Codex CLI with BigModel.io: models and setup
OpenAI's open-source coding agent for the terminal. Add BigModel.io as a provider that uses the Responses API.
Who it is for
Developers who let an agent read, write and run code in a terminal or editor. Agents send long contexts and many tool calls, so per-key spend limits are worth setting.
Website: github.com
Set up Codex CLI in three steps
- Create an API key in the BigModel.io console. Give it a spend limit if the app runs unattended.
- On the API Keys page, click Import to CCS to hand the key to CC Switch, or add a provider in the tool's config with base URL https://bigmodel.io/v1.
- Choose a model whose endpoints include the API the tool calls, and set its ID.
- OpenAI base URL
https://bigmodel.io/v1- API key
sk-...
Prefer one click? CC Switch can switch Claude Code and Codex to BigModel.io from the API Keys page. CC Switch guide
The full guide covers model choice, limits and common errors. Codex CLI guide →
