The complete guide to pre-action gates, feedback capture, and automatic prevention rules.
Your AI coding agent force-pushes to main. You correct it. Next session, it force-pushes again. You add a rule to CLAUDE.md. It ignores it. You lose an afternoon reverting.
This happens because prompt rules are suggestions. The agent can read them, forget them, or override them. There is no enforcement at the tool-call level.
ThumbGate adds an enforcement layer between your agent and its tools. When the agent tries to execute a tool call, a PreToolUse hook fires before the action runs. The hook checks the call against known failure patterns. If it matches a gate, the action is blocked.
Agent: git push --force origin main
Result: Force-pushed. You lose 3 commits. Again.
Agent: git push --force origin main
[gate] Blocked: no-force-push (confidence: 0.94)
Agent: git push origin feature-branch
[gate] Passed
# Auto-detect your agent and configure hooks
npx mcp-memory-gateway init
# Or specify your agent directly
npx mcp-memory-gateway init --agent claude-code
npx mcp-memory-gateway init --agent codex
npx mcp-memory-gateway init --agent cursor
npx mcp-memory-gateway init --agent gemini
When your agent makes a mistake, tell it. ThumbGate captures the feedback as structured data with context, tags, and domain.
# Your agent force-pushed. You say:
"thumbs down — force-pushed to main, lost commits"
# ThumbGate captures:
{
signal: "negative",
context: "force-pushed to main, lost commits",
tags: ["git", "force-push", "destructive"],
domain: "version-control"
}
After repeated failures with the same pattern, ThumbGate generates a prevention rule automatically. No manual rule writing needed.
Prevention rules are enforced as pre-action gates. The gate fires at the PreToolUse hook level — inside the agent's runtime, before the tool call executes.
Gates that block too aggressively (high false-positive rate) get their confidence reduced automatically. Gates that catch real mistakes get reinforced. This is Bayesian multi-armed bandit optimization, not static rules.
ThumbGate stores feedback in a local SQLite database with FTS5 full-text indexing. Lookups are sub-millisecond even at tens of thousands of entries. Old entries that contradict newer evidence are auto-pruned via Bayesian belief decay.
recall — injects relevant context at session startsearch_lessons — finds promoted lessons with corrective actionssession_handoff — preserves continuity across sessions| Feature | Prompt Rules | Pre-Action Gates |
|---|---|---|
| Where they live | CLAUDE.md, .cursorrules | PreToolUse hooks |
| Enforcement | Suggestion (can be ignored) | Blocks execution |
| When they fire | At prompt load | Before every tool call |
| Auto-generated | No — hand-written | Yes — from feedback |
| Adaptive | No | Yes — Thompson Sampling |
| Persist across sessions | Only if in a file | SQLite + JSONL |
| Feature | ThumbGate | SpecLock | Mem0 |
|---|---|---|---|
| Blocks mistakes before execution | Yes — PreToolUse gates | Yes — Patch Firewall | No |
| Learns from feedback | Yes — thumbs up/down | No — manual specs | Yes — auto-capture |
| Auto-generates rules | Yes — from repeated failures | No | No |
| Agent support | Claude Code, Codex, Gemini, Amp, Cursor, OpenCode | Claude Code, Cursor, Windsurf, Cline | Claude, Cursor |
| Install | npx mcp-memory-gateway init | npx speclock setup | Cloud signup |
| Cost | Free (Pro $49 for teams) | Free | Free tier + paid |
Give a thumbs-down: "deleted production config file." After 2-3 occurrences, ThumbGate generates a gate that blocks rm commands targeting config files.
Give a thumbs-down: "committed code with failing tests." ThumbGate learns the pattern and gates future commits when test results show failures.
Give a thumbs-down: "called staging API in production code." The gate blocks tool calls that reference staging URLs in production contexts.
npx mcp-memory-gateway init
One command. Works with Claude Code, Cursor, Codex, Gemini, Amp, and OpenCode.
Get Pro — $49Free is fully featured — unlimited captures, recalls, gates, and blocking. Pro adds a searchable dashboard to query, edit, and delete entries.