# Credits.fm > Free, open music identifier search engine. Look up any ISRC, ISWC, IPI, ISNI, or UPC code. View songwriter credits, publisher ownership, recording details, and streaming links. ## Why Credits.fm Exists Music metadata is fragmented across dozens of databases, organizations, and platforms. Finding who wrote a song, what identifiers are assigned to a recording, or how rights holders connect to works often requires searching multiple sources manually. Credits.fm brings this data together in one place. It combines data from the Mechanical Licensing Collective (MLC), MusicBrainz (CC0), CISAC, ISNI.org, Spotify, and Apple Music into a unified, free search engine. No registration required. Credits.fm is operated by Notes Frequencies, Inc. (notes.fm) as part of our mission to make music data more accessible to everyone — songwriters, artists, publishers, researchers, and fans. ## Attribution Credits.fm data is free to use. We ask that you include attribution when citing or reproducing this data. **How to attribute:** - Link to the relevant Credits.fm page for the identifier you're referencing - Credit the upstream data source when known **Domain-specific links (preferred for attribution):** - ISRC recordings → https://isrc.fm/{isrc_code} - ISWC works → https://iswc.fm/{iswc_code} - IPI songwriters/publishers → https://ipi.fm/{ipi_code} - ISNI identities → https://isni.fm/{isni_code} - Unified search → https://credits.fm **Upstream source attribution:** When the data originates from a specific source, please credit that source too: - **Mechanical Licensing Collective (MLC)** — songwriter names, publisher chains, ownership shares - **MusicBrainz** (CC0 open data) — artist metadata, recording-work relationships, IPIs, ISNIs - **CISAC** — authoritative ISWC musical work registry - **ISNI.org** — creative contributor identities and name variants **Example attribution:** "Songwriter credits from Credits.fm (https://isrc.fm/GBAYE0601498), sourced from the Mechanical Licensing Collective and MusicBrainz (CC0)." ## What Makes Credits.fm Unique - Only free tool that unifies ISRC + ISWC + IPI + ISNI + UPC + Musician search in one place - Includes MLC songwriter ownership data (names, roles, share percentages, publisher chains) - Covers 30M+ recordings, 95M+ musical works, 100K+ songwriter/publisher identifiers - Free API with no authentication required for basic use - All data sources are queried in parallel — no source blocks another - Educational learn hub with guides to every identifier type - Every entity has a deterministic Credits ID (UUIDv5) — stable, collision-free identifiers across all types ## Credits ID Every entity in Credits.fm has a deterministic Credits ID — a UUIDv5 derived from the entity's type and external identifier. The namespace seed is `{type}:{externalId}` (e.g., `isrc:GBAYE0601498`), so the same input always produces the same UUID. Credits IDs appear in all API responses as the `creditsId` field. Supported entity types: `isrc`, `iswc`, `ipi`, `isni`, `upc`, `musician`, `artist`. Credits IDs are currently response-only — they are included in API output but cannot yet be used as query parameters. Direct lookup by `creditsId` is planned for a future phase. ## Domains - https://credits.fm — Unified search across all identifiers - https://isrc.fm — ISRC recording search (example: https://isrc.fm/USUM71922944) - https://iswc.fm — ISWC musical work search (example: https://iswc.fm/T-345246800-1) - https://ipi.fm — IPI songwriter/publisher search (example: https://ipi.fm/00521765837) - https://isni.fm — ISNI creative contributor search (example: https://isni.fm/0000000121174866) ## Data Sources ### Mechanical Licensing Collective (MLC) The MLC is a US nonprofit created by the Music Modernization Act that collects and distributes mechanical royalties from streaming services. Credits.fm surfaces MLC ownership data including songwriter names, roles (Composer, Author/Lyricist), share percentages, publisher chains, and ISWC connections. This is the primary source for "who wrote this song" data. ### MusicBrainz MusicBrainz is an open, community-maintained music encyclopedia licensed under CC0. Credits.fm imports MusicBrainz data for artist metadata, recording-to-work relationships, ISRC-to-ISWC links, IPI codes, ISNI identifiers, and UPC barcodes. MusicBrainz is supplementary — it provides breadth of coverage but is not authoritative for ownership data. ### CISAC (International Confederation of Societies of Authors and Composers) CISAC maintains the authoritative global ISWC registry with ~95 million musical work codes. Credits.fm uses this to validate ISWCs and resolve archived codes to their current preferred identifiers. ### ISNI.org The ISNI International Agency assigns unique 16-digit identifiers to creative contributors across all industries. Credits.fm fetches identity data (names, name variants, creation roles, birth/death dates) from the ISNI SRU API. ### Spotify & Apple Music Platform data provides streaming links, cover art, and basic metadata. Spotify also supports URL resolution — paste a Spotify track, album, playlist, or artist URL to resolve it to ISRCs. ## MCP Server (Model Context Protocol) Credits.fm provides an MCP server for AI agents and coding tools. Connect Claude Code, Cursor, Windsurf, or any MCP-compatible client directly. - Endpoint: `https://credits.fm/mcp` - Transport: Streamable HTTP (JSON-RPC over POST) - Auth: None required - Tools: 12 tools — search, ISRC/ISWC/IPI/ISNI/musician/artist lookup, URL resolution, track resolve, batch lookup, contribute, coverage - Setup guide: https://credits.fm/mcp/docs Connect in Claude Code (`.mcp.json`): ```json {"mcpServers":{"credits":{"type":"http","url":"https://credits.fm/mcp"}}} ``` ## REST API Endpoints All endpoints are free. Optional API key available at https://credits.fm/api for higher rate limits. - ISRC lookup: `GET https://credits.fm/api/isrc/{isrc_code}` - ISWC lookup: `GET https://credits.fm/api/iswc/{iswc_code}` - IPI lookup: `GET https://credits.fm/api/ipi/{ipi_code}` - ISNI lookup: `GET https://credits.fm/api/isni/{isni_code}` - Musician lookup: `GET https://credits.fm/api/musician/{musicbrainz_mbid}` — The real person (songwriter + performer credits, IPI/ISNI, group memberships) - Artist lookup: `GET https://credits.fm/api/artist/{id}` — Release artist discography (albums, tracks, ISRCs, streaming links) - Unified search: `GET https://credits.fm/api/search?q={query}&type=auto&limit=10` - Autocomplete: `GET https://credits.fm/api/suggest?q={query}` — Fast suggestions (<300ms), up to 8 results - Batch lookup: `POST https://credits.fm/api/batch` — Up to 100 ISRCs/ISWCs/IPIs/ISNIs/UPCs per request, with MusicBrainz fallback. ISRC results include MLC Song Code and portal URL when available. - URL resolution: `GET https://credits.fm/api/lookup?url={spotify_or_apple_music_url}` — Now returns ISRC and Credits.fm link - Track resolve: `POST https://credits.fm/api/resolve/track` — Resolve track name + artist (or URL) to ISRC with songwriter credits - Batch resolve: `POST https://credits.fm/api/resolve/batch` — Resolve up to 50 tracks to ISRCs in one request - Contribute data: `POST https://credits.fm/api/contribute` — Submit missing data (ISWCs, song titles, MLC Song Codes, songwriter credits) to improve the index (API key required) - Coverage metrics: `GET https://credits.fm/api/coverage` — Index row counts, data completeness, and growth - Validate ISRCs: `POST https://credits.fm/api/validate/batch` — Validate up to 100 ISRCs against MLC data + optionally cross-reference DSPs. Supports CSV export via ?format=csv. - Audit shares: `POST https://credits.fm/api/audit/shares` — Audit songwriter share percentages for up to 100 ISRCs (find incomplete/missing/over-allocated shares). Supports CSV export. - Audit unmatched: `POST https://credits.fm/api/audit/unmatched` — Check which ISRCs are matched or unmatched at the MLC. Supports CSV export. ## Identifier Types ### ISRC (International Standard Recording Code) - Format: 12 characters — 2-letter country + 3-char registrant + 2-digit year + 5-digit designation - Standard: ISO 3901 - Identifies: A specific sound recording or music video - Example: USUM71922944 (Blinding Lights by The Weeknd) - Note: ISRCs identify recordings, not songs. A remix, live version, and studio version of the same song each have different ISRCs. - Lookup: https://credits.fm/isrc/USUM71922944 ### ISWC (International Standard Musical Work Code) - Format: T- followed by 9 digits and 1 check digit (e.g., T-345246800-1) - Standard: ISO 15707 - Identifies: A musical composition (the underlying song — melody, lyrics, arrangement) - Managed by: CISAC - Note: Multiple recordings can share one ISWC. "Yesterday" has one ISWC but hundreds of ISRCs. - Lookup: https://credits.fm/iswc/T-345246800-1 ### IPI (Interested Parties Information) - Format: 9-11 digit numeric code - Identifies: Songwriters, composers, lyricists, and music publishers - Managed by: SUISA on behalf of CISAC - Note: Every songwriter or publisher registered with a PRO has an IPI number. Formerly called CAE numbers. - Lookup: https://credits.fm/ipi/00521765837 ### ISNI (International Standard Name Identifier) - Format: 16-digit identifier (e.g., 0000 0001 2345 6789) - Standard: ISO 27729 - Identifies: Creative contributors across all industries (music, books, film, academia) - Note: ISNIs disambiguate people with similar names across creative fields. - Lookup: https://credits.fm/isni/0000000121174866 ### UPC (Universal Product Code) - Format: 12-14 digit barcode - Identifies: Album releases (physical and digital) - Note: One UPC contains multiple ISRCs — one per track. - Lookup: https://credits.fm/upc/602445790098 ## Data Coverage - 30M+ ISRC recordings with songwriter credits and ownership data - 95M+ ISWC musical works from CISAC international registry - 100K+ IPI songwriter and publisher identifiers