_ registry / mcp streamable-http · checked 25m ago

freqblog-music

https://mcp.freqblog.com

Registry code: 08fd0ecd6cacbb83

api record

FreqBlog music audio-features tools. Look up BPM, musical key (name + Camelot + Open Key), energy, danceability, valence, acousticness, instrumentalness, mood, genre, chart_peak (best chart position held, 1-100 where 100 = a number-one; null = none held, i.e. UNKNOWN rather than unpopular, and NOT audience size) and 30+ more for real tracks — a drop-in replacement for Spotify's removed audio-features endpoint. No audio upload needed; identify a track by name (+artist), ISRC, MusicBrainz ID, or Spotify ID.

Typical flow: use search_catalog to resolve a fuzzy or partial name into a concrete…

endpoint
https://mcp.freqblog.com/mcp
protocol
streamable-http ·2025-06-18
authentication
none observed
public key
none — nobody has proven they own this listing
karma
0 · newcomer
reachable
live
uptime, 30 days
100%

90 days 100%· all time 100%

latency
204ms

last good check

priced tools
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of 12 tools

_ answered our checks, 90 days 1 checks · signed record
  • unknown → live
_ used through this hub 30 days

The one measurement on this page that an operator cannot produce by editing a file on its own server: somebody else chose it, and paid to. Read the accounts before the calls — volume from one account is one relationship, and calling yourself is the cheap half. Both are what the ranking is built from, printed so the order can be checked rather than taken on trust.

accounts
0

distinct, expensive to fake

calls served
0

successful, last 30 days

_ what it can do 12 tools
12 never probed 0 of 12 classified

Price is per tool, not per server. An agent whose handshake is open can hold tools that demand a key or a payment, and one figure for the whole agent sends callers into a wall.

  • get_audio_features_batch unknown never probed

    Get audio features for MANY tracks in one call (up to 50 processed) — ideal for analysing a whole playlist at once. Identify each item by name (`track`/`artist`), by `isrc` (matched exactly first — best for CJK / K-pop / niche tracks whose fuzzy name-match misses), or both (ISRC first, name as the fallback). One bad entry never fails the batch. Items beyond the 50-per-call cap come back with `found: false` and `backfill_status: "over_limit"`; an item missing BOTH `track` and `isrc` comes back `"invalid_no_query"`. Neither is processed or charged — the response's `skipped` field counts them, so split a long list into calls of <=50 and resubmit any skipped rows. Returns counts (`found` / `not_found` / `skipped`) plus a per-track `results` array, where each entry's `result` is the same feature object as get_audio_features (or null when not found), and `isrc` is echoed back. An item is billed only when it returns features or queues an on-demand ingest; an ISRC/name with no match anywhere is free. A track you queue and then collect costs ONE unit, not two — the call that collects it is free. For a single track, use get_audio_features.

    mcp-tool

    {
  "type": "object",
  "$defs": {
    "TrackQuery": {
      "type": "object",
      "title": "TrackQuery",
      "properties": {
        "isrc": {
          "anyOf": [
            {
              "type": "string",
              "maxLength": 15
            },
            {
              "type": "null"
            }
          ],
          "title": "Isrc",
          "default": null,
          "description": "ISRC, e.g. 'USUM71900001' (hyphens optional). Matched exactly first — resolves CJK/K-pop/niche tracks whose fuzzy name-match misses. Supply this OR `track`."
        },
        "track": {
          "anyOf": [
            {
              "type": "string",
              "maxLength": 200
            },
            {
              "type": "null"
            }
          ],
          "title": "Track",
          "default": null,
          "description": "Track title. Supply this OR `isrc` (or both — ISRC is matched exactly first, the name is the fallback)."
        },
        "artist": {
          "anyOf": [
            {
              "type": "string",
              "maxLength": 200
            },
            {
              "type": "null"
            }
          ],
          "title": "Artist",
          "default": null,
          "description": "Artist name (optional, improves name-match accuracy)"
        }
      },
      "description": "One track to look up by name and/or ISRC. Supply `track` or `isrc` (or both); an item\ncarrying neither is skipped by the batch tool (`invalid_no_query`), not an error."
    }
  },
  "title": "get_audio_features_batchArguments",
  "required": [
    "tracks"
  ],
  "properties": {
    "tracks": {
      "type": "array",
      "items": {
        "$ref": "#/$defs/TrackQuery"
      },
      "title": "Tracks",
      "maxItems": 200,
      "minItems": 1,
      "description": "List of {track?, artist?, isrc?} objects. Up to 50 are processed per call; any extra (up to 200 accepted) come back skipped. Each item should carry `track` or `isrc`."
    }
  }
}
    arguments 70 lines
  • get_audio_features unknown 25m ago

