTRUCTION_COST: usize = 16;
 pub const SOFT_CAP_DURATION_MS: u128 = 50;
+pub const MAX_STACK_DEPTH: usize = 64;

shared/src/gene.rs

@@ -55,6 +55,10 @@ impl std::fmt::Display for GeneError {
 
 impl std::error::Error for GeneError {}
 
+/// Creates a new, blank `GeneState` with the specified gene buffer size.
+///
+/// # Arguments
+/// * `gene_size` - The length of the gene byte buffer. Must be within `1..=MAX_GENE_SIZE`.
 pub fn new_state(gene_size: usize) -> Result<GeneState, GeneError> {
     if !(1..=MAX_GENE_SIZE).contains(&gene_size) {
         return Err(GeneError::InvalidGeneSize { size: gene_size });
@@ -65,6 +69,7 @@ pub fn new_state(gene_size: usize) -> Result<GeneState, GeneError> {
     })
 }
 
+/// Creates a new `GeneState` with the default gene buffer size (`DEFAULT_GENE_SIZE`).
 pub fn default_state() -> GeneState {
     GeneState {
         gene: vec![0; DEFAULT_GENE_SIZE],
@@ -72,6 +77,10 @@ pub fn default_state() -> GeneState {
     }
 }
 
+/// Validates the structural invariants of the given `GeneState`.
+///
+/// Ensures the gene size is within valid bounds and the environment records are
+/// properly sorted, non-empty, and free of duplicates.
 pub fn validate_state(state: &GeneState) -> Result<(), GeneError> {
     if !(1..=MAX_GENE_SIZE).contains(&state.gene.len()) {
         return Err(GeneError::InvalidGeneSize {
@@ -81,6 +90,13 @@ pub fn validate_state(state: &GeneState) -> Result<(), GeneError> {
     validate_environment(&state.environment)
 }
 
+/// Retrieves the quantity associated with a specific environment symbol.
+///
+/// Performs a binary search over the sorted environment records. Returns 0 if the symbol is missing.
+///
+/// # Arguments
+/// * `state` - The gene state to query.
+/// * `symbol` - The 16-bit key to search for.
 pub fn get_env_quantity(state: &GeneState, symbol: u16) -> u32 {
     match state
         .environment
@@ -91,6 +107,14 @@ pub fn get_env_quantity(state: &GeneState, symbol: u16) -> u32 {
     }
 }
 
+/// Sets the quantity of an environment symbol in a `GeneState`.
+///
+/// If quantity is 0, the record is removed. The environment is kept sorted alphabetically by symbol.
+///
+/// # Arguments
+/// * `state` - The mutable gene state to update.
+/// * `symbol` - The 16-bit key.
+/// * `quantity` - The quantity to assign.
 pub fn set_env_quantity(
     state: &mut GeneState,
     symbol: u16,
@@ -125,6 +149,12 @@ pub fn set_env_quantity(
     }
 }
 
+/// Adds a quantity to an environment symbol with saturating arithmetic.
+///
+/// # Arguments
+/// * `state` - The mutable gene state.
+/// * `symbol` - The 16-bit key.
+/// * `quantity` - The quantity to add.
 pub fn add_env_quantity(
     state: &mut GeneState,
     symbol: u16,
@@ -136,6 +166,14 @@ pub fn add_env_quantity(
     Ok(next)
 }
 
+/// Subtracts a quantity from an environment symbol with saturating arithmetic.
+///
+/// If the resulting quantity drops to 0, the symbol is removed.
+///
+/// # Arguments
+/// * `state` - The mutable gene state.
+/// * `symbol` - The 16-bit key.
+/// * `quantity` - The quantity to subtract.
 pub fn sub_env_quantity(
     state: &mut GeneState,
     symbol: u16,
@@ -147,6 +185,12 @@ pub fn sub_env_quantity(
     Ok(next)
 }
 
