@cortexkit/opencode-openai-auth

ChatGPT Plus/Pro OAuth support for OpenCode.

This OpenCode plugin lets OpenCode talk to the OpenAI Codex backend using a ChatGPT Plus/Pro subscription instead of a pay-as-you-go API key. It rewrites OpenCode's outbound OpenAI requests into Codex's request shape, filters the model list to OAuth-eligible models, zeroes provider costs for those models, and adds a prompt-cache stabilizer.

The plugin registers the built-in openai provider id. OpenCode loads external plugins after its built-ins, so this package supersedes OpenCode's internal OpenAI auth hook without any change to your model configuration.

Install

{
  "plugin": ["@cortexkit/[email protected]"]
}

Restart OpenCode after changing plugin config, then authenticate:

/login openai

Features

• ChatGPT Plus/Pro OAuth login (browser and headless device flows), plus a manual API-key fallback.
• Codex request rewriting for OAuth requests, with Codex identity parity.
• OAuth model filtering and zero-cost display.
• Prompt-cache stabilizer (web_search) that keeps tool-continuation requests on the backend's cached path (on by default).
• Multiple ChatGPT accounts with automatic reactive fallback on rate limits, configurable routing, and a per-account quota killswitch.
• Per-turn quota tracking (5-hour + weekly windows) on both transports, with a sidebar readout and an explicit all-accounts refresh.
• Idle prompt-cache keep-warm, with an optional subagent mode.
• Leveled, secret-redacting, rotating log file.
• Interactive in-TUI control surfaces for every command, plus an openai-auth CLI for managing fallback accounts headlessly.
• Optional OpenAI Responses WebSocket transport (HTTP is the default).

Commands

Each opens an interactive dialog in the TUI and also accepts explicit arguments:

| Command | Arguments | Purpose | | --- | --- | --- | | /openai-quota | — | Show 5h + weekly quota for all accounts. | | /openai-account | add [label] · switch <id> · remove <id> · order <a> <b> | Manage main + fallback accounts (non-destructive switch). | | /openai-routing | main-first · fallback-first | Account preference order. | | /openai-killswitch | on · off · set <acct>:<5h>,<1w> ... | Hard-block accounts below quota thresholds. | | /openai-cachekeep | on · off · subagents on · subagents off | Idle prompt-cache keep-warm. | | /openai-logging | <level> | Set log level live. | | /openai-dump | on · off | Toggle transport request dumps. |

CLI (fallback accounts only; the main account comes from /login openai):

openai-auth login [--label <name>] [--headless]
openai-auth list
openai-auth remove <id>

Configuration

Settings resolve as environment variable → config file (~/.config/opencode/openai-auth.json) → default.

| Config field | Environment variable | Default | Purpose | | --- | --- | --- | --- | | webSearch | CORTEXKIT_OPENAI_AUTH_NO_WEB_SEARCH (set to disable) | true | Inject the web_search prompt-cache stabilizer. | | webSockets | CORTEXKIT_OPENAI_AUTH_WEBSOCKETS | false | Use the Codex Responses WebSocket transport instead of HTTP. | | rawWebSocket | CORTEXKIT_OPENAI_AUTH_RAW_WS | false | Use the hand-rolled raw TCP/TLS client with Codex-style incremental streaming. Bun uses Bun.connect; Node/OpenCode Desktop uses node:net/node:tls. | | dump | CORTEXKIT_OPENAI_AUTH_DUMP | false | Dump final Codex request bodies for cache debugging. | | dumpDir | OPENCODE_OPENAI_AUTH_DUMP_DIR | OS temp dir: opencode-openai-auth-dumps | Directory for request dump files. | | codexApiEndpoint | CORTEXKIT_OPENAI_AUTH_CODEX_ENDPOINT | https://chatgpt.com/backend-api/codex/responses | Send rewritten Codex requests to a compatible proxy/relay instead of ChatGPT's backend endpoint. |

See the repository README for transport differences and why web_search is needed.

License

MIT