Spotify Streamable

This server is a remote Model Context Protocol (MCP) server for Spotify. A model can use it to search music, to read and control playback, and to manage playlists and saved songs. The server runs on Cloudflare Workers and on Bun. It uses the MCP server template 2.1 and the official MCP TypeScript SDK 2.3.0.

The server URL is the deployed Worker's MCP_PUBLIC_URL, for example https://spotify-mcp.<subdomain>.workers.dev/mcp.

The server uses protocol version 2026-07-28. It also accepts clients that use the 2025 protocol versions.

Author: overment

[!WARNING] You connect this server to your MCP client at your own risk. A model can make mistakes. The server can change your playlists and saved songs, and it can control playback on your devices.

Alice, a desktop AI assistant

Claude Desktop

Tools

The tools do not copy Spotify's API one to one. Each tool takes a batch (queries[], operations[]), and each result has a sentence for the model (_msg) and structured data.

Tool	Function
player_status	Shows the player state, the devices with their device_id, the queue and the current track. Call it before you control playback.
search_catalog	Finds tracks, albums, artists and playlists, for one or more queries. It uses the server's own Spotify app, not the user's account.
spotify_control	Runs a batch of playback operations: play, pause, next, previous, seek, volume, shuffle, repeat, transfer and queue.
spotify_playlist	Lists, reads, creates and changes playlists: list_user, get, items, create, update_details, add_items, remove_items, reorder_items.
spotify_library	Lists, adds, removes and checks saved songs: tracks_get, tracks_add, tracks_remove, tracks_contains.

Tracks, albums, artists and playlists in the results carry image, a thumbnail URL about 300 px wide. For a track, it is the album cover.

spotify_control reports a play or transfer as successful only after Spotify's player state confirms it. When play names no device, the tool prefers the active desktop app to a Web Player. For the details, refer to docs/playback.md.

A device_id is a long identifier from player_status, not a device name such as "MacBook Pro".

Connect a client

Use the server URL and the Streamable HTTP transport. The client signs you in with Spotify the first time.

Client	Procedure
Claude	In Settings → Connectors, add a custom connector with the server URL.
Claude Code	Run claude mcp add --transport http spotify <server URL>.
MCP Inspector	Run bun run inspector. Select Streamable HTTP. Enter the server URL.

Alice and Wonderlands use the same URL.

Authentication

The server is its own OAuth authorization server, in front of Spotify's OAuth. MCP clients do not receive Spotify tokens.

1. The client registers at /register and signs the user in at /authorize. The client must use PKCE S256.
2. The server sends the user to Spotify. Spotify asks for the nine scopes of the server.
3. Spotify returns the user to the server's /oauth/callback. The server keeps the Spotify tokens, encrypted.
4. The client gets a code, and exchanges the code at /token for an access token and a refresh token. These tokens are opaque and have meaning only for this server.
5. On each MCP request, the server finds the Spotify token for the access token. If the Spotify token expires in less than one minute, the server refreshes it first. The tools use the Spotify token. They do not see the client's token.

For the complete flow, the storage and the redirect rules, refer to docs/oauth.md.

Configuration

The deployment settings are in wrangler.production.jsonc (Workers; gitignored, with wrangler.production.example.jsonc as its shape) or .env (Bun). .env.example describes all variables.

Variable	Production value	Function
MCP_PUBLIC_URL	https://spotify-mcp.<subdomain>.workers.dev/mcp	The public URL of the MCP endpoint. It is also the resource that tokens are issued for.
MCP_ALLOWED_HOSTS	spotify-mcp.<subdomain>.workers.dev	The Host headers that the server accepts.
MCP_ALLOWED_ORIGIN_HOSTNAMES	The server host, claude.ai, claude.com, and the hosts of the operator's own browser clients	The browser origins that the server accepts.
AUTH_MODE	oauth	The server checks the tokens that it issued.
OAUTH_ISSUER_URL, OAUTH_AUTHORIZATION_URL, OAUTH_TOKEN_URL, OAUTH_REGISTRATION_URL	This server's origin, /authorize, /token and /register	The authorization server that clients use. The server does not start if they name another server.
PROXY_REDIRECT_ALLOWLIST	Alice, Claude, Wonderlands and overment callbacks	The client redirect URIs that the proxy accepts, in addition to native loopback URIs.
MCP_MAX_REQUEST_BYTES	1048576	The largest MCP request body.
MCP_LEGACY_MODE	stateless	The server also accepts 2025-era clients.
SPOTIFY_INCLUDE_JSON_IN_CONTENT	unset (false)	When true, each tool result also has its structured data as JSON text, for clients that ignore structured content.

Secrets:

Secret	Function
SPOTIFY_CLIENT_ID	The client ID of the server's Spotify app.
SPOTIFY_CLIENT_SECRET	The client secret of the server's Spotify app.
RS_TOKENS_ENC_KEY	32 random bytes, base64url. The key encrypts the stored tokens. If you change it, all users must sign in again.
TOKENS_ENC_KEY	The older name of the key. The server uses it only when RS_TOKENS_ENC_KEY is not set.

The Spotify accounts endpoints and the scopes are constants in src/services/spotify-oauth.ts. For the setup at Spotify and at Cloudflare, refer to docs/deploy.md.

Development

Requirements: Bun 1.4 or later, and Node.js 22.18 or later.

1. Install the dependencies:

   bun install
   

2. Copy .env.example to .env. Set SPOTIFY_CLIENT_ID, SPOTIFY_CLIENT_SECRET and RS_TOKENS_ENC_KEY. In the Spotify dashboard, add the redirect URI http://127.0.0.1:3000/oauth/callback.

3. Start the server:

   bun run dev
   

   The server URL is http://127.0.0.1:3000/mcp. To use the Cloudflare local runtime, run bun run dev:worker (port 8787). Put its secrets in .dev.vars.

4. Before you commit, run the checks:

   bun run check
   bun run test:smoke
   

bun run check does the type check, the lint check and the tests. bun run test:smoke starts the real server on Bun and on workerd. It signs in through a Spotify stand-in on loopback and calls the tools. No test uses the network.

Script	Function
bun run dev	Starts the server on Bun.
bun run dev:worker	Starts the server in the Cloudflare local runtime.
bun run check	Type check, lint check, tests, and the check of the generated Worker types.
bun run test:smoke	Smoke tests on Bun and on workerd.
bun run deploy	Deploys with the gitignored wrangler.production.jsonc (wrangler deploy --config wrangler.production.jsonc).
bun run types:worker	Makes the Worker types again after a change to wrangler.jsonc.

Project structure

src/
  server.ts       Identity, Runtime, Deps, and the hooks that connect the OAuth proxy
  settings.ts     The Spotify app, the encryption keys, the redirect allowlist
  tools/          One file for each tool; shared/ has the schemas, playback checks and helpers
  services/       Spotify Web API clients, and spotify-oauth.ts: Spotify as the OAuth provider
  oauth/          The OAuth proxy. It is the same as in gmail-mcp (docs/oauth.md)
  platform/       Template code. Do not change it
  bun.ts          Entry point for Bun: file storage
  worker.ts       Entry point for Workers: KV and the NativeOAuthAuthority Durable Object
tests/            Tests for the tools, the proxy and the platform; fixtures from before 1.1.0
scripts/          Smoke tests and the Spotify stand-in

For the template's concepts (the request path, defineTool, the error policy, the configuration checks), refer to the template documentation.

License

MIT