dsh-agents-md-editor

A DSH bundle: one left-sidebar entry that opens an editor page for the Agent instructions file, ~/.dsh/AGENTS.md.

• Left sidebar entry — registered in sidebar.panellist; the matching main keyed panel is the page the entry opens.
• Live — the page polls the file's sha1 version every 2s. An edit made elsewhere (the agent, another editor) appears automatically while the buffer is clean; with unsaved text it raises a banner instead of overwriting.
• Safe save — POST /agents-md-editor/api/save carries the version the page loaded and is refused with conflict (409) if the file changed meanwhile. Writes go to a temp sibling and are renamed into place, so a crash never leaves a truncated instructions file.
• Draft survives panel switches — switching to the conversation and back restores unsaved text.
• Follows the host type scale — every size reads the theme's own variables (--dsh-content-font-size, --dsh-content-font-size-secondary), so Settings → General → body font size resizes this page too; no px values are hardcoded.

Install

From the registry:

dsh plugin --profile desktop add dsh-agents-md-editor

From a local checkout (development):

dsh plugin --profile desktop add ./dsh-agents-md-editor

Either way the bundle lands in the profile, and the left sidebar grows one entry (「代理说明编辑器」/「Agent Instructions Editor」).

Configuration

filePath (default ~/.dsh/AGENTS.md) is the only file the plugin reads and writes. ~ and ~/ are expanded; a relative value resolves against the Host process working directory.

- id: agents-md-editor
  name: 'dsh-agents-md-editor'
  config:
    filePath: '~/.dsh/AGENTS.md'

Routes

Both routes are gated by ctx.connection.requestRejection — the same browser-trust fence the shipped plugins use — and neither accepts a path:

Route	Method	Body / result
/agents-md-editor/api/state	GET	{ exists, path, content, version, mtimeMs, size }
/agents-md-editor/api/save	POST	{ content, baseVersion } → { path, version, mtimeMs, size, savedAt }

version is the sha1 of the file's UTF-8 bytes.

Notes

The Host half writes with node:fs rather than the file sandbox, because the target deliberately lives outside the session workspace and a UI action has no approval channel. The route table takes no user-supplied path, so the reachable surface is the single configured file.

Verifying

node test/host.test.mjs   # or: npm test

22 checks against a throwaway file in the OS temp directory: missing file, first create, normal save, stale baseVersion → 409 with the file untouched, 405/404/400, the trust fence → 403, and ~ expansion. The real ~/.dsh/AGENTS.md is never opened.

License

MIT — see LICENSE.