Problem

After an admin configures a GitHub Copilot AI provider and creates a model for it, the Coder Agents page still shows "set up a provider then add a model" and the model never appears in the selector. Configuring an Anthropic provider + model works.

Root cause

The chat model catalog only surfaces providers it marks available: true. For a Copilot provider, that flag is never set:

• chatprovider.NormalizeProvider had no copilot case, so "copilot" normalized to "" and was dropped before availability was ever computed (in ResolveUserProviderKeys, ListConfiguredModels, and orderProviders via supportedProviderNames).
• Even if it were normalized, ResolveUserProviderKeys had no path to mark Copilot available. Copilot rejects API keys by design (coderd/ai_providers.go) and authenticates via request-time GitHub OAuth tokens injected by aibridge, so it can never satisfy the key-based availability check. The only keyless ("ambient credentials") path was hard-coded to Bedrock.

Net effect on the frontend: getAvailableProviders filters to provider.available === true, so countConfiguredProviderConfigs and getModelOptionsFromConfigs both drop Copilot, collapsing providerCount/modelCount to 0 and rendering the setup notice. Anthropic works only because it carries a stored API key.

Execution was never the problem: chatd already routes Copilot through the AI Gateway via the OpenAI-compatible default branch of fantasyConfigForAIBridge, with credentials delegated to aibridged.

Fix

In coderd/x/chatd/chatprovider/chatprovider.go:

• Recognize copilot as a supported provider (NormalizeProvider, supportedProviderNames, display name GitHub Copilot).
• Treat Copilot like Bedrock's ambient-credential path: ProviderAllowsAmbientCredentials returns true for Copilot, and ResolveUserProviderKeys resolves a configured Copilot provider as available without an API key. A missing GitHub link now surfaces as a runtime error instead of silently hiding the provider.

In site/src/utils/aiProviders.ts:

• Add a GitHub Copilot display label for the model selector.

Tests

• TestResolveUserProviderKeys_Copilot — a keyless Copilot provider resolves Available: true with an ambient (empty) key entry.
• TestListConfiguredModels_Copilot — a Copilot provider + model appears in the catalog and is available.

Both fail on main and pass with this change. Existing TestListChatModels and the full chatprovider package still pass.

go test ./coderd/x/chatd/chatprovider/ -count=1   # ok
go test ./coderd/ -run TestListChatModels -count=1 # ok
go build ./coderd/... ; go vet ./coderd/x/chatd/chatprovider/ ; gofmt -l (clean)

Notes / follow-ups

• Availability here means "the provider is configured and routable." It intentionally does not pre-validate that the requesting user has a linked GitHub external-auth token; that failure surfaces at request time, consistent with Bedrock's ambient-credential model. If we want a pre-flight check that the user has a usable GitHub link, that can be a follow-up.