opencode2: Model unavailable error for OpenAI-compatible provider despite working API #37531

Summary

opencode2 (next) reports "Model unavailable" for 9router provider models configured via aisdk:@ai-sdk/openai-compatible, despite the provider API being reachable and responding correctly.

Environment

• opencode version: 0.0.0-next-15747 (next channel)
• OS: Linux 6.17.0-1018-oracle aarch64 (Ubuntu 24.04)
• Terminal: TERM_PROGRAM=tmux, TERM=tmux-256color
• Shell: /bin/bash
• Install/channel: next (via volta)
• Active plugins: superpowers, oh-my-openagent

Reproduction

1. Configure 9router provider in ~/.config/opencode/opencode.json:

   {
     "providers": {
       "9router": {
         "package": "aisdk:@ai-sdk/openai-compatible",
         "settings": {
           "baseURL": "http://127.0.0.1:20127/v1",
           "apiKey": "<key>"
         },
         "models": {
           "balanced-fallback": {
             "modelID": "balanced-fallback",
             "capabilities": { "input": ["text"], "output": ["text"] }
           }
         }
       }
     },
     "model": "9router/balanced-fallback"
   }

2. Ensure 9router service is running on port 20127
3. Run: opencode2 run --model 9router/balanced-fallback "hello"

Expected Behavior

opencode2 should use the model and return a response, since the 9router API is live and responds correctly to both model listing and chat completion requests.

Actual Behavior

Error: Model unavailable: 9router/balanced-fallback

Additional Context

• Confirmed the 9router API works: GET /v1/models returns balanced-fallback in the model list, and POST /v1/chat/completions with model: "balanced-fallback" returns streaming completions.
• Server logs show previous sessions successfully used 9router/balanced-fallback with llm.runtime=ai-sdk.
• The opencode2 models 9router command also fails with ENOENT: no such file or directory, chdir '/home/ubuntu' -> 'models' — a separate bug where "9router" is treated as a directory path instead of a provider name.
• The run subcommand in opencode2 does not accept a --model flag (unlike opencode v1), so the model must come from config or background server state.