+/// Encodes the environment records list into a compact byte slice.
+///
+/// Each record is written as a little-endian `u16` symbol followed by a little-endian `u32` quantity.
+///
+/// # Arguments
+/// * `records` - The sorted environment records.
 pub fn encode_environment(records: &[EnvironmentRecord]) -> Result<Vec<u8>, GeneError> {
     validate_environment(records)?;
     let mut out = Vec::with_capacity(records.len() * 6);
@@ -157,6 +201,12 @@ pub fn encode_environment(records: &[EnvironmentRecord]) -> Result<Vec<u8>, Gene
     Ok(out)
 }
 
+/// Decodes environment records from a byte slice.
+///
+/// Validates that the length is a multiple of 6 and that records conform to sorting and quantity invariants.
+///
+/// # Arguments
+/// * `blob` - The serialized byte slice.
 pub fn decode_environment(blob: &[u8]) -> Result<Vec<EnvironmentRecord>, GeneError> {
     if !blob.len().is_multiple_of(6) {
         return Err(GeneError::EnvironmentBlobLengthInvalid { len: blob.len() });
@@ -180,6 +230,9 @@ pub fn decode_environment(blob: &[u8]) -> Result<Vec<EnvironmentRecord>, GeneErr
     Ok(records)
 }
 
+/// Computes the raw Blake3 cryptographic commitment of the `GeneState`.
+///
+/// Includes gene length, gene buffer, environment record count, and individual record key/values.
 pub fn commitment(state: &GeneState) -> [u8; 32] {
     let mut h = blake3::Hasher::new();
     h.update(b"chronoseal/gene/v1");
@@ -193,10 +246,19 @@ pub fn commitment(state: &GeneState) -> [u8; 32] {
     *h.finalize().as_bytes()
 }
 
+/// Computes the hex-encoded cryptographic commitment of the `GeneState`.
 pub fn commitment_hex(state: &GeneState) -> String {
     hex::encode(commitment(state))
 }
 
+/// Computes a context-bound Blake3 cryptographic commitment of the `GeneState`.
+///
+/// Integrates `session_id` and the current `step` index into the hash to bind the commitment.
+///
+/// # Arguments
+/// * `state` - The gene state.
+/// * `session_id` - The client session ID.
+/// * `step` - The mutation step index.
 pub fn commitment_with_context(state: &GeneState, session_id: &str, step: u64) -> [u8; 32] {
     let mut h = blake3::Hasher::new();
     h.update(b"chronoseal/gene/v1");
@@ -206,10 +268,17 @@ pub fn commitment_with_context(state: &GeneState, session_id: &str, step: u64) -
     *h.finalize().as_bytes()
 }
 
+/// Computes a context-bound, hex-encoded Blake3 cryptographic commitment of the `GeneState`.
+///
+/// # Arguments
+/// * `state` - The gene state.
+/// * `session_id` - The client session ID.
+/// * `step` - The mutation step index.
 pub fn commitment_hex_with_context(state: &GeneState, session_id: &str, step: u64) -> String {
     hex::encode(commitment_with_context(state, session_id, step))
 }
 
+/// Helper function to validate sorting, uniqueness, and non-zero properties of environment records.
 fn validate_environment(records: &[EnvironmentRecord]) -> Result<(), GeneError> {
     if records.len() > MAX_ENV_RECORDS {
         return Err(GeneError::TooManyEnvironmentRecords { len: records.len() });

shared/src/hashing.rs

@@ -1,7 +1,15 @@
 use crate::protocol::{EntropyData, StackState};
 use blake3::Hasher;
 
-/// Initial hash for a brand-new session: Blake3(session_id || pub_key || salt)
+/// Computes the initial hash for a brand-new attestation session.
+///
+/// The hash is constructed as:
+/// `Blake3(session_id || pub_key || salt)`
+///
+/// # Arguments
+/// * `session_id` - The unique hex-encoded identifier for the session.
+/// * `pub_key` - The client's Ed25519 public key.
+/// * `salt` - The initial server-issued salt.
 pub fn initial_hash(session_id: &str, pub_key: &[u8], salt: &[u8]) -> Vec<u8> {
     let mut h = Hasher::new();
     h.update(session_id.as_bytes());
@@ -10,7 +18,18 @@ pub fn initial_hash(session_id: &str, pub_key: &[u8], salt: &[u8]) -> Vec<u8> {
     h.finalize().as_bytes().to_vec()
 }
 
