Fixing a 404 "No route for POST" error

This 404 is about the address, not your key or model. The request reached the server but at a path with no API behind it.

What the error says

HTTP 404
{
  "error": {
    "message": "No route for POST /chat/completions",
    "type": "invalid_request_error"
  }
}

The path in the message is the one your client actually requested, which makes this the easiest error to diagnose: read the path and compare it with the list below.

The paths that exist

POST /v1/chat/completions for OpenAI-style chat (what SillyTavern uses)
POST /v1/messages for Anthropic-style clients
POST /v1/responses for the OpenAI Responses format
GET /v1/models for the model list

The base URL to configure is https://wildwestapi.com/v1. Clients append /chat/completions themselves.

Common causes

Missing /v1. Base URL set to https://wildwestapi.com gives No route for POST /chat/completions.
Doubled path. Pasting the full endpoint into a base URL field gives /v1/chat/completions/chat/completions.
Doubled /v1. Some clients add /v1 on their own, so .../v1 becomes /v1/v1/chat/completions. If that is in the message, drop /v1 from the field.
A text completion endpoint. SillyTavern's Text Completion mode posts to paths like /v1/completions, which this API does not serve. Use Chat Completion mode.

Step by step fix

Read the path in the error message.
In SillyTavern, set API to Chat Completion and source to Custom (OpenAI-compatible).
Set the endpoint to exactly https://wildwestapi.com/v1, no trailing path.
In SDK code, pass base_url="https://wildwestapi.com/v1" (Python) or baseURL (Node).
Retry and confirm the error is gone.

For reference, the working SillyTavern setup is: API set to Chat Completion, source set to Custom (OpenAI-compatible), endpoint https://wildwestapi.com/v1, your sk-ww- key in the API key field, and a model id such as outlaw-1. The full walkthrough is on the SillyTavern setup page.

Telling it apart from similar errors

An unknown model id also fails with 400 on the right path, with code model_not_found; see Unknown model. If the request is sent from a browser page and you see no HTTP status at all, that is a CORS error; the server's preflight answer is this same 404, which the browser then reports as CORS.

FAQ

Is a trailing slash on the base URL a problem?

Usually not, since most clients normalize it. If the error path shows a double slash, remove the trailing slash.

Does a 404 cost anything?

No. No route means nothing ran.

Fixing "Unknown model" (model_not_found)This error means the model field held an id the API does not serve. The key and balance were fine; the name was not. Fixing CORS errors in JanitorAI and other browser clientsA CORS error means a web page in your browser tried to call the API directly and the browser blocked it. The API does not answer cross-origin browser requests. Fixing a 401 "Invalid or disabled API key" errorA 401 means the API could not match the key you sent to a live key on an account. Nothing was generated and nothing was charged.