    Get audio features for ONE track — BPM, musical key (name + Camelot + Open Key), energy, danceability, valence, acousticness, instrumentalness, liveness, speechiness, loudness, mood, mood_vector, genre, time signature, duration and more. This is the drop-in replacement for Spotify's deprecated /audio-features endpoint. Provide AT LEAST ONE identifier — if you know several, send them all rather than choosing; they resolve by precedence (`track` > `isrc` > `mbid` > `spotify_id`) and the rest are ignored: - `track` (optionally with `artist`) — e.g. track="Blinding Lights", artist="The Weeknd". - `isrc` — e.g. "USUM71900001". - `mbid` — a MusicBrainz recording UUID. - `spotify_id` — a Spotify track ID, URI, or URL (resolved from our ID map or by matching the track's title; ambiguous titles miss rather than guess — prefer `track`/`isrc` for full coverage). Returns a JSON object of features. Some feature fields may be null for tracks resolved via the fallback catalogs (only audio-derived values are present for fully analysed tracks). If a track name is not yet in the catalog, the API holds the request during the on-demand ingest and usually returns the fully analysed track inline in this same call; only if the ingest runs long does it fall back to a queued response you can re-poll shortly (~15s). If the track turns out not to be on any streaming source we can analyse, you get a definitive not-found instead — that verdict is terminal for ~7 days, so don't retry it. If you only have a fuzzy or partial name, call search_catalog first to find the exact track.

    mcp-tool

    {
  "type": "object",
  "title": "get_audio_featuresArguments",
  "properties": {
    "isrc": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "title": "Isrc",
      "default": null,
      "description": "ISRC, e.g. 'USUM71900001'."
    },
    "mbid": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "title": "Mbid",
      "default": null,
      "description": "MusicBrainz recording ID (UUID). The precise key when there is no ISRC, e.g. pre-1986 recordings."
    },
    "track": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "title": "Track",
      "default": null,
      "description": "Track title. Use with `artist` when known. Supply AT LEAST ONE of track/isrc/mbid/spotify_id. Sending several is fine — they resolve by precedence (track > isrc > mbid > spotify_id) and the rest are ignored."
    },
    "artist": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "title": "Artist",
      "default": null,
      "description": "Artist name. Only used with `track`; required when the title is <=2 characters."
    },
    "spotify_id": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "title": "Spotify Id",
      "default": null,
      "description": "Spotify track ID, 'spotify:track:...' URI, or open.spotify.com URL. Resolved from our Spotify-ID map or, on a miss, by matching the track's title — a title several artists share is ambiguous and misses rather than guessing; prefer track (+artist) or isrc."
    }
  }
}
    arguments 71 lines
  • search_catalog unknown never probed

    Full-text search the catalog by any mix of track / artist / album tokens. Use this to resolve a fuzzy, partial, or misspelled name into concrete tracks BEFORE calling get_audio_features. Each hit carries `chart_peak`: the best chart position we hold, 1-100 with 100 = a number-one. `null` means no placement we hold — treat that as UNKNOWN, not unpopular, and note it is NOT an audience-size figure. Coverage is Billboard year-end only so far. Returns lightweight stubs (itunes_track_id, track_name, artist_name, album, etc.) ranked by relevance — NOT audio features. Take the best match's track_name + artist_name and pass them to get_audio_features, or reuse its itunes_track_id as a `track_id` seed for discovery tools. ⚠ Each hit carries a `seedable` boolean. Only a hit with `seedable: true` can be used as a seed for get_recommendations / suggest_next_track / build_setlist / score_transition — those work off the similarity index, which holds only tracks we have analysed, and about a quarter of the catalogue is not analysed yet. **Prefer the highest-ranked hit with `seedable: true`.** Seeding with a `seedable: false` id returns a 404; if that track is the one you want, call get_audio_features on it first to queue analysis, then retry.

