256-Tile WASM Fabric

The coherence gate runs on a distributed fabric of 256 tiles, with TileZero acting as the central arbiter:

+-------------------------------------------------------------------------+
|                         256-TILE COGNITUM FABRIC                        |
+-------------------------------------------------------------------------+
|                                                                         |
|  +-------------------------------------------------------------------+  |
|  |                        TILE ZERO (Arbiter)                        |  |
|  |                                                                   |  |
|  |  * Merge worker reports      * Hierarchical min-cut              |  |
|  |  * Global gate decision      * Permit token issuance             |  |
|  |  * Witness receipt log       * Hash-chained eventlog             |  |
|  +-------------------------------+-----------------------------------+  |
|                                  |                                      |
|             +--------------------+--------------------+                 |
|             |                    |                    |                 |
|             v                    v                    v                 |
|  +----------------+   +----------------+   +----------------+           |
|  |  Workers       |   |  Workers       |   |  Workers       |   ...    |
|  |  [1-85]        |   |  [86-170]      |   |  [171-255]     |           |
|  |                |   |                |   |                |           |
|  |  Shard A       |   |  Shard B       |   |  Shard C       |           |
|  |  Local cuts    |   |  Local cuts    |   |  Local cuts    |           |
|  |  E-accum       |   |  E-accum       |   |  E-accum       |           |
|  +----------------+   +----------------+   +----------------+           |
|                                                                         |
+-------------------------------------------------------------------------+

Worker Tile Responsibilities

Each of the 255 worker tiles maintains a local shard with:

• CompactGraph (~42KB): Vertices, edges, adjacency lists with union-find connectivity
• EvidenceAccumulator (~2KB): Hypothesis tracking and sliding observation window
• Delta buffer (1KB): Circular buffer for incoming graph updates
• Total: ~46KB per tile, fitting within the 64KB WASM memory budget

Worker tiles perform:

1. Ingest deltas - Edge additions, removals, weight updates, observations
2. Process ticks - Deterministic tick loop updates local state
3. Produce reports - 64-byte cache-aligned reports with coherence metrics
4. Emit witness fragments - Boundary information for global aggregation

TileZero Arbiter Role

TileZero collects reports from all worker tiles and:

1. Merges reports into a reduced supergraph
2. Applies three filters: structural, shift, and evidence
3. Issues decisions: Permit, Defer, or Deny
4. Signs permit tokens with Ed25519
5. Maintains receipt log with hash-chained audit trail

Data Flow

                    +-------------------+
                    |   Graph Updates   |
                    | (Edges, Weights)  |
                    +---------+---------+
                              |
                              v
+---------------------------------------------------------------+
|                    WORKER TILES [1-255]                       |
|                                                               |
|   Delta --> CompactGraph --> Connectivity --> WitnessFragment |
|         --> EvidenceAccum --> LogEValue                       |
|                                                               |
+---------------------------+-----------------------------------+
                            |
                    TileReports (64 bytes each)
                            |
                            v
+---------------------------------------------------------------+
|                      TILEZERO ARBITER                         |
|                                                               |
|   Structural Filter: global_cut >= min_cut_threshold?         |
|   Shift Filter: shift_pressure < max_shift_threshold?         |
|   Evidence Filter: e_aggregate in [tau_deny, tau_permit]?     |
|                                                               |
|              +-------> PERMIT (proceed autonomously)          |
|   DECISION --+-------> DEFER  (escalate to human)             |
|              +-------> DENY   (block the action)              |
|                                                               |
+---------------------------+-----------------------------------+
                            |
                            v
                    +-------------------+
                    |   PermitToken     |
                    | (signed + TTL)    |
                    +-------------------+
                            |
                            v
                    +-------------------+
                    |  WitnessReceipt   |
                    | (hash-chained)    |
                    +-------------------+

CompactGraph Internals

The CompactGraph structure is optimized for cache-efficient access on WASM:

