fix(core): reject GitHub Copilot login without chat entitlement

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

@@ -30,6 +30,8 @@ const Token = Schema.Struct({
   interval: Schema.optional(Schema.Number),
 })
 const User = Schema.Struct({
+  chat_enabled: Schema.optional(Schema.Boolean),
+  can_signup_for_limited: Schema.optional(Schema.Boolean),
   endpoints: Schema.optional(
     Schema.Struct({
       api: Schema.optional(Schema.String),
@@ -107,23 +109,30 @@ const oauth = (app: App.Info) =>
                     },
                   },
                 ).pipe(
-                  Effect.map((user) => Option.getOrUndefined(decodeUser(user))?.endpoints?.api?.replace(/\/+$/, "")),
+                  Effect.map((user) => Option.getOrUndefined(decodeUser(user))),
+                  // Only an explicit entitlement answer blocks login; a failed
+                  // or malformed lookup must not turn a GitHub hiccup into a denial.
                   Effect.orElseSucceed(() => undefined),
-                  Effect.map((apiEndpoint) =>
-                    Credential.OAuth.make({
-                      type: "oauth",
-                      methodID,
-                      refresh: access,
-                      access,
-                      expires: 0,
-                      ...((enterprise || apiEndpoint) && {
-                        metadata: {
-                          ...(enterprise ? { enterpriseUrl: domain } : {}),
-                          ...(apiEndpoint ? { apiEndpoint } : {}),
-                        },
+                  Effect.flatMap((user) => {
+                    const denied = user && copilotEntitlementError(user)
+                    if (denied) return Effect.fail(new Error(denied))
+                    const apiEndpoint = user?.endpoints?.api?.replace(/\/+$/, "")
+                    return Effect.succeed(
+                      Credential.OAuth.make({
+                        type: "oauth",
+                        methodID,
+                        refresh: access,
+                        access,
+                        expires: 0,
+                        ...((enterprise || apiEndpoint) && {
+                          metadata: {
+                            ...(enterprise ? { enterpriseUrl: domain } : {}),
+                            ...(apiEndpoint ? { apiEndpoint } : {}),
+                          },
+                        }),
                       }),
-                    }),
-                  ),
+                    )
+                  }),
                 )
               }
               if (token.error === "authorization_pending")
@@ -298,6 +307,15 @@ function baseURL(enterprise?: string) {
   return enterprise ? `https://copilot-api.${normalizeDomain(enterprise)}` : "https://api.githubcopilot.com"
 }
 
+// GitHub reports Copilot access on /copilot_internal/user; OAuth itself succeeds
+// for any GitHub account, so this is the only signal that the account can chat.
+export function copilotEntitlementError(user: { chat_enabled?: boolean; can_signup_for_limited?: boolean }) {
+  if (user.chat_enabled !== false) return
+  if (user.can_signup_for_limited)
+    return "This GitHub account is not signed up for GitHub Copilot. Sign up for Copilot Free at https://github.com/features/copilot/plans and connect again."
+  return "This GitHub account does not have GitHub Copilot access. It needs an active Copilot subscription or a seat assigned by an organization."
+}
+
 export function copilotBaseURL(metadata?: Readonly<Record<string, unknown>>) {
   const endpoint = metadata?.apiEndpoint
   if (typeof endpoint === "string" && endpoint) return endpoint

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

@@ -10,7 +10,12 @@ import { ModelResolver } from "@opencode-ai/core/model-resolver"
 import { Plugin } from "@opencode-ai/core/plugin"
 import { PluginHost } from "@opencode-ai/core/plugin/host"
 import { PluginHooks } from "@opencode-ai/core/plugin/hooks"
-import { copilotBaseURL, copilotFetch, GithubCopilotPlugin } from "@opencode-ai/core/plugin/provider/github-copilot"
+import {
+  copilotBaseURL,
+  copilotEntitlementError,
+  copilotFetch,
+  GithubCopilotPlugin,
+} from "@opencode-ai/core/plugin/provider/github-copilot"
 import { Provider } from "@opencode-ai/core/provider"
 import { Integration } from "@opencode-ai/core/integration"
 import { fakeSelectorSdk } from "../fixture/selector"
@@ -40,6 +45,20 @@ describe("GithubCopilotPlugin", () => {
     ).toBe("https://api.business.githubcopilot.com")
   })
 
+  test("rejects accounts without Copilot chat access", () => {
+    expect(copilotEntitlementError({ chat_enabled: false, can_signup_for_limited: true })).toContain("Copilot Free")
+    expect(copilotEntitlementError({ chat_enabled: false, can_signup_for_limited: false })).toContain(
+      "subscription or a seat",
+    )
+    expect(copilotEntitlementError({ chat_enabled: false })).toContain("subscription or a seat")
+  })
+
+  test("only blocks on an explicit entitlement denial", () => {
+    expect(copilotEntitlementError({ chat_enabled: true })).toBeUndefined()
+    expect(copilotEntitlementError({ chat_enabled: true, can_signup_for_limited: true })).toBeUndefined()
+    expect(copilotEntitlementError({})).toBeUndefined()
+  })
+
   it.effect("registers GitHub Copilot device OAuth", () =>
     Effect.gen(function* () {
       yield* addPlugin()