fix: Plugin client returns 401 Unauthorized when OPENCODE_SERVER_PASSWORD is set (Desktop)

[jonnyhoo]

Bug Description

When running OpenCode via Desktop app, plugins that use client.session.create(), client.session.prompt(), or other HTTP API calls receive 401 Unauthorized errors.

Root Cause

OpenCode Desktop (Tauri) automatically generates a UUID password and sets OPENCODE_SERVER_PASSWORD environment variable when spawning the local server:

packages/desktop/src-tauri/src/lib.rs:416

let password = uuid::Uuid::new_v4().to_string();

packages/desktop/src-tauri/src/lib.rs:159

.env("OPENCODE_SERVER_PASSWORD", password)

This enables the basicAuth middleware in server.ts:

packages/opencode/src/server/server.ts:100-104

const password = Flag.OPENCODE_SERVER_PASSWORD
if (!password) return next()
return basicAuth({ username, password })(c, next)

However, the client created for plugins in plugin/index.ts does not include the corresponding Basic Auth credentials, causing all plugin HTTP requests to fail with 401.

Steps to Reproduce

1. Install OpenCode Desktop (exe version)
2. Install a plugin that uses client.session.create() (e.g., @menkan/opencode with sisyphus_task)
3. Run the plugin tool
4. Observe 401 Unauthorized error

Proposed Fix

Add Basic Auth headers to the plugin client when OPENCODE_SERVER_PASSWORD is configured:

packages/opencode/src/plugin/index.ts

const authHeaders: Record<string, string> = {}
if (Flag.OPENCODE_SERVER_PASSWORD) {
  const username = Flag.OPENCODE_SERVER_USERNAME ?? "opencode"
  const credentials = Buffer.from(`${username}:${Flag.OPENCODE_SERVER_PASSWORD}`).toString("base64")
  authHeaders["Authorization"] = `Basic ${credentials}`
}

const client = createOpencodeClient({
  baseUrl: "http://localhost:4096",
  fetch: async (...args) => Server.App().fetch(...args),
  headers: Object.keys(authHeaders).length > 0 ? authHeaders : undefined,
})

Workaround

Use CLI version (opencode command) instead of Desktop, as CLI does not set OPENCODE_SERVER_PASSWORD.

Environment

• OpenCode Desktop on Windows
• Plugin SDK version: 1.1.21