The API endpoint for muse-spark-1.2-contributor is unreachable

Description

I received a response without any issues using the opencode CLI. (This is the standard version, not the free version.)
Muse Spark 1.2 Contributor · 3.1s

Does anyone know the cause and how to fix it? Is this a server-side issue?

• location: japan (This country is not subject to API service restrictions.)
• os: windows 11 enterprise latest
• terminal: windows terminal, wezterm (latest)
• shell: pwsh(latest)
• curl 8.21.0 (Windows) libcurl/8.21.0 Schannel zlib/1.3.2 WinIDN WinLDAP

ocgo official endpoint: https://opencode.ai/zen/go/v1/chat/response

 $KEY = (Get-Content "D:\OpenCode_api_key.txt" -Raw).Trim(); '{"model":"muse-spark-1.2-contributor","messages":[{"role":"user","content":"say:a"}]}' | Set-Content -Encoding ascii "$env:TEMP\ocbody.json"; curl.exe -sS -i --max-time 30 -H "Authorization: Bearer $KEY" -H "Content-Type: application/json" -d "@$env:TEMP\ocbody.json" https://opencode.ai/zen/go/v1/chat/response
HTTP/1.1 404 Not Found
Date: Mon, 24 Aug 2026 05:57:50 GMT
Content-Type: text/html
Transfer-Encoding: chunked
Connection: keep-alive
Cf-Placement: remote-ORD
Server: cloudflare
CF-RAY: a3001f2c5c1d5ecd-PDX

<ocgo 404 not found page html raw>

endpoint https://opencode.ai/zen/go/v1/chat/completions

 $KEY = (Get-Content "D:\OpenCode_api_key.txt" -Raw).Trim(); '{"model":"muse-spark-1.2-contributor","messages":[{"role":"user","content":"say:a"}]}' | Set-Content -Encoding ascii "$env:TEMP\ocbody.json"; curl.exe -sS -i --max-time 30 -H "Authorization: Bearer $KEY" -H "Content-Type: application/json" -d "@$env:TEMP\ocbody.json" https://opencode.ai/zen/go/v1/chat/completions
HTTP/1.1 500 Internal Server Error
Date: Mon, 24 Aug 2026 05:55:26 GMT
Content-Type: text/plain;charset=UTF-8
Content-Length: 75
Connection: keep-alive
Cf-Placement: remote-ORD
Server: cloudflare
CF-RAY: a3001bad3a95e653-DEN

{"type":"error","error":{"type":"error","message":"Internal server error"}}

mimo-v2.5 is 200 ok

$KEY = (Get-Content "D:\OpenCode_api_key.txt" -Raw).Trim(); '{"model":"mimo-v2.5","messages":[{"role":"user","content":"only say->a"}],"max_tokens":5}' | Set-Content -Encoding ascii "$env:TEMP\ocbody.json"; curl.exe -sS -i --max-time 30 -H "Authorization: Bearer $KEY" -H "Content-Type: application/json" -d "@$env:TEMP\ocbody.json" https://opencode.ai/zen/go/v1/chat/completions
HTTP/1.1 200 OK
Date: Mon, 24 Aug 2026 07:32:24 GMT
Content-Type: application/json
Content-Length: 479
Connection: keep-alive
Cf-Placement: remote-ORD
Server: cloudflare
CF-RAY: a300a98a48027537-SEA

Plugins

No response

OpenCode version

latset

Steps to reproduce

No response

Screenshot and/or share link

No response

Operating System

windows11 latest

Terminal

windows terminal, wezterm latest

Start by rerunning the supplied curl requests against both chat endpoints, comparing the failing muse-spark-1.2-contributor responses with the successful mimo-v2.5 request. Trace the endpoint handling or service configuration that determines model availability, if those entry points are present in the repository. Done means identifying whether this is an unsupported model or a server-side failure and documenting or fixing the confirmed cause.