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

[Ish-oota]

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:

Provider	SDK Package	message.part.delta	Result
Google	@ai-sdk/google	✅ Received	Works
OpenCode GO	@ai-sdk/openai-compatible	❌ Empty	Fails

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+

[github-actions]

This issue might be a duplicate of existing issues. Please check:

• {env:...} substitution not working for apiKey in custom provider options — {file:...} works #19946: {env:...} substitution not working for apiKey in custom provider options — same bug as your Bug 1, where environment variable substitution in provider apiKey does not resolve correctly.

[Ish-oota]

Thanks for the detailed report and cross-references — very helpful for triaging.

Bug 1 (${env:VAR} substitution):
This appears to be a duplicate of #19946. The syntax differs slightly, but the root cause is the same: env-var substitution fails to resolve inside custom provider options. Happy to close this in favour of #19946.

Bug 2 (baseURL silently overriding catalog URL):
I couldn't find an existing duplicate for this. Unlike #5674 where options aren't applied at all, here the user-defined baseURL is applied but silently overrides the correct catalog URL, producing a misleading Invalid API key error. I think this is worth tracking as a separate issue.

Bug 3 (opencode run returning tokens=0):
This looks like a match for #5210. The debug logs show message.part.delta is empty and the stream ends with finish: "other" rather than "stop" — consistent with text-delta events being dropped in processor.ts when text-start is missing. The fact that TUI works correctly on the same machine confirms this is isolated to the opencode run headless code path.

I'd suggest keeping this issue open to track Bug 2 and Bug 3 (linked to #5210), while closing Bug 1 as a duplicate of #19946. Happy to provide additional logs if needed.