# Best Pre-Action Check Tools for AI Coding Agents (2026 Comparison)

Your AI coding agent force-pushed to main again. Which tool actually prevents that? We compared the five most common approaches to AI agent safety.

## Comparison Table

Feature | ThumbGate | Manual Code Review | Post-hoc Git Revert | Cursor Rules / .cursorrules | ESLint / Linters
--- | --- | --- | --- | --- | ---
Intercepts bad actions before execution | Yes -- PreToolUse hooks warn by default; hard-block high-risk classes and strict mode | Partially -- after PR only | No -- damage already done | Partially -- suggestions only | Partially -- static checks only
Learns from past mistakes | Yes -- auto-generates rules from feedback | No -- relies on reviewer memory | No | No -- rules are hand-written | No -- rules are hand-written
Works with Claude / Codex / Gemini / Forge | Yes -- all MCP-compatible agents | Yes -- agent-agnostic | Yes -- agent-agnostic | Cursor only | Partial -- code-level only
Zero config setup | Yes -- `npx thumbgate init` | No -- requires process + people | No -- manual intervention each time | Partial -- requires writing rules | Partial -- requires config + plugins
Captures feedback for improvement | Yes -- thumbs up/down with context | Partial -- PR comments only | No | No | No
Generates prevention rules automatically | Yes -- from repeated failure patterns | No | No | No | No
Real-time pre-action checks | Yes -- fires before every tool call | No -- asynchronous review | No -- reactive only | No -- prompt-time only | No -- build-time only
Cost | Free tier + Pro $19/mo | Engineer time per review | Time lost + recovery cost | Free | Free (open source)
Academic validation | Memento-Skills architecture (arXiv 2603.18743) | — | — | — | —

## Why ThumbGate Wins

- Enforcement, not suggestions. Prompt rules in CLAUDE.md or .cursorrules are instructions the agent can ignore. ThumbGate intercepts tool calls at the PreToolUse hook level, flags and logs risky actions, and hard-blocks the most dangerous classes (secret exfiltration, supply-chain installs, rm -rf-class deletes) before they execute — with force-push, off-scope edits, and skip-tests escalated to hard blocks under strict enforcement mode.
- Learns and adapts automatically. Every thumbs-down becomes a data point. After repeated failures with the same pattern, ThumbGate auto-generates a prevention rule. Checks adapt their sensitivity over time using Thompson Sampling -- aggressive checks that over-block get tuned down, effective checks get reinforced.
- Works across all major AI coding agents. One install command covers Claude Code, Cursor, Codex, Gemini CLI, Amp, Cline, and OpenCode. No per-agent configuration needed.
- Prevention is cheaper than recovery. Manual code review catches mistakes after the PR. Git revert catches them after the push. ThumbGate catches them before the tool call executes -- saving the time, context switches, and cleanup cost of undoing damage.

### Evaluating bigger orchestration platforms?

Journey orchestration and AI workflow routing are different from execution enforcement. If you are comparing ThumbGate to a broader AI orchestration stack, start here.

Read orchestration vs enforcement

### Comparing custom AI agent agencies?

AI automation agencies validate the same buyer pain: production agents need safe action execution, policy checks, observability, and approval boundaries. ThumbGate owns the productized enforcement layer under those workflows.

Read ThumbGate vs Agentix Labs

### Already using a supply-chain scanner?

HEIDI (Meterian) catches AI assistants suggesting vulnerable npm/pip/maven packages — the supply-chain half of AI coding safety. ThumbGate is the behavior half: it blocks the agent's tool call before it fires a known-bad pattern. Different threat surfaces, both local-first, both free at base. Run both.

Read ThumbGate vs HEIDI

### Evaluating Rein for AI agent governance?

Rein is a Python decorator that wraps tool functions with policy checks, audit trails, and circuit breakers — targeted at production apps in trading, healthcare, and legal. ThumbGate is the coding-agent specialist with a learning feedback loop and MIT licensing. Same category (infrastructure firewalls), different layer and stack.

Read ThumbGate vs Rein

## All ThumbGate comparisons

Every head-to-head in one place. ThumbGate is the local-first, learning enforcement layer at the tool-call boundary — most of these tools sit at a different layer and are complementary.

