Pi 1.0: Earendil's Minimal Agent Harness Reaches Stability

On October 1, 2026, Earendil released the stable 1.0 version of the Pi CLI agent — a minimal TypeScript-based agent harness with native MCP support, virtual models, and an MIT license.

Compiled by Sergey KostenchukPublished 2026-10-01Updated 2026-10-01

2026-10-01 Coding Anthropic

🛠 Earendil's Minimal Agent Harness Pi Reaches Version 1.0

At 19:20 UTC on October 1, v1.0.0 of the TypeScript-based coding CLI agent was released, which is used by hundreds of thousands of users per week, and the earendil-works/pi repository has gathered approximately 111,000 stars. Pi 1.0 features MCP support via 'Codemode' (the model writes JavaScript in a QuickJS sandbox and calls tools in parallel) and virtual models with request routing between Claude Opus and GPT-6 Luna.

🌍 The minimal harness has become a product: the core is compact, extensibility is provided through an extension SDK and npm, and 1.0 is a public signal of API stability for those building agents on the SDK.

👤 An open (MIT) alternative to Claude Code and Codex CLI: installed via a curl script from pi.dev, works with 15+ providers from Anthropic to Ollama without permission pop-ups; to get started — 50+ extension examples on GitHub.

Source 1: https://earendil.com/posts/pi-1-0/ Source 2: https://github.com/earendil-works/pi/releases

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