Pi - Open-Source Coding Agent

May 13, 2026

An open-source coding agent rivaling claude code and openai codex.
Built to be hackable: here is a great intro from the creator.
Vanilla Pi is bare bones and should be configured via extensions - or start with a preconfigured version like oh-my-pi (though oh-my-pi can feel bloated compared to vanilla Pi with its long system prompt, many features and tools). Another intersting open-source coding agent that promises very efficient token usage is Dirac, via hash-anchored edits and AST code edits - check it out.

Install

$ npm install -g @earendil-works/pi-coding-agent

Then run: $ pi
And add your provider with: /login

LLM Providers

Best bang for the buck right now:

OpenCode Go
- Qwen3.7 Plus has best intelligence vs usage limit ratio
OpenRouter: one API to access all big models
Self-host a model on GPU/s

Customize Pi

Prompts

~/.pi/agent/SYSTEM.md : overwrites the global Pi system prompt (be careful)
~/.pi/agent/APPEND_SYSTEM.md : appends to the global Pi system prompt

Pi loads AGENTS.md or CLAUDE.md at startup from:

~/.pi/agent/AGENTS.md for global instructions
parent directories, walking up from the current working directory
the current directory

Packages

Install extensions (packages) from the pi packages marketplace (review code before you use them): https://pi.dev/packages

Your custom extensions live in: $home/.pi/agent/extensions
Installed extensions (packages) are in: TODO

show complete prompt context: https://pi.dev/packages/pi-system-prompt
dynamic workflows (explicit subagent workflow): https://github.com/Michaelliv/pi-dynamic-workflows
sub-agents: https://pi.dev/packages/pi-subagents
plan mode:
- https://pi.dev/packages/@plannotator/pi-extension
- https://pi.dev/packages/pi-pledit
hashline edit: https://github.com/RimuruW/pi-hashline-edit
btw command: https://github.com/dbachelder/pi-btw
goal command: https://pi.dev/packages/@capyup/pi-goal
beads (task management): https://pi.dev/packages/pi-beads-extension
code index / search:
- https://github.com/colbymchenry/codegraph
  - pi extension: https://github.com/SeanPedersen/pi-codegraph
- https://github.com/MinishLab/semble

Skills

Skills are useful to dynamically load relevant documents / tools into the prompt context to solve advanced tasks / use pre-defined complex workflows.

Located in $home/.agents/skills

Contextual Skills

An extension that selects relevant skills per project on first start of Pi (user may edit skills selection later on) - this saves context, as only skills relevant to the each project are in the agents prompt.

https://github.com/SeanPedersen/pi-context-skills

Mobile Access

https://www.pipulse.dev/
https://github.com/jademind/pi-statusbar

References

#coding #tutorial #AI