pi-codegraph

A pi coding agent extension that wires codegraph as an MCP sidecar and injects structured usage instructions into the system prompt.

What it does

When a project has a .codegraph/ index, this extension:

1. Spawns codegraph serve --mcp as a sidecar process
2. Registers all codegraph tools (codegraph_search, codegraph_callers, codegraph_callees, codegraph_impact, codegraph_node, codegraph_context, codegraph_explore, codegraph_files, codegraph_status) directly in the session
3. Injects a ## CodeGraph section into the base system prompt via APPEND_SYSTEM.md so the instructions are present from session startup — not just on the first agent turn

If the project has no .codegraph/ directory the extension is a no-op.

Requirements

• codegraph CLI must be on $PATH
• A .codegraph/ index must exist in the project root (run codegraph init -i to build one)

Install

Recommneded to install semble as well: https://github.com/MinishLab/semble

As a pi package

/add @sean_pedersen/pi-codegraph

Manual (git)

/add https://github.com/SeanPedersen/pi-codegraph

Building the index

codegraph init -i        # initial index build

The file watcher keeps the index current while pi is running.