#[repr(C, align(64))]  // Cache-line aligned
pub struct CompactGraph {
    // HOT FIELDS (first cache line - 64 bytes)
    pub num_vertices: u16,      // Active vertex count
    pub num_edges: u16,         // Active edge count
    pub free_edge_head: u16,    // Free list for edge reuse
    pub generation: u16,        // Structural change counter
    pub num_components: u16,    // Connected component count
    pub status: u16,            // Dirty/connected flags
    _hot_pad: [u8; 52],         // Padding to 64 bytes

    // COLD FIELDS (subsequent cache lines)
    pub vertices: [VertexEntry; 256],     // 256 * 8 = 2KB
    pub edges: [ShardEdge; 1024],         // 1024 * 8 = 8KB
    pub adjacency: [[AdjEntry; 32]; 256], // 256 * 32 * 4 = 32KB
}
// Total: ~42KB

Key optimizations:

• #[inline(always)] on all hot-path accessors
• Unsafe unchecked array access after bounds validation
• Union-find with iterative path compression (no recursion)
• Branchless flag manipulation for partition sides

E-Value Accumulator Math

The evidence accumulator uses fixed-point log2 representation for numerical stability:

pub type LogEValue = i32;  // log2(e-value) * 65536

// Pre-computed threshold constants (avoid runtime log)
pub const LOG_E_STRONG: LogEValue = 282944;      // log2(20) * 65536
pub const LOG_E_VERY_STRONG: LogEValue = 436906; // log2(100) * 65536
pub const LOG_LR_CONNECTIVITY_POS: LogEValue = 38550;  // log2(1.5) * 65536
pub const LOG_LR_CONNECTIVITY_NEG: LogEValue = -65536; // log2(0.5) * 65536

E-value composition (multiplicative):

log(e1 * e2) = log(e1) + log(e2)

This enables efficient sequential evidence accumulation with saturating addition:

self.log_e_value = self.log_e_value.saturating_add(log_lr);

Anytime-valid property: Because e-values are nonnegative supermartingales with E[E_0] = 1, the decision is valid at any stopping time:

P_H0(E_tau >= 1/alpha) <= alpha

TileReport Structure (64 bytes, cache-line aligned)

#[repr(C, align(64))]
pub struct TileReport {
    // Header (8 bytes)
    pub tile_id: u8,           // Tile ID (0-255)
    pub status: TileStatus,    // Processing status
    pub generation: u16,       // Epoch number
    pub tick: u32,             // Current tick

    // Graph state (8 bytes)
    pub num_vertices: u16,
    pub num_edges: u16,
    pub num_components: u16,
    pub graph_flags: u16,

    // Evidence state (8 bytes)
    pub log_e_value: LogEValue,  // 4 bytes
    pub obs_count: u16,
    pub rejected_count: u16,

    // Witness fragment (16 bytes)
    pub witness: WitnessFragment,

    // Performance metrics (8 bytes)
    pub delta_time_us: u16,
    pub tick_time_us: u16,
    pub deltas_processed: u16,
    pub memory_kb: u16,

    // Cross-tile coordination (8 bytes)
    pub ghost_vertices: u16,
    pub ghost_edges: u16,
    pub boundary_vertices: u16,
    pub pending_sync: u16,

    // Reserved (8 bytes)
    pub _reserved: [u8; 8],
}

Memory Layout (~41KB per tile)

Example 1: Network Security Gate

Protect network device configuration changes with coherence gating:

use cognitum_gate_kernel::{TileState, Delta, Observation};
use cognitum_gate_tilezero::{TileZero, GateThresholds, ActionContext, ActionTarget, ActionMetadata};

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    // Create gate with security-focused thresholds
    let thresholds = GateThresholds {
        tau_deny: 0.01,      // Very conservative: 1% false alarm rate
        tau_permit: 100.0,   // Require strong evidence for autonomous action
        min_cut: 10.0,       // High structural integrity required
        max_shift: 0.3,      // Low tolerance for distribution shift
        permit_ttl_ns: 60_000_000_000, // 60 second token lifetime
    };

    let tilezero = TileZero::new(thresholds);
    let mut tile = TileState::new(1);

