opencode-codex-auth

Local OpenCode plugin that rotates between multiple Codex OAuth accounts for Codex-capable models.

What it does

• Routes OpenCode openai/* requests through a local account registry.
• Supports ChatGPT/Codex OAuth logins only. No API-key mode.
• Supports easy login, remove, enable, disable, default, and strategy account management.
• Injects common Codex and GPT-5 coding model entries into the OpenCode openai provider config.
• Adds a fast model variant that maps to serviceTier: "priority" / *-fast model IDs.
• Defaults OpenCode requests to reasoningEffort: "low" when no provider default is already set.

The plugin refreshes ChatGPT/Codex OAuth tokens and forwards OpenCode's Responses API traffic to the ChatGPT Codex backend.

Files

• index.js
• lib/accounts.js
• lib/openai-fetch.js
• lib/oauth.js
• scripts/accounts.mjs
• opencode.example.jsonc

Setup

1. Add the plugin to your OpenCode config:

{
  "$schema": "https://opencode.ai/config.json",
  "plugin": [
    [
      "file:///absolute/path/to/opencode-codex",
      {
        "accountsPath": "~/.config/opencode/codex-accounts.json",
        "fastVariantName": "fast",
        "reasoningEffort": "low"
      }
    ]
  ]
}

2. Create or import the account registry:

node ./scripts/accounts.mjs init
node ./scripts/accounts.mjs import-legacy

3. Add accounts:

node ./scripts/accounts.mjs login personal
node ./scripts/accounts.mjs login work

4. Choose how selection works:

node ./scripts/accounts.mjs strategy round-robin
node ./scripts/accounts.mjs default personal

5. Start OpenCode and pick models from the openai provider, for example:

• openai/gpt-5-codex
• openai/gpt-5.1-codex
• openai/gpt-5.1-codex-mini
• openai/gpt-5.1-codex-max
• openai/gpt-5.2-codex
• openai/gpt-5.4
• openai/gpt-5.4/fast

Registry format

The default registry path is ~/.config/opencode/codex-accounts.json.

{
  "version": 2,
  "selection": {
    "strategy": "round-robin",
    "defaultAccountId": "personal"
  },
  "accounts": [
    {
      "id": "personal",
      "label": "Personal",
      "type": "oauth",
      "accessToken": "...",
      "refreshToken": "...",
      "idToken": "...",
      "accountId": "...",
      "email": "you@example.com",
      "expiresAt": 1777590611000,
      "lastRefresh": "2026-04-20T23:10:10.889Z",
      "enabled": true,
      "includeModels": [],
      "excludeModels": []
    }
  ]
}

Commands

node ./scripts/accounts.mjs list
node ./scripts/accounts.mjs login personal
node ./scripts/accounts.mjs import-legacy
node ./scripts/accounts.mjs remove work
node ./scripts/accounts.mjs disable personal
node ./scripts/accounts.mjs enable personal
node ./scripts/accounts.mjs default work

Run those commands from the repository root, or replace ./scripts/accounts.mjs with the absolute path to the script.

Environment overrides

• OPENCODE_CODEX_ACCOUNTS_FILE overrides the registry path.
• OPENCODE_CODEX_ACCOUNT forces a specific configured account for the current process.
• OPENCODE_CODEX_DEBUG=1 enables plugin debug logging.
• OPENCODE_CODEX_REASONING_EFFORT overrides the default reasoning effort used when OpenCode does not set one.

Notes

• OAuth accounts are sent to https://chatgpt.com/backend-api/codex/responses with account-specific OAuth headers.
• Unsupported non-OAuth entries are ignored if they appear in imported legacy registries.
• The fast variant maps request intent to serviceTier: "priority". On ChatGPT-backed Codex OAuth accounts, the backend currently reports service_tier: "auto" in responses even when the fast variant is requested.