Align GitHub Copilot quota usage with AI credits

packages/web/server/lib/quota/DOCUMENTATION.md

@@ -82,6 +82,15 @@ In 2025/2026 MiniMax rebranded "Coding Plan" to "Token Plan" alongside the M3 mo
 
 The provider computes `usedPercent` from whichever of `used`/`remaining` is present (`used` takes precedence when both exist) rather than assuming one field name. Both `packages/web/server/lib/quota/providers/kimi.js` and `packages/vscode/src/quotaProviders.ts` (`fetchKimiQuota`) must stay in sync — the VS Code extension duplicates this parsing logic rather than importing it.
 
+## GitHub Copilot quota semantics
+
+GitHub Copilot usage exposes only the `premium_interactions` snapshot as the
+`premium_interactions` window. Shared UI labels that window **AI Credits** and treats it as
+the provider's primary usage marker. Legacy chat-request quota and unlimited
+completion quota are intentionally omitted. Keep
+`packages/web/server/lib/quota/providers/copilot.js` and
+`packages/vscode/src/quotaProviders.ts` in sync.
+
 ## Notes for contributors
 - Keep provider IDs stable; clients use them directly.
 - Avoid adding alias-based dispatch in `fetchQuotaForProvider`; dispatch currently expects exact provider IDs.

packages/web/server/lib/quota/providers/copilot.js

@@ -31,9 +31,7 @@ const buildCopilotWindows = (payload) => {
     });
   };
 
-  addWindow('chat', quota.chat);
-  addWindow('completions', quota.completions);
-  addWindow('premium', quota.premium_interactions);
+  addWindow('premium_interactions', quota.premium_interactions);
 
   return windows;
 };
@@ -144,7 +142,9 @@ export const fetchQuotaAddon = async () => {
 
     const payload = await response.json();
     const windows = buildCopilotWindows(payload);
-    const premium = windows.premium ? { premium: windows.premium } : windows;
+    const premium = windows.premium_interactions
+      ? { premium_interactions: windows.premium_interactions }
+      : windows;
 
     return buildResult({
       providerId: providerIdAddon,

packages/web/server/lib/quota/providers/copilot.test.js

@@ -0,0 +1,42 @@
+import { afterEach, describe, expect, it, vi } from 'vitest';
+
+vi.mock('../../opencode/auth.js', () => ({
+  readAuthFile: () => ({ 'github-copilot': { access: 'test-token' } }),
+}));
+
+import { fetchQuota, fetchQuotaAddon } from './copilot.js';
+
+afterEach(() => {
+  vi.unstubAllGlobals();
+});
+
+const payload = {
+  quota_reset_date: '2026-09-01T00:00:00Z',
+  quota_snapshots: {
+    chat: { entitlement: 100, remaining: 80 },
+    completions: { entitlement: 1000, remaining: 900 },
+    premium_interactions: { entitlement: 300, remaining: 225 },
+  },
+};
+
+const mockResponse = () => ({
+  ok: true,
+  status: 200,
+  json: async () => payload,
+});
+
+describe('GitHub Copilot quota provider', () => {
+  it.each([
+    ['primary provider', fetchQuota],
+    ['add-on provider', fetchQuotaAddon],
+  ])('exposes only premium interactions for the %s', async (_name, fetchProviderQuota) => {
+    vi.stubGlobal('fetch', vi.fn().mockResolvedValue(mockResponse()));
+
+    const result = await fetchProviderQuota();
+
+    expect(result.ok).toBe(true);
+    expect(Object.keys(result.usage.windows)).toEqual(['premium_interactions']);
+    expect(result.usage.windows.premium_interactions.usedPercent).toBe(25);
+    expect(result.usage.windows.premium_interactions.valueLabel).toBe('225 / 300 left');
+  });
+});