Pi can now directly use Claude Pro/Max subscriptions. pi-anthropic-auth specifically addresses Pi’s compatibility gap with Anthropic OAuth. It doesn’t rewrite the provider but adds a thin wrapper layer on Pi’s native Anthropic transport: • Preserves the native /login anthropic command • Retains the complete model list • API Key requests and other providers remain completely unaffected • Activates only when an sk-ant-oat OAuth token is detected • Covers both interactive turns and compaction

Install with one line:

pi install npm:@gotgenes/pi-anthropic-auth

Then proceed as usual with /login anthropic. The project currently has 181 stars, with the latest release at v2.0.6.

Note: Background agents that run their own agent loop in Pi 0.80.8 and later are a known exception, requiring workarounds as documented in the project’s documentation.

If you want to reuse your existing Claude Pro/Max subscription in Pi, this extension is worth bookmarking.

gotgenes/pi-anthropic-auth

Source: https://github.com/gotgenes/pi-anthropic-auth

pi-anthropic-auth

A Pi extension that improves compatibility with Anthropic Claude Pro/Max OAuth (i.e., your Claude subscription) while preserving Pi’s normal Anthropic behavior.

What It Does

Pi works great with Anthropic API keys out of the box. This extension fills in the gaps for users who want to use their Claude Pro or Max subscription via OAuth instead. It keeps everything you’d expect — the built-in anthropic provider, the full model list, API-key behavior, and the native /login anthropic flow — and layers on the compatibility fixes needed to make OAuth subscriptions work reliably.

Requests to non-Anthropic providers and plain API-key Anthropic requests pass through completely untouched — the extension only activates when it detects an Anthropic OAuth access token (sk-ant-oat). Shaping runs in a thin transport wrapper around Pi’s own Anthropic transport, so it applies to interactive turns and to compaction — not just the main turn.

Background agents that run their own agent loop are a known exception on Pi 0.80.8 and later. See docs/architecture.md for how this works, and for the workaround if you write such an extension.

Install

pi install npm:@gotgenes/pi-anthropic-auth

To try it without permanently installing:

pi -e npm:@gotgenes/pi-anthropic-auth

Usage

1. Run /login anthropic as usual — Pi’s native Anthropic login flow is preserved.
2. Select a Claude Pro/Max model and start chatting. The extension handles compatibility transparently.
3. API-key behavior is unaffected; the extension’s changes apply only to OAuth sessions.

Troubleshooting

Verify the extension is loaded

Run /anthropic-auth:status in Pi to print a diagnostics report:

pi-anthropic-auth diagnostics
version: 0.6.5
module: /root/.pi/agent/.../src/index.ts
built-in Anthropic transport: resolved

The module line shows which copy of the extension loaded. If the command is not found, the extension is not loaded at all.

ANTHROPIC_API_KEY is ignored when OAuth credentials exist

Pi’s auth resolver gives stored credentials priority over environment variables. If you have previously run /login anthropic and credentials are stored in ~/.pi/agent/auth.json, Pi uses the stored OAuth token on every request — even when ANTHROPIC_API_KEY is also set.

To use the API key instead, run /logout anthropic inside Pi to remove the stored credentials, or delete auth.json before starting the session.

Docker: extension missing after volume mount

If you install the extension at image build time with RUN pi install npm:@gotgenes/pi-anthropic-auth and then mount a persistent volume over ~/.pi/agent at runtime, Docker may mask the build-time install. Docker seeds a named volume with the image directory only on its first creation. If the volume already exists from a previous image, the extension directory inside it may be empty or out of date.

To fix this, either:

• Remove the volume and let Docker re-seed it: docker volume rm <volume_name>.
• Or install the extension at container startup rather than at image build time, after the volume is mounted.

Development

Requirements

• pnpm
• a local pi installation
• Anthropic OAuth credentials configured through Pi

Commands

pnpm install # install dependencies
pnpm run check # typecheck
pnpm test # run tests
pnpm run build # compile

Load a Local Build

pi -e /absolute/path/to/pi-anthropic-auth/dist/index.js

Debug Logging

Set PI_ANTHROPIC_AUTH_DEBUG to enable structured debug logs from the OAuth shaping layer.

Modes:

• PI_ANTHROPIC_AUTH_DEBUG=all — log all Anthropic OAuth shaping events
• PI_ANTHROPIC_AUTH_DEBUG=tool-use — log only requests that include tool_use

Example:

PI_ANTHROPIC_AUTH_DEBUG=tool-use \
pi \
--model anthropic/claude-haiku-4-5 \
--no-session \
--tools read,grep,find,ls \
-e /absolute/path/to/pi-anthropic-auth/src/index.ts \
-p "How many lines are in @AGENTS.md ?"

Similar Projects

• opencode-anthropic-auth — Anthropic OAuth compatibility work for OpenCode.
• pi-anthropic-oauth — a Pi extension that takes a fuller provider-override approach.

For notes on how this project compares to similar work, see docs/comparison-to-similar-projects.md.

Acknowledgments

This project was inspired by opencode-anthropic-auth, which solved the same Anthropic OAuth compatibility problem for OpenCode.

License

MIT