feat: make gh copilot use msgs api when available (#22106)

packages/opencode/test/plugin/github-copilot-models.test.ts

@@ -1,5 +1,6 @@
 import { afterEach, expect, mock, test } from "bun:test"
 import { CopilotModels } from "@/plugin/github-copilot/models"
+import { CopilotAuthPlugin } from "@/plugin/github-copilot/copilot"
 
 const originalFetch = globalThis.fetch
 
@@ -115,3 +116,45 @@ test("preserves temperature support from existing provider models", async () =>
   expect(models["gpt-4o"].capabilities.temperature).toBe(true)
   expect(models["brand-new"].capabilities.temperature).toBe(true)
 })
+
+test("remaps fallback oauth model urls to the enterprise host", async () => {
+  globalThis.fetch = mock(() => Promise.reject(new Error("timeout"))) as unknown as typeof fetch
+
+  const hooks = await CopilotAuthPlugin({
+    client: {} as never,
+    project: {} as never,
+    directory: "",
+    worktree: "",
+    serverUrl: new URL("https://example.com"),
+    $: {} as never,
+  })
+
+  const models = await hooks.provider!.models!(
+    {
+      id: "github-copilot",
+      models: {
+        claude: {
+          id: "claude",
+          providerID: "github-copilot",
+          api: {
+            id: "claude-sonnet-4.5",
+            url: "https://api.githubcopilot.com/v1",
+            npm: "@ai-sdk/anthropic",
+          },
+        },
+      },
+    } as never,
+    {
+      auth: {
+        type: "oauth",
+        refresh: "token",
+        access: "token",
+        expires: Date.now() + 60_000,
+        enterpriseUrl: "ghe.example.com",
+      } as never,
+    },
+  )
+
+  expect(models.claude.api.url).toBe("https://copilot-api.ghe.example.com")
+  expect(models.claude.api.npm).toBe("@ai-sdk/github-copilot")
+})