TL;DR
Get tech for your team delivered free — and shop member deals
- Fast, free delivery on millions of items
- Access to Prime Big Deal Days deals on October 6–7
- Prime Video, Amazon Music and more included
Earendil has released Pi 1.0, a hardened and extensible agent harness, with features including Codemode, extension support for virtual models, and deferred tool loading. The company also launched Pi Durable, an experimental package for building longer-running agent applications. Both are available now under the MIT license.
Software company Earendil has released Pi 1.0, a stable, minimal and extensible agent harness, adding features for tool use, model routing and customization. Alongside it, the company introduced Pi Durable, an experimental package intended to help developers build longer-running agent applications beyond a coding agent in a terminal.
Pi 1.0 adds Codemode, described by Earendil as bringing native support for MCP and non-LLM models, including Jev and image models. Other additions include extensions for virtual models, deferred tool loading, cache warming for Anthropic models, and mid-conversation system messages that account for transcript and tool changes. The release also changes the terminal interface, introducing a new theme and making full-screen mode the default.
Earendil says the release follows months of development informed by user feedback, issues and pull requests. The company describes Pi as a tool used by hundreds of thousands of people each week, but does not provide a measurement method or timeframe for that figure. Pi 1.0 is available through installation instructions on Pi’s website, and its code is hosted on GitHub. Pi and Pi Durable are MIT licensed.
Pi Durable is a separate experimental package, not a replacement for Pi 1.0. Earendil describes it as a substrate for building long-running agentic applications that can be accessed through different interfaces and support sustained conversations and tasks. The company lists the package as available through npm; its experimental status means its design and use may continue to change.
From Terminal Agent to Longer Tasks
Pi 1.0 gives developers a more established release point for building with the agent harness while retaining its deliberately minimal approach. Features such as virtual-model extensions and deferred tool loading give builders additional ways to configure models and tools without requiring every capability to be loaded at once. Codemode also broadens the kinds of models and tools Pi says it can work with.
The separate Pi Durable release addresses a different need: applications that persist beyond a single terminal session. If it develops as Earendil intends, it could let developers put Pi-based intelligence behind other interfaces and use it for longer-running tasks. For now, that is the company’s stated direction, not evidence of adoption or performance in production. Pi Durable remains experimental, and the announcement provides no independent evaluation or adoption figures for it.
As an affiliate, we earn on qualifying purchases.
Why Earendil Kept Pi Minimal
Earendil says Pi was already used as a coding agent and as a base for building agentic applications before the 1.0 release. The company presents the new version as the result of selectively adding capabilities rather than adopting every new tool or pattern in the fast-changing agent software field. Its stated approach is to wait until a feature has proved useful and weigh that usefulness against added complexity.
The announcement distinguishes that ongoing refinement from the work behind Pi Durable. Earendil says some users want to use Pi outside the coding-agent and terminal setting, and that longer-running tasks call for a more durable foundation. Rather than expand Pi beyond its intended shape, the company put that effort into a separate experimental package. The release note refers readers to additional writing about Pi Durable and Earendil’s approach to Codemode and MCP.
“Pi does not work that way. We wait until something has proven itself, and only then do we consider adopting it; weighing its true functionality against its inherent added complexity.”
— Earendil, in its Pi 1.0 announcement
long-running AI application hosting
As an affiliate, we earn on qualifying purchases.
As an affiliate, we earn on qualifying purchases.
What Pi Durable Still Needs to Prove
Earendil has not specified how Pi Durable’s experimental status will affect its roadmap, when it might reach a stable release, or what support and compatibility guarantees users can expect. The announcement also does not provide benchmarks, independent assessments, or details about how the package handles persistence, reliability and oversight across long-running tasks.
The company’s claim that hundreds of thousands of people use Pi weekly is not accompanied by a source, measurement method or defined reporting period. It is also not clear how many of those users have adopted the new 1.0 release, or how widely the added features will be used. Those questions will require further information from Earendil or evidence from use of the software.
As an affiliate, we earn on qualifying purchases.
Feedback and Experimental Development
Pi 1.0 and Pi Durable are available now, and Earendil is asking users to provide feedback. The company points developers to Pi’s documentation and GitHub repository for information and code. It has not announced a date for a Pi Durable update or a stable release, so its future milestones remain open.
The next useful signals will be how developers use the new Pi 1.0 features, whether Earendil responds with revisions, and how the experimental Pi Durable package develops. Until further release plans or technical details are published, users considering Pi Durable should treat its current availability as an invitation to experiment, not a promise of production-ready support.
As an affiliate, we earn on qualifying purchases.
Key Questions
What is Pi 1.0?
Pi 1.0 is a minimal, extensible agent harness released by Earendil. The company says it is intended for use as a coding agent and as a base for agentic applications.
What features are new in Pi 1.0?
The release adds Codemode, virtual-model extensions, deferred tool loading, Anthropic cache warming and mid-conversation system messages. It also introduces a new terminal theme and makes full-screen mode the default.
What is Pi Durable?
Pi Durable is a separate experimental package Earendil says is designed as a foundation for longer-running agent applications and tasks beyond a terminal coding session.
Are Pi 1.0 and Pi Durable available?
Yes. Earendil says both are available now and MIT licensed. Pi Durable is marked experimental, and the company has not announced when or whether it will reach a stable release.
Source: hn
Halloween Picks
halloween
As an affiliate, we earn on qualifying purchases.
