Create songs from separated stems with MCP
LangBeat’s Model Context Protocol server gives Codex and compatible agents tools to find recorded vocals, drums, bass, guitar, piano and effects, select compatible recordings, and build songs for private listening.
The connector uses your signed-in account. Source discovery and downloads follow your permissions. Automatic stem rendering is currently in private QC; get_create_capabilities tells your agent whether your account can render.
Connect from the Create tab
- Sign in to LangBeat, open Create, and choose Connect assistant.
- Choose Connect Codex. LangBeat refreshes your session when needed and verifies the connection.
- Choose Copy complete setup, paste it into your Codex MCP configuration, and reconnect LangBeat. The setup includes your session credential; no separate environment variable is needed.
Connections expire within one hour. Return to Connect assistant to renew. Keep the copied setup private. Codex supports static authorization headers in its MCP configuration.
Optional: environment variable setup
If you manage credentials through your environment, use the session credential from the complete setup as LANGBEAT_MCP_TOKEN with this configuration instead.
[mcp_servers.langbeat]
url = "https://langbeat.live/api/mcp"
bearer_token_env_var = "LANGBEAT_MCP_TOKEN"
tool_timeout_sec = 120This is a Streamable HTTP MCP endpoint. Other clients can use the same URL with an Authorization: Bearer header containing the session token. A public catalogue API key is a separate, read-only credential and does not authorize this connector.
Music tools for agents
| Tool | What it does |
|---|---|
get_create_capabilities | Check which song engines your account can use before starting work. |
find_stem_sources | Find analyzed vocals or backing recordings, optionally matched to an anchor track. |
get_track_stems | Read a recording's available separated stems, measured tempo and key. |
create_stem_song | Render one selected vocal/backing pair or three fresh stem arrangements into your Private Tracks. |
get_song_job | Read actual render progress and completed outputs. A queued job is not a finished song. |
list_private_downloads | List your private Create songs and obtain short-lived listening download links. |
Try a three-song session
Check LangBeat’s Create capabilities. Make three fresh songs using separated stems, with different source recordings. Keep them private. Wait for completed renders, then show each song’s title, duration, tempo, sources and private download.
The agent checks availability, inspects sources, and starts create_stem_song with count: 3 and stable request and project UUIDs. It polls get_song_job every 15–30 seconds, then verifies all three outputs through list_private_downloads. A queued job or a partial result is not three completed songs.
Choose your own vocal and backing
Use find_stem_sources with the vocal role first, then search the backing role with that recording’s anchorId. Inspect the separated parts using get_track_stems. Pass the two recording IDs to create_stem_song with count: 1. Compatibility uses recorded analysis; a matching BPM or key alone does not prove that a pair sounds good.
Private downloads and ownership
Finished songs appear in Create → Your Songs, where you can search, listen and download. Download links expire after ten minutes. The connector has no publishing, sharing, deletion or account-settings tools. Source recording rights still apply; stem separation and private creation do not grant a licence to release a remix.
How this differs from the catalogue API
The LangBeat REST API searches public music measurements and charts. The MCP connector performs an authenticated Create workflow. For music concepts, see stem energy, harmonic mixing and measured BPM and key.