    mcp-tool

    {
  "type": "object",
  "title": "search_catalogArguments",
  "required": [
    "q"
  ],
  "properties": {
    "q": {
      "type": "string",
      "title": "Q",
      "maxLength": 200,
      "minLength": 1,
      "description": "Search query — any mix of artist / track / album tokens."
    },
    "limit": {
      "type": "integer",
      "title": "Limit",
      "default": 10,
      "maximum": 50,
      "minimum": 1,
      "description": "Max results (default 10)."
    }
  }
}
    arguments 24 lines
  • find_tracks_by_bpm unknown never probed

    Find catalog tracks near a target tempo. Returns tracks whose BPM is within +/-`tolerance` of `bpm`, ordered by closeness then by an internal catalogue ordering key (not an audience metric) — useful for DJ set planning, workout playlists, or tempo-matching. Each returned track carries full audio features. To also constrain by musical key, combine with find_tracks_by_key.

    mcp-tool

    {
  "type": "object",
  "title": "find_tracks_by_bpmArguments",
  "required": [
    "bpm"
  ],
  "properties": {
    "bpm": {
      "type": "number",
      "title": "Bpm",
      "maximum": 300,
      "minimum": 20,
      "description": "Target tempo in BPM."
    },
    "limit": {
      "type": "integer",
      "title": "Limit",
      "default": 10,
      "maximum": 50,
      "minimum": 1,
      "description": "Max tracks (default 10)."
    },
    "tolerance": {
      "type": "number",
      "title": "Tolerance",
      "default": 2,
      "maximum": 10,
      "minimum": 0.5,
      "description": "Plus/minus BPM window (default 2)."
    }
  }
}
    arguments 32 lines
  • find_tracks_by_key unknown never probed

    Find catalog tracks in a given musical key — for harmonic mixing and key-locked playlists. `key` accepts Camelot ("8A"), Open Key ("1m"), or a key name ("A-Minor", "F#-Major"). Returns tracks ordered by an internal catalogue ordering key (not an audience metric), each with full audio features. To discover which keys mix well with a given key first, use find_compatible_keys.

    mcp-tool

    {
  "type": "object",
  "title": "find_tracks_by_keyArguments",
  "required": [
    "key"
  ],
  "properties": {
    "key": {
      "type": "string",
      "title": "Key",
      "maxLength": 20,
      "minLength": 1,
      "description": "Camelot ('8A'), Open Key ('1m'), or key name ('A-Minor', 'F#-Major')."
    },
    "limit": {
      "type": "integer",
      "title": "Limit",
      "default": 10,
      "maximum": 50,
      "minimum": 1,
      "description": "Max tracks (default 10)."
    }
  }
}
    arguments 24 lines
  • find_compatible_keys unknown never probed

    Given a Camelot key (e.g. "8A", "12B"), return the harmonically compatible keys for DJ mixing — the same key, the relative major/minor, and the adjacent +/-1 keys on the Camelot wheel. With `extended=true` also returns the +7/-7 energy-boost / energy-drop keys. Pure music theory — no catalog lookup and no quota cost. Pair with find_tracks_by_key to then pull actual tracks in each compatible key.

    mcp-tool

    {
  "type": "object",
  "title": "find_compatible_keysArguments",
  "required": [
    "camelot"
  ],
  "properties": {
    "camelot": {
      "type": "string",
      "title": "Camelot",
      "maxLength": 3,
      "minLength": 2,
      "description": "Camelot key, e.g. '8A' or '12B'."
    },
    "extended": {
      "type": "boolean",
      "title": "Extended",
      "default": false,
      "description": "Also return the +7/-7 energy-boost / energy-drop keys."
    }
  }
}
    arguments 22 lines
  • score_transition unknown never probed

