OpenCode Go rejects documented deepseek-v4-flash ID via direct API call

[GH-Mason]

Description

A direct request to the documented OpenCode Go endpoint returns HTTP 400 for the documented model ID deepseek-v4-flash.

This was reproduced with curl, outside Hermes. The API key was accepted; it is redacted and not included here.

Expected: a successful response, or an error identifying a different invalid field.

Actual: the response says the only supported names are deepseek-v4-pro or deepseek-v4-flash, then says that deepseek-v4-flash was passed.

Docs: https://opencode.ai/docs/go/

Plugins

N/A - direct HTTP request; no plugins

OpenCode version

N/A - direct OpenCode Go HTTP API request; no OpenCode CLI invoked

Steps to reproduce

1. Set a valid OpenCode Go API key in OPENCODE_GO_KEY.
2. Send this direct request. Replace the placeholder locally; no real key is included here.

curl -sS "https://opencode.ai/zen/go/v1/chat/completions" -H "Authorization: Bearer <redacted>" -H "Content-Type: application/json" --data-raw "{"model":"deepseek-v4-flash","messages":[{"role":"user","content":"OK"}]}"

3. Observe HTTP 400:

Error from provider (Console Go): Upstream request failed: [invalid_request_error] The supported API model names are deepseek-v4-pro or deepseek-v4-flash, but you passed deepseek-v4-flash.

Screenshot and/or share link

No response

Operating System

macOS

Terminal

zsh (terminal emulator not recorded)

[github-actions]

This issue might be a duplicate of existing issues. Please check:

• [Bug] Leading space in model name when using opencode-go/deepseek-v4-flash #41300: Leading space in model name when using opencode-go/deepseek-v4-flash (same HTTP 400 error)
• [Bug] deepseek-v4-flash still broken on Console Go after #41211: gateway forwards model name with a leading space (verified 2026-08-09) #41306: deepseek-v4-flash still broken on Console Go after [Bug] opencode.ai/zen/go/v1 returns 400 "Model is unavailable" for deepseek-v4-flash (CLI works; same key, same pool) #41211 — gateway forwards model name with a leading space
• [Bug] OpenCode Go relay injects leading space into model string for deepseek-v4-flash (HTTP 400) #41314: OpenCode Go relay injects leading space into model string for deepseek-v4-flash (HTTP 400)

These reports describe the identical root cause and error message (note the double space in "but you passed deepseek-v4-flash") as your report.

[krasnikau-andrei]

@thdxr can someone take a look on this? Most popular model down for all day