Desktop v1.14.39: Bun-target plugins fail to load (Node.js sidecar lacks Bun APIs)

[ckforce]

Description

OpenCode Desktop v1.14.30 → v1.14.39 update: the sidecar runtime switched from Bun to Node.js/Electron's bundled Node.js. This breaks all third-party plugins built with --target bun, because they depend on Bun-specific APIs such as globalThis.Bun.spawn, Bun.file, Bun.serve, Bun.which, etc.

Reproduction

1. Install OpenCode Desktop v1.14.39
2. Add a Bun-built plugin to config, e.g. oh-my-openagent@latest
3. Start Desktop → sidecar crashes, logs show:
   • Cannot destructure property 'spawn' of 'globalThis.Bun' as it is undefined
   • Or 0-byte sidecar log files

Affected Plugins

• oh-my-openagent (v3.17.14): uses Bun.spawn, Bun.file, Bun.write, Bun.which, Bun.serve, Bun.hash, Bun.readableStreamToText
• opencode-pty: depends on bun-pty native module (cannot work in Node.js)
• @tarquinen/opencode-dcp: ESM directory import resolution issue

Workaround (temporary)

A Bun → Node.js polyfill can be injected at the top of the cached plugin file to fix oh-my-openagent, but it's fragile:

• It gets overwritten when Desktop re-downloads the plugin
• Some plugins (opencode-pty) use native Bun addons and cannot be polyfilled

Suggested Fix

1. Restore Desktop sidecar to use Bun runtime, or
2. Provide a config option to select sidecar runtime (Bun / Node.js), or
3. Ship a Bun API polyfill layer in Desktop's Node.js sidecar

Related Issues

• v1.14.32 regression: plugin agents and MCPs silently fail to register (ALS context lost during InstanceStore.boot) #25457 v1.14.32 regression: plugin agents and MCPs silently fail to register
• Version v1.14.35 is unable to load OMO normally again #25799
• v1.14.35 Desktop shows plugin loaded, but oh-my-openagent custom agents not visible in GUI (TUI works when launched from same exe) #25824
• After update to v.14.37, in desktop app. Agent not showing up the plugin list. In CLI it is working fine. #25840

Environment

• OS: Windows 11
• OpenCode Desktop: 1.14.39
• OpenCode CLI: 1.14.39 (via Bun, works fine)
• Node.js: bundled with Desktop

[herjarsa]

Additional confirmation: affects multiple users with same root cause

I can confirm this exact same issue. After extensive debugging:

What we found

• CLI mode (opencode in PowerShell): All Bun plugins work perfectly ✅
• Desktop v1.14.39: All Bun-target plugins fail to load ❌

Root cause confirmed

The issue is NOT in the plugins themselves. It's the Desktop sidecar runtime change from Bun → Node.js in v1.14.35+.

Affected plugins tested

• oh-my-openagent@latest (v3.17.15) — agents invisible in Desktop, works in CLI
• @cortexkit/opencode-magic-context@latest (v0.16.3) — fails in Desktop
• opencode-mission-control@latest (v1.6.0) — fails in Desktop
• @plannotator/opencode@latest (v0.19.8) — fails in Desktop

All of them:

• Work perfectly in CLI (Bun runtime)
• Fail in Desktop (Node.js sidecar lacks Bun.* APIs)

Temporary workaround for users

Use CLI mode instead of Desktop:
`�ash

CLI works fine

opencode
`

Downgrading Desktop to v1.14.33 also restores functionality.

This is definitively a Desktop runtime regression, not individual plugin bugs. Plugin developers cannot fix this — it needs to be addressed in OpenCode Desktop's sidecar runtime selection or polyfill layer.

cc @Brendonovich

[herjarsa]

Consolidated tracking issue for this Bun sidecar regression: #DESCONOCIDO

[criticalcognition]

Hey @herjarsa. Question for you and the OpenCode team. Are you considering a fix/patch for this? I have a plugin that requires the Bun version to access the shell using $. I am using the CLI Web version for now as a workaround. Either way we should probably update the docs to reflect reality. Specifically this from https://opencode.ai/docs/plugins/ :
$: Bun’s shell API for executing commands
If you use $ in your plugin it will fail if you are running in Desktop.