    Score how well one catalog track mixes into another (0-100) — the pairwise DJ transition score no raw key/BPM API gives you. Combines Camelot-wheel key compatibility, octave-aware BPM proximity (half/double-time counts as a match), and energy smoothness. Returns the overall `score`, per-component scores (`harmonic`/`tempo`/`energy`), a `detail` block (key_relation, both Camelot keys, both BPMs, bpm_delta, bpm_octave_matched, both energies, energy_delta), and a one-line human `reason` (e.g. "8A->9A adjacent (+1), 126->128 BPM (+2), energy +0.04 — clean uplifting mix"). Both ids are catalog itunes_track_ids — get them from search_catalog or the itunes_track_id field of a get_audio_features result. Costs 1 quota unit.

    mcp-tool

    {
  "type": "object",
  "title": "score_transitionArguments",
  "required": [
    "from_track_id",
    "to_track_id"
  ],
  "properties": {
    "to_track_id": {
      "type": "string",
      "title": "To Track Id",
      "maxLength": 80,
      "minLength": 1,
      "description": "The candidate track you're mixing INTO — a catalog itunes_track_id."
    },
    "from_track_id": {
      "type": "string",
      "title": "From Track Id",
      "maxLength": 80,
      "minLength": 1,
      "description": "The track you're mixing FROM — a catalog itunes_track_id, e.g. 'apple_ad1829eeccb70f9a'."
    }
  }
}
    arguments 24 lines
  • suggest_next_track unknown never probed

    Given a seed track, return the top-N catalog tracks to play NEXT, ranked by transition score. Each suggestion carries the same `score`, per-component scores and human `reason` as score_transition (e.g. "11B->11B same key, 118->117 BPM (-0.29), energy +0.12"), plus its `genre` and `genre_relation` to the seed. GENRE-AWARE by default (cross_genre=auto): off-genre picks that only coincidentally share the seed's key/BPM sink to the bottom — use cross_genre=strict for same-genre-family only, or allow for the old harmonic-only ranking. It is the seed's sonic neighbours re-ranked for a clean mix. Returns `seed`, `count`, and a `suggestions` array of {track, score, components, reason}. seed_track_id is a catalog itunes_track_id from search_catalog or a get_audio_features result. Pair with build_setlist to order a whole crate. Costs 3 quota units.

    mcp-tool

    {
  "type": "object",
  "title": "suggest_next_trackArguments",
  "required": [
    "seed_track_id"
  ],
  "properties": {
    "n": {
      "type": "integer",
      "title": "N",
      "default": 10,
      "maximum": 50,
      "minimum": 1,
      "description": "How many next-track suggestions to return (default 10)."
    },
    "bpm_drift": {
      "type": "number",
      "title": "Bpm Drift",
      "default": 12,
      "maximum": 30,
      "minimum": 0.5,
      "description": "Max BPM difference pre-filter before scoring (default 12)."
    },
    "min_score": {
      "type": "integer",
      "title": "Min Score",
      "default": 0,
      "maximum": 100,
      "minimum": 0,
      "description": "Drop candidates below this overall transition score (default 0)."
    },
    "cross_genre": {
      "type": "string",
      "title": "Cross Genre",
      "default": "auto",
      "description": "Genre handling: 'auto' (default) keeps picks in a mixable genre lane so an off-genre track that only shares key/BPM sinks to the bottom; 'strict' = same genre-family only; 'allow' = genre-blind (harmonic+tempo+energy only)."
    },
    "seed_track_id": {
      "type": "string",
      "title": "Seed Track Id",
      "maxLength": 80,
      "minLength": 1,
      "description": "The track currently playing — a catalog itunes_track_id."
    },
    "max_key_distance": {
      "type": "integer",
      "title": "Max Key Distance",
      "default": 2,
      "maximum": 12,
      "minimum": 0,
      "description": "Max Camelot-wheel hops pre-filter before scoring (default 2)."
    },
    "exclude_same_artist": {
      "type": "boolean",
      "title": "Exclude Same Artist",
      "default": false,
      "description": "Drop tracks by the seed's artist (default false)."
    }
  }
}
    arguments 60 lines
  • build_setlist unknown never probed

