GeezerVison

Why Pi?

Pi is a minimal agent harness. Adapt Pi to your workflows, not the other way around. Customize Pi with extensions, skills, prompt templates, and themes. Bundle them as Pi packages and share via npm or git.

Pi ships with powerful defaults but skips features like sub-agents and plan mode. Ask Pi to build what you want, or install a package that does it your way.

Four modes: interactive, print/JSON, RPC, and SDK. See OpenClaw for a real-world integration.

Read the documentation

Change the harness, not your workflow

Pi isn't a sealed product. If you need a command, tool, provider, workflow, or UI tweak, just ask Pi to build it. It will customize itself on the fly.

Have Pi manipulate itself in place, hit /reload, and keep going. If you think others will find what you built useful, share it!

15+ providers, hundreds of models

Anthropic, OpenAI, Google, Azure, Bedrock, Mistral, Groq, Cerebras, xAI, Hugging Face, Kimi For Coding, MiniMax, NVIDIA, OpenRouter, Ollama, and more. Authenticate via API keys or OAuth.

Switch models mid-session with /model or Ctrl+L. Cycle through your favorites with Ctrl+P.

Add custom providers and models via models.json or extensions.

Tree-structured, shareable history

Sessions are stored as trees. Use /tree to navigate to any previous point and continue from there. All branches live in a single file. Filter by message type, label entries as bookmarks.

Export to HTML with /export, or upload to a GitHub gist with /share and get a shareable URL that renders it. Example session.

Context engineering

Pi's minimal system prompt and extensibility let you do actual context engineering. Control what goes into the context window and how it's managed.

AGENTS.md: Project instructions loaded at startup from ~/.pi/agent/, parent directories, and the current directory.

SYSTEM.md: Replace or append to the default system prompt per-project.

Compaction: Auto-summarizes older messages when approaching the context limit. Fully customizable via extensions: implement topic-based compaction, code-aware summaries, or use different summarization models.

Skills: Capability packages with instructions and tools, loaded on-demand. Progressive disclosure without busting the prompt cache. See skills.

Prompt templates: Reusable prompts as Markdown files. Type /name to expand. See prompt templates.

Dynamic context: Extensions can inject messages before each turn, filter the message history, implement RAG, or build long-term memory.

Steer or follow up

Submit messages while the agent works. Enter sends a steering message (delivered after current tool, interrupts remaining tools). Alt+Entersends a follow-up (waits until the agent finishes).

Four modes

Interactive: The full TUI experience.

Print/JSON: pi -p "query" for scripts, --mode json for event streams.

RPC: JSON protocol over stdin/stdout for non-Node integrations. See docs/rpc.md.

SDK: Embed Pi in your apps. See OpenClaw for a real-world example.

Primitives, not features

Features that other agents bake in, you can build yourself. Extensions are TypeScript modules with access to tools, commands, keyboard shortcuts, events, and the full TUI.

Sub-agents, plan mode, permission gates, path protection, SSH execution, sandboxing, MCP integrations (still supported alongside built-in MCP), custom editors, status bars, overlays.

Don't want to build it? Ask Pi to build it for you. Or install a package that does it your way. See the 50+ examples.

Bundle extensions, skills, prompts, and themes as packages. Install from npm or git: