[FEATURE]: Make desktop "Open in" menu configurable with custom editors (re-open of #15500) #57477

Summary

The desktop "Open in" dropdown is populated from a hardcoded list (OPEN_APPS in packages/app/src/components/session/open-in-app.tsx). Users cannot add their own apps (Obsidian, PhpStorm, Emacs, Neovim, Helix, Positron, …).

#15500 requested exactly this (9 👍, several "we need this" comments) and was auto-closed as not-planned by the 60-day stale bot on 2026-07-18 — no maintainer ever decided on it. #18141 (Windsurf missing from the list) was closed the same way on 2026-07-03. This issue recreates the request so it doesn't get lost again.

Proposed solution

Allow custom entries in opencode.json:

{
  "open": {
    "apps": [
      { "label": "Obsidian", "command": "Obsidian" },
      { "label": "Emacs", "command": "emacsclient" }
    ]
  }
}

Entries would appear alongside the auto-detected apps. command would feed into the existing platform.openPath(path, openWith) (app name on macOS, CLI on Windows/Linux). An optional icon field would be a nice addition.

Current behavior

Dropdown = file manager + hardcoded list filtered by platform.checkAppExists. Every missing editor currently needs its own "add X to the list" PR (#14412 VS Code Insiders, #18141 Windsurf, #29696 Positron) — a configurable list would end that churn.

Environment

• opencode v2.0.32 (desktop), macOS arm64

Related

• Closed by stale bot: [FEATURE]: Make the desktop app "Open in" menu configurable with custom editors #15500, fix(desktop): Windsurf is not a valid option in "Open In" dropdown #18141 · closed as duplicate: Add Positron (VS Code fork) to Open in... #29696 · closed as not planned: [FEATURE]: Re-add "Open in external editor" to the new TUI  #30135 (TUI), v1.16.X Desktop (Windows): "Open with..." dropdown gone from session header — regression from v1.15.10 #31101, "Open in" drop-down menu #31507
• Open, overlapping: [FEATURE]: Allow users to customize how project files are opened from the TUI (e.g. Typora, VS Code, Notepad++) #48648 (TUI externalEditors), [FEATURE]: Map file types to external applications when opened from chat (like link handling) #47765 (file-type → app mapping)