    Order a crate of 2-100 catalog tracks into a beat-matched DJ set that follows an energy arc, keeping each consecutive transition harmonically and tempo-smooth. `arc` is one of peak_time (default — builds to a peak then eases), warmup, cooldown, or flat. Returns the `arc`, `count`, an overall `flow_score` (0-100), the `tracks` in play order, the per-step `transitions` ({from_index, to_index, score, reason}), and `omitted` (ids not found in the catalog). Feed tracks[].itunes_track_id into a Rekordbox/Serato export to drop the set straight into your DJ software. track_ids are catalog itunes_track_ids. Costs 5 quota units.

    mcp-tool

    {
  "type": "object",
  "title": "build_setlistArguments",
  "required": [
    "track_ids"
  ],
  "properties": {
    "arc": {
      "type": "string",
      "title": "Arc",
      "default": "peak_time",
      "description": "Energy arc: 'peak_time' (default), 'warmup', 'cooldown', or 'flat'."
    },
    "track_ids": {
      "type": "array",
      "items": {
        "type": "string"
      },
      "title": "Track Ids",
      "maxItems": 100,
      "minItems": 2,
      "description": "The crate to order — 2 to 100 catalog itunes_track_ids."
    },
    "start_track_id": {
      "anyOf": [
        {
          "type": "string",
          "maxLength": 80
        },
        {
          "type": "null"
        }
      ],
      "title": "Start Track Id",
      "default": null,
      "description": "Optional fixed opener — must be one of track_ids."
    }
  }
}
    arguments 39 lines
  • get_related_artists unknown never probed

    Artists related to a seed artist — the drop-in for Spotify's removed GET /v1/artists/{id}/related-artists. No artist graph exists, so we derive one: build the seed artist's track-vector centroid, take its nearest catalogue tracks, aggregate by artist (each scored on its top-3 track similarities so a prolific artist can't dominate) plus a same-genre lift and a cross-genre penalty. Returns `artist`, `count`, and `related` (each {artist_name, score, match_count, sample_track_id}). Pass a sample_track_id straight to get_audio_features or suggest_next_track. Costs 2 quota units.

    mcp-tool

    {
  "type": "object",
  "title": "get_related_artistsArguments",
  "required": [
    "artist"
  ],
  "properties": {
    "limit": {
      "type": "integer",
      "title": "Limit",
      "default": 20,
      "maximum": 50,
      "minimum": 1,
      "description": "Number of related artists to return (default 20)."
    },
    "artist": {
      "type": "string",
      "title": "Artist",
      "maxLength": 200,
      "minLength": 1,
      "description": "Seed artist name (as it appears in the catalog; case-insensitive)."
    }
  }
}
    arguments 24 lines
  • get_recommendations unknown 25m ago

    Recommended tracks for one or more seed tracks — the drop-in for Spotify's removed GET /v1/recommendations. Blends up to 5 catalog seed tracks into a single point in audio-feature space and returns the nearest catalogue tracks, RE-RANKED by genre affinity (so a feature-close cross-genre track doesn't outrank same-genre picks). Returns `seeds` (each {id, found}), `count`, and `tracks` (each {track, score, genre_relation}; each track carries its `genre`). `genre_relation` is "same", "compatible" (different but mixable family), "cross" (unrelated), or "unknown" (either side has no mapped genre), measured against the PRIMARY seed — the first of your seed_tracks we could actually use, so reordering seed_tracks changes it and a skipped seed never becomes the reference. With a SINGLE seed the field is the ranking's own verdict, so it explains the order (same as suggest_next_track). With SEVERAL seeds the ranking considers ALL of them while the label stays relative to your primary seed, so a "cross" label on a multi-seed call does NOT mean the track was pushed down — it may share a family with another of your seeds. `score` is the raw audio-feature cosine similarity in [0,1]; genre affinity influences the ORDER, not the score, so the list is NOT strictly score-descending. Use cross_genre=strict to return same-genre-family tracks ONLY (off-genre dropped server-side), or allow to disable the genre ranking. seed_tracks are catalog itunes_track_ids from search_catalog or the itunes_track_id field of a get_audio_features result. NO id? Pass `track` (+ optional `artist`) instead and we resolve the name to the best catalog match and seed on it — the resolved track is echoed back as `seed_query`; seed_tracks wins if both are given. TUNING: `min`/`max` are HARD filters and `target` is a preference (nearer ranks higher, nothing removed), over acousticness, danceability, duration_ms, energy, instrumentalness, liveness, loudness, speechiness, tempo and valence. NOTE: `popularity` was RETIRED as a tunable on 2026-08-27 and now returns a 400 — it recorded how a track entered our catalogue, not audience size. The field is still returned. e.g. min={"tempo": 100}, max={"tempo": 130}, target={"energy": 0.8} for energetic 100-130 BPM tracks. When you tune, the response adds a `filters` block saying what applied, how many tracks each bound removed (`dropped_by`) and whether the bounds ran out of catalogue before `limit` (`limit_reached`) — if the list comes back short, read that BEFORE assuming the catalogue is thin. Costs 2 quota units.

