v0.2.6: Built-in OpenCode Go provider doesn't send x-opencode-session (routing rejected since 2026-09-05)

[moemcb]

Title

v0.2.6: Built-in OpenCode Go provider doesn't send x-opencode-session (routing rejected since 2026-09-05)

Summary

OpenCode Go began enforcing the x-opencode-session header on 2026-09-05 to optimize routing and prompt caching (docs). Every request made through pentestcode v0.2.6's built-in opencode-go provider is now rejected with:

AI_APICallError: Error from provider (Console Go): Request is missing x-opencode-session and cannot be routed efficiently. Please see https://opencode.ai/docs/go/#where-can-i-use-it

Upstream OpenCode (v1.18.x) works against the same endpoint because it sends the header natively per session.

Reproduction

1. Connect OpenCode Go (/connect), select any opencode-go/* model.
2. Send any prompt.

Every stream fails with the routing error above (main agent requests and auxiliary requests alike).

Root cause

The embedded opencode-go provider (endpoint https://opencode.ai/zen/go/v1, internally displayed as "Console Go") never sets x-opencode-session. Per the Go docs, clients must send "a stable session ID in x-opencode-session for each conversation". The OpenCode session ID (ses_...) is the natural value, as upstream OpenCode already does.

Note: a static provider-level "headers" block in the config is not picked up for built-in providers, so users cannot work around this through config alone.

Suggested fix

Pass the current session ID as x-opencode-session on all requests to OpenCode providers (main and auxiliary paths) — the same behavior upstream OpenCode and validated clients (Hermes fix, jcode ≥ 0.81.6, Kilo Code PR #13752) now implement.

Workaround (verified working)

A local plugin that tracks the current session via the session.created / session.updated event hook and injects the header through an auth.loader custom fetch wrapper (pattern from opencode-helicone-session):

let currentSessionID = ""

export const GoSessionHeader = async () => ({
  auth: {
    provider: "opencode-go",
    methods: [],
    loader: async () => ({
      fetch: (url, init) => {
        const headers = new Headers(init?.headers)
        if (currentSessionID && !headers.has("x-opencode-session")) {
          headers.set("x-opencode-session", currentSessionID)
        }
        return fetch(url, { ...init, headers })
      },
    }),
  },
  event: async ({ event }) => {
    if (event.type === "session.created" || event.type === "session.updated") {
      currentSessionID = event.properties?.info?.id || currentSessionID
    }
  },
})

Tested on v0.2.6/Linux: requests to opencode-go/glm-5.3-flash succeed again, with the real per-conversation session ID sent in the header.