vestige/docs/COGNITIVE_SANDWICH.md

Cognitive Sandwich

Vestige's defense-in-depth safety architecture for Claude Code.

The Cognitive Sandwich wraps every Claude Code response in two layers of cognitive scaffolding:

┌────────────────────────────────────────────────┐
│  🥪 TOP BREAD  — UserPromptSubmit hooks         │
│   • Vestige memory graph injection              │
│   • CWD / git / CI state injection              │
│   • Synthesis-protocol gate (decision-adjacent) │
│   • Lateral-thinker subconscious swarm          │
│   • Pulse daemon (background dream insights)    │
├────────────────────────────────────────────────┤
│  🥩 MEAT       — Claude Code reasons            │
├────────────────────────────────────────────────┤
│  🥪 BOTTOM BREAD — Stop hooks                   │
│   • Veto-detector (fast 50ms regex pre-screen)  │
│   • Sanhedrin Executioner (optional verifier)   │
│   • Synthesis stop validator (hedge detector)   │
└────────────────────────────────────────────────┘

Sanhedrin is optional. The default installer wires the lightweight preflight and stop hooks only; it does not start MLX, require a 19 GB model download, or require 20+ GB of RAM. Users who want the post-response semantic verifier can opt in and point it at any OpenAI-compatible /v1/chat/completions endpoint. On Apple Silicon, an additional --with-launchd flag can auto-start the local MLX Qwen backend.

---

How a single response flows through the Sandwich

1. You type a prompt in Claude Code.
2. UserPromptSubmit hooks fire in parallel (none can block — all fail-open):
   • load-all-memory.sh (opt-in) — dumps every memory MD into context
   • synthesis-preflight.sh — POSTs your prompt to vestige-mcp /api/deep_reference, injects the trust-scored reasoning chain
   • cwd-state-injector.sh — captures git status, branch, open PRs/issues, modified files
   • vestige-pulse-daemon.sh — injects fresh Vestige dream insights from the past 20 min into the next prompt context
   • preflight-swarm.sh — spawns the lateral-thinker subagent in fresh context to surface cross-disciplinary structural parallels
3. Claude reads the assembled context and generates a draft.
4. Stop hooks fire serially (any can VETO with exit 2, forcing a rewrite):
   • veto-detector.sh — fast regex against veto-tagged Vestige memories (~50ms)
   • sanhedrin.sh → sanhedrin-local.py — optional single-shot semantic verdict
   • synthesis-stop-validator.sh — regex against forbidden patterns (hedging, summary-instead-of-composition)
5. If all enabled Stop hooks return exit 0, the response is delivered.

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The Sanhedrin Executioner protocol

The Executioner extracts atomic claims from Claude's draft across 10 classes:

TECHNICAL · BIOGRAPHICAL · FINANCIAL · ACHIEVEMENT · TIMELINE · QUANTITATIVE · ATTRIBUTION · CAUSAL · COMPARATIVE · EXISTENTIAL · plus v2.1.0 additions: VAGUE-QUANTIFIER · UNVERIFIED-POSITIVE

For each claim, it checks Vestige's deep_reference for high-trust contradicting memories. Decision rules:

Class	Rule
TECHNICAL / EXISTENTIAL / TIMELINE	VETO if memory trust > 0.55 directly contradicts
BIOGRAPHICAL / FINANCIAL / ACHIEVEMENT / ATTRIBUTION	VETO if contradicted OR if factual-shaped with zero supporting evidence (fail-closed)
VAGUE-QUANTIFIER	VETO on "a few wins / some prize money / most placed" without enumeration
UNVERIFIED-POSITIVE	VETO on specific named institutions/dates/employers not in evidence

False-positive guards (added v2.1.0 after dogfood):

• Subject-equality gate (memory about Vestige codebase ≠ contradiction with external tools)
• Version-discriminator rule (M3 Max ≠ M5 Max; Qwen3.5 ≠ Qwen3.6)
• Agreement-is-not-contradiction (memory that AGREES with draft → PASS)
• Architecture-vs-component (overall architecture memory doesn't contradict component-level draft)
• Inference-verb ban (no implies / suggests / must mean in veto reasons)

---

Installation

One-liner

curl -fsSL https://raw.githubusercontent.com/samvallad33/vestige/v2.1.0/scripts/install-sandwich.sh | sh

From a checkout

git clone https://github.com/samvallad33/vestige
cd vestige
./scripts/install-sandwich.sh           # add --force to overwrite existing hooks
./scripts/check-sandwich-prereqs.sh     # verify everything's wired

Optional Sanhedrin

Sanhedrin is a separate opt-in layer.

