By name: thumbgate description: >- Pre-action checks for AI coding agents — capture thumbs-up/down feedback, generate prevention rules, and block known-bad patterns before they execute. Use when setting up ThumbGate, capturing feedback on agent actions, checking active prevention rules, debugging blocked actions, or exporting DPO training data. Triggers on: "thumbgate", "check", "block mistake", "prevention rule", "feedback", "thumbs up", "thumbs down", "capture feedback", "what went wrong".
ThumbGate — Pre-Action Checks for AI Agents
ThumbGate turns thumbs-up/down feedback into hard enforcement checks that block known-bad agent actions before they execute. Think of it as an immune system for your AI agent.
npm package: thumbgate
Docs: https://github.com/IgorGanapolsky/ThumbGate
Quick Start
If ThumbGate is not yet installed in this project:
npx thumbgate init
This bootstraps .thumbgate/ data directory and .mcp.json config. Works with
Codex, Cursor, Codex, Gemini CLI, Amp, OpenCode, and any MCP-compatible agent.
Core Commands
Capture feedback
When an agent action succeeds or fails, capture it:
# Thumbs down — something went wrong
node .Codex/scripts/feedback/capture-feedback.js \
--feedback=down \
--context="what happened" \
--what-went-wrong="specific failure" \
--what-to-change="specific fix" \
--tags="tag1,tag2"
# Thumbs up — something worked
node .Codex/scripts/feedback/capture-feedback.js \
--feedback=up \
--context="what happened" \
--what-worked="specific thing that worked" \
--tags="tag1,tag2"
View active gates and rules
npm run feedback:rules # Show prevention rules generated from feedback
npm run feedback:stats # Feedback counts by signal, domain, importance
npm run feedback:summary # Aggregated summary of all feedback
Check system health
npm run self-heal:check # Verify 4/4 subsystems healthy
Export training data (Pro)
npm run feedback:export:dpo # Export DPO preference pairs for fine-tuning
How Gates Work
- Feedback — You give thumbs-up or thumbs-down on agent actions
- Rules — Repeated failures auto-promote into prevention rules via Thompson Sampling
- Gates — Rules become PreToolUse hooks that block the agent before it repeats the mistake
Gates are enforced via MCP PreToolUse hooks — the agent literally cannot execute a blocked action. This is hard enforcement, not a soft suggestion.
Architecture
| Component | What it does |
|---|---|
| SQLite+FTS5 lesson DB | Fast full-text search across all feedback |
| Thompson Sampling | Adaptive gate sensitivity per failure domain |
| LanceDB + HuggingFace | Local vector search for semantic similarity |
| ContextFS | Hierarchical context assembly with semantic caching |
| PreToolUse hooks | Hard enforcement — blocks before execution |
MCP Tools Available
When the MCP server is running, these tools are available to your agent:
| Tool | Purpose |
|---|---|
capture_feedback |
Record thumbs-up/down on an agent action |
search_lessons |
Search past feedback by keyword, tag, or domain |
recall |
Retrieve relevant memories for current context |
prevention_rules |
View active prevention rules |
gate_stats |
See which gates are firing and their block rates |
feedback_stats |
Feedback counts and trends |
export_dpo_pairs |
Export DPO training pairs (Pro) |
construct_context_pack |
Build bounded context from feedback history |
Pro Features
Pro users ($19/mo or $149/yr) unlock:
- Visual gate debugger — see every blocked action and the gate that fired
- Multi-hop recall — chain related lessons across hops for deeper context
- Synthetic DPO augmentation — expand real feedback into larger training datasets
- Gate wiring support — help enforcing your riskiest flows in the first week
Team rollout ($49/seat/mo, 3-seat minimum after intake) adds the shared hosted lesson DB, org dashboard, approval boundaries, and proof-backed workflow hardening sprint.
Upgrade: https://thumbgate-production.up.railway.app/go/pro?utm_source=skill
Detailed Reference
For setup guides per agent, see: <references/setup-guides.md> For gate configuration, see: <references/gate-config.md>