Desktop v1.18.9: npm plugin install still fails with @opencode-ai/plugin@local (regression of #26085)

Description

OpenCode Desktop v1.18.9 (Windows 11, Electron) still fails to load npm plugins. The sidecar resolves @opencode-ai/plugin peer dependency as @local, which does not exist in the npm registry, causing NpmInstallFailedError. Plugins registered in ~/.config/opencode/opencode.json never load — no agents, no hooks, no tools from plugins.

This appears to be a regression or incomplete fix of #26085 (closed).

Environment

• OpenCode Desktop: v1.18.9 (packaged: true)
• OS: Windows 11
• Plugin: oh-my-openagent@latest (v4.19.3+)
• Config location: ~/.config/opencode/opencode.json

Reproduction

1. Install OpenCode Desktop v1.18.9
2. Add to ~/.config/opencode/opencode.json:

   {
     "plugin": ["oh-my-openagent@latest"]
   }
   

3. Launch Desktop
4. Observe: only native build and plan agents available; no plugin agents (Sisyphus, etc.)

Error Log

From ~/.local/share/opencode/log/opencode.log:

timestamp=2026-07-29T15:16:33.344Z level=WARN run=da74ead9 message="background dependency install failed" dir="C:\\Users\\godboss\\.config\\opencode" error="Cause([Fail(NpmInstallFailedError (cause: @opencode-ai/plugin: No matching version found for @opencode-ai/plugin@local.))])"

The sidecar spawns successfully (sidecar connection started { version: 'v1' }) and the server is ready, but the plugin npm install fails silently (only a WARN log, no user-facing error).

Expected Behavior

Plugins listed in opencode.json should load correctly. If install fails, the error should be surfaced to the user (toast/dialog), not silently swallowed.

Workaround

Side-load the plugin via the ~/.config/opencode/plugins/ directory, which bypasses the npm install entirely:

// ~/.config/opencode/plugins/omo-loader.js
import plugin from "oh-my-openagent";
export default plugin;

This works because OpenCode auto-discovers JS files in the plugins/ directory and the package is already present in ~/.config/opencode/node_modules/.

Related

• #26085 (closed) — same root cause, reportedly fixed
• #30725 — Desktop not picking up project config (related but different scope)
• code-yeongyu/oh-my-openagent#3456 — downstream report of missing agents
• code-yeongyu/oh-my-openagent#5025 — downstream known-issue + workaround docs