    // Model network topology as graph
    // Devices are vertices, connections are edges
    tile.ingest_delta(&Delta::edge_add(0, 1, 100));  // core-router -> firewall
    tile.ingest_delta(&Delta::edge_add(1, 2, 100));  // firewall -> switch
    tile.ingest_delta(&Delta::edge_add(2, 3, 100));  // switch -> server-rack
    tile.ingest_delta(&Delta::edge_add(2, 4, 100));  // switch -> workstations

    // Add connectivity hypothesis for firewall
    tile.evidence.add_connectivity_hypothesis(1);

    // Add observations about healthy connectivity
    for tick in 1..=10 {
        let obs = Observation::connectivity(1, true);  // firewall is connected
        tile.ingest_delta(&Delta::observation(obs));
        tile.tick(tick);
    }

    // Now request permission to push a config change
    let ctx = ActionContext {
        action_id: "cfg-push-001".into(),
        action_type: "config_change".into(),
        target: ActionTarget {
            device: Some("firewall".into()),
            path: Some("/rules/allow-list".into()),
            extra: Default::default(),
        },
        context: ActionMetadata {
            agent_id: "netops-agent".into(),
            session_id: Some("session-123".into()),
            prior_actions: vec![],
            urgency: "normal".into(),
        },
    };

    // Get decision
    let token = tilezero.decide(&ctx).await;

    match token.decision {
        GateDecision::Permit => {
            println!("Action permitted. Token valid for {} ns", token.ttl_ns);
            println!("Witness hash: {:?}", &token.witness_hash[..8]);
        }
        GateDecision::Defer => {
            println!("Uncertain. Escalating to human operator.");
            // Wait for human approval...
        }
        GateDecision::Deny => {
            println!("Blocked: network topology unstable");
        }
    }

    // Verify receipt exists
    if let Some(receipt) = tilezero.get_receipt(token.sequence).await {
        println!("Receipt sequence: {}", receipt.sequence);
    }

    Ok(())
}

Example 2: Config Change Approval

Gate infrastructure changes based on dependency graph stability:

use cognitum_gate_kernel::{TileState, Delta, Observation};

fn main() {
    let mut tile = TileState::new(1);

    // Build dependency graph for microservices
    // Service 0: API Gateway
    // Service 1: Auth Service
    // Service 2: User Service
    // Service 3: Database

    // Dependencies: API -> Auth, API -> User, Auth -> DB, User -> DB
    tile.ingest_delta(&Delta::edge_add(0, 1, 200));  // API -> Auth (critical)
    tile.ingest_delta(&Delta::edge_add(0, 2, 150));  // API -> User
    tile.ingest_delta(&Delta::edge_add(1, 3, 200));  // Auth -> DB (critical)
    tile.ingest_delta(&Delta::edge_add(2, 3, 150));  // User -> DB

    // Process initial state
    let report = tile.tick(1);
    println!("Connected: {}", report.is_connected());
    println!("Components: {}", report.num_components);
    assert!(report.is_connected());
    assert_eq!(report.num_components, 1);

    // Add hypothesis to track auth connectivity
    tile.evidence.add_connectivity_hypothesis(1);

    // Ingest recent health checks (all healthy)
    for tick in 2..=12 {
        let obs = Observation::connectivity(1, true);
        tile.ingest_delta(&Delta::observation(obs));
        tile.tick(tick);
    }

    // Check if we have enough evidence to permit changes
    let e_value = tile.evidence.global_e_value();
    println!("Accumulated evidence: {:.2}", e_value);

    if e_value > 20.0 {
        println!("Strong evidence of stability. Config change may proceed.");
    } else if e_value > 1.0 {
        println!("Some evidence of stability. Human review recommended.");
    } else {
        println!("Insufficient evidence. Config change blocked.");
    }

