# Pi Developer Reference Wiki

> pi is a TypeScript monorepo for a provider-neutral coding-agent harness, spanning model APIs, an agent runtime, a CLI, and a terminal UI library. Repository code is the source of truth; no STRATEGY.md or docs/solutions sources were present, and the requested bundled Compound Engineering page-shape guidance is treated as portable workflow guidance.

This is a Grok-Wiki source-grounded repository wiki. Use the complete Markdown link when an agent needs the full repo context.

## Context Links

- [Complete Markdown wiki](https://grok-wiki.com/public/wiki/earendil-works-pi-121d322b171c/llms-full.txt)
- [Complete Markdown alias](https://grok-wiki.com/public/wiki/earendil-works-pi-121d322b171c.md)
- [Human interactive wiki](https://grok-wiki.com/public/wiki/earendil-works-pi-121d322b171c)
- [GitHub repository](https://github.com/earendil-works/pi)

## Repository

- Repository: earendil-works/pi

- Generated: 2026-05-25T04:52:33.091Z
- Updated: 2026-05-25T05:00:27.990Z
- Runtime: Pi · Codex · gpt-5.5
- Format: Technical
- Pages: 6

## Pages

- [Technical Orientation](https://grok-wiki.com/public/wiki/earendil-works-pi-121d322b171c/pages/01-technical-orientation.md): What the repo is, how the four packages fit together, the main entry points, and how to navigate the rest of the developer reference.
- [Agent Core Runtime](https://grok-wiki.com/public/wiki/earendil-works-pi-121d322b171c/pages/02-agent-core-runtime.md): The reusable agent loop, event stream, tool-call execution model, harness layer, session storage, and compaction responsibilities.
- [Model and Provider Abstraction](https://grok-wiki.com/public/wiki/earendil-works-pi-121d322b171c/pages/03-model-and-provider-abstraction.md): The provider-neutral LLM surface: model metadata, stream contracts, lazy provider registration, API-key resolution, OAuth hooks, and custom provider wiring.
- [CLI, Session, and Tool Lifecycle](https://grok-wiki.com/public/wiki/earendil-works-pi-121d322b171c/pages/04-cli-session-and-tool-lifecycle.md): How the pi executable parses inputs, creates cwd-bound services, resolves models and settings, persists sessions, dispatches built-in tools, and bridges into the core agent.
- [Interactive, Print, RPC, and TUI Surfaces](https://grok-wiki.com/public/wiki/earendil-works-pi-121d322b171c/pages/05-interactive-print-rpc-and-tui-surfaces.md): The runtime adapters above AgentSession: terminal interaction, print and JSON modes, JSONL RPC protocol, keybindings, editor components, overlays, and differential rendering.
- [Resources, Extensions, Skills, and Packages](https://grok-wiki.com/public/wiki/earendil-works-pi-121d322b171c/pages/06-resources-extensions-skills-and-packages.md): The portable extension layer for loading repository, file, npm, git, and catalog-like resources without binding the architecture to one model provider or hosted service.

## Source Files

- `package.json`
- `packages/agent/package.json`
- `packages/agent/src/agent-loop.ts`
- `packages/agent/src/agent.ts`
- `packages/agent/src/harness/agent-harness.ts`
- `packages/agent/src/harness/compaction/compaction.ts`
- `packages/agent/src/harness/messages.ts`
- `packages/agent/src/harness/session/jsonl-repo.ts`
- `packages/agent/src/harness/session/session.ts`
- `packages/agent/src/harness/types.ts`
- `packages/agent/src/index.ts`
- `packages/ai/package.json`
- `packages/ai/src/api-registry.ts`
- `packages/ai/src/env-api-keys.ts`
- `packages/ai/src/models.ts`
- `packages/ai/src/oauth.ts`
- `packages/ai/src/providers/register-builtins.ts`
- `packages/ai/src/stream.ts`
- `packages/ai/src/types.ts`
- `packages/coding-agent/package.json`
- `packages/coding-agent/src/cli/args.ts`
- `packages/coding-agent/src/core/agent-session-services.ts`
- `packages/coding-agent/src/core/agent-session.ts`
- `packages/coding-agent/src/core/extensions/loader.ts`
- `packages/coding-agent/src/core/extensions/runner.ts`
- `packages/coding-agent/src/core/extensions/types.ts`
- `packages/coding-agent/src/core/keybindings.ts`
- `packages/coding-agent/src/core/model-registry.ts`
- `packages/coding-agent/src/core/package-manager.ts`
- `packages/coding-agent/src/core/prompt-templates.ts`
- `packages/coding-agent/src/core/resource-loader.ts`
- `packages/coding-agent/src/core/sdk.ts`
- `packages/coding-agent/src/core/session-manager.ts`
- `packages/coding-agent/src/core/settings-manager.ts`
- `packages/coding-agent/src/core/skills.ts`
- `packages/coding-agent/src/core/tools/bash.ts`
- `packages/coding-agent/src/core/tools/index.ts`
- `packages/coding-agent/src/main.ts`
- `packages/coding-agent/src/modes/interactive/interactive-mode.ts`
- `packages/coding-agent/src/modes/print-mode.ts`
- `packages/coding-agent/src/modes/rpc/rpc-mode.ts`
- `packages/coding-agent/src/modes/rpc/rpc-types.ts`
- `packages/tui/package.json`
- `packages/tui/src/components/editor.ts`
- `packages/tui/src/keybindings.ts`
- `packages/tui/src/tui.ts`
- `README.md`