pi-revdiff-plan

Plan-first workflow for Pi using revdiff for interactive markdown plan review.

What it does

This extension adds a lightweight state machine to Pi:

• idle → normal Pi behavior
• planning → the agent can explore, but may only write/edit markdown plan files
• executing → after plan approval, full tools are restored and checklist progress is tracked

The review loop is simple:

1. Start plan mode with /revdiff-plan-mode
2. Let the agent explore and write a Markdown plan
3. The agent calls revdiff_submit_plan("PLAN.md")
4. revdiff opens for review
5. Quit with no annotations to approve, or annotate lines to request revisions
6. After approval, the agent executes the checklist; each completed step updates its checkbox in the submitted plan
7. When every checklist item is complete, the extension reports completion and returns to idle

Prerequisites

• Node.js 20+ recommended

• Pi coding agent

• revdiff available in PATH

  • macOS/Homebrew example:

    brew install umputun/apps/revdiff

• A terminal environment where Pi can launch TUI tools

Install

pi install npm:pi-revdiff-plan

Then verify:

pi list

From source

git clone <this-repo>
cd pi-revdiff-plan
pi install .

Usage

Start in normal mode

pi

Start directly in plan mode

pi --revdiff-plan

Typical session

/revdiff-plan-mode
# agent explores codebase and writes PLAN.md
# agent calls revdiff_submit_plan("PLAN.md")
# revdiff opens for review
# annotate and quit, or quit clean to approve

After approval, the extension restores the previously active tool set and adds revdiff_mark_done. The submitted plan is the progress record: completing a step updates its checkbox. When every checklist item is complete, the extension reports completion and returns to idle automatically.

Commands

/revdiff-plan-mode

Toggles plan mode when safe:

• idle → planning
• planning → idle
• during executing with an incomplete or empty checklist, it warns you to use /revdiff-plan-abort
• during executing with every checklist item complete, it returns to idle

/revdiff-plan-abort

Cancels the current execution phase and returns to idle mode.

/revdiff-plan-status

Shows:

• current phase
• current plan file, if any
• checklist progress
• remaining unchecked steps

Flags

--revdiff-plan

Starts Pi with plan mode enabled.

Example:

pi --revdiff-plan

How plan files should look

The agent is prompted to create a markdown plan with sections like:

• Context
• Approach
• Files to modify
• Steps
• Verification

Checklist items should be standard markdown task items, for example:

- [ ] Add parser tests
- [ ] Refactor state restoration
- [ ] Update README

During execution, the extension tracks completion by either of these mechanisms:

• The agent calls revdiff_mark_done with a zero-based checklist index.
• The agent emits a [DONE:n] marker in its response, where n is a zero-based checklist index.

For example:

[DONE:0]
[DONE:1]

Markers are recognized anywhere outside fenced code blocks. Each completed item is written back to the submitted plan as [x].

Validation commands

This project currently uses a minimal validation flow through npm scripts:

npm run typecheck
npm run build
npm run test
npm run lint
npm run validate

Script details

• typecheck — run TypeScript with --noEmit
• build — compile project to dist/
• test — build and run Node test suites
• lint — currently aliases the type-safe validation baseline
• validate — run typecheck and tests together

Troubleshooting

revdiff binary not found

Make sure revdiff is installed and available in PATH.

You can verify with:

command -v revdiff

You can also point to a custom binary path with REVDIFF_BIN.

Plan submit is rejected

The extension only allows plan files that:

• are inside the current working directory
• end with .md or .mdx
• exist and are not empty

Examples of rejected paths:

• ../PLAN.md
• /absolute/path/outside/repo.md
• plan.txt

An absolute path is judged by containment, so one that points inside the working directory (for example /repo/PLAN.md while working in /repo) is accepted.

The review closed without a decision

If revdiff cannot launch, or exits with anything other than its clean-quit (0) or annotations (10) codes, the plan is neither approved nor rejected. The agent is told to call revdiff_submit_plan again rather than treating the failure as plan feedback.

The agent cannot edit source files in plan mode

That is expected. During planning, write and edit are restricted to markdown files only. Approve the plan first to restore full tool access.

Progress did not update

Checklist progress only updates in executing mode. The agent should call revdiff_mark_done with a zero-based checklist index; [DONE:n] markers are also recognized as a fallback. Each completed item updates its matching checkbox in the submitted plan file. A plan without checklist items cannot complete automatically; use /revdiff-plan-abort to leave execution.

Restored session looks wrong

The extension restores plan state from Pi session history. If the approved plan file was deleted or moved, restore falls back to idle.

CI and releases

GitHub Actions runs type checking and tests on pushes and pull requests. Releases are published from GitHub.

Project structure

index.ts                # extension entrypoint and all extension logic
test/parsing.test.ts    # parsing, progress, path, and review-outcome tests
test/state.test.ts      # session-state restoration tests
.github/workflows/      # CI and release workflows
readme.md               # this file

License

MIT