Lexicon MCP

Manage your Lexicon DJ library from an MCP-compatible AI assistant. Search tracks, inspect library health, organize playlists, and review bulk changes before applying them.

Runs locally through Lexicon's documented Local API. No companion plugin or native installer is needed.

Quick start

1. Prepare Lexicon and Node.js

• Install Node.js 24, which includes npm and npx. Check with node --version; it should start with v24..

• Open Lexicon DJ on Windows or macOS and enable Settings → Integrations → Local API. Keep Lexicon running while using library tools.

• Choose an MCP client: Claude Desktop, Claude Code, Codex, Cursor, or VS Code / Copilot. Your client supplies the model; this server needs no separate model API key.

2. Run the installer

Copy one command into your terminal. Packages download directly from GitHub; no npm account is required.

Stable release

For published stable releases. The release workflow maintains this command separately from prereleases.

npx --yes https://github.com/DavidNiessen/lexicon-mcp/releases/download/v0.1.0/lexicon-mcp-0.1.0.tgz install

Prerelease

The newest verified build from main. Choose this channel to try current features before a stable release.

npx --yes https://github.com/DavidNiessen/lexicon-mcp/releases/download/v0.1.0-dev.41136651697.1/lexicon-mcp-0.1.0-dev.41136651697.1.tgz install

All releases and package checksums

3. Select your agents and restart them

The installer asks for the installation scope and the agents to configure:

• User scope: available across projects. Use this for Claude Desktop.

• Project scope: available in the current directory for clients that support it. Run the command from that project.

It preserves unrelated settings, backs up changed configurations, and saves the server in persistent user storage. You can select several agents in one run. Restart or reconnect each selected client to load the server and its tools.

To skip the selection prompts, append the relevant options to the install command above:

See agent configuration paths and scope support for details. --dry-run leaves configuration and runtime files unchanged; npm may still download the package into its cache.

4. Try your first request

Start with a small, read-only check:

Use Lexicon to check MCP UI support and list five tracks. Do not change anything.

Then try a report or a reviewed change:

Audit my library's metadata and show the findings without making changes.

Prepare one plan to add an existing tag to selected tracks, show its preview, and request approval.

Plan creation and inspection return compact text summaries. The assistant shows one read-only preview widget, then sends a separate approval question in chat. It should offer Approve changes and Cancel through its own native question controls when available, such as Claude Code’s AskUserQuestion; otherwise it asks a plain chat question. Only your explicit answer authorizes the exact saved plan. The preview never applies changes by itself.

Related MCP server: Codex Local Gateway

What you can do

All persistent library edits require a saved plan and explicit approval, including edits to a single track. Splitting a bulk request into individual calls cannot bypass review. Plans record exact targets, before-values, and per-operation outcomes; stale plans are rejected. The assistant should prepare one plan for the task. See changes and recovery.

This is an independent integration and requires Lexicon DJ for live library access. Client UI support and Lexicon compatibility vary; see the verification record. No audio or proprietary Lexicon implementation is distributed.

Update or remove

• Update: rerun the install command for your preferred channel and select the agents to update, then restart them.

• Remove: use the same command with uninstall instead of install, keeping your agent and scope selection. Restart the affected clients afterward.

Other MCP servers and saved library reports remain separate from registration. See updating and uninstalling for details.

Troubleshooting

Previews do not use widget tool-call bridges. After showing the proposed values, the assistant must send its own approval question in chat; it must not direct you to an approval button inside the preview. Lexicon MCP does not open a server-side approval dialog. If native chat question controls are unavailable, the assistant asks for an explicit text reply. Update and restart the client to load this flow. The installer removes the former LEXICON_APPROVAL_UI override while preserving other settings.

lexicon_get_change_plan only inspects data. lexicon_preview_change_plan shows the read-only widget, and lexicon_review_change_plan prepares the exact-plan question that the assistant must send. Approval happens through the assistant’s chat question, never inside the preview or a separate Lexicon DJ window.

More: installation and troubleshooting, including manual configuration, read-only mode, and authenticated loopback HTTP.

Documentation

• Installation and configuration

• Tools, commands, workflows, and previews

• Review policy, outcomes, and recovery

• Architecture

• Compatibility and verification

• Development and releases

• Contributing · Security · Code of conduct

Develop

Use Node.js 24 and the pnpm version pinned in package.json:

pnpm install --frozen-lockfile
pnpm check
pnpm test
pnpm build
pnpm package

Packaging creates a platform-neutral Node tarball, installation guide, checksums, SBOM, and dependency notices. CI verifies Linux, Windows, and macOS. Successful main builds publish prereleases; the manual Release workflow can publish either channel. After publication, it updates only that channel's marked install block above. npm registry publishing is disabled.

License

MIT. Dependency licenses accompany release artifacts.