# Bug: ${env:VAR} substitution in provider apiKey and baseURL override from models catalog #27853

Description

Bug Summary

Two related bugs prevent opencode run from working with OpenCode GO models.

Bug 1: ${env:VAR} substitution fails in provider apiKey

Using ${env:OPENCODE_API_KEY} in opencode.json provider options does not resolve
to the environment variable value. The raw string is sent as the API key, causing
authentication failures.

Bug 2: baseURL in opencode.json silently overrides the models catalog

If a user defines baseURL for opencode-go in opencode.json, it silently overrides
the correct URL from the models catalog with no warning.

The correct endpoint from the models catalog (https://opencode.ai/zen/go/models-api.json) is:

"opencode-go": {
  "id": "opencode-go",
  "env": ["OPENCODE_API_KEY"],
  "npm": "@ai-sdk/openai-compatible",
  "api": "https://opencode.ai/zen/go/v1"
}

A common mistake is using https://api.opencode.ai/v1 (OpenAI-compatible style),
which is incorrect and causes auth failures.

Bug 3: opencode run returns tokens=0 with OpenCode GO models

Even after resolving Bugs 1 and 2, opencode run produces no output with OpenCode GO models.

Debug log comparison:

Token result from opencode run:

{
  "tokens": { "input": 0, "output": 0, "reasoning": 0 },
  "finish": "other"
}

Key observation: TUI mode works correctly with the same model (mimo-v2.5-pro).
This indicates opencode run uses a different code path than TUI for OpenCode GO
provider routing, and that code path fails to parse the streaming response via
@ai-sdk/openai-compatible.

Workaround (confirmed working)

Remove the opencode-go provider block from opencode.json entirely:

{
  "provider": {
    // Do NOT define opencode-go here
  }
}

The CLI will automatically use:

• Authentication from auth.json (registered via opencode providers login)
• URL from the models catalog (https://opencode.ai/zen/go/v1)

This workaround restores TUI functionality but does not fix opencode run.

Plugins

No response

OpenCode version

1.15.1

Steps to reproduce

Bug 1: ${env:VAR} substitution failure

1. Authenticate with OpenCode GO:

   opencode providers login
   

2. Add the following to opencode.json:

   {
     "provider": {
       "opencode-go": {
         "options": {
           "apiKey": "${env:OPENCODE_API_KEY}"
         }
       }
     }
   }

3. Set the environment variable:

   $env:OPENCODE_API_KEY = "sk-..."

4. Run:

   opencode run -m opencode-go/mimo-v2.5-pro "test"
   

5. Expected: Model responds normally
   Actual: Error: Invalid API key — ${env:OPENCODE_API_KEY} is sent as a literal string

Bug 2: baseURL silently overrides models catalog

1. Add the following to opencode.json:

   {
     "provider": {
       "opencode-go": {
         "options": {
           "baseURL": "https://api.opencode.ai/v1"
         }
       }
     }
   }

2. Run:

   opencode run -m opencode-go/mimo-v2.5-pro "test"
   

3. Expected: Warning that baseURL differs from models catalog
   Actual: Incorrect URL silently overrides https://opencode.ai/zen/go/v1,
   causing Error: Invalid API key with no diagnostic message

Bug 3: opencode run returns tokens=0

1. Remove all opencode-go config from opencode.json (use workaround above)
2. Confirm TUI mode works:

   opencode   # interactive TUI → mimo-v2.5-pro responds ✅
   

3. Run headless:

   opencode run -m opencode-go/mimo-v2.5-pro "Say OK"
   

4. Expected: Model responds with text, non-zero token count
   Actual:

   { "tokens": { "input": 0, "output": 0, "reasoning": 0 }, "finish": "other" }

5. Enable debug logging and compare providers:
   • @ai-sdk/google → message.part.delta received ✅
   • @ai-sdk/openai-compatible → message.part.delta empty ❌

Screenshot and/or share link

No response

Operating System

Windows 11

Terminal

Windows Terminal PowerShell 7+