TL;DR

Pi Coding Agent is built as a layered TypeScript toolkit, not a sealed coding assistant product.

Its architecture separates provider access, agent runtime, coding workflow, and terminal UI into distinct packages.

Context engineering is a first-class feature through AGENTS.md, SYSTEM.md, APPEND_SYSTEM.md, skills, and extension hooks.

Pi can run interactively, headlessly over JSONL RPC, or be embedded through its SDK using the same underlying runtime.