Provider errors shaped like OpenAI { error: { message } } skip the real message #36410

Description

When a provider returns JSON like OpenAI's error shape:

{
  "error": {
    "message": "Rate limit exceeded",
    "type": "rate_limit_error"
  }
}

OpenCode tries to pull a useful string out of the body in packages/opencode/src/provider/error.ts with:

body.message || body.error || body.error?.message

body.error is an object, so it wins before body.error.message is ever read. The typeof errMsg === "string" check then fails, and the real message is dropped. Users often get a generic status line or a raw JSON dump instead of "Rate limit exceeded".

Plugins

None

OpenCode version

current dev

Steps to reproduce

1. Open packages/opencode/src/provider/error.ts around the responseBody JSON parse
2. Note the extraction order: body.message || body.error || body.error?.message
3. For a body of { "error": { "message": "Rate limit exceeded" } }, body.error is truthy and not a string, so the message is never used
4. Same class of response from OpenAI-compatible providers shows up as a vague/HTTP-only error in the UI instead of the provider message

Screenshot and/or share link

No response

Operating System

any

Terminal

any