feat(core): port GitHub Copilot OAuth (#36336)

Co-authored-by: Dax Raad <d@ironbay.co>

packages/core/test/github-copilot/models.test.ts

@@ -0,0 +1,76 @@
+import { expect, test } from "bun:test"
+import { CopilotModels } from "@opencode-ai/core/github-copilot/models"
+import { ModelV2 } from "@opencode-ai/core/model"
+import { ProviderV2 } from "@opencode-ai/core/provider"
+
+test("defensively syncs advertised Copilot models", async () => {
+  const server = Bun.serve({
+    port: 0,
+    fetch: () =>
+      Response.json({
+        data: [
+          {
+            model_picker_enabled: true,
+            id: "gpt-5",
+            name: "GPT-5 remote",
+            version: "gpt-5-2026-06-01",
+            supported_endpoints: ["/responses"],
+            billing: {
+              token_prices: {
+                batch_size: 0,
+                default: { input_price: 10, output_price: 20, cache_price: 5 },
+              },
+            },
+            capabilities: {
+              family: "gpt",
+              limits: {
+                max_context_window_tokens: 200000,
+                max_output_tokens: 16384,
+                max_prompt_tokens: 180000,
+              },
+              supports: { tool_calls: true, reasoning_effort: ["low", "high"] },
+            },
+          },
+          {
+            model_picker_enabled: false,
+            id: "utility",
+            name: "Utility",
+            version: "utility-2026-06-01",
+            capabilities: {
+              family: "utility",
+              limits: { max_output_tokens: 1000, max_prompt_tokens: 8000 },
+              supports: { tool_calls: false },
+            },
+          },
+          { model_picker_enabled: true, id: "incomplete" },
+        ],
+      }),
+  })
+
+  try {
+    const existing = ModelV2.Info.make({
+      ...ModelV2.Info.empty(ProviderV2.ID.githubCopilot, ModelV2.ID.make("gpt-5")),
+      modelID: ModelV2.ID.make("gpt-5"),
+      name: "GPT-5 local",
+    })
+    const stale = ModelV2.Info.make({
+      ...ModelV2.Info.empty(ProviderV2.ID.githubCopilot, ModelV2.ID.make("stale")),
+      modelID: ModelV2.ID.make("stale"),
+    })
+    const models = await CopilotModels.get(server.url.origin, {}, [existing, stale])
+    const model = models.get(ModelV2.ID.make("gpt-5"))
+
+    expect(model?.name).toBe("GPT-5 local")
+    expect(model?.settings).toMatchObject({ baseURL: server.url.origin, endpoint: "responses" })
+    expect(model?.cost[0]).toMatchObject({ input: 0, output: 0, cache: { read: 0, write: 0 } })
+    expect(model?.variants.map((variant) => variant.id)).toEqual([
+      ModelV2.VariantID.make("low"),
+      ModelV2.VariantID.make("high"),
+    ])
+    expect(models.get(ModelV2.ID.make("utility"))?.enabled).toBe(false)
+    expect(models.has(ModelV2.ID.make("stale"))).toBe(false)
+    expect(models.has(ModelV2.ID.make("incomplete"))).toBe(false)
+  } finally {
+    await server.stop(true)
+  }
+})

packages/core/test/plugin/provider-github-copilot.test.ts

@@ -5,8 +5,9 @@ import { Catalog } from "@opencode-ai/core/catalog"
 import { ModelV2 } from "@opencode-ai/core/model"
 import { PluginV2 } from "@opencode-ai/core/plugin"
 import { PluginHost } from "@opencode-ai/core/plugin/host"
-import { GithubCopilotPlugin } from "@opencode-ai/core/plugin/provider/github-copilot"
+import { copilotFetch, GithubCopilotPlugin } from "@opencode-ai/core/plugin/provider/github-copilot"
 import { ProviderV2 } from "@opencode-ai/core/provider"
+import { Integration } from "@opencode-ai/core/integration"
 import type { LanguageModelV3 } from "@ai-sdk/provider"
 import { testEffect } from "../lib/effect"
 import { PluginTestLayer } from "./fixture"
@@ -39,6 +40,46 @@ function fakeSelectorSdk(calls: string[]) {
 }
 
 describe("GithubCopilotPlugin", () => {
+  it.effect("registers GitHub Copilot device OAuth", () =>
+    Effect.gen(function* () {
+      yield* addPlugin()
+      expect((yield* (yield* Integration.Service).get(Integration.ID.make("github-copilot")))?.methods).toContainEqual({
+        id: Integration.MethodID.make("device"),
+        type: "oauth",
+        label: "Login with GitHub Copilot",
+        prompts: expect.any(Array),
+      })
+    }),
+  )
+
+  it.live("adds Copilot authentication and request metadata headers", () =>
+    Effect.gen(function* () {
+      const requests: Headers[] = []
+      const send = copilotFetch(
+        "token",
+        async (_input: Parameters<typeof fetch>[0], init?: RequestInit) => {
+          requests.push(new Headers(init?.headers))
+          return Response.json({ ok: true })
+        },
+        false,
+      )
+      yield* Effect.promise(() =>
+        send("https://api.githubcopilot.com/chat/completions", {
+          method: "POST",
+          headers: { "x-api-key": "old" },
+          body: JSON.stringify({
+            messages: [{ role: "user", content: [{ type: "image_url", image_url: { url: "data:image/png" } }] }],
+          }),
+        }),
+      )
+      expect(requests[0]?.get("authorization")).toBe("Bearer token")
+      expect(requests[0]?.has("x-api-key")).toBe(false)
+      expect(requests[0]?.get("x-initiator")).toBe("user")
+      expect(requests[0]?.get("copilot-vision-request")).toBe("true")
+      expect(requests[0]?.get("x-github-api-version")).toBe("2026-06-01")
+    }),
+  )
+
   it.effect("creates the bundled Copilot SDK for the GitHub Copilot package", () =>
     Effect.gen(function* () {
       const plugin = yield* PluginV2.Service