dsh-mcp-diff

A client plugin for the DeepSeek Harness (Web GUI) that renders every file mutation in the chat as uniform diff cards — collapsed by default, with per-line highlighting (green for additions, red for deletions).

Covers both the filesystem MCP server (edit_file / write_file) and the built-in DSH tools (edit / write), bringing them to one look.

Why

By default DSH draws a diff only for its own file tools (edit, write), with its own renderer. When the agent edits files through the @modelcontextprotocol/server-filesystem MCP server, the call is named mcp__filesystem__edit_file / mcp__filesystem__write_file — there is no registered toolview for it, so the chat shows only a generic block with no diff.

The plugin:

• registers a toolview under the MCP keys and builds the diff from the server response (a ready unified diff with context and @@ headers) or from the call arguments when there is no response yet (write_file, a still-running edit_file);
• also overrides the built-in edit / write, unifying their contextual hunks (a per-line LCS: shared lines read as neutral context instead of being doubled);
• renders everything as one card built on a native <details> — collapsed by default, the header shows the path + +N -M, and it expands on click.

Install

# from npm (prebuilt, recommended)
dsh plugin --profile web add dsh-mcp-diff

# or from GitHub (built on install)
dsh plugin --profile web add github:Fakek0f3sT/dsh-mcp-diff

dsh plugin add is a pnpm forwarder: it adds the package to your profile (~/.dsh/profiles/web) and, since the plugin declares dsh.bundle, automatically includes it in dsh.profile.bundles — nothing to wire by hand. Installed from GitHub, lib/ is built in place (the prepare script); from npm it ships prebuilt.

Important: DSH picks up its plugin set only at startup — after installing, restart dsh web and refresh the GUI page.

Check that the bundle is served:

curl -s http://127.0.0.1:3080/plugins/dsh-mcp-diff/client.js | head -c 80

git clone https://github.com/Fakek0f3sT/dsh-mcp-diff.git
cd dsh-mcp-diff && npm install && npm run build
cd ~/.dsh/profiles/web
npm install /path/to/dsh-mcp-diff

{
  "dependencies": { "dsh-mcp-diff": "link:./node_modules/dsh-mcp-diff" },
  "dsh": { "profile": { "bundles": [ "…", "dsh-mcp-diff" ] } }
}

Configuring for another MCP server

The toolview keys are set for the server name filesystem. If your filesystem MCP server is named differently (the serverName field in the config), edit the TOOL_KEYS constant in src/client/index.tsx (keys of the form mcp__<serverName>__edit_file). The edit / write keys live there too — remove them if you do not want to override the built-in renderer.

Development

npm install
npm run build
node --import tsx/esm src/client/parse-diff.test.ts   # diff-parser self-check

Compatibility

Tested on DSH 0.1.1-rc.2. The plugin imports only platform modules (react, ui-primitives, ui-slots, runtime/client) — ui-tool internals are not imported.

License

MIT