pi-codegraph-fix

The CodeGraph plugin for pi that actually works.

中文版

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Features

• Switch projects freely — uses ctx.cwd instead of process.cwd(), no more silent tool loss when you change projects
• Zero zombie processes — cleanup on session shutdown, process exit, and SIGTERM/SIGHUP. No more pile-up
• Lazy start — spawns codegraph only when you first use it, doesn't slow down session launch
• Multi-project friendly — each project gets its own MCP client, switches automatically
• No misleading hints — injects CodeGraph instructions only when tools are actually ready

Quick Install

pi install npm:pi-codegraph-fix

You also need CodeGraph CLI (npm install -g @colbymchenry/codegraph) and your project indexed (codegraph init).

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The Problems

1. CodeGraph goes silent when you switch projects

You pi session=<other-project> or launch pi from ~ instead of your project root. Suddenly codegraph tools disappear. No error, just nothing.

Why: The original plugin used process.cwd() to find .codegraph/codegraph.db. That always points to wherever pi was first launched — not your current session's project. Wrong project → no DB → no tools → silent failure.

2. Zombie process pile-up

Every time you close pi, the codegraph serve --mcp subprocess doesn't die. After a few sessions you have a dozen of them fighting over the same socket — causing "server disconnected" errors on every codegraph call.

Real case: 12 zombie processes accumulated over 9 hours across 6 sessions. Every codegraph call spun the roulette wheel on which zombie had the socket lock.

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The Fix

Two changes from the originals (codegraph-pi, pi-codegraph):

ctx.cwd instead of process.cwd() — reads the current session's working directory from pi, so it works no matter where or how you launched pi.

Three-path cleanup — kills the MCP subprocess on normal exit, crash, or terminal close:

Path	When
session_shutdown	pi exits normally
process.once("exit")	Node process ends
SIGTERM / SIGHUP	Terminal close, kill

No more zombies. No more "server disconnected".

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Features

Feature	Source
ctx.cwd instead of process.cwd()	pi-codegraph-fix
spawn with explicit cwd	pi-codegraph-fix
Multi-project MCP clients (one per CWD)	SeanPedersen/pi-codegraph
Dynamic tool discovery via MCP tools/list	SeanPedersen/pi-codegraph
Process cleanup hooks (exit, SIGTERM, SIGHUP)	SeanPedersen/pi-codegraph
Self-contained single file	SeanPedersen/pi-codegraph
before_agent_start system prompt injection	colbymchenry/codegraph-pi
.codegraph/codegraph.db exact check	colbymchenry/codegraph-pi

How It Works

1. On session_start, check if ctx.cwd/.codegraph/codegraph.db exists (instant file check)
2. On first codegraph tool call, spawn codegraph serve --mcp in background (lazy, doesn't block session)
3. Discover available tools via MCP tools/list protocol
4. Register all tools with pi.registerTool()
5. Inject usage instructions into system prompt via before_agent_start after tools are ready
6. On session_shutdown or process exit, clean up all MCP clients

Credits

• colbymchenry/codegraph-pi — original pi extension
• SeanPedersen/pi-codegraph — multi-client architecture