[Bug] OpenCode Go: some models return 403 Forbidden: {"model":"<model>"} while others work (subscription active, limits not reached)

Description

Using the OpenCode Go provider (opencode-go) with an active subscription and API key, certain models fail with AI_APICallError: Forbidden. The error body echoes the requested model id:

Forbidden: {"model":"mimo-v2.5"}

The subscription is active and usage limits are not exhausted. Other Go models work fine with the same key.

Environment

opencode version: 1.18.11
OS: Windows
Provider: opencode-go (OpenCode Go subscription)
Key type: sk-... API key from the Zen console

Models affected

With the same API key, direct requests to https://opencode.ai/zen/go/v1/chat/completions:

Model	Status
`mimo-v2.5`	403 `{"model":"mimo-v2.5"}`
`mimo-v2.5-pro`	403 `{"model":"mimo-v2.5-pro"}`
`hy3`	403 `{"model":"hy3"}`
`gpt-5.6-luna` (via `/responses`)	403
`deepseek-v4-flash`	200 OK
`deepseek-v4-pro`	200 OK
`glm-5.2`	200 OK
`glm-5.1`	200 OK
`kimi-k3`	200 OK
`kimi-k2.7-code`	200 OK
`qwen3.8-max`	200 OK
`grok-4.5`	500 (separate server error)

The affected models are listed in the gateway's catalog (GET https://opencode.ai/zen/go/v1/models includes mimo-v2.5, mimo-v2.5-pro, hy3, gpt-5.6-luna), so this is an authorization/entitlement decision, not "unknown model".

Repro (no opencode needed)

POST https://opencode.ai/zen/go/v1/chat/completions
Authorization: Bearer <opencode-go-api-key>
Content-Type: application/json

{ "model": "mimo-v2.5",
  "messages": [{ "role": "user", "content": "hi" }],
  "max_tokens": 3 }

Response:

HTTP/1.1 403 Forbidden
Content-Type: application/json

{"model":"mimo-v2.5"}

Not user-agent dependent (tested opencode, opencode/1.18.11, Mozilla/5.0 ..., curl/8.0, Python-urllib/3.11 — all return the same 403 body for the affected models; only Python-urllib triggers the separate Cloudflare 1010 block).

Expected behavior

All models advertised for the Go subscription (including mimo-v2.5) should be usable while the subscription is active and limits are not reached.

Additional context

A related issue (HTTP Error 403: Forbidden if user agent starts with Python-urllib #39374) describes a Python-urllib user-agent 403 — this is a different case: here the 403 is model-specific and independent of user-agent.
Docs page lists MiMo-V2.5 as a current Go model: https://opencode.ai/docs/go/

Plugins

No response

OpenCode version

No response

Steps to reproduce

No response

Screenshot and/or share link

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Operating System

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Terminal

No response

+1

I have the same issue:

Works (HTTP 200): deepseek-v4-flash, deepseek-v4-pro, minimax-m3, minimax-m2.7, qwen3.5-plus.
Fails (HTTP 403): mimo-v2.5, mimo-v2.5-pro, mimo-v2-pro, mimo-v2-omni, hy3, minimax-m2.5.

Repro:

curl -sS https://opencode.ai/zen/go/v1/models -H "Authorization: Bearer $KEY" → 200, list includes all mimo models.
curl -sS -o /dev/null -w "%{http_code}" https://opencode.ai/zen/go/v1/chat/completions -H "Authorization: Bearer $KEY" -H "Content-Type: application/json" -d
'{"model":"mimo-v2.5","messages":[{"role":"user","content":"hi"}],"max_tokens":8}' → 403.
Same request with "model":"deepseek-v4-flash" → 200 (full completion).

Has the solution to the problem still not been found?

fix: recognise real OpenCode Go keys, and correct the Go catalog