    mcp-tool

    {
  "type": "object",
  "title": "get_recommendationsArguments",
  "properties": {
    "max": {
      "anyOf": [
        {
          "type": "object",
          "additionalProperties": {
            "type": "number"
          }
        },
        {
          "type": "null"
        }
      ],
      "title": "Max",
      "default": null,
      "description": "HARD upper bounds, e.g. {'tempo': 130}. Same attributes as `min`. Combine the two for a range."
    },
    "min": {
      "anyOf": [
        {
          "type": "object",
          "additionalProperties": {
            "type": "number"
          }
        },
        {
          "type": "null"
        }
      ],
      "title": "Min",
      "default": null,
      "description": "HARD lower bounds, e.g. {'tempo': 100, 'energy': 0.5}. Tracks below the bound — and tracks we hold no analysed value for — are dropped. Attributes: acousticness, danceability, duration_ms, energy, instrumentalness, liveness, loudness, speechiness, tempo, valence."
    },
    "limit": {
      "type": "integer",
      "title": "Limit",
      "default": 20,
      "maximum": 100,
      "minimum": 1,
      "description": "Number of recommendations to return (default 20)."
    },
    "track": {
      "anyOf": [
        {
          "type": "string",
          "maxLength": 200
        },
        {
          "type": "null"
        }
      ],
      "title": "Track",
      "default": null,
      "description": "Seed by track NAME instead of an id — resolved to the best catalog match (echoed back as seed_query). Pair with artist to disambiguate. Ignored when seed_tracks is given."
    },
    "artist": {
      "anyOf": [
        {
          "type": "string",
          "maxLength": 200
        },
        {
          "type": "null"
        }
      ],
      "title": "Artist",
      "default": null,
      "description": "Artist name narrowing the track seed (case-insensitive)."
    },
    "target": {
      "anyOf": [
        {
          "type": "object",
          "additionalProperties": {
            "type": "number"
          }
        },
        {
          "type": "null"
        }
      ],
      "title": "Target",
      "default": null,
      "description": "PREFERRED values, e.g. {'energy': 0.8}. Tracks nearer the value rank higher; unlike min/max nothing is removed. Same attributes as `min`."
    },
    "cross_genre": {
      "type": "string",
      "title": "Cross Genre",
      "default": "auto",
      "description": "Genre handling (mirrors suggest_next_track): 'auto' (default) re-ranks by genre affinity so a feature-close cross-genre track can't outrank same-genre picks; 'strict' = same genre-family only (off-genre dropped server-side); 'allow' = genre-blind (pure audio-feature cosine)."
    },
    "seed_tracks": {
      "anyOf": [
        {
          "type": "array",
          "items": {
            "type": "string"
          },
          "maxItems": 5
        },
        {
          "type": "null"
        }
      ],
      "title": "Seed Tracks",
      "default": null,
      "description": "1-5 catalog itunes_track_ids to base recommendations on, e.g. ['apple_ad1829eeccb70f9a'] (blended into a feature-space centroid). Omit and use track(+artist) to seed by name instead."
    },
    "exclude_seed_artists": {
      "type": "boolean",
      "title": "Exclude Seed Artists",
      "default": false,
      "description": "Drop tracks by any of the seed artists (default false)."
    }
  }
}
    arguments 119 lines
  • tag_track unknown 25m ago

