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

• 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
  • 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.

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:
  • standard-tier → "Paid"
  • free-tier + hd claim → "Workspace"
  • free-tier → "Free"
  • legacy-tier → "Legacy"
• Email from id_token JWT claims.

Key files

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