AIToday
GIGAZINE AIPublished: Oct 2, 2026, 19:00 JST

Pi 1.0: Earendil ships MCP and virtual models

Pi 1.0: Earendil ships MCP and virtual models

3 Key Points

  1. What happened

    Earendil released Pi 1.0 on October 1, 2026, with standard MCP support, Codemode, Deferred tool loading, virtual models, and a new Pi Durable package for long-running agents.

  2. Why it matters

    Pi 1.0 aims to keep the 'small harness' feel while adding features, so existing users get more capability without losing the simple design, and businesses get a stable version they can adopt with confidence.

  3. What to watch

    The test is whether Pi 1.0's added complexity — Codemode, Deferred tool loading, virtual models — stays balanced enough for users, and whether Pi Durable gathers enough feedback before any eventual mainline merge.

WHO IT HITSThis lands on developers and teams already using or evaluating open-source AI coding tools, who now get a stable Pi 1.0 with MCP support and multi-model flexibility, and on businesses that need a dependable, extensible coding assistant.

Not sure about something? Ask the AI

Questions and answers are published on this page.

Summaries like this, in your inbox every morning.

Context & Analysis

Earendil's release of Pi 1.0 marks a maturation point for the open-source AI coding tool, which the company says is used by hundreds of thousands of people weekly. Over several months, Earendil incorporated user bug reports and code fixes to produce a stable version suitable for individuals and businesses. The update keeps Pi's long-standing 'small harness' philosophy while adding capabilities that were previously either absent or left to extensions.

The addition of standard MCP support lets AI interact with external tools like search and databases, but more tools mean more tool descriptions passed to the AI. Codemode addresses this by letting multiple tool calls run as JavaScript code, filtering results before they reach the model. Deferred tool loading further reduces the information passed by loading only needed tools on demand. Virtual models let users combine multiple AI models into one, as shown in an Earendil demo where Claude Opus planned, Jev classified, and GPT executed.

Alongside Pi 1.0, Earendil introduced Pi Durable, an experimental package for long-running agents that saves state so work can resume after a process ends. Earendil says it waits to adopt new features until they prove useful and keeps complexity in check. The outcome hinges on whether users find the new features genuinely helpful and whether Pi Durable's feedback loop leads to further integration.

FAQ
What is new in Pi 1.0?
Pi 1.0 adds standard MCP support, Codemode, Deferred tool loading, virtual models, cache pre-warming for Anthropic models, mid-conversation changes to system messages and tools, and new terminal themes. Fullscreen terminal mode is now standard.
What is Pi Durable?
Pi Durable is an experimental package for building long-running AI agents. It saves work state so conversations and tasks can resume after a process ends.
Which AI providers does Pi 1.0 support?
Pi 1.0 supports over 15 providers, including Anthropic, OpenAI, Google, Amazon Bedrock, Mistral, xAI, Hugging Face, OpenRouter, and Ollama. You can switch models mid-conversation.

AI news that matters for your work, delivered every morning.

Pick your industry and the AI tools you use, and get news related to your work every day.

Free · 30 seconds with Google · unsubscribe anytimeWhat is AIToday? →

Ask AI

Ask AI anything about this article. The AI reads this article, earlier AIToday articles, and Wikipedia, and cites its sources. Q&As are published on this page for other readers too.

Questions and answers are published on this page.

Next articleObjective-See Found Flaw Let Attackers Take Over ChatGPT Mac App