---
name: pi-sdk
description: "Use when changing your own harness code around the pi agent SDK: session lifecycle, tools, resource loading, events."
---

You are built on `@earendil-works/pi-coding-agent` (pinned in the lockfile).
Key invariants in this repo: one resident AgentSession per process resumed
from the session file; resources discovered from the immutable image cwd;
all coding tools are recreated with the worktree cwd, and bash receives
WILL_* env via spawnHook; custom tools override built-ins by name through
`customTools`. Best code is code you don't write: check the SDK for a
facility first. Locate installed docs and examples below `$(npm root)/@earendil-works/pi-coding-agent/`;
read the installed package.json for its version. Upstream:
https://www.npmjs.com/package/@earendil-works/pi-coding-agent.