- ThumbGate vs SigmaShake — learns the rule from your thumbs-down vs a hand-picked ruleset hub
- ThumbGate vs claude-code-hooks — personal recall, exports, and managed adapters on top of local shell-script hooks
- ThumbGate vs Arcjet — agent-outbound gate pairs with an app-inbound firewall
- ThumbGate vs Bumblebee — runtime enforcement pairs with static inventory
- ThumbGate vs Anthropic's Claude Containment — an IDE-agent extension of Anthropic's published architecture
- ThumbGate vs Gatekeeper (Oak & Sparrow) — agent-action gate pairs with a workforce-input gate
- ThumbGate vs Fallow — static analysis vs agent-action enforcement
- ThumbGate vs HEIDI — behavior enforcement vs supply-chain scanning
- ThumbGate vs Rein — coding-agent governance vs generic decorator governance
- ThumbGate vs Claude for Legal — runtime gate pairs with Anthropic's practice-area plugins
- ThumbGate vs Mem0 — enforcement vs memory for AI agents
- ThumbGate vs SpecLock — thumbs-feedback enforcement vs manual specs
- ThumbGate vs AI Experience Orchestration — orchestration vs execution enforcement
- ThumbGate vs Agentix Labs — productized enforcement vs custom AI-agent services
- ThumbGate vs Adopt AI — pre-execution firewall vs evals-first gating for production blast radius
- ThumbGate vs Arcade — coding-agent guardrails vs enterprise API auth delegation
- ThumbGate vs Databricks Unity AI Gateway — enterprise gateway vs local pre-action gates
- ThumbGate vs Hermes and EverOS — local-first behavior gates vs passive agent memory stores

## How It Works

1

### Install

Run `npx thumbgate init`. ThumbGate auto-detects your AI coding agent and configures PreToolUse hooks. No manual setup needed.

2

### Check

Every tool call your agent makes passes through a pre-action check. Known-bad patterns are blocked before execution. Good actions pass through instantly.

3

### Learn

When your agent makes a mistake, give it a thumbs-down. In the current Claude auto-capture path, vague negative signals can reuse up to 8 prior recorded entries plus the failed tool call, then stay linked to a 60-second follow-up session before repeated failures harden into prevention rules.

## Get Started

Install ThumbGate in one command:

    npx thumbgate init

Then start giving feedback. ThumbGate handles the rest.

View on npm View on GitHub

## Frequently Asked Questions

### What is a pre-action check?

A pre-action check is an enforcement layer that intercepts AI agent tool calls before they execute. Unlike prompt rules that agents can ignore, pre-action checks flag and log risky actions and hard-block the most dangerous classes by default (secret exfiltration, supply-chain installs, rm -rf-class deletes). Actions such as force-pushing to main, off-scope edits, or skipping tests warn by default and hard-block under strict enforcement mode.

### Does ThumbGate work with Claude Code?

Yes. ThumbGate works with Claude Code, Cursor, Codex, Gemini CLI, Amp, Cline, OpenCode, and any MCP-compatible agent. Run `npx thumbgate init --agent claude-code` to auto-configure PreToolUse hooks.

### Is ThumbGate free?

ThumbGate free includes local enforcement with 2 captures/day, 10 total captures, 3 active auto-promoted prevention rules, and pre-action blocking. Pro ($19/mo or $149/yr) adds personal recall, search, a local dashboard, managed adapters, unlimited captures/rules, and DPO export. Enterprise adds a shared hosted lesson DB and org dashboard.

### How is ThumbGate different from .cursorrules or CLAUDE.md rules?

Cursor rules and CLAUDE.md are prompt-level instructions that the AI agent can read, forget, or override. ThumbGate enforces rules at the tool-call level via PreToolUse hooks. When a tool call matches a known failure pattern, it is flagged and logged, and hard-blocked before execution for the most dangerous classes or under strict enforcement mode. Additionally, ThumbGate auto-generates prevention rules from feedback -- no manual rule writing.

### Can ThumbGate learn from mistakes automatically?

Yes. When your AI agent makes a mistake, give a thumbs-down with context. In the current Claude auto-capture path, vague negative signals can reuse up to 8 prior recorded entries plus the failed tool call, then stay linked to a 60-second follow-up session. After repeated failures with the same pattern, ThumbGate auto-generates a prevention rule and wires it as a pre-action check. Checks adapt over time using Thompson Sampling, a Bayesian multi-armed bandit algorithm.