Pi on One Page

What Pi is

An open-source, minimal AI agent harness you reshape around your workflow (Mario Zechner / earendil-works). github.com/earendil-works/pi. Not a platform — a toolkit that gets out of your way.

The packages

@earendil-works/pi-ai	Unified multi-provider LLM API (OpenAI, Anthropic, Google…)
…/pi-agent-core	Agent runtime: the loop, tool calling, state
…/pi-coding-agent	Interactive coding-agent CLI
…/pi-tui	Terminal UI, differential rendering

The 4 core tools

Read · Write · Edit · Bash. The entire default toolset — deliberately minimal. Everything else you add via extensions.

The 4 run modes → 4 product shapes

Interactive	Human at a terminal — the cockpit
Print / JSON	Headless, scriptable — batch, farms, CI
RPC	Drive it from another process
SDK	Embed the loop in your own app

What extensions can do (TypeScript, full system access)

• Add custom tools · register commands + keyboard shortcuts
• Handle events + inject UI · inject messages before each turn · filter history
• RAG / custom retrieval · long-term memory · spawn sub-agents
• Permission gates · SSH execution · MCP integration · custom editors

Bundled as Pi Packages — 4 layers: extensions · skills · prompt templates · themes. Distributed via npm or git.

Install & auth (BYOK)

shell# install (blocks install-time scripts)
npm install -g --ignore-scripts @earendil-works/pi-coding-agent

# auth — bring your own key
export ANTHROPIC_API_KEY=…
export OPENAI_API_KEY=…
export GEMINI_API_KEY=…
# …or /login for Claude Pro/Max, ChatGPT Plus/Pro, GitHub Copilot

BYOK = your keys, your account, your data path. earendil-works is never in the loop.

Trust & sandboxing (read before shipping)

No built-in permissions Pi does not restrict filesystem / process / network / credential access. You build the guardrails.

• Sandbox: Gondolin extension · Docker · OpenShell
• Gate every write; audit every call; scope the data.
• Supply-chain: pinned deps · npm shrinkwrap · --ignore-scripts

The Opportunity Lens (5 questions)

Point at any vertical; each "yes" maps to a Pi capability. Three-plus yeses + high stakes = an opening.

Custom tools?	Extension adds a tool
Private data?	RAG / retrieval extension
Memory?	Long-term memory extension
Guardrails?	Permission gates + audit
Where it runs?	Modes + containerization

Opportunity checklist by domain

Domain	Lead play	Key Pi lever
Finance	Research copilot · overnight reconciliation · audit-native assistant	Custom tools + RAG + gates, BYOK data room
Healthcare	Prior-auth & clinical-ops copilots	On-prem + BYOK, RAG, write-gated
Law	Matter memory · batch contract review	Long-term memory + RAG + print/JSON
Industry / edge	Runbook operator · field-service brain	SSH execution + RPC, hard interlocks
Studio	Pipeline conductor · render-farm worker	Custom tools + print/JSON + themes
Ship a vertical	Package it or embed it	Pi Packages (npm/git) or SDK/RPC; BYOK economics

The moat, in one line

Not the model — your tools + your data + your workflow, welded by a harness. A smarter base model makes your product better, not obsolete. Specificity is the defense.