# Wire the Sanhedrin Stop hook, using the default OpenAI-compatible endpoint.
./scripts/install-sandwich.sh --enable-sanhedrin

# Apple Silicon only, and only if the machine has enough memory:
./scripts/install-sandwich.sh --enable-sanhedrin --with-launchd

# x86 / Linux / Intel Mac: use any OpenAI-compatible endpoint.
./scripts/install-sandwich.sh \
  --enable-sanhedrin \
  --sanhedrin-endpoint=http://127.0.0.1:11434/v1/chat/completions \
  --sanhedrin-model=qwen2.5:14b

Prerequisites

Tool	Install
Python 3.10+	typically preinstalled
jq	brew install jq
vestige-mcp	cargo install vestige-mcp
Claude Code	https://claude.ai/code

Optional Apple Silicon local Sanhedrin backend:

Tool	Install
macOS Apple Silicon (M1+)	required for MLX launchd only
uv	brew install uv
mlx-lm	uv tool install mlx-lm
huggingface_hub[cli]	uv tool install 'huggingface_hub[cli]'
Qwen3.6-35B-A3B-4bit	hf download mlx-community/Qwen3.6-35B-A3B-4bit (~19 GB)

What the installer does

1. Verifies prereqs (warnings for missing tools, fatal only on jq/python3).
2. Copies hooks to ~/.claude/hooks/, agents to ~/.claude/agents/.
3. Backs up existing ~/.claude/settings.json to .bak.pre-sandwich, then jq-merges the lightweight hooks block.
4. With --enable-sanhedrin, writes ~/.claude/hooks/vestige-sanhedrin.env and merges a Sanhedrin-enabled hooks block.
5. With --enable-sanhedrin --with-launchd on Apple Silicon, renders and loads launchd/com.vestige.mlx-server.plist.template.

Uninstall

launchctl unload ~/Library/LaunchAgents/com.vestige.mlx-server.plist
rm ~/Library/LaunchAgents/com.vestige.mlx-server.plist
cp ~/.claude/settings.json.bak.pre-sandwich ~/.claude/settings.json
# Hook files in ~/.claude/hooks/ can be deleted manually.

---

Performance notes

Optional local MLX backend on M3 Max 16-core (400 GB/s memory bandwidth):

• Sanhedrin verdict: 5–15 seconds end-to-end (single deep_reference + single Qwen call)
• mlx_lm.server token generation: ~82 tok/s
• mlx_lm.server peak resident memory: ~19.7 GB
• Cold model load: ~5 seconds

On M3 Max 14-core or M2/M1 Max: closer to 3–7s prompt processing, ~50–60 tok/s generation.

---

Configuration

Env var	Default	Effect
VESTIGE_SANHEDRIN_ENABLED	0	Set to 1 to enable the optional Sanhedrin Stop hook
VESTIGE_SWARM_ENABLED	1	Set to 0 to disable preflight lateral-thinker swarm
VESTIGE_DASHBOARD_PORT	3927	Vestige MCP HTTP API port used by hooks
VESTIGE_SANHEDRIN_ENDPOINT	http://127.0.0.1:8080/v1/chat/completions	OpenAI-compatible chat completions endpoint for Sanhedrin
VESTIGE_SANHEDRIN_MODEL	mlx-community/Qwen3.6-35B-A3B-4bit	Model name sent to the Sanhedrin endpoint
MLX_ENDPOINT / VESTIGE_SANDWICH_MODEL	legacy aliases	Backward-compatible names still read by the bridge
VESTIGE_MEMORY_DIR	(auto)	Override per-user Claude memory dir

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Architecture provenance

The Cognitive Sandwich originated April 2026 as a defense against the AIMO3 36/50 failure mode — Claude retrieving relevant memories but summarizing them instead of composing them into recommendations. The pre-cognitive layer enforces composition; the post-cognitive layer catches contradictions before they ship.

Full architecture memory: search Vestige for god-tier-plan or cognitive-sandwich tags after install.

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Linux / Intel Mac / x86

The base hook harness runs on x86. The launchd MLX helper is macOS-arm64-only.

On Linux, Windows under WSL, or Intel Mac:

• Run scripts/install-sandwich.sh normally for lightweight hooks.
• If you want Sanhedrin, run an OpenAI-compatible endpoint such as vLLM, Ollama, llama.cpp server, or a remote MLX/vLLM box.
• Install with --enable-sanhedrin --sanhedrin-endpoint=<url> --sanhedrin-model=<model>.
• If the endpoint is unreachable, Sanhedrin fails open and does not block Claude Code.