Send x-opencode-session header on API requests (required by OpenCode Go from 09/05)

[thdxr]

Hi — we operate the OpenCode Go managed-inference API, and 280 of your users' orgs call it through MiMoCode (UA mimocode/0.1.13 ai-sdk/provider-utils/4.0.23 runtime/bun/1.3.14).

Starting 09/05, requests without an x-opencode-session header will error on our side — we need a stable per-conversation ID for routing/optimization. MiMoCode doesn't send it in any version we've seen.

Ask: include x-opencode-session: <stable-id-per-conversation> on all outbound inference HTTP requests. Any stable UUID per conversation works. Happy to confirm from our telemetry once a build ships it. Thanks!

[romeo88845]

Is there a work around if MimoCode hasn't fixed this issue before 09/05?

[Moviw]

PR is up: #2327.

It adds x-opencode-session next to the existing x-session-affinity in session/llm.ts, carrying the same stable sessionID under the same non-ephemeral condition — so it's a real per-conversation ID, not one per process or per install. Tests cover both the normal and the ephemeral path.

@thdxr happy to have you confirm from your telemetry once a build ships it.

Heads up that the PR is still waiting on maintainer approval to run CI (first-time contributor), so it hasn't been reviewed yet — flagging because of the 09/05 date.

@romeo88845 as a stopgap you can set the header yourself, per model:

{
  "provider": {
    "<providerID>": {
      "models": {
        "<modelID>": {
          "headers": { "x-opencode-session": "<any-uuid>" }
        }
      }
    }
  }
}

That clears the hard error, but it's one fixed ID for every conversation, so you lose the per-conversation routing the header exists for.

[est]

雷军！金凡！ 萝福莉！

还是优先看看这个issue吧！！影响天才程序员发挥了！！