zen: RegionError on muse-spark contributor free tier while other free models work from same IP #53069

Summary

muse-spark-1.3-contributor-free and muse-spark-1.2-contributor-free return 403 RegionError: This model is not available in your country. from my IP, while 10 of the 13 free Zen models work normally from the same IP and endpoint. This does not look like a country-level restriction, so I suspect an IP-to-region mapping error for my address.

Environment

• opencode version: 2.0.22 (latest, desktop app)
• OS: Windows 10, version 10.0.19045, x64
• Terminal: TERM=xterm-256color; TERM_PROGRAM, COLORTERM and WT_SESSION unset (desktop app session)
• Shell: C:\Windows\system32\cmd.exe
• Install/channel: latest
• Active plugins: none found in config (no opencode.json present)

Reproduction

1. Send a request to the Zen endpoint with the anonymous public credential:

curl -sS -X POST https://opencode.ai/zen/v1/chat/completions \
  -H "Authorization: Bearer public" \
  -H "Content-Type: application/json" \
  -d '{"model":"muse-spark-1.3-contributor-free","messages":[{"role":"user","content":"hi"}],"max_tokens":3}'

2. Observe the response:

{"type":"error","error":{"type":"RegionError","message":"This model is not available in your country."}}

3. Repeat with any other free model, for example longcat-2.5-preview-free or space-bunny-free, to compare.

Alternatively from the CLI:

opencode run --model opencode/muse-spark-1.3-contributor-free "hi"

Expected Behavior

Either the model is served, or the region decision reflects a correct mapping of my address. Since the same IP reaches every other free model on the same endpoint, a country-level block would have to apply inconsistently within one credential.

Actual Behavior

Two distinct error types are returned from the same IP, same endpoint, same credential:

FreeTierError: OpenCode's free tier can only be used from within OpenCode is a separate client-identification check and is not the issue here; those models work when called through the OpenCode client. The three models above fail with RegionError regardless of client.

My address as resolved by three independent geolocation providers, none of which flags it as a proxy or hosting:

IP:      77.222.98.81
Country: RU
City:    Chelyabinsk
ASN:     AS8369 Intersvyaz-2 JSC
Type:    residential, proxy=false, hosting=false

Cloudflare  /cdn-cgi/trace -> loc=RU
ipinfo.io  /json           -> country=RU, org=AS8369 Intersvyaz-2 JSC
ip-api.com /json           -> countryCode=RU, proxy=false, hosting=false

Additional Context

• Consistent on every attempt across multiple retries and several hours. Not intermittent.
• No local configuration is involved: no opencode.json, no plugins, no custom provider settings, no proxy or VPN.
• Note that fledge-alpha-free is blocked the same way and is not a Meta model, which suggests the region decision is made at the Zen layer rather than solely by the upstream provider.
• I understand this may be a deliberate license restriction rather than a bug. If so, I would appreciate confirmation, plus the region your geolocation service assigns to this address, so I can tell whether the mapping is what I would expect.

Workarounds tried: none available for the contributor tier. The non-contributor muse-spark-1.3 is not affected, but it is a paid model and not the tier I need.