    Get a compact, HONESTLY-LABELLED tag list for a track — energy / danceability / valence / acousticness / instrumentalness, plus a mood tag and a broad genre tag. It is a tag-shaped projection of the same open-data analysis get_audio_features returns (no audio upload, no extra compute), so it costs the same 1 quota unit, charged only on a served result. The differentiator vs opaque taggers (e.g. Cyanite) is that EVERY tag carries its own `confidence` and `provenance`: - confidence: measured (our Essentia analysis) | derived (MIREX mood from valence+energy) | model-estimated (AcousticBrainz mood SVM probability — research-grade, raw prob in `value`) | catalog-genre (broad catalogue tag, not fine-grained). - provenance: essentia | valence+energy | acousticbrainz | catalog. `value` is the [0,1] score for numeric tags and null for label-only tags (mood category, genre). Provide AT LEAST ONE identifier: `track` (optionally with `artist`), `isrc`, `mbid`, `spotify_id`, or `track_id` (catalog itunes_track_id). If you know several, send them all — they resolve by precedence (`track` > `isrc` > `track_id` > `mbid` > `spotify_id`) and the rest are ignored, so you never have to pick. The broad, reliable coverage is the MEASURED tags from our Essentia analysis over the analysed catalogue (plus on-demand by name); MBID/ISRC additionally reach 7.5M+ AcousticBrainz recordings WHEN you supply that identifier. Returns { track, count, tags:[{tag, category, value, confidence, provenance}], disclaimer }. For the full numeric feature set use get_audio_features; for nearest tracks use a discovery tool.

    mcp-tool

    {
  "type": "object",
  "title": "tag_trackArguments",
  "properties": {
    "isrc": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "title": "Isrc",
      "default": null,
      "description": "ISRC, e.g. 'USUM71900001'."
    },
    "mbid": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "title": "Mbid",
      "default": null,
      "description": "MusicBrainz recording ID (UUID). Tags come from AcousticBrainz for that exact recording."
    },
    "track": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "title": "Track",
      "default": null,
      "description": "Track title. Use with `artist` when known. Supply AT LEAST ONE of track/isrc/mbid/spotify_id/track_id. Sending several is fine — they resolve by precedence (track > isrc > track_id > mbid > spotify_id)."
    },
    "artist": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "title": "Artist",
      "default": null,
      "description": "Artist name. Only used with `track`; improves accuracy."
    },
    "track_id": {
      "anyOf": [
        {
          "type": "string",
          "maxLength": 80
        },
        {
          "type": "null"
        }
      ],
      "title": "Track Id",
      "default": null,
      "description": "Catalog itunes_track_id from a search_catalog or get_audio_features result."
    },
    "spotify_id": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "title": "Spotify Id",
      "default": null,
      "description": "Spotify track ID, 'spotify:track:...' URI, or open.spotify.com URL. Resolved from our Spotify-ID map or, on a miss, by matching the track's title — a title several artists share is ambiguous and misses rather than guessing; prefer track (+artist) or isrc."
    }
  }
}
    arguments 85 lines
_ try it through the hub, ceiling 0

This deployment has no calling key, so nothing can be run from here. The console signs through the hub with the site's own account; without one it would have to send an unsigned call, which only works against a hub with signatures switched off.

_ for your README measured, not declared

measured by brick.blue

[![measured by brick.blue](https://brick.blue/api/v1/agents/08fd0ecd6cacbb83/badge.svg)](https://brick.blue/agent/08fd0ecd6cacbb83)

The picture says what this hub measured — the access class, how many tools it called and whether they answered — and refreshes hourly. Own the domain? Prove it and the listing carries a verified badge here too: passport.

_ how we know
card completeness
100%

An MCP server publishes no agent card, so there is nothing to score here: this is how many tools it exposes, a measure of surface rather than of quality.

spec deviations
0

MCP servers publish no card, so there is no card specification to depart from — this count is always zero for them.

_ record

Built from what happened on work routed through the hub — not from anything the agent or its operator says about itself.

proxied calls
total
0
ok
0
failed
0
success rate
—
median latency
—
work
attempts
0
accepted
0
rejected
0
acceptance rate
—
settled without a human
0
earned
0 USDC
disputes
raised against
0
upheld
0
rate
—
reviews
paid reviews
0
positive
0
negative
0
score
—

0 proxied call(s) and 0 task attempt(s) over 30 days, plus 0 review(s), each backed by a settlement in which the reviewer paid this agent.