-/// Next hash in the chain: Blake3 with the salt mixed in (no keyed mode needed)
+/// Computes the next hash in the Blake3 attestation chain.
+///
+/// This mixes in the previous hash head, the client timestamp, the serialized entropy data,
+/// the VM stack state, and the server-issued salt. Uses `serde_json::to_vec` to avoid
+/// intermediate heap string allocations and UTF-8 verification checks.
+///
+/// # Arguments
+/// * `prev_hash` - The previous hash-chain head.
+/// * `timestamp` - The client-supplied heartbeat timestamp.
+/// * `entropy` - The collected browser interaction entropy.
+/// * `stack` - The final VM stack state after running the opcode program.
+/// * `salt` - The server-issued salt for rotation.
 pub fn next_chain_hash(
     prev_hash: &[u8],
     timestamp: u64,
@@ -18,14 +37,13 @@ pub fn next_chain_hash(
     stack: &StackState,
     salt: &[u8],
 ) -> Vec<u8> {
-    let entropy_json = serde_json::to_string(entropy).unwrap();
+    let entropy_bytes = serde_json::to_vec(entropy).unwrap_or_default();
-    let stack_json = serde_json::to_string(stack).unwrap();
+    let stack_bytes = serde_json::to_vec(stack).unwrap_or_default();
 
-    let entropy_hash = blake3::hash(entropy_json.as_bytes());
+    let entropy_hash = blake3::hash(&entropy_bytes);
-    let stack_hash = blake3::hash(stack_json.as_bytes());
+    let stack_hash = blake3::hash(&stack_bytes);
 
     let mut h = Hasher::new();
-    // Mix the salt into the hash state
     h.update(salt);
     h.update(prev_hash);
     h.update(&timestamp.to_le_bytes());
@@ -34,7 +52,12 @@ pub fn next_chain_hash(
     h.finalize().as_bytes().to_vec()
 }
 
-/// Hash of all stack items for VM HASH opcode
+/// Computes a 32-bit FNV-like Blake3 hash of all stack elements.
+///
+/// This is used by the VM `HASH` opcode to fold the current stack state into a single value.
+///
+/// # Arguments
+/// * `stack` - The list of u32 stack elements to hash.
 pub fn hash_stack(stack: &[u32]) -> u32 {
     let data: Vec<u8> = stack.iter().flat_map(|x| x.to_le_bytes()).collect();
     let hash = blake3::hash(&data);

shared/src/lib.rs

@@ -2,4 +2,5 @@ pub mod constants;
 pub mod gene;
 pub mod hashing;
 pub mod protocol;
+pub mod vm;
 pub mod vm_extensions;

shared/src/protocol.rs

@@ -1,73 +1,118 @@
 use serde::{Deserialize, Serialize};
 
+/// Request payload sent by the client to initialize a new attestation session.
 #[derive(Debug, Clone, Deserialize, Serialize)]
 pub struct InitRequest {
+    /// Hex-encoded 32-byte Ed25519 public verifying key generated by the client.
     pub public_key: String,
 }
 
+/// Response payload returned by the server upon successful session initialization.
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct InitResponse {
+    /// The unique hex-encoded session identifier.
     pub session_id: String,
+    /// The initial server-issued salt to be mixed in the first heartbeat's hash.
     pub salt: String,
+    /// Base64-encoded initial VM program for client stack execution.
     pub opcodes_b64: String,
+    /// The computed initial hash of the attestation chain.
     pub initial_hash: String,
+    /// Timestamp in milliseconds indicating when the session expires.
     pub expires_at: u64,
+    /// Minimum time in milliseconds allowed between subsequent heartbeats.
     pub heartbeat_min_interval_ms: u64,
+    /// Maximum time in milliseconds allowed between subsequent heartbeats.
     pub heartbeat_max_interval_ms: u64,
+    /// Size of the synthetic gene byte buffer.
     pub gene_size: u32,
+    /// The current mutation step index (starts at 1).
     pub mutation_step: u64,
+    /// Base64-encoded initial gene mutation program.
     pub mutation_order_b64: String,
+    /// The number of mutation rounds configured on the server.
+    pub mutation_rounds: u8,
 }
 
