SoundStat Recommendations API

openapi: 3.1.0
info:
  title: SoundStat Genres Recommendations API
  description: API for accessing music track audio analysis, features (tempo, key, mode, energy, danceability, valence, instrumentalness, acousticness, loudness), search, and recommendations. SoundStat is an independent audio-analysis alternative to the deprecated Spotify audio-features endpoints.
  version: 1.0.0
servers:
- url: https://soundstat.info
  description: SoundStat production API
security:
- ApiKeyAuth: []
tags:
- name: Recommendations
paths:
  /api/v1/recommendations/similar:
    get:
      summary: Get Similar Tracks
      description: "Get track recommendations based on a seed track.\n\nParameters:\n----------\n<b>seed_track_id</b> : str (Spotify ID of the reference track)<br>\n<b>limit</b> : int, default=20 (Number of recommendations, max 100)<br>\n<b>min_popularity</b> : int, optional (Minimum popularity score 0-100)<br>\n<b>genre_match</b> : bool, default=False (Prioritize same genre)<br>\n<b>x_api_key</b> : str (API key for authentication)<br>\n\nReturns:\n-------\nTrackIDList<br>\n    List of recommended track IDs<br>\n\nNotes:\n-----\nUses audio features to find tracks with similar characteristics."
      operationId: get_similar_tracks_api_v1_recommendations_similar_get
      parameters:
      - name: seed_track_id
        in: query
        required: true
        schema:
          type: string
          title: Seed Track Id
      - name: limit
        in: query
        required: false
        schema:
          type: integer
          maximum: 100
          minimum: 1
          default: 20
          title: Limit
      - name: min_popularity
        in: query
        required: false
        schema:
          anyOf:
          - type: integer
            maximum: 100
            minimum: 0
          - type: 'null'
          title: Min Popularity
      - name: genre_match
        in: query
        required: false
        schema:
          type: boolean
          default: false
          title: Genre Match
      - name: x-api-key
        in: header
        required: false
        schema:
          type: string
          title: X-Api-Key
      responses:
        '200':
          description: Successful Response
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/TrackIDList'
        '422':
          description: Validation Error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/HTTPValidationError'
      tags:
      - Recommendations
  /api/v1/recommendations/by-features:
    post:
      summary: Get Recommendations By Features
      description: "Get track recommendations matching specific audio features.\n\nParameters:\n----------\n<b>features</b> : TargetFeatures (Target audio characteristics)<br>\n    - tempo: float, optional (Target BPM, 0-300)<br>\n    - energy: float, optional (Target energy level, 0-1)<br>\n    - danceability: float, optional (Target danceability, 0-1)<br>\n    - duration_ms: int, optional (Target duration in ms, 30000-900000)<br>\n    - other audio features...<br>\n<b>x_api_key</b> : str (API key for authentication)<br>\n\nReturns:\n-------\nTrackIDList<br>\n    List of matching track IDs<br>\n\nNotes:\n-----\nFinds tracks that best match the specified audio characteristics."
      operationId: get_recommendations_by_features_api_v1_recommendations_by_features_post
      parameters:
      - name: x-api-key
        in: header
        required: false
        schema:
          type: string
          title: X-Api-Key
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/TargetFeatures'
      responses:
        '200':
          description: Successful Response
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/TrackIDList'
        '422':
          description: Validation Error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/HTTPValidationError'
      tags:
      - Recommendations
  /api/v1/recommendations/mixed:
    post:
      summary: Get Mixed Recommendations
      operationId: get_mixed_recommendations_api_v1_recommendations_mixed_post
      parameters:
      - name: x-api-key
        in: header
        required: false
        schema:
          type: string
          title: X-Api-Key
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/MixedRecommendationParams'
      responses:
        '200':
          description: Successful Response
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/TrackIDList'
        '422':
          description: Validation Error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/HTTPValidationError'
      tags:
      - Recommendations
  /api/v1/recommendations/progression:
    post:
      summary: Get Progression Recommendations
      description: Get tracks with progressively changing audio characteristics.
