Gemini provider

Gemini uses the Gemini CLI OAuth credentials and private quota APIs. No browser cookies.

Data sources + fallback order

1. OAuth-backed quota API (only path used in fetch())

   • Reads auth type from ~/.gemini/settings.json.
   • Supported: oauth-personal (or unknown → try OAuth creds).
   • Unsupported: api-key, vertex-ai (hard error).

2. Legacy CLI parsing (parser exists but not used in current fetch path)

   • GeminiStatusProbe.parse(text:) can parse /stats output.

OAuth credentials

• File: ~/.gemini/oauth_creds.json.
• Required fields: access_token, refresh_token (optional), id_token, expiry_date.
• If access token is expired, we refresh via Google OAuth using client ID/secret extracted from the Gemini CLI install (see below).

OAuth client ID/secret extraction

• Resolution order:
  1. GEMINI_OAUTH_CLIENT_ID + GEMINI_OAUTH_CLIENT_SECRET environment override.
  2. GEMINI_OAUTH2_JS_PATH pointing at a readable oauth2.js file.
  3. Installed Gemini CLI package (oauth2.js / bundle regex extraction).
  4. Known global Gemini CLI install paths (Homebrew npm prefix layouts, then Homebrew Cellar/opt libexec package roots when the GUI cannot resolve the gemini binary).
• We locate the installed gemini binary, then search for:
  • Homebrew nested path:
    • .../libexec/lib/node_modules/@google/gemini-cli/node_modules/@google/gemini-cli-core/dist/src/code_assist/oauth2.js
  • Homebrew Cellar/opt package root (no-binary fallback):
    • /opt/homebrew/Cellar/gemini-cli/<version>/libexec/lib/node_modules/@google/gemini-cli
    • /opt/homebrew/opt/gemini-cli/libexec/lib/node_modules/@google/gemini-cli
    • same under /usr/local
  • Bun/npm sibling path:
    • .../node_modules/@google/gemini-cli-core/dist/src/code_assist/oauth2.js
• Regex extraction:
  • OAUTH_CLIENT_ID and OAUTH_CLIENT_SECRET from oauth2.js or Homebrew bundle chunks.

API endpoints

• Quota:
  • POST https://cloudcode-pa.googleapis.com/v1internal:retrieveUserQuota
  • Body: { "project": "<projectId>" } (or {} if unknown)
  • Header: Authorization: Bearer <access_token>
• Project discovery (quota project ID):
  • Primary: cloudaicompanionProject from loadCodeAssist.
  • Fallback: GET https://cloudresourcemanager.googleapis.com/v1/projects
    • Picks gen-lang-client* or label generative-language.
• Tier detection:
  • POST https://cloudcode-pa.googleapis.com/v1internal:loadCodeAssist
  • Body: { "metadata": { "ideType": "GEMINI_CLI", "pluginType": "GEMINI" } }
• Token refresh:
  • POST https://oauth2.googleapis.com/token
  • Form body: client_id, client_secret, refresh_token, grant_type=refresh_token.

Parsing + mapping

• Quota buckets:
  • remainingFraction, resetTime, modelId.
  • For each model, lowest remainingFraction wins.
  • percentLeft = remainingFraction * 100.
• Reset:
  • resetTime parsed as ISO-8601, formatted as "Resets in Xh Ym".
• UI mapping:
  • Primary: Pro models (lowest percent left).
  • Secondary: Flash models (lowest percent left).

Plan detection

• Tier from loadCodeAssist:
  • paidTier.name → paid subscription label from Google, preferred whenever present
  • standard-tier → "Paid" (fallback when paidTier.name is absent)
  • free-tier + hd claim → "Workspace" (fallback when paidTier.name is absent)
  • free-tier → "Free"
  • legacy-tier → "Legacy"
• Email from id_token JWT claims.

Consumer-tier migration (June 2026)

• Google stopped serving Gemini CLI OAuth for individual, AI Pro, and Ultra accounts on 2026-06-18. Standard and Enterprise subscriptions remain supported; paid API-key access is outside CodexBar's OAuth-backed Gemini provider.
• When quota, loadCodeAssist, or token-refresh responses include Google's unsupported-client migration signal (UNSUPPORTED_CLIENT, IneligibleTierError, or Antigravity migration copy), CodexBar surfaces consumerTierDeprecated with guidance to use the Antigravity provider.
• Google's live shape is an HTTP 200 loadCodeAssist body with no currentTier and the consumer tier listed under ineligibleTiers[].reasonCode == "UNSUPPORTED_CLIENT"; the follow-up retrieveUserQuota call then fails with HTTP 403 SUBSCRIPTION_REQUIRED and no migration wording. CodexBar reads the 200 body's ineligibleTiers directly, and maps that 403 to consumerTierDeprecated only when the same fetch saw the unsupported-client flag and the account is not on standard-tier — a licensed account's 403 stays HTTP 403.
• The unsupported-client flag itself is suppressed for accounts the shutdown does not cover: a named paidTier.name (authoritative even without currentTier) and an hd claim (Workspace/education, which resolveAccountPlan reads as Workspace when paired with free-tier). Both would otherwise be pre-empted by the earlier loadCodeAssist branch, which runs before the plan resolver.
• UsageStore.geminiMigrationObservation records which sentinel the last refresh produced (none / localAntigravityHandoff / googleConsumerTierShutdown); a later local-tooling failure never downgrades a shutdown already seen. geminiObservedConsumerTierDeprecation (either sentinel) drives the settings action; the narrower geminiObservedGoogleConsumerTierShutdown drives the login guard. While the narrow one is set for this session, the Gemini login action stops clearing ~/.gemini/oauth_creds.json and launching Gemini CLI — whose OAuth step fails with the same message — and shows the Antigravity guidance instead. The local oauthCredentialsUnavailableWithAntigravity handoff deliberately does not guard login: there, reinstalling or relaunching Gemini CLI is the fix, and Workspace accounts must keep that path.
• The guard warns rather than blocks: its alert offers Switch Account… next to Cancel (Cancel is the default, since confirming clears credentials). Confirming re-runs the ordinary login without the guard, which is how a user moves from a shut-down consumer account to a Workspace, education, or Code Assist Standard/Enterprise one. The observation is not cleared by confirming, so the settings action stays put and the next attempt warns again.
• Settings shows an Enable Antigravity provider action only after CodexBar observes consumerTierDeprecated during a Gemini refresh (typed sentinel state, not user-facing text matching).
• The action is explicit: CodexBar never automatically enables Antigravity or falls back to it.
• Ordinary Gemini login, notLoggedIn, and Antigravity setup errors remain unchanged. CodexBar does not capture Terminal gemini OAuth output, so Terminal-only failures cannot activate the migration action.
• Workspace and education Google accounts are outside the June 2026 consumer shutdown; keep using the Gemini provider. Antigravity remains the consumer replacement path for individual, AI Pro, and Ultra.

Key files

• Sources/CodexBarCore/Providers/Gemini/GeminiStatusProbe.swift