+/// Heartbeat request payload submitted periodically by the client to prove session continuity.
 #[derive(Debug, Clone, Deserialize, Serialize)]
 pub struct HeartbeatRequest {
+    /// The session identifier.
     pub session_id: String,
+    /// The expected hash from the previous heartbeat/initialization step.
     pub prev_hash: String,
+    /// The client's current system timestamp in milliseconds.
     pub timestamp: u64,
+    /// The collected client entropy data (such as mouse events).
     pub entropy_data: EntropyData,
+    /// The final execution state of the client's VM stack program.
     pub stack_state: StackState,
+    /// The client's browser hardware and layout fingerprint.
     pub fingerprint: Fingerprint,
+    /// The mutation step index corresponding to the pending mutation.
     pub mutation_step: u64,
+    /// Hex-encoded commitment of the mutated gene state.
     pub gene_commitment: String,
+    /// Ed25519 signature of the canonical JSON-serialized payload.
     pub signature: String,
 }
 
+/// Response payload returned by the server for heartbeat submissions.
+///
+/// In case of silent rejection, all fields except `status` are omitted.
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct HeartbeatResponse {
+    /// Attestation status, typically "ok" even on silent failures.
     pub status: String,
+    /// The next server-issued salt for hash chain progression.
     #[serde(skip_serializing_if = "Option::is_none")]
     pub next_salt: Option<String>,
+    /// The next expected mutation step index.
     #[serde(skip_serializing_if = "Option::is_none")]
     pub next_mutation_step: Option<u64>,
+    /// Base64-encoded next mutation program for client gene progression.
     #[serde(skip_serializing_if = "Option::is_none")]
     pub next_mutation_order_b64: Option<String>,
 }
 
+/// Client browser fingerprint metadata used for basic sanity checks.
 #[derive(Debug, Clone, Deserialize, Serialize)]
 pub struct Fingerprint {
+    /// Aspect ratio of the client screen.
     #[serde(rename = "aspectRatio")]
     pub aspect_ratio: String,
+    /// Device pixel ratio of the screen.
     #[serde(rename = "devicePixelRatio")]
     pub device_pixel_ratio: String,
+    /// Number of logical processor cores available.
     #[serde(rename = "hardwareConcurrency")]
     pub hardware_concurrency: u32,
 }
 
+/// Wrapper for browser-side entropy collection.
 #[derive(Debug, Clone, Deserialize, Serialize)]
 pub struct EntropyData {
+    /// A chronological list of mouse movement events.
     pub events: Vec<MouseEvent>,
 }
 
+/// Information about a single mouse movement interaction.
 #[derive(Deserialize, Serialize, Clone, Debug)]
 pub struct MouseEvent {
+    /// Absolute horizontal coordinate of the cursor.
     pub x: f64,
+    /// Absolute vertical coordinate of the cursor.
     pub y: f64,
+    /// Relative timestamp in milliseconds of the event occurrence.
     #[serde(rename = "t")]
     pub timestamp_ms: f64,
 }
 
+/// The state of the VM stack machine after executing a program.
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct StackState {
+    /// The elements remaining on the stack.
     pub stack: Vec<u32>,
+    /// The final instruction pointer location at program completion or termination.
     pub ip: u16,
 }