      operationId: get_progression_recommendations_api_v1_recommendations_progression_post
      parameters:
      - name: x-api-key
        in: header
        required: false
        schema:
          type: string
          title: X-Api-Key
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/ProgressionParams'
      responses:
        '200':
          description: Successful Response
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/TrackIDList'
        '422':
          description: Validation Error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/HTTPValidationError'
      tags:
      - Recommendations
  /api/v1/recommendations/compatible:
    post:
      summary: Get Compatible Tracks
      description: "Get tracks that are musically compatible with a reference track.\n\nParameters:\n----------\n<b>params</b> : CompatibleParams<br>\n    - track_id: str (Reference track ID)<br>\n    - compatibility_type: str, default=\"both\" (key, bpm, both)<br>\n    - limit: int, default=20 (Number of recommendations)<br>\n    - min_popularity: int, optional (Minimum popularity score)<br>\n<b>x_api_key</b> : str (API key for authentication)<br>\n\nReturns:\n-------\nTrackIDList<br>\n    List of tracks compatible with the reference track<br>\n\nNotes:\n-----\nUseful for DJ mixing, creating smooth transitions, or harmonic playlists."
      operationId: get_compatible_tracks_api_v1_recommendations_compatible_post
      parameters:
      - name: x-api-key
        in: header
        required: false
        schema:
          type: string
          title: X-Api-Key
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/CompatibleParams'
      responses:
        '200':
          description: Successful Response
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/TrackIDList'
        '422':
          description: Validation Error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/HTTPValidationError'
      tags:
      - Recommendations
  /api/v1/recommendations/contrast:
    post:
      summary: Get Contrast Recommendations
      description: "Get tracks with characteristics contrasting to a reference track.\n\nParameters:\n----------\n<b>params</b> : ContrastParams<br>\n    - track_id: str (Reference track ID)<br>\n    - contrast_features: List[str], default=[\"energy\", \"valence\"] (Features to contrast)<br>\n    - limit: int, default=20 (Number of recommendations)<br>\n<b>x_api_key</b> : str (API key for authentication)<br>\n\nReturns:\n-------\nTrackIDList<br>\n    List of tracks with contrasting characteristics<br>\n\nNotes:\n-----\nCreates variety in playlists by finding tracks with opposite characteristics."
      operationId: get_contrast_recommendations_api_v1_recommendations_contrast_post
      parameters:
      - name: x-api-key
        in: header
        required: false
        schema:
          type: string
          title: X-Api-Key
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/ContrastParams'
      responses:
        '200':
          description: Successful Response
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/TrackIDList'
        '422':
          description: Validation Error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/HTTPValidationError'
      tags:
      - Recommendations
  /api/v1/recommendations/cross-genre:
    post:
      summary: Get Cross Genre Recommendations
      description: Get tracks from different genres with similar audio characteristics.
      operationId: get_cross_genre_recommendations_api_v1_recommendations_cross_genre_post
      parameters:
      - name: x-api-key
        in: header
        required: false
        schema:
          type: string
          title: X-Api-Key
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/CrossGenreParams'
      responses:
        '200':
          description: Successful Response
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/TrackIDList'
        '422':
          description: Validation Error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/HTTPValidationError'
      tags:
      - Recommendations
  /api/v1/recommendations/time-of-day:
    post:
      summary: Get Time Of Day Recommendations
      description: "Get track recommendations suitable for a specific time of day.\n\nParameters:\n----------\n<b>params</b> : TimeOfDayParams<br>\n    - time: str (One of: morning, afternoon, evening, night)<br>\n    - genre: str, optional (Specific genre filter)<br>\n    - limit: int, default=20 (Number of recommendations)<br>\n<b>x_api_key</b> : str (API key for authentication)<br>\n\nReturns:\n-------\nTrackIDList<br>\n    List of recommended track IDs suitable for the time of day<br>\n\nNotes:\n-----\nDifferent times of day have different energy/mood profiles."
      operationId: get_time_of_day_recommendations_api_v1_recommendations_time_of_day_post
      parameters:
      - name: x-api-key
        in: header
        required: false
        schema:
          type: string
          title: X-Api-Key
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/TimeOfDayParams'
      responses:
        '200':
          description: Successful Response
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/TrackIDList'
        '422':
          description: Validation Error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/HTTPValidationError'
      tags:
      - Recommendations
  /api/v1/recommendations/hidden-gems:
    post:
      summary: Get Hidden Gems Recommendations
      description: Get recommendations for lesser-known tracks with high-quality audio features.
