canonical: https://jentic.com/apis/freqblog.com/freqblog

# Freqblog Music Metadata API

The Music Metadata API returns audio features such as BPM, musical key, energy, danceability, and valence for a track, and extracts the same features from an uploaded file, so an application can analyse music without running its own audio pipeline. You look up a track by name, ISRC, MusicBrainz ID, or Spotify ID, fetch Spotify-shape audio features for compatibility, or analyse and fingerprint-identify your own audio. Catalog, harmonic-mixing, and recommendation endpoints add search by BPM or key, similar-track discovery, radio and setlist building, and bulk enrichment of a CSV of tracks.

## For AI agents

Look up track audio features by name, ISRC, MusicBrainz ID, or Spotify ID, analyse uploaded audio, and build harmonic setlists in the Music Metadata API. Authenticates with an API key in the X-Api-Key header.

## Scope

Does not stream audio, host music files, or handle licensing and royalties. Use for audio-feature lookup, analysis, and harmonic-mixing metadata only.

## Capabilities

- Look up a track's audio features by name, ISRC, MusicBrainz ID, or Spotify ID
- Extract BPM, key, energy, and more from an uploaded audio file
- Identify a recording by its audio fingerprint
- Find tracks by BPM or by musical key, including harmonically compatible keys
- Discover acoustically similar tracks and build a harmonic radio playlist
- Order a crate into a beat-matched, energy-arced setlist
- Bulk-enrich a CSV of artist and title pairs with audio features

## Use cases

### Agent-Driven Track Analysis

An AI agent connected through Jentic answers a question about a song by looking it up and returning its BPM, key, energy, and valence, so a product can tag or filter music without a separate analysis step. Because the lookup accepts a name, ISRC, MusicBrainz ID, or Spotify ID, the agent can resolve a track from whatever identifier it already holds.

Example prompt: Look up this track by name and artist and return its BPM, key, energy, and danceability

### Audio Feature Extraction

A workflow that holds its own audio extracts features directly by posting the file for analysis, and can fingerprint-identify an unknown recording, so a library gets consistent metadata whether or not the track is already catalogued. The analysis returns the same feature set as the catalog lookups, so downstream logic treats both sources the same way.

Example prompt: Analyze this uploaded audio file and return its BPM, key, and energy, then identify the recording

### Harmonic Mixing and Playlists

A DJ or playlist tool builds sets that flow by finding harmonically compatible keys, scoring how well two tracks mix, and ordering a crate into a beat-matched, energy-arced setlist, so a mix holds together without manual key-matching. Radio and next-track endpoints extend a seed into a continuous playlist tuned for harmony and tempo.

Example prompt: Order this crate into a beat-matched, energy-arced set and suggest the next track after the closer

## Key endpoints

| Method | Path | Description |
| --- | --- | --- |
| POST | `/analyze` | Extract audio features from an uploaded file |
| GET | `/lookup` | Look up a track by name, ISRC, MusicBrainz ID, or Spotify ID |
| GET | `/v1/audio-features/{identifier}` | Get Spotify-compatible audio features for a track |
| POST | `/identify` | Identify a recording by audio fingerprint |
| GET | `/bpm` | Find tracks by BPM |
| GET | `/recommendations` | Get recommended tracks for seed tracks |
| GET | `/search` | Search the catalog by track, artist, or album |
| POST | `/setlist` | Order a crate into a beat-matched set |

## Key resources

- **Audio Features** — BPM, key, energy, danceability, and valence by lookup or file analysis
- **Catalog** — Track, artist, genre, and chart lookups with search by BPM or key
- **Harmonic Mixing** — Compatible keys, transition scoring, radio, next-track, and setlist building
- **Bulk** — Batch lookup and CSV enrichment of artist and title pairs

## AI readiness

This API is usable in Jentic One now. Its AI-readiness score against Jentic's framework shows where it stands today and where improvements would make it even easier for agents to use.

