Description

Calls to models with the string claude or anthropic in the id fail when they are not actual anthropic upstream providers.

I have this custom provider in my config:

  "provider": {
    "custom": {
      "models": {
        "claude-opus-4.1": {
          "name": "claude-opus-4.1"
        },
      },
      "npm": "@ai-sdk/openai-compatible",
      "options": {
        "apiKey": "na",
        "baseURL": "https://custom.com"
      }
    }
  },

Chatting with this model fails with

litellm.BadRequestError: Vertex_aiException BadRequestError - b'{"type":"error","error":{"type":"invalid_request_error","message":"invalid beta flag"},"request_id":"req_vrtx_011CWdZLV7UDvRZBkvyfXcKJ"}'. Received Model Group=claude-opus-4.1
Available Model Group Fallbacks=None

Because of this logic https://github.com/sst/opencode/blob/3fe5d91372fdf859e09ed5a2aefe359e0648ed10/packages/opencode/src/provider/transform.ts#L198-L208

Even though my model has claude in the name I am explicitly saying it is an openai provider with "npm": "@ai-sdk/openai-compatible". In this case I am using LiteLLM proxy to front all LLM access and it does not support the added "cache_control" key this injects to every message.

Some possible solutions that could be done:

• config option to disable the applyCaching functionality, either per model or provider
• (... existing ors) && model.api.npm !== "@ai-sdk/openai-compatible" be added to the if statement logic there. Though I am not sure if that is the best approach or if it should apply to other providers as well.

OpenCode version

1.0.212

Steps to reproduce

1. Setup LiteLLM in front of Anthropic models where model id includes claude or anthropic
2. Setup a custom provider in opencode using LiteLLM as a @ai-sdk/openai-compatible provider
3. call on a model and it fails due to injected cache keys in messages array.

Screenshot and/or share link

Operating System

NixOS/macos

Terminal

Kitty/Iterm2