Earendil ships Pi 1.0 agent harness plus Pi Durable
Original: Pi 1.0
Why This Matters
A stable, MIT-licensed agent harness with a large active user base sets a baseline for open agentic tooling.
Earendil released Pi 1.0 on October 1, 2026 — a minimal, extensible agent harness used by hundreds of thousands of people weekly. The release adds Codemode with native MCP support, extension and virtual model support, and a new TUI theme. A companion experimental package, Pi Durable, targets long-running agentic applications. Both are MIT licensed.
Earendil shipped Pi 1.0, the stable release of its terminal-based AI agent harness that the company says hundreds of thousands of users run each week. The team spent months hardening the codebase based on community issues and pull requests before declaring 1.0 readiness.
Key additions in Pi 1.0: Codemode with native MCP support and non-LLM model integration (including image models and the company's own Jev model), extension support for virtual models, deferred tool loading, cache warming for Anthropic models, mid-conversation system messages, and a new full-screen TUI theme. Earendil frames its feature philosophy as deliberate — waiting for capabilities to prove out before adopting them, explicitly trading off new tooling churn against added complexity.
Alongside Pi 1.0, Earendil introduced Pi Durable as a separate experimental npm package. It targets longer-running, multi-surface agentic applications — use cases the company says don't fit Pi's terminal-native design. Pi Durable shares Pi's minimalism principles but extends them for durable, steerable workflows. Installation is via a one-line shell script or PowerShell command; Pi Durable is available via npm. All code is MIT licensed and hosted at github.com/earendil-works/pi.