      operationId: get_hidden_gems_recommendations_api_v1_recommendations_hidden_gems_post
      parameters:
      - name: x-api-key
        in: header
        required: false
        schema:
          type: string
          title: X-Api-Key
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/HiddenGemsParams'
      responses:
        '200':
          description: Successful Response
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/TrackIDList'
        '422':
          description: Validation Error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/HTTPValidationError'
      tags:
      - Recommendations
  /api/v1/recommendations/beat-structure:
    post:
      summary: Get Beat Structure Recommendations
      description: "Get recommendations for tracks with specific beat structure characteristics.\n\nParameters:\n----------\n<b>params</b> : BeatStructureParams<br>\n    - min_regularity: float, default=0.7 (Minimum beat regularity score 0-1)<br>\n    - tempo_min: float, optional (Minimum tempo in BPM)<br>\n    - tempo_max: float, optional (Maximum tempo in BPM)<br>\n    - genre: str, optional (Specific genre filter)<br>\n    - limit: int, default=20 (Number of recommendations)<br>\n<b>x_api_key</b> : str (API key for authentication)<br>\n\nReturns:\n-------\nTrackIDList<br>\n    List of recommended track IDs matching beat structure criteria<br>\n\nNotes:\n-----\nUseful for finding tracks with consistent, predictable beat patterns."
      operationId: get_beat_structure_recommendations_api_v1_recommendations_beat_structure_post
      parameters:
      - name: x-api-key
        in: header
        required: false
        schema:
          type: string
          title: X-Api-Key
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/BeatStructureParams'
      responses:
        '200':
          description: Successful Response
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/TrackIDList'
        '422':
          description: Validation Error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/HTTPValidationError'
      tags:
      - Recommendations
  /api/v1/recommendations/duration:
    post:
      summary: Get Duration Recommendations
      description: Get track recommendations based on specific duration requirements.
      operationId: get_duration_recommendations_api_v1_recommendations_duration_post
      parameters:
      - name: x-api-key
        in: header
        required: false
        schema:
          type: string
          title: X-Api-Key
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/DurationParams'
      responses:
        '200':
          description: Successful Response
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/TrackIDList'
        '422':
          description: Validation Error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/HTTPValidationError'
      tags:
      - Recommendations
  /api/v1/recommendations/mood:
    post:
      summary: Get Mood Recommendations
      description: Get track recommendations based on desired mood.
      operationId: get_mood_recommendations_api_v1_recommendations_mood_post
      parameters:
      - name: x-api-key
        in: header
        required: false
        schema:
          type: string
          title: X-Api-Key
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/MoodParams'
      responses:
        '200':
          description: Successful Response
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/TrackIDList'
        '422':
          description: Validation Error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/HTTPValidationError'
      tags:
      - Recommendations
  /api/v1/recommendations/activity:
    post:
      summary: Get Activity Recommendations
      description: Get track recommendations suitable for specific activities.
      operationId: get_activity_recommendations_api_v1_recommendations_activity_post
      parameters:
      - name: x-api-key
        in: header
        required: false
        schema:
          type: string
          title: X-Api-Key
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/ActivityParams'
      responses:
        '200':
          description: Successful Response
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/TrackIDList'
        '422':
          description: Validation Error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/HTTPValidationError'
      tags:
      - Recommendations
  /api/v1/recommendations/instrumental:
    post:
      summary: Get Instrumental Recommendations
      description: Get recommendations for instrumental tracks.
      operationId: get_instrumental_recommendations_api_v1_recommendations_instrumental_post
      parameters:
      - name: x-api-key
        in: header
        required: false
        schema:
          type: string
          title: X-Api-Key
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/InstrumentalParams'
      responses:
        '200':
          description: Successful Response
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/TrackIDList'
        '422':
          description: Validation Error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/HTTPValidationError'
      tags:
      - Recommendations
  /api/v1/recommendations/acoustic:
    post:
      summary: Get Acoustic Recommendations
      description: Get recommendations for acoustic tracks.
