Earendil Ships Pi 1.0 With MCP Support Its Creator Once Dismissed

Earendil released Pi 1.0 on Oct. 1, the first stable version of its terminal coding agent, and added support for the Model Context Protocol (MCP), a standard for plugging tools into agents, which Pi's creator Mario Zechner had previously dismissed as unnecessary. The code is MIT-licensed and the repository stood at 112,000 GitHub stars when this was written.

Earendil's announcement describes Pi as a hardened, minimal, extensible agent harness, meaning the loop and tool layer around a model rather than a model itself. The Register reported the reversal on MCP on Oct. 2.

What 1.0 adds

The release ships six things, according to Earendil.

Addition	What Earendil says it does
Codemode	Sandboxed tool calls, with native MCP support
Virtual model extensions	Listed in the release; no detail given
Deferred tool loading	Tools loaded when needed, not up front
Cache warming	For Anthropic models
Mid-conversation system messages	Prompt and tool changes that see the transcript
Full-screen TUI	Now the default, with an updated theme

The announcement frames the slow pace as policy: "We wait until something has proven itself, and only then do we consider adopting it; weighing its true functionality against its inherent added complexity." By that rule MCP counts as proven. The Register said Earendil acknowledged that "things change" and pointed to improvements in both MCP and Pi's implementation of it.

Pi Durable and the Flask comparison

Earendil kept the new weight out of Pi itself. Long-running work goes into Pi Durable, a separate experimental package installed with npm install @earendil-works/pi-durable @earendil-works/pi-ai @earendil-works/chord.

The Register said Pi Durable handles conversation management and storage through SQLite and JSONL files, and that Earendil compares Pi to Flask rather than Django. Earendil's own text says Pi Durable extends Pi's principles to applications that run for a long time.

What the repository shows

The repository lists 186 open issues and requires Node.js 22.19 or newer. Pi runs interactively, from the command line for automation, over RPC, or through a TypeScript SDK, and extensions, skills, prompt templates and themes can be bundled as Pi packages and shared through npm or git. It publishes seven packages under the @earendil-works scope, including pi-ai, pi-agent-core, pi-coding-agent, pi-tui and pi-telemetry.

It also states supply-chain rules: exact version pinning for external dependencies, lockfile verification and scheduled security audits. Those are statements of practice, not an audit result.

Stars are not adoption. Pi's 112,000 sits below Ponytail, which reached 151,400 stars on a claim measured by its own author. Neither count says how many people run the tool daily.

What is unproven

Earendil's announcement gives no benchmark for codemode, no figure for how much deferred tool loading saves, and no count of Pi installs. Pi Durable is labelled experimental, so its storage format could change.

Sandboxing is the open question for an agent that gains MCP. Codemode is described as a sandbox for tool calls, but Earendil's post gives no account of what it blocks. NVIDIA's OpenShell was written up on that question separately. Earendil has announced no date for a release after 1.0.