pre-flight 📝 ✈️

Love the speed and developer experience of using Claude Code but feel like you have to babysit it so it doesn't over-engineer, or worse, miss some important detail? By injecting a second opinion into the planning process you can now have both!

A Claude Code plugin that reviews your implementation plans with the Codex or Gemini CLI before they reach you for approval.

Your implementation plans, cleared for takeoff. ✈️

How it works

1. You ask Claude Code to plan something
2. Claude writes the plan and calls ExitPlanMode
3. NEW pre-flight intercepts — sends the plan to your configured provider for review
4. NEW The provider returns prioritized feedback (P1–P3)
5. NEW Claude receives the feedback and decides whether to incorporate or ignore it
6. You approve, revise, or reject with the review in hand

If the plan changes after feedback, it gets re-reviewed automatically.

🚀 Demo

Requirements

• Claude Code CLI
• One of the following review providers:
  • Codex CLI installed and authenticated (default)
  • Gemini CLI installed and authenticated (free tier: 1000 req/day, 1M token context)
• python3 and jq in your PATH

Install

claude plugin marketplace add Abeansits/pre-flight
claude plugin install pre-flight@pre-flight

Restart Claude Code after installing - hooks load at session start

Config

Create ~/.config/pre-flight/config to override defaults:

provider=codex
codex_model=gpt-5.3-codex
codex_reasoning_effort=high
gemini_model=gemini-2.5-pro

Setting	Default	Description
provider	codex	Review provider (codex or gemini)
codex_model	gpt-5.3-codex	Codex model to use for reviews
codex_reasoning_effort	high	Reasoning effort (low/medium/high)
gemini_model	gemini-2.5-pro	Gemini model to use for reviews

Backwards compatibility: Existing configs using model= and reasoning_effort= (without prefix) continue to work and map to codex_model and codex_reasoning_effort respectively.

Updating

claude plugin marketplace update pre-flight
claude plugin update pre-flight@pre-flight

Uninstall

claude plugin remove pre-flight
claude plugin marketplace remove pre-flight

Restart Claude Code after uninstalling.

Debugging

Run Claude Code with claude --debug to see hook execution logs. If no plan is found in the transcript, the hook exits silently.

Technical details

Hook event

pre-flight registers a PreToolUse:ExitPlanMode hook. This fires every time Claude calls ExitPlanMode (i.e., right before presenting a plan for approval) — before the tool actually executes.

Deny-then-retry pattern

The hook uses a two-pass approach:

1. First call — extracts the plan from the transcript, sends it to the configured provider (Codex or Gemini), and denies ExitPlanMode. The denial reason contains the review, which Claude surfaces to the user in conversation.
2. Second call — Claude retries ExitPlanMode after incorporating the feedback. The hook detects the plan was already reviewed and passes through, allowing the tool to execute normally.

Content hashing & loop prevention

A SHA-256 hash of the plan content is written to a marker file in /tmp (pre-flight-<session-hash>.marker). On each invocation the hook compares the current plan hash to the stored one:

• Same hash → plan unchanged, pass through (second call after deny)
• Different hash → plan was revised, trigger a fresh review
• Marker files older than 24 hours are automatically cleaned up

Provider abstraction

The review logic is split into provider-specific functions (review_with_codex, review_with_gemini) behind a shared prompt builder. A case statement routes to the configured provider. Adding a new provider requires only a new function and case branch — everything else (plan extraction, hashing, deny/retry flow) is shared.

Transcript parsing

The hook reads Claude Code's session transcript (JSONL format) and extracts the most recent Write tool call — this is the plan file Claude writes just before calling ExitPlanMode. It handles both type: "assistant" entries (tool calls nested in obj.message.content[]) and type: "message" entries (content directly in obj.content).

License

MIT