      operationId: get_acoustic_recommendations_api_v1_recommendations_acoustic_post
      parameters:
      - name: x-api-key
        in: header
        required: false
        schema:
          type: string
          title: X-Api-Key
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/AcousticParams'
      responses:
        '200':
          description: Successful Response
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/TrackIDList'
        '422':
          description: Validation Error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/HTTPValidationError'
      tags:
      - Recommendations
components:
  schemas:
    DurationParams:
      properties:
        min_duration_ms:
          type: integer
          title: Min Duration Ms
          description: Minimum track duration in milliseconds
          default: 30000
        max_duration_ms:
          type: integer
          title: Max Duration Ms
          description: Maximum track duration in milliseconds
          default: 600000
        genre:
          anyOf:
          - type: string
          - type: 'null'
          title: Genre
          description: Optional genre filter
        limit:
          type: integer
          maximum: 100.0
          minimum: 1.0
          title: Limit
          description: Number of recommendations
          default: 20
      type: object
      title: DurationParams
    ContrastParams:
      properties:
        track_id:
          type: string
          title: Track Id
          description: Reference track ID
        contrast_features:
          items:
            type: string
          type: array
          title: Contrast Features
          description: Features to contrast
          default:
          - energy
          - valence
        limit:
          type: integer
          maximum: 100.0
          minimum: 1.0
          title: Limit
          description: Number of recommendations
          default: 20
      type: object
      required:
      - track_id
      title: ContrastParams
    MoodParams:
      properties:
        mood:
          type: string
          title: Mood
          description: 'Target mood: happy, sad, energetic, relaxed, danceable'
        genre:
          anyOf:
          - type: string
          - type: 'null'
          title: Genre
          description: Optional genre filter
        limit:
          type: integer
          maximum: 100.0
          minimum: 1.0
          title: Limit
          description: Number of recommendations
          default: 20
      type: object
      required:
      - mood
      title: MoodParams
    CompatibleParams:
      properties:
        track_id:
          type: string
          title: Track Id
          description: Reference track ID
        compatibility_type:
          type: string
          title: Compatibility Type
          description: 'Type of compatibility: key, bpm, both'
          default: both
        limit:
          type: integer
          maximum: 100.0
          minimum: 1.0
          title: Limit
          description: Number of recommendations
          default: 20
        min_popularity:
          anyOf:
          - type: integer
            maximum: 100.0
            minimum: 0.0
          - type: 'null'
          title: Min Popularity
          description: Minimum popularity score
      type: object
      required:
      - track_id
      title: CompatibleParams
    BeatStructureParams:
      properties:
        min_regularity:
          type: number
          maximum: 1.0
          minimum: 0.0
          title: Min Regularity
          description: Minimum beat regularity (0-1)
          default: 0.7
        tempo_min:
          anyOf:
          - type: number
            minimum: 0.0
          - type: 'null'
          title: Tempo Min
          description: Minimum tempo (BPM)
        tempo_max:
          anyOf:
          - type: number
            maximum: 300.0
          - type: 'null'
          title: Tempo Max
          description: Maximum tempo (BPM)
        genre:
          anyOf:
          - type: string
          - type: 'null'
          title: Genre
          description: Optional genre filter
        limit:
          type: integer
          maximum: 100.0
          minimum: 1.0
          title: Limit
          description: Number of recommendations
          default: 20
      type: object
      title: BeatStructureParams
    ProgressionParams:
      properties:
        parameter:
          type: string
          title: Parameter
          description: Parameter to progress (energy, tempo, danceability, valence)
        direction:
          type: string
          title: Direction
          description: Progression direction (increase, decrease)
        steps:
          type: integer
          maximum: 10.0
          minimum: 2.0
          title: Steps
          description: Number of tracks in progression
          default: 5
        start_value:
          anyOf:
          - type: number
          - type: 'null'
          title: Start Value
          description: Starting value for parameter (0-1, or BPM for tempo)
        genre:
          anyOf:
          - type: string
          - type: 'null'
          title: Genre
          description: Optional genre filter
      type: object
      required:
      - parameter
      - direction
      title: ProgressionParams
    AcousticParams:
      properties:
        min_acousticness:
          type: number
          maximum: 1.0
          minimum: 0.0
          title: Min Acousticness
          description: Minimum acousticness score
          default: 0.5
        genre:
          anyOf:
          - type: string
          - type: 'null'
          title: Genre
          description: Optional genre filter
        limit:
          type: integer
          maximum: 100.0
          minimum: 1.0
          title: Limit
          description: Number of recommendations
          default: 20
      type: object
      title: AcousticParams
    InstrumentalParams:
      properties:
        min_instrumentalness:
          type: number
          maximum: 1.0
          minimum: 0.0
          title: Min Instrumentalness
          description: Minimum instrumentalness score
          default: 0.5
        genre:
