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Using Kimi in Codex: CC Switch Local Routing Guide

docs/guides/codex-kimi-routing-guide-en.md

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Using Kimi in Codex: CC Switch Local Routing Guide

Applies to CC Switch 3.16.5 and nearby versions. This guide is based on the repository documentation and code, and uses Kimi as an example of an OpenAI Chat Completions-compatible API. Screenshots are generated from the current frontend UI with de-identified sample data to avoid exposing a real API key or account balance.

Why local routing is needed

The newer Codex CLI targets the OpenAI Responses API, while both the Kimi Open Platform and Kimi For Coding expose the OpenAI Chat Completions shape, /chat/completions. These two protocols use different request bodies, streaming events, and response structures. If you put a Kimi endpoint directly into Codex configuration, the usual result is a 404 on /responses, or streaming responses that Codex cannot parse correctly.

The third-party tools officially supported by Kimi For Coding are Anthropic-compatible coding agents such as Claude Code and Roo Code — Codex is not on the list. To use Kimi inside Codex, you need a protocol conversion layer, and that is exactly what CC Switch Local Routing does.

CC Switch solves this by making Codex always talk to a local route and continue sending Responses API requests. The route detects whether the active provider is Chat-format, rewrites the request into Chat Completions for the upstream provider, and finally converts the Chat response back into the Responses shape that Codex understands.

The chain has four main steps:

  1. When Codex routing is enabled, the local configuration is written as http://127.0.0.1:15721/v1, while wire_api = "responses" is kept in place.
  2. The provider's meta.apiFormat = "openai_chat" tells the route that the real upstream is Chat Completions.
  3. The route rewrites /responses or /v1/responses to /chat/completions, and converts the Responses request body into a Chat request body.
  4. After the upstream responds, the route converts the Chat JSON or SSE stream back into Responses JSON/SSE.

Prerequisites

Prepare these three things first:

  • CC Switch installed and able to start.
  • Codex CLI installed and run at least once, so the ~/.codex/config.toml directory structure exists.
  • A Kimi API key.

Kimi API keys come from two different places, matching two different built-in presets in CC Switch:

  • Kimi Open Platform (platform.kimi.com): pay-as-you-go API keys billed by token usage, matching the Kimi preset. The OpenAI-compatible base URL is https://api.moonshot.cn/v1 and the default model is kimi-k2.7-code.
  • Kimi For Coding (kimi.com/code): a dedicated key generated from the Kimi Code membership benefits, matching the Kimi For Coding preset. The base URL is https://api.kimi.com/coding/v1 and the unified model is kimi-for-coding.

Both presets already contain the correct endpoint and model details, so prefer the presets and do not manually assemble the endpoint path.

Step 1: Add a Codex provider

Open CC Switch, switch to the top-level Codex tab, and click the plus button in the upper-right corner to add a provider.

Depending on which kind of key you have, choose the built-in Kimi preset (Open Platform, pay-as-you-go) or Kimi For Coding preset (membership subscription). You only need to do two things:

  • Enter the matching Kimi API key.
  • Save the provider.

The preset already includes Kimi's request base URL, default model, model menu, thinking/reasoning parameters, and presets Upstream Format under Advanced Options to Chat Completions (routing required). You can adjust the default model or model display names if needed — for example, the Open Platform preset defaults to kimi-k2.7-code, and you can switch to kimi-k2.7-code-highspeed following the official documentation. The protocol conversion is handled by the routing layer.

Step 2: Enable local routing and route Codex

Go to the Routing page in Settings, expand Local Routing, and complete two toggles:

  1. Turn on the main routing switch to start the local service. The default address is 127.0.0.1:15721.
  2. Turn on Codex under Routing Enabled. If you only want Codex to use local routing, you can leave Claude and Gemini off.

After routing is enabled, CC Switch points Codex's live configuration to the local route and manages authentication with a placeholder. The real Kimi key stays in the CC Switch provider configuration and is injected by the local route while forwarding requests, so you do not need to expose the key in Codex's live configuration.

Step 3: Switch providers and restart Codex

Return to the Codex provider list and click Enable on the Kimi provider. If you see the Needs Routing marker, that provider must be used while routing is running; when the route is not started, CC Switch shows a prompt saying the routing service is required.

After switching, restart the current Codex terminal session. This is recommended because:

  • The Codex process may already have read the old config.toml.
  • After model_catalog_json is generated, the /model menu usually needs a fresh process before it refreshes.

Inside Codex, use /model to check whether the current model comes from the Kimi preset, such as Kimi K2.7 Code or Kimi For Coding. The Codex app currently does not support multi-model selection, so it defaults to the first configured model. Then send a small test prompt and confirm that the request count increases in the routing panel, or that a Codex request appears in usage/request logs.

How to handle other Chat providers

Kimi, DeepSeek, MiniMax, SiliconFlow, and other common Chat-format providers already have presets in CC Switch, so use presets first. Only choose custom configuration for providers that are not covered by presets; in that case, fill in the API key, base URL, and models according to the provider's documentation, and set Upstream Format under Advanced Options to Chat Completions (routing required).

If the upstream provider directly supports the OpenAI Responses API, set Upstream Format to Responses; CC Switch then connects through Responses directly without Chat conversion.

FAQ

Codex reports 404 or cannot find /responses

Usually Codex routing is not enabled, or the Kimi Chat base URL was written directly into Codex manually — the Kimi upstream has no /responses endpoint, so that always 404s. Check whether ~/.codex/config.toml points to http://127.0.0.1:15721/v1.

Kimi upstream reports 401 or 403

First confirm the key matches the preset: Open Platform keys only work with the Kimi preset, and Kimi Code membership keys only work with the Kimi For Coding preset. The two key families are not interchangeable.

Kimi upstream reports 404

If you are using a built-in Kimi preset, first confirm that the active provider really comes from the preset and that Codex routing is enabled. Only custom providers require extra base URL checks: the base URL should be the service root, not the full endpoint path with /chat/completions.

/model does not show Kimi models

Restart Codex after saving the provider. CC Switch generates cc-switch-model-catalog.json and writes its path to model_catalog_json, but a running Codex process may not hot-load the model catalog. The Codex app currently does not support multi-model selection, so it uses the first configured model by default.

Routing is enabled, but requests still go to the wrong provider

Confirm that all three states match: the current provider under the Codex tab is Kimi; the local routing service is running; and the Codex toggle is enabled under Routing Enabled.

Can I use an official OpenAI Codex account through local routing?

Not recommended. CC Switch blocks switching to official providers while local routing takeover is enabled, because accessing official APIs through a proxy may create account risk. Routing is mainly intended for third-party, aggregator, or protocol-conversion scenarios.

References