Flanner

A plan-file manager for AI coding agents, wired into Claude Code and other assistants over MCP (Model Context Protocol).

Why

AI agents write markdown constantly: design docs, migration plans, architecture notes. It piles up fast, scattered across your repo, quietly going stale, and easy to commit by accident. Flanner gives those files one home, versions them automatically as the agent revises, and keeps them out of git until you decide otherwise, with a browsable reading view and an audit trail on top.

No, I'm not convinced. But why?

Those plan files pile up in two directions at once: scattered across your projects locally, and scattered across open issues in your project-management tool. Flanner is the choke point for both, keeping you organized on disk and linked to the issue each plan belongs to.

Today Flanner is local-first; the goal is cloud-hosted plans: shared workspaces for easier collaboration, effectively unlimited storage and history, and clean links to the tools teams already work in, from product trackers and chat to second brains like Notion.

Features

• MCP integration: exposes plan-file tools to Claude Code and Codex.
• Automatic headers and versioning: every plan gets YAML frontmatter, and each revision is a new version with a full history.
• Git protection: plans live in .plans/ and are kept out of commits automatically.
• Agent integration: flanner init wires CLAUDE.md, AGENTS.md, and a guard hook so agents save plans through flanner instead of scattering raw markdown.
• Issue tracker links: tie a plan to its Linear (or JIRA) issue; with a LINEAR_API_KEY, flanner verifies the issue and shows its live state, in the CLI and the dashboard.
• Reading view: a browser dashboard to read, edit, and walk the history of plans (light and dark, fully offline).
• Per-project config: customize the plan directory per repository.

Quick start

pip install flanner

cd your-project      # a git repo where plans should live
flanner init         # sets up the database, MCP registration, and a project

Then ask your agent to work with plans:

"Create an architecture plan for the auth service"

"Show me the history of the architecture plan"

And open the dashboard to browse them:

flanner web --open-browser     # http://localhost:8080

flanner init is safe to re-run. It detects your git root, creates .plans/, updates .gitignore, registers the MCP server with Claude Code, and installs the agent integration.

CLI commands

flanner init [--project-root PATH] [--plan-dir DIR]     # set up a project
flanner status                                          # projects, plan files, db path
flanner list [--project NAME] [--output json]           # list projects or a project's plans
flanner sync [--project NAME] [--dry-run]               # import existing .plans/ files
flanner config NAME [--plan-dir DIR] [...]              # change project settings
flanner web [--port 8080] [--host 127.0.0.1] [--open-browser]
flanner register [--force] / flanner unregister         # MCP registration with Claude Code
flanner claude-info                                     # integration status

---
mcp_plan_file: true
project_id: 3d816ecd-489a-4fa0-abe2-15ec93f60d5a
plan_file_id: 59c34f9c-8471-47fc-97f2-8dcfefa15434
plan_name: architecture
version: 2
created_by: claude
---

# Architecture Plan

Your plan content here...

flanner linear auth                                     # verify LINEAR_API_KEY, print MCP snippet
flanner linear config PROJECT --workspace acme          # linear.app/acme
flanner linear link PLAN --issue ENG-123 [--notes ...]  # link a plan to an issue
flanner linear links [--project PROJECT]                # list all links
flanner linear show PLAN [--project PROJECT]            # links for one plan
flanner linear unlink PLAN [--issue ENG-123 | --all]
flanner linear refresh PLAN                             # re-pull title/state (needs API key)

flanner peer serve                                      # answer authorised peers
flanner peer pull <device-id>                           # pull what a peer holds
flanner peer status [<device-id>]                       # how this device is reached

How it works

An agent calls get_plan_config to learn where plans go, then create_plan_file_tool or update_plan_file_tool to write them. Flanner places the file in the project's plan directory, adds the header, and bumps the version. Files stay in .plans/ (git-ignored), so they never land in a commit by accident.

Nothing is pruned, and nothing is erased. Every version, comment and review decision is kept. The store is append-only, there is no cleanup command, and the Settings page shows what that costs in bytes so the choice is visible rather than assumed. Deletion follows from the same design: flanner retire <plan> asks every peer to stop showing and serving a plan, and --restore undoes it, but it is a claim other devices honour rather than an erasure. A teammate who was offline when you ran it keeps the content until they next sync, and anyone already holding the bytes keeps them. That is the strongest promise an append-only store spread across machines you do not control can honestly make, so it is the one made here.

Keeping the agent on the rails. The MCP tools are the how; flanner init also installs two layers that make the agent actually use them. It writes a managed block into CLAUDE.md and AGENTS.md (guidance Claude Code and Codex read every session) plus a flanner-plan skill, so the agent knows to route plan docs through flanner. On top of that, a guard-write PreToolUse hook denies any raw write into the plan directory and points the agent back to create_plan_file_tool, so even if it ignores the guidance a plan cannot land as unmanaged markdown. The hook fails open and never blocks writes elsewhere.

Roadmap

Flanner is local-first today. Planned next:

• Cloud-hosted plans: a PostgreSQL catalog and S3-backed storage for effectively unlimited history
• Shared workspaces for team collaboration
• Full-text search across plans
• Links out to product trackers, chat, and second brains like Notion
• Real-time updates in the web UI

Contributing

Setup, the CI gates, benchmarks, and the release process are in CONTRIBUTING.md.

License

MIT