          anyOf:
          - type: string
          - type: 'null'
          title: Genre
          description: Optional genre filter
        limit:
          type: integer
          maximum: 100.0
          minimum: 1.0
          title: Limit
          description: Number of recommendations
          default: 20
      type: object
      title: InstrumentalParams
    HTTPValidationError:
      properties:
        detail:
          items:
            $ref: '#/components/schemas/ValidationError'
          type: array
          title: Detail
      type: object
      title: HTTPValidationError
    ValidationError:
      properties:
        loc:
          items:
            anyOf:
            - type: string
            - type: integer
          type: array
          title: Location
        msg:
          type: string
          title: Message
        type:
          type: string
          title: Error Type
        input:
          title: Input
        ctx:
          type: object
          title: Context
      type: object
      required:
      - loc
      - msg
      - type
      title: ValidationError
    TargetFeatures:
      properties:
        tempo:
          anyOf:
          - type: number
            maximum: 300.0
            minimum: 0.0
          - type: 'null'
          title: Tempo
        energy:
          anyOf:
          - type: number
            maximum: 1.0
            minimum: 0.0
          - type: 'null'
          title: Energy
        danceability:
          anyOf:
          - type: number
            maximum: 1.0
            minimum: 0.0
          - type: 'null'
          title: Danceability
        valence:
          anyOf:
          - type: number
            maximum: 1.0
            minimum: 0.0
          - type: 'null'
          title: Valence
        instrumentalness:
          anyOf:
          - type: number
            maximum: 1.0
            minimum: 0.0
          - type: 'null'
          title: Instrumentalness
        acousticness:
          anyOf:
          - type: number
            maximum: 1.0
            minimum: 0.0
          - type: 'null'
          title: Acousticness
        duration_ms:
          anyOf:
          - type: integer
            maximum: 900000.0
            minimum: 30000.0
          - type: 'null'
          title: Duration Ms
          description: Target track duration in milliseconds (30s-15min)
        genre:
          anyOf:
          - type: string
          - type: 'null'
          title: Genre
        limit:
          type: integer
          maximum: 100.0
          minimum: 1.0
          title: Limit
          default: 20
      type: object
      title: TargetFeatures
    HiddenGemsParams:
      properties:
        similar_to_track_id:
          anyOf:
          - type: string
          - type: 'null'
          title: Similar To Track Id
          description: Optional reference track
        max_popularity:
          type: integer
          maximum: 70.0
          minimum: 0.0
          title: Max Popularity
          description: Maximum popularity score (0-100)
          default: 40
        genre:
          anyOf:
          - type: string
          - type: 'null'
          title: Genre
          description: Optional genre filter
        limit:
          type: integer
          maximum: 100.0
          minimum: 1.0
          title: Limit
          description: Number of recommendations
          default: 20
      type: object
      title: HiddenGemsParams
    TimeOfDayParams:
      properties:
        time:
          type: string
          title: Time
          description: 'Time of day: morning, afternoon, evening, night'
        genre:
          anyOf:
          - type: string
          - type: 'null'
          title: Genre
          description: Optional genre filter
        limit:
          type: integer
          maximum: 100.0
          minimum: 1.0
          title: Limit
          description: Number of recommendations
          default: 20
      type: object
      required:
      - time
      title: TimeOfDayParams
    CrossGenreParams:
      properties:
        track_id:
          type: string
          title: Track Id
          description: Reference track ID
        exclude_genres:
          items:
            type: string
          type: array
          title: Exclude Genres
          description: Genres to exclude
          default: []
        limit:
          type: integer
          maximum: 100.0
          minimum: 1.0
          title: Limit
          description: Number of recommendations
          default: 20
      type: object
      required:
      - track_id
      title: CrossGenreParams
    ActivityParams:
      properties:
        activity:
          type: string
          title: Activity
          description: 'Activity type: workout, study, sleep, party, focus'
        genre:
          anyOf:
          - type: string
          - type: 'null'
          title: Genre
          description: Optional genre filter
        limit:
          type: integer
          maximum: 100.0
          minimum: 1.0
          title: Limit
          description: Number of recommendations
          default: 20
      type: object
      required:
      - activity
      title: ActivityParams
    TrackIDList:
      properties:
        track_ids:
          items:
            type: string
          type: array
          title: Track Ids
      type: object
      required:
      - track_ids
      title: TrackIDList
    MixedRecommendationParams:
      properties:
        seed_tracks:
          items:
            type: string
          type: array
          maxItems: 5
          minItems: 1
          title: Seed Tracks
        target_features:
          anyOf:
          - $ref: '#/components/schemas/TargetFeatures'
          - type: 'null'
        limit:
          type: integer
          maximum: 100.0
          minimum: 1.0
          title: Limit
          default: 20
      type: object
      required:
      - seed_tracks
      title: MixedRecommendationParams
  securitySchemes:
    ApiKeyAuth:
      type: apiKey
      in: header
      name: x-api-key
      description: API key issued after registration at https://soundstat.info/auth.html. Passed in the x-api-key request header.