Coze models still report 405 or 400 after configuration, which can easily be mistaken for "model not supported" or "platform incompatibility", but the more common root cause in public issues is actually misaligned addresses, protocols, and paths. Just because you can see the model in the interface doesn't mean that the runtime request is necessarily correct.
For example, when someone uses a third-party model service, they assign 'base_url' to the console address, or miss the API prefix that should be included. Some people chose the right protocol type, but the request path did not connect to the provider's chat completions specification. The last thing that manifests itself is that it directly returns 405 or 400 during testing, or JSON parsing fails.
It is not the same thing to distinguish between "being able to see" and "being able to run through"
The model can appear in the background, only that the configuration file has been read; When the request is actually made, Coze will also splice the full interface, verify the protocol, and parse the return value. As long as one of the links is inconsistent, an error will be reported. This logic is common on OpenRouter, Qwen proxy, and OpenAI compatible interfaces.
The three easiest pits to step on
- 'base_url' points to the web page address, not the API root address.
- The path is missing '/v1', or there is an additional layer of proxy, causing the request to end up on the wrong interface.
- The inconsistency between the protocol type and the actual support of the provider looks like a model problem on the surface, but is actually an interface convention problem.
How to tell if the address is wrong
The easiest way is to make a minimal HTTP request with the same 'base_url' and key to see if it returns standard JSON. As long as the return is mixed with HTML, jump pages, or static resource errors, the problem is not the quality of the model, but the deviation of the access link.
The experience in the community is also very consistent: the model name is not the most critical, whether the correct interface can be hit is the key. Calibrate the path and protocol first, and the 405 and 400 tend to disappear together.
One sentence conclusion
Coze models also report 405 or 400 after configuration, usually not "wrong model name", but 'base_url', paths and protocols are not aligned. Check the interface address first, and then check the model itself.
