ZEN gemini-3.6-flash returns "Upstream request failed" while gemini-3.5-flash works #39293
Closed as not planned
Description
Description
gemini-3.6-flash consistently returns an upstream error, while gemini-3.5-flash works with the exact same request.
Plugins
No response
OpenCode version
No response
Steps to reproduce
Request
curl -X POST \
"https://opencode.ai/zen/v1/models/gemini-3.6-flash:generateContent" \
-H "x-goog-api-key: <ZEN_KEY>" \
-H "Content-Type: application/json" \
-d '{
"contents": [
{
"parts": [
{
"text": "Hello!"
}
]
}
]
}'
**Result**
{
"error": {
"code": 400,
"message": "Error from provider (Console): Upstream request failed",
"status": "INVALID_ARGUMENT"
}
}
**Expected**
The request should succeed and return a normal Gemini response.
**Additional information**
GET /v1/models includes gemini-3.6-flash.
Replacing the model with gemini-3.5-flash (same endpoint, same API key, same payload) works correctly.
Calling the official Google Gemini API directly with gemini-3.6-flash and the same payload also works.
### Screenshot and/or share link
_No response_
### Operating System
_No response_
### Terminal
_No response_Metadata
Metadata
Assignees
Labels
No labels
Activity
github-actions commentedon Jul 28, 2026
This issue might be a duplicate of existing issues. Please check:
400 Upstream request failedwhenthinkingis enabled for latest Claude models (fable-5, sonnet-5, opus-4-8); older models (opus-4-6, haiku-4-5) work fine #35124: Zen returns400 Upstream request failedfor latest Claude models (similar upstream failure pattern)If your issue is specifically about
gemini-3.6-flashbeing listed inGET /v1/modelsbut not actually working (unlikegemini-3.5-flash), it may be a distinct model availability bug rather than a general upstream failure — in that case, please clarify that in your report so maintainers can triage it separately.kai-kleinbard-tyto commentedon Jul 30, 2026
Closing — insufficient information to investigate (no template, no version, no repro steps, or support question). Please reopen with the Bug Report template.
github-actions commentedon Sep 29, 2026
To stay organized issues are automatically closed after 60 days of no activity. If the issue is still relevant please open a new one.