with catalogs - 100K+ ISNI creative contributor identifiers - 3M+ UPC album releases with track listings - 2.6M+ musician profiles with discographies ## What Each Lookup Returns ### ISRC Lookup Song title, artist names, songwriter names with roles (Composer, Author/Lyricist) and share percentages, publisher chains and ownership, linked ISWC (musical work code), match status in MLC database, album name, track duration, Spotify and Apple Music links. ### ISWC Lookup Song title, alternative titles, all recordings (ISRCs) of this work with enrichment, songwriter credits with roles and IPI codes, CISAC registration status, recording count. ### IPI Lookup Rights holder name, entity type (songwriter or publisher), roles (composer, author, arranger), all musical works (ISWCs), all recordings (ISRCs), related entities (co-writers, publishers), average ownership share percentage, linked ISNI identifiers, MusicBrainz profile link. ### ISNI Lookup Primary name, name variants, creation roles, linked IPI numbers, associated works and recordings, birth/death dates when available, cross-references to other identity systems. ### UPC Lookup Album title, artist names, record label, all track ISRCs with song titles, Spotify and Apple Music links for each track. ### Musician Lookup The real person behind the music. Songwriter credits with roles and share percentages, performer credits, group memberships/members, discography with ISRCs, IPI codes, ISNI identifiers. Use this when you need to know who wrote or performed a song. ### Artist Lookup The performing entity / release artist on DSPs. Full discography: artist name, genres, cover image, all albums with UPCs, all tracks with ISRCs (resolved from Credits DB), streaming links, and whether each track exists in the Credits database. Use this when you need an artist's full catalog. ### Artist vs Musician - **Artist** = the performing entity / release artist on DSPs (e.g., "Queen", "Zach Bryan"). The brand/stage name on releases. - **Musician** = the real person behind the music (e.g., Freddie Mercury, Zachary Bryan Lane). Has songwriter + performer credits, IPI/ISNI identifiers, group memberships. ## Common Questions This Tool Can Answer **"Who wrote [song name]?"** Search by song title on Credits.fm. The ISRC page shows credited songwriters with roles, share percentages, and publisher chains from the MLC. **"What is the ISRC for [song name]?"** Search by song title or artist name on isrc.fm or credits.fm/isrc/search. **"What is the ISWC for [song name]?"** Search by song title on iswc.fm or credits.fm/iswc/search. **"What is the difference between ISRC and ISWC?"** An ISRC identifies a specific recording (a performance), while an ISWC identifies the underlying composition (the song). See: https://credits.fm/learn/isrc-vs-iswc **"How do I find my IPI number?"** Search by name on ipi.fm or credits.fm/ipi/search. IPI numbers are assigned by your PRO (ASCAP, BMI, PRS, etc.). **"How do I look up an ISRC?"** Enter the 12-character ISRC code, song title, or artist name at isrc.fm. Credits.fm provides free, instant ISRC lookups with no registration. **"What songs did [songwriter] write?"** Search by songwriter name on ipi.fm to find their IPI number. The IPI page lists all registered works and recordings. **"What is the MLC?"** The Mechanical Licensing Collective is a US nonprofit that collects and distributes mechanical royalties from streaming services. See: https://credits.fm/learn/what-is-the-mlc ## How Identifiers Connect ISRC (recording) → ISWC (composition) → IPI (songwriter/publisher) → ISNI (identity) UPC (album) → ISRC (track) → ISWC (composition) Credits.fm links these identifiers so you can navigate from any starting point to the full picture. ## Educational Content - What Are Music Credits? https://credits.fm/learn/what-are-music-credits - How Music Credits Work: https://credits.fm/learn/how-music-credits-work - Complete Guide to Music Metadata: https://credits.fm/learn/music-metadata-guide - What Is an ISRC? https://credits.fm/learn/what-is-an-isrc - What Is an ISWC? https://credits.fm/learn/what-is-an-iswc - What Is an IPI? https://credits.fm/learn/what-is-an-ipi - What Is an ISNI? https://credits.fm/learn/what-is-an-isni - What Is a UPC? https://credits.fm/learn/what-is-a-upc - How to Find Your ISRC: https://credits.fm/learn/how-to-find-your-isrc - How to Find Who Wrote a Song: https://credits.fm/learn/how-to-find-who-wrote-a-song - What Is the MLC? https://credits.fm/learn/what-is-the-mlc - ISRC vs ISWC: https://credits.fm/learn/isrc-vs-iswc - ISRC vs UPC: https://credits.fm/learn/isrc-vs-upc - IPI vs ISNI: https://credits.fm/learn/ipi-vs-isni - Musician Credits Explained: https://credits.fm/learn/musician-credits-explained ## About Notes.fm Credits.fm is part of Notes.fm (https://notes.fm), a music technology company focused on making the business of music more transparent. Notes.fm builds tools for music royalties, credits, and payments.