pi-copilot-discovery

A pi extension that replaces pi's built-in github-copilot provider with one that discovers your Copilot tenant's full model catalog at runtime instead of using pi-ai's bundled static list.

Why

pi-ai ships a hand-curated models.generated.js listing the GitHub Copilot models pi knows about. That list lags real Copilot tenants in two ways:

• Preview / tenant-private models are invisible. Internal model families, early-access SKUs, and anything your enterprise has been allow-listed for never show up in /model.
• New public models need a pi-ai release. When Copilot exposes a new model id, pi can't talk to it until pi-ai cuts a release that adds it.

This extension solves both by calling Copilot's own /models endpoint on startup and registering every chat-capable model the signed-in account is entitled to. Routing to the right pi-ai streamer (anthropic-messages, openai-responses, openai-completions) is derived from each model's family.

What it does

• Replaces the built-in github-copilot provider. Same provider name, so existing credentials, sessions, and /login github-copilot workflows keep working. pi --list-models and /model simply show a larger, more accurate catalog.
• Live discovery on start, login, and command. Fetches /models once on extension load (async), once after successful /login github-copilot, and on demand via /copilot-refresh.
• Re-injects Copilot dynamic headers. pi-ai's built-in streamers add X-Initiator, Openai-Intent, and Copilot-Vision-Request only when the built-in handler is the one running; this extension installs its own streamSimple wrapper that re-adds them, preserving agent-vs-user quota accounting and vision support.
• Enables tenant policies post-login. Runs POST /models/<id>/policy {state:"enabled"} against every discovered model after /login github-copilot, so preview-tier models accept requests on first use. (pi-ai's built-in flow only enables its hardcoded list.)
• Supports GitHub Enterprise. The login flow prompts for an enterprise domain; enterpriseUrl is preserved across pi restarts via OAuthCredentials's open-ended index signature.

The personal github-copilot credentials, sessions, and behavior stay intact — this is a drop-in upgrade of the provider, not a parallel one.

Install

As a pi package (recommended once published)

pi install npm:@milespossing/pi-copilot-discovery

Or try it for one session without installing:

pi -e npm:@milespossing/pi-copilot-discovery

Directly from git

pi install git:github.com/milespossing/pi-copilot-discovery
pi -e git:github.com/milespossing/pi-copilot-discovery

From a local checkout

git clone https://github.com/milespossing/pi-copilot-discovery ~/src/pi-copilot-discovery
ln -s ~/src/pi-copilot-discovery ~/.pi/agent/extensions/copilot-discovery

Either form auto-discovers as a global pi extension. Restart pi (or run /reload) and the live model list takes effect.

After installing

• If you already have a github-copilot entry in ~/.pi/agent/auth.json, no action needed — the existing token is reused.
• Otherwise: /login github-copilot. The flow prompts for an enterprise host (leave blank for github.com).

Commands

Command	What it does
/login github-copilot	Device-code login + enable policies on all live models
/copilot-refresh	Re-fetch the /models catalog without restarting pi
/copilot-discovery-refresh	Alias of /copilot-refresh (back-compat)
/logout github-copilot	(Built-in) Clear stored credentials

How it works

pi starts
  └─ extension factory runs
       ├─ register provider override immediately (without `models`)
       │    └─ keeps pi's built-in static github-copilot catalog usable
       └─ async startup discovery
            ├─ read ~/.pi/agent/auth.json["github-copilot"]
            ├─ if credentials present: GET <proxy>/models → ProviderModelConfig[]
            └─ pi.registerProvider("github-copilot", { models, oauth, streamSimple, ... })

/login github-copilot
  └─ oauth.login mints fresh creds, enables model policies, then triggers one
     model discovery pass so /model updates immediately

/copilot-refresh
  └─ one manual re-fetch of /models

per request
  └─ pi resolves apiKey via oauth.getApiKey(creds)
       └─ pi auth-storage owns token refresh + persistence

Family → API routing

Model family pattern	pi-ai api	Reasoning
claude-* (3.5+, 4.x, 5.x)	anthropic-messages	yes
claude-2.x, claude-3 (3.0–3.4)	anthropic-messages	no
gpt-5*, o1, o3	openai-responses	yes
gpt-4*, gemini-*, grok-*, other	openai-completions	no

Heuristics live in families.ts and are intentionally conservative — when uncertain we choose an api the model is usable under even if not optimal.

Troubleshooting

Symptom	Likely cause	Fix
/model shows no Copilot entries before login	No credentials yet.	Run /login github-copilot.
/model empty after login on a fresh pi start	Startup discovery failed (network/auth/tenant outage) before the live catalog could load.	Run /copilot-refresh; if that also fails, re-run /login github-copilot.
Some model returns 403 the first time you use it	Tenant policy was "unconfigured" and post-login policy enable didn't succeed.	Run /copilot-refresh (or re-run /login github-copilot).
Editor-Version / User-Agent rejected by the work proxy	pi-ai bumped its hardcoded Copilot client strings.	Update COPILOT_HEADERS in models.ts and index.ts to the new values.
A new family is misrouted to openai-completions	Default fallback.	Open an issue with the model id and tenant capabilities.family, or send a PR refining families.ts.

Compatibility

• pi-coding-agent ≥ 0.78.0 (uses the async extension factory, per-model api override, OAuth ProviderConfig, and the streamSimple escape hatch).
• pi-ai ≥ 0.78.0 (uses loginGitHubCopilot, refreshGitHubCopilotToken, getGitHubCopilotBaseUrl, normalizeDomain, and the streamSimple* family).
• Node.js ≥ 22.19.0 (matches pi's engines requirement).

Publishing

npm version patch
git push origin main --follow-tags

Pushing a v*.*.* tag triggers the npm publish workflow, which verifies the tag matches package.json and publishes the package to npm.

Layout

.
├── package.json     pi extension manifest, no runtime npm deps
├── src/
│   ├── index.ts     async factory: registerProvider + /command
│   ├── oauth.ts     wraps pi-ai loginGitHubCopilot/refresh; enables policies
│   ├── models.ts    fetch /models, build ProviderModelConfig[]
│   ├── families.ts  pure: family/id → { api, reasoning, thinkingLevelMap, compat }
│   ├── stream.ts    streamSimple wrapper: inject headers, dispatch
│   └── headers.ts   local re-impl of pi-ai's Copilot dynamic headers
├── docs/
│   └── PLAN.md      original design / build plan
├── AGENTS.md        contributor guide for AI agents
├── README.md
└── LICENSE

License

MIT