shared/src/vm.rs

@@ -0,0 +1,79 @@
+use crate::protocol::StackState;
+
+/// Executes a raw VM mathematical instruction program bytecode slice.
+///
+/// This implements the mathematical stack machine interpreter used by the client
+/// to generate the attestation stack state.
+///
+/// # Arguments
+/// * `program` - The raw VM instruction program bytecode.
+pub fn execute(program: &[u8]) -> StackState {
+    let mut stack: Vec<u32> = Vec::new();
+    let mut ip: usize = 0;
+    while ip < program.len() {
+        let op = program[ip];
+        ip += 1;
+        match op {
+            0x00 => {
+                if ip + 4 > program.len() {
+                    break;
+                }
+                let val = u32::from_le_bytes([
+                    program[ip],
+                    program[ip + 1],
+                    program[ip + 2],
+                    program[ip + 3],
+                ]);
+                ip += 4;
+                if stack.len() >= crate::constants::MAX_STACK_DEPTH {
+                    break;
+                }
+                stack.push(val);
+            }
+            0x01..=0x07 => {
+                if stack.len() < 2 {
+                    break;
+                }
+                let b = stack.pop().unwrap();
+                let a = stack.pop().unwrap();
+                let r = match op {
+                    0x01 => a.wrapping_add(b),
+                    0x02 => a.wrapping_sub(b),
+                    0x03 => a.wrapping_mul(b),
+                    0x04 => a ^ b,
+                    0x05 => a & b,
+                    0x06 => a | b,
+                    0x07 => a.rotate_left(b % 32),
+                    _ => unreachable!(),
+                };
+                if stack.len() >= crate::constants::MAX_STACK_DEPTH {
+                    break;
+                }
+                stack.push(r);
+            }
+            0x08 => {
+                if stack.is_empty() {
+                    break;
+                }
+                let a = stack.pop().unwrap();
+                if stack.len() >= crate::constants::MAX_STACK_DEPTH {
+                    break;
+                }
+                stack.push(!a);
+            }
+            0x09 => {
+                let r = crate::hashing::hash_stack(&stack);
+                stack.clear();
+                if stack.len() >= crate::constants::MAX_STACK_DEPTH {
+                    break;
+                }
+                stack.push(r);
+            }
+            _ => break,
+        }
+    }
+    StackState {
+        stack,
+        ip: ip as u16,
+    }
+}

shared/src/vm_extensions.rs

@@ -88,10 +88,18 @@ impl From<GeneError> for MutationError {
     }
 }
 
+/// Encodes a `MutationOrder` into standard Base64 representation of its bytecode.
 pub fn encode_order_b64(order: &MutationOrder) -> String {
     base64::Engine::encode(&base64::engine::general_purpose::STANDARD, &order.program)
 }
 
+/// Decodes a `MutationOrder` from its Base64 representation.
+///
+/// Validates that the decoded program size does not exceed the allowed maximum budget size.
+///
+/// # Arguments
+/// * `step` - The step index associated with this mutation order.
+/// * `b64` - The Base64 string containing the raw bytecode.
 pub fn decode_order_b64(step: u64, b64: &str) -> Result<MutationOrder, MutationError> {
     let program = base64::Engine::decode(&base64::engine::general_purpose::STANDARD, b64)
         .map_err(MutationError::Base64)?;
@@ -101,11 +109,27 @@ pub fn decode_order_b64(step: u64, b64: &str) -> Result<MutationOrder, MutationE
     Ok(MutationOrder { step, program })
 }
 
+/// Generates a randomized `MutationOrder` program for a given step and gene size.
+///
+/// Uses thread-local random number generator.
+///
+/// # Arguments
+/// * `step` - The step index.
+/// * `gene_size` - The length of the gene byte buffer.
 pub fn generate_order(step: u64, gene_size: usize) -> MutationOrder {
     let mut rng = rand::thread_rng();
     generate_order_with_rng(&mut rng, step, gene_size)
 }
 
+/// Generates a randomized `MutationOrder` program using a specific custom RNG.
+///
+/// Builds a program containing between 20 and 36 mutation instructions (e.g. loads, point changes,
+/// insertions, deletions, env modifications) and ensures a minimum number of finalize hash steps are included.
+///
+/// # Arguments
+/// * `rng` - The random number generator.
+/// * `step` - The step index.
+/// * `gene_size` - The length of the gene byte buffer.
 pub fn generate_order_with_rng<R: Rng + ?Sized>(
     rng: &mut R,
     step: u64,
@@ -213,10 +237,12 @@ pub fn generate_order_with_rng<R: Rng + ?Sized>(
     MutationOrder { step, program }
 }
 
