Earendil has released Pi 1.0, a hardened and stable version of its minimal agent harness that the company says hundreds of thousands of people use weekly. According to the announcement, Pi 1.0 represents months of refinement based on community feedback, issues, and pull requests.
The new version introduces several features designed to enhance functionality while preserving Pi’s minimal approach. These additions include native support for Codemode and MCP (Model Context Protocol), alongside support for non-LLM models like Jev and image models. Other features include extension support for virtual models, deferred tool loading, cache warming for Anthropic models, mid-conversation system messages for transcript-aware prompt and tool changes, a new TUI theme, and full-screen mode by default.
Earendil emphasizes that its development philosophy involves waiting for features to prove themselves before adoption, carefully weighing functionality against added complexity. According to the company, many proposed features were rejected during this evaluation process.
Beyond Pi 1.0, Earendil is also releasing Pi Durable, an experimental package designed to address use cases beyond the terminal and coding agent context. According to the announcement, Pi Durable extends Pi’s core principles of minimalism and “supermalleability” into new dimensions, supporting longer-running conversations and agentic applications while allowing users to “wield and steer the underlying intelligence with tremendous dexterity.”
Pi Durable ships as part of a new experimental package that includes related components. Both Pi 1.0 and Pi Durable are released under the MIT license. Installation instructions for Pi 1.0 are provided for both Unix-like systems and Windows, with documentation available at pi.dev and code at github.com/earendil-works/pi. Pi Durable can be installed via npm.
Earendil states that the company was formed to create software and open protocols that strengthen human agency, framing these releases as tools toward that goal.
Key facts
- Pi 1.0 adds native Codemode support, extension capabilities, and cache warming for Anthropic models
- The release includes mid-conversation system messages, a new TUI theme, and full-screen mode by default
- Pi Durable is an experimental package extending Pi’s principles to support longer-running agentic applications
- Both tools are released under the MIT license
- Hundreds of thousands of people reportedly use Pi weekly