    // Simulate removing a critical edge (partition risk)
    tile.ingest_delta(&Delta::edge_remove(1, 3));  // Remove Auth -> DB
    let report = tile.tick(13);

    if !report.is_connected() {
        println!("ALERT: Graph partition detected! {} components",
                 report.num_components);
        // Gate would DENY any action touching these services
    }
}

Example 3: Multi-Agent Coordination

Coordinate multiple agents through the coherence gate:

use cognitum_gate_kernel::{TileState, Delta, Observation};
use std::collections::HashMap;

struct AgentCoordinator {
    tiles: HashMap<u8, TileState>,
}

impl AgentCoordinator {
    fn new(num_tiles: u8) -> Self {
        let mut tiles = HashMap::new();
        for id in 1..=num_tiles {
            tiles.insert(id, TileState::new(id));
        }
        Self { tiles }
    }

    /// Model agent interactions as graph edges
    fn register_interaction(&mut self, agent_a: u16, agent_b: u16, tile_id: u8) {
        if let Some(tile) = self.tiles.get_mut(&tile_id) {
            tile.ingest_delta(&Delta::edge_add(agent_a, agent_b, 100));
        }
    }

    /// Process a tick across all tiles
    fn tick_all(&mut self, tick: u32) -> Vec<(u8, bool)> {
        let mut results = vec![];
        for (&id, tile) in &mut self.tiles {
            let report = tile.tick(tick);
            results.push((id, report.is_connected()));
        }
        results
    }

    /// Evaluate action safety based on tile coherence
    fn evaluate_action(&self, tile_id: u8) -> ActionResult {
        if let Some(tile) = self.tiles.get(&tile_id) {
            let witness = tile.get_witness_fragment();
            let e_value = tile.evidence.global_e_value();

            if !tile.last_report.is_connected() {
                ActionResult::Deny("Tile graph disconnected".into())
            } else if witness.local_min_cut < 50 {
                ActionResult::Defer("Low min-cut detected".into())
            } else if e_value < 1.0 {
                ActionResult::Defer("Insufficient evidence".into())
            } else if e_value > 20.0 {
                ActionResult::Permit
            } else {
                ActionResult::Defer("Moderate evidence".into())
            }
        } else {
            ActionResult::Deny("Unknown tile".into())
        }
    }
}

enum ActionResult {
    Permit,
    Defer(String),
    Deny(String),
}

fn main() {
    let mut coordinator = AgentCoordinator::new(4);

    // Register agent interactions across tiles
    coordinator.register_interaction(0, 1, 1);  // Agents 0,1 interact on tile 1
    coordinator.register_interaction(1, 2, 1);
    coordinator.register_interaction(2, 3, 2);  // Agents 2,3 interact on tile 2
    coordinator.register_interaction(3, 4, 2);

    // Run simulation ticks
    for tick in 1..=20 {
        let results = coordinator.tick_all(tick);
        for (tile_id, connected) in results {
            if !connected {
                println!("Tick {}: Tile {} lost connectivity!", tick, tile_id);
            }
        }
    }

    // Evaluate pending action on tile 1
    match coordinator.evaluate_action(1) {
        ActionResult::Permit => println!("Action on tile 1: PERMITTED"),
        ActionResult::Defer(reason) => println!("Action on tile 1: DEFERRED - {}", reason),
        ActionResult::Deny(reason) => println!("Action on tile 1: DENIED - {}", reason),
    }
}

Custom Update Rules for E-Process

Extend the evidence accumulator with custom likelihood ratio functions:

use cognitum_gate_kernel::evidence::{LogEValue, f32_to_log_e, LOG_E_STRONG};

/// Custom e-value update for domain-specific hypothesis testing
pub trait CustomEUpdateRule {
    /// Compute log likelihood ratio for domain-specific observation
    fn compute_log_lr(&self, observation: &DomainObservation) -> LogEValue;

