Codex

Before you start

• Install the Codex CLI, or the Codex extension in VS Code, Cursor or Windsurf, and create an API key in the console.
• Codex only uses the OpenAI Responses API (/v1/responses), where NezhaGate serves the GPT models. For Claude, Gemini and the other models, use the chat endpoint or a tool such as Claude Code.

Models you can use in Codex:

gpt-5.6-sol · gpt-5.6-terra · gpt-5.6-luna · gpt-5.5 · gpt-6-astra · gpt-6.1-sol · gpt-6-sol · gpt-6-luna

Add a provider in config.toml

Open ~/.codex/config.toml (%USERPROFILE%\.codex\config.toml on Windows), create it if needed, and add:

model = "gpt-6.1-sol"
model_provider = "nezhagate"
web_search = "disabled"

[model_providers.nezhagate]
name = "NezhaGate"
base_url = "https://nezhagate.com/v1"
wire_api = "responses"
env_key = "NEZHAGATE_API_KEY"

• Top-level keys such as model and model_provider must come before the first [...] table, or Codex reads them as part of that table.
• web_search = "disabled": Codex's built-in web search relies on an OpenAI-hosted tool that is not guaranteed through another provider, so turn it off.
• The provider must live in the user-level config.toml: model_provider in a project's .codex/config.toml is ignored. The provider id cannot be openai, ollama or lmstudio; Codex reserves them.

Set the API key

Codex reads the key from the NEZHAGATE_API_KEY environment variable (the env_key above) and sends it as Authorization: Bearer; no codex login is needed.

export NEZHAGATE_API_KEY=YOUR_API_KEY
codex

setx NEZHAGATE_API_KEY "YOUR_API_KEY"

On macOS / Linux, put the export line in ~/.zshrc or ~/.bashrc so it sticks. On Windows, reopen the terminal or VS Code after setx so the variable is picked up.

Run and test

Run the command below; a reply of gateway-ok means you are connected:

codex exec "Reply with exactly: gateway-ok"

• Type /status in Codex to see the current model and provider.
• To switch models, start with codex -m gpt-6.1-sol or change model in config.toml. Codex's /model menu lists its own built-in models only, not NezhaGate's list.
• Then ask for something that needs a tool (for example, list the files here) to check that tool calls work too.

The IDE extension

The Codex extension in VS Code, Cursor and Windsurf reads the same config.toml: gear icon in the extension panel → Codex Settings → Open config.toml. Restart the editor after editing, and make sure an editor not launched from a terminal can see the API key variable.

Troubleshooting