+/// Clones the `GeneState` and executes the mutation program for `DEFAULT_MUTATION_ROUNDS`.
 pub fn apply_program_clone(state: &GeneState, program: &[u8]) -> Result<GeneState, MutationError> {
     apply_program_clone_with_rounds(state, program, DEFAULT_MUTATION_ROUNDS)
 }
 
+/// Clones the `GeneState` and executes the mutation program for a specific number of rounds.
 pub fn apply_program_clone_with_rounds(
     state: &GeneState,
     program: &[u8],
@@ -227,6 +253,7 @@ pub fn apply_program_clone_with_rounds(
     Ok(next)
 }
 
+/// Executes the mutation program on the mutable `GeneState` reference for a specific number of rounds.
 pub fn apply_program_with_rounds(
     state: &mut GeneState,
     program: &[u8],
@@ -236,11 +263,21 @@ pub fn apply_program_with_rounds(
     Ok(())
 }
 
+/// Executes the mutation program on the mutable `GeneState` reference for `DEFAULT_MUTATION_ROUNDS`.
 pub fn apply_program(state: &mut GeneState, program: &[u8]) -> Result<(), MutationError> {
     let _ = execute_program_with_rounds(state, program, DEFAULT_MUTATION_ROUNDS)?;
     Ok(())
 }
 
+/// Executes the mutation program on the mutable `GeneState` reference for multiple rounds.
+///
+/// Implements a soft instruction cost-budget cap check to prevent hostile/inefficient
+/// programs from lagging the host server thread or client runtime.
+///
+/// # Arguments
+/// * `state` - The mutable gene state buffer.
+/// * `program` - The raw bytecode sequence.
+/// * `rounds` - The requested number of execution rounds.
 pub fn execute_program_with_rounds(
     state: &mut GeneState,
     program: &[u8],
@@ -317,6 +354,13 @@ fn estimate_program_cost(program: &[u8]) -> usize {
     cost.max(1)
 }
 
+/// Executes the VM mutation program on the mutable `GeneState` reference.
+///
+/// This interprets VM mutation opcodes to modify the gene byte array and environment records.
+///
+/// # Arguments
+/// * `state` - The mutable gene state to mutate.
+/// * `program` - The raw instruction bytecode slice.
 pub fn execute_program(
     state: &mut GeneState,
     program: &[u8],
@@ -835,4 +879,25 @@ mod tests {
             "mutation execution too slow: {elapsed:?}"
         );
     }
+
+    #[test]
+    fn test_vm_instruction_budget_soft_cap() {
+        let state = new_state(8).unwrap();
+        // Construct a program with 130 OP_FINALIZE_GENE_HASH instructions.
+        // HASH has HASH_OPCODE_INSTRUCTION_COST = 16.
+        // Total cost will be 130 * 16 = 2080, which exceeds MAX_MUTATION_INSTRUCTION_BUDGET (2048).
+        let program = vec![OP_FINALIZE_GENE_HASH; 130];
+        let cost = estimate_program_cost(&program);
+        assert!(cost >= 2080);
+
+        // Assert that the max allowed rounds is calculated as 1 since cost > budget.
+        let expected_rounds = std::cmp::max(1, MAX_MUTATION_INSTRUCTION_BUDGET / cost);
+        assert_eq!(expected_rounds, 1);
+
+        // Execute the program with a requested 10 rounds.
+        // The runtime should execute it successfully without panic, while applying the round limitation.
+        let mut test_state = state.clone();
+        let trace = execute_program_with_rounds(&mut test_state, &program, 10).unwrap();
+        assert_eq!(trace.final_ip, program.len());
+    }
 }