- **Score:** 66 / 100
- **Maturity:** AI-Aware
- **Dimensions:**
  - Foundational Compliance: 67 / 100
  - Developer Experience & Jentic Compatibility: 67 / 100
  - AI-Readiness & Agent Experience: 56 / 100
  - Agent Usability: 94 / 100
  - Security: 50 / 100
  - AI Discoverability: 83 / 100
- **View full report:** https://jentic.com/apis/freqblog.com/freqblog/scorecard
- **How the score is calculated:** https://docs.jentic.com/reference/api-readiness-framework/overview/
- **More about the dimensions:** https://docs.jentic.com/reference/api-readiness-framework/specification/#dimensional-model-overview

### Score it yourself

Every API in the directory is allowlisted, so you can re-score it with no key required.

- **Score your own API:** https://jentic.com/scorecard.md
- **Scoring CLI agent skill:** https://github.com/jentic/jentic-api-scorecard/blob/main/skills/jentic-api-scorecard/SKILL.md

```sh
npx @jentic/api-scorecard-cli score <openapi-url>
```

## Why Jentic

- **Setup:** Wiring the Music Metadata API by hand means handling X-Api-Key auth and picking the right lookup path for whichever identifier you hold, whether a name, ISRC, MusicBrainz ID, or Spotify ID. Through Jentic you install once, import the Music Metadata API from the API Directory, store the key once, and your agent calls it.
- **Permission scoping:** You choose which operations your agent may call, so you can allow track lookups and audio analysis while leaving webhook configuration out. Rules bound which operations run, so the agent analyses the music you grant and nothing else.
- **Credential handling:** Your Music Metadata API key is stored once, encrypted, by your own Jentic One instance and injected at execution time. It never enters the agent's prompt, logs, or context.
- **Discovery method:** Agents search Jentic by intent such as 'get a track's BPM and key' or 'analyze an audio file', and Jentic returns the matching Music Metadata operation with its input schema so the agent calls the right endpoint without browsing the reference docs.

## Related APIs

- **Spotify Web API** — Music catalog and playback API whose audio-features endpoint this service replaces
- **MusicBrainz API** — Open music encyclopedia with recordings, releases, and MusicBrainz IDs
- **Last.fm API** — Music metadata and listening-data API with artist and track information

## FAQ

### Is there a Freqblog MCP server?

You don't need an MCP server to give your agent the Music Metadata API. Jentic connects it directly from the API Directory: import it, store your key once, and your agent can look up audio features and analyze audio straight away, with no extra server to run and no tool definitions sitting in the agent's context.

### Can I limit what my agent is allowed to do with the Music Metadata API?

Yes. The API is mostly read and analysis operations, so you can write a rule that allows only lookups and feature extraction and leaves webhook changes out. Every call the agent makes is logged, so you can see exactly which tracks it analysed.

### What authentication does the Music Metadata API use?

The Music Metadata API authenticates with an API key sent in the X-Api-Key header per its OpenAPI spec. Through Jentic the key is stored encrypted by your own instance and added to each request at call time, so it never appears in the agent's prompt or logs.

### Can I use the Music Metadata API as a Spotify audio-features replacement?

Yes. Dedicated endpoints return audio features in a Spotify-compatible shape by identifier, including a batch form, so code written against the deprecated Spotify audio-features endpoint can switch over. You can also look up tracks by ISRC or MusicBrainz ID when you do not have a Spotify ID.

### What are the rate limits for the Music Metadata API?

The OpenAPI spec does not state request rate limits for the Music Metadata API. For current limits and fair-use guidance, check the provider documentation at https://freqblog.com.

### How do I analyze a track through Jentic?

Import the Music Metadata API from the Jentic API Directory, then have your agent issue a request such as 'get the BPM and key for this track'. Jentic matches the intent to the lookup operation and returns its input schema so the agent builds the correct request, with your stored key injected at call time. To run it on your own infrastructure, install Jentic One from its GitHub repo.