[Bug] OpenCode Go: return 401 Request blocked by upstream provider — chat/completions blocked while /v1/models works

Description

Starting today (2026-07-22), all models under my OpenCode Go subscription are returning 401 Request blocked by upstream provider when calling the chat/completions endpoint. The /v1/models endpoint works fine.

This appears to be a server-side issue affecting Go subscriptions, not a client configuration problem.

Account Details

• Subscription: OpenCode Go
• Expiry: 2026-08-13
• Console status: All usage limits (5h / weekly / monthly) show sufficient balance
• API Key: Valid (tested with newly created key, same result)

Affected Models

All of the following models return the same error:

Model	Result
deepseek-v4-flash	❌ 401
kimi-k2.6	❌ 401
glm-5.2	❌ 401
mimo-v2.5	❌ 401

Reproduction Steps

Step 1: List models (works)

curl -H "Authorization: Bearer $OPENCODE_API_KEY" \
  https://opencode.ai/zen/go/v1/models

Result: 200 OK — returns full model list including all 4 models above.

Step 2: Chat completion (fails)

curl -X POST https://opencode.ai/zen/go/v1/chat/completions \
  -H "Authorization: Bearer $OPENCODE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"deepseek-v4-flash","messages":[{"role":"user","content":"hello"}]}'

Result:

{"type":"error","error":{"type":"AuthError","message":"Request blocked by upstream provider."}}

What I've Verified

• API Key is valid and active
• Base URL is correct (https://opencode.ai/zen/go/v1)
• Tested directly with curl to eliminate client-side issues
• Created a brand new API Key — same result
• All models affected, not just one
• Console shows sufficient usage quota remaining

Related Issues

Possibly related to #21097 and #20984 which report similar symptoms.

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Expected Behavior

chat/completions should return a valid response when the API Key is valid, subscription is active, and usage quotas are not exceeded.

Actual Behavior

All chat/completions requests return 401 Request blocked by upstream provider, while GET /v1/models works fine with the same key.

Plugins

No response

OpenCode version

No response

Steps to reproduce

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Screenshot and/or share link

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Operating System

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Terminal

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