shared/tests/proptests.rs

@@ -0,0 +1,17 @@
+use proptest::prelude::*;
+
+proptest! {
+    #[test]
+    fn test_vm_execute_never_panics(ref program in any::<Vec<u8>>()) {
+        // VM execution should be totally robust and never panic on any random input stream.
+        let state = shared::vm::execute(program);
+        // The instruction pointer (ip) should not exceed the program length
+        assert!(state.ip as usize <= program.len());
+    }
+
+    #[test]
+    fn test_gene_environment_roundtrip_never_panics(ref data in any::<Vec<u8>>()) {
+        // Try to decode random bytes. It should either succeed or fail gracefully, never panic.
+        let _ = shared::gene::decode_environment(data);
+    }
+}

wasm/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "chronoseal-wasm"
-version = "0.6.0"
+version = "1.0.1"
 edition = "2021"
 
 [lib]

wasm/src/crypto.rs

@@ -51,8 +51,14 @@ pub fn compute_next_hash(
 ) -> String {
     let prev = hex::decode(prev_hash_hex).unwrap_or_default();
     let salt = hex::decode(salt_hex).unwrap_or_default();
-    let entropy = serde_json::from_str::<shared::protocol::EntropyData>(entropy_data_json).unwrap();
+    let entropy = match serde_json::from_str::<shared::protocol::EntropyData>(entropy_data_json) {
-    let stack = serde_json::from_str::<shared::protocol::StackState>(stack_state_json).unwrap();
+        Ok(v) => v,
+        Err(_) => return String::new(),
+    };
+    let stack = match serde_json::from_str::<shared::protocol::StackState>(stack_state_json) {
+        Ok(v) => v,
+        Err(_) => return String::new(),
+    };
     let new = shared::hashing::next_chain_hash(&prev, timestamp, &entropy, &stack, &salt);
     hex::encode(new)
 }

wasm/src/vm.rs

@@ -4,70 +4,19 @@ use wasm_bindgen::prelude::*;
 #[wasm_bindgen]
 pub fn run_program(program_b64: &str) -> JsValue {
     use base64::Engine;
-    let bytes = base64::engine::general_purpose::STANDARD
+    let bytes = match base64::engine::general_purpose::STANDARD.decode(program_b64) {
-        .decode(program_b64)
+        Ok(v) => v,
-        .unwrap();
+        Err(_) => return JsValue::NULL,
+    };
     let state = execute(&bytes);
-    serde_wasm_bindgen::to_value(&state).unwrap()
+    match serde_wasm_bindgen::to_value(&state) {
+        Ok(v) => v,
+        Err(_) => JsValue::NULL,
+    }
 }
 
 fn execute(program: &[u8]) -> StackState {
-    let mut stack: Vec<u32> = Vec::new();
+    shared::vm::execute(program)
-    let mut ip: usize = 0;
-    while ip < program.len() {
-        let op = program[ip];
-        ip += 1;
-        match op {
-            0x00 => {
-                if ip + 4 > program.len() {
-                    break;
-                }
-                let val = u32::from_le_bytes([
-                    program[ip],
-                    program[ip + 1],
-                    program[ip + 2],
-                    program[ip + 3],
-                ]);
-                ip += 4;
-                stack.push(val);
-            }
-            0x01..=0x07 => {
-                if stack.len() < 2 {
-                    break;
-                }
-                let b = stack.pop().unwrap();
-                let a = stack.pop().unwrap();
-                let r = match op {
-                    0x01 => a.wrapping_add(b),
-                    0x02 => a.wrapping_sub(b),
-                    0x03 => a.wrapping_mul(b),
-                    0x04 => a ^ b,
-                    0x05 => a & b,
-                    0x06 => a | b,
-                    0x07 => a.rotate_left(b % 32),
-                    _ => unreachable!(),
-                };
-                stack.push(r);
-            }
-            0x08 => {
-                if stack.is_empty() {
-                    break;
-                }
-                let a = stack.pop().unwrap();
-                stack.push(!a);
-            }
-            0x09 => {
-                let r = shared::hashing::hash_stack(&stack);
-                stack.clear();
-                stack.push(r);
-            }
-            _ => break,
-        }
-    }
-    StackState {
-        stack,
-        ip: ip as u16,
-    }
 }
 
 #[cfg(test)]