    /// Apply custom stopping rule
    fn should_stop(&self, cumulative_log_e: LogEValue, obs_count: u32) -> StopDecision;
}

/// Financial anomaly detection e-process
struct FinancialAnomalyRule {
    baseline_volatility: f32,
    alert_multiplier: f32,
}

impl CustomEUpdateRule for FinancialAnomalyRule {
    fn compute_log_lr(&self, obs: &DomainObservation) -> LogEValue {
        let volatility = obs.value as f32 / 1000.0;
        let ratio = volatility / self.baseline_volatility;

        // Evidence for anomaly increases when volatility exceeds baseline
        if ratio > self.alert_multiplier {
            f32_to_log_e(ratio)
        } else {
            f32_to_log_e(1.0 / ratio)  // Evidence against anomaly
        }
    }

    fn should_stop(&self, cumulative_log_e: LogEValue, obs_count: u32) -> StopDecision {
        if obs_count < 10 {
            return StopDecision::Continue;  // Minimum sample size
        }
        if cumulative_log_e > LOG_E_STRONG {
            StopDecision::Reject  // Strong evidence of anomaly
        } else if cumulative_log_e < -LOG_E_STRONG {
            StopDecision::Accept  // Strong evidence of normality
        } else {
            StopDecision::Continue
        }
    }
}

enum StopDecision { Continue, Accept, Reject }
struct DomainObservation { value: u32 }

SIMD Optimization Hooks

For high-throughput scenarios, inject SIMD-optimized paths:

#[cfg(target_arch = "x86_64")]
mod simd_opt {
    use std::arch::x86_64::*;

    /// Batch e-value computation with AVX2
    #[target_feature(enable = "avx2")]
    pub unsafe fn compute_log_lr_batch_avx2(
        h1: &[f64; 4],
        h0: &[f64; 4],
    ) -> [f64; 4] {
        let v_h1 = _mm256_loadu_pd(h1.as_ptr());
        let v_h0 = _mm256_loadu_pd(h0.as_ptr());
        let ratio = _mm256_div_pd(v_h1, v_h0);

        let mut out = [0f64; 4];
        _mm256_storeu_pd(out.as_mut_ptr(), ratio);
        out
    }
}

#[cfg(target_arch = "wasm32")]
mod simd_opt {
    use core::arch::wasm32::*;

    /// WASM SIMD128 optimized log likelihood ratio
    #[target_feature(enable = "simd128")]
    pub unsafe fn compute_log_lr_simd128(h1: v128, h0: v128) -> v128 {
        f32x4_div(h1, h0)
    }
}

Distributed Coordination with ruvector-raft

Integrate with RuVector's Raft consensus for distributed gate deployment:

use cognitum_gate_tilezero::{TileZero, GateThresholds, GateDecision};

/// Distributed coherence gate with Raft consensus
pub struct DistributedCoherenceGate {
    local_gate: TileZero,
    peers: Vec<String>,
    node_id: u64,
}

impl DistributedCoherenceGate {
    pub async fn new(node_id: u64, peers: Vec<String>) -> Self {
        let thresholds = GateThresholds::default();
        Self {
            local_gate: TileZero::new(thresholds),
            peers,
            node_id,
        }
    }

    /// Make a distributed decision (requires consensus)
    pub async fn decide_with_consensus(
        &self,
        ctx: &ActionContext,
    ) -> Result<PermitToken, DistributedError> {
        // Step 1: Local evaluation
        let local_token = self.local_gate.decide(ctx).await;

        // Step 2: Propose to Raft cluster
        let proposal = GateProposal {
            sequence: local_token.sequence,
            action_id: ctx.action_id.clone(),
            decision: local_token.decision,
            witness_hash: local_token.witness_hash,
        };

        // Step 3: Wait for consensus (majority agreement)
        self.propose_and_wait(proposal).await?;

