> ## Documentation Index
> Fetch the complete documentation index at: https://docs.prem.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Codex compatibility

> Understand why Codex cannot currently connect to Prem API.

Codex is not compatible with Prem API today.

> [!WARNING]
>
> Codex custom providers use the OpenAI Responses API. Prem API does not expose
> `/v1/responses`, so changing `base_url` is not enough.

## Use a supported coding harness

* Use [OpenCode](https://docs.prem.io/guides/opencode.md) for an OpenAI-compatible coding agent.
* Use [Claude Code](https://docs.prem.io/guides/claude-code.md) through Prem's Anthropic-compatible launcher.

Codex support requires a verified Responses API adapter. See the [Codex configuration reference](https://developers.openai.com/codex/config-reference#configtoml) for its current provider protocol.


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