        // Step 4: Return token only after consensus
        Ok(local_token)
    }

    async fn propose_and_wait(&self, proposal: GateProposal) -> Result<(), DistributedError> {
        // In production, this would use ruvector-raft
        Ok(())
    }
}

struct GateProposal {
    sequence: u64,
    action_id: String,
    decision: GateDecision,
    witness_hash: [u8; 32],
}
struct DistributedError;
struct ActionContext { action_id: String }
struct PermitToken { sequence: u64, decision: GateDecision, witness_hash: [u8; 32] }

Hardware Integration (Cognitum Chip)

For deployment on dedicated Cognitum ASIC/FPGA:

//! Hardware abstraction layer for Cognitum coherence gate chip

use cognitum_gate_kernel::{Delta, TileState};
use cognitum_gate_kernel::report::TileReport;

/// Hardware register interface
#[repr(C)]
pub struct CognitumRegisters {
    pub control: u32,
    pub status: u32,
    pub delta_fifo_addr: u64,
    pub report_fifo_addr: u64,
    pub tile_config_base: u64,
    pub clock_mhz: u32,
}

/// Hardware-accelerated tile driver
pub struct HardwareTile {
    registers: *mut CognitumRegisters,
    tile_id: u8,
}

impl HardwareTile {
    /// Initialize hardware tile
    pub unsafe fn new(base_addr: *mut u8, tile_id: u8) -> Self {
        Self {
            registers: base_addr as *mut CognitumRegisters,
            tile_id,
        }
    }

    /// Submit delta to hardware FIFO
    pub fn submit_delta(&mut self, delta: &Delta) {
        unsafe {
            let fifo_addr = (*self.registers).delta_fifo_addr as *mut Delta;
            core::ptr::write_volatile(fifo_addr, *delta);
        }
    }

    /// Trigger hardware tick
    pub fn trigger_tick(&mut self) {
        unsafe {
            (*self.registers).control |= 0x1;
        }
    }

    /// Read report from hardware
    pub fn read_report(&self) -> TileReport {
        unsafe {
            let fifo_addr = (*self.registers).report_fifo_addr as *const TileReport;
            core::ptr::read_volatile(fifo_addr)
        }
    }

    /// Check if tile is ready
    pub fn is_ready(&self) -> bool {
        unsafe { ((*self.registers).status & 0x1) != 0 }
    }
}

Extending the Witness Receipt Format

Add custom fields to witness receipts for domain-specific auditing:

use cognitum_gate_tilezero::{WitnessReceipt, WitnessSummary, GateDecision};
use serde::{Serialize, Deserialize};

/// Extended witness receipt with compliance fields
#[derive(Clone, Serialize, Deserialize)]
pub struct ComplianceWitnessReceipt {
    pub base: WitnessReceipt,
    pub jurisdiction: String,
    pub framework: String,  // e.g., "SOC2", "GDPR", "HIPAA"
    pub controls_checked: Vec<String>,
    pub risk_score: u8,     // 0-100
    pub human_reviewer: Option<String>,
    pub extended_signature: [u8; 64],
}

impl ComplianceWitnessReceipt {
    pub fn from_base(base: WitnessReceipt, jurisdiction: &str, framework: &str) -> Self {
        Self {
            base,
            jurisdiction: jurisdiction.to_string(),
            framework: framework.to_string(),
            controls_checked: vec![],
            risk_score: 0,
            human_reviewer: None,
            extended_signature: [0u8; 64],
        }
    }

    pub fn add_control(&mut self, control_id: &str) {
        self.controls_checked.push(control_id.to_string());
    }

    /// Calculate risk score based on receipt data
    pub fn calculate_risk_score(&mut self) {
        let mut score: u32 = 0;

        score += match self.base.token.decision {
            GateDecision::Permit => 0,
            GateDecision::Defer => 30,
            GateDecision::Deny => 70,
        };

        if self.base.witness_summary.min_cut < 5.0 {
            score += 20;
        }

        self.risk_score = score.min(100) as u8;
    }
}