MusicBrainz MCP Server

Instructions

Implementation Reference

• mcp_musicbrainz/server.py:677-739 (handler)

  The 'get_entity_relationships' function implementation which fetches entity metadata from the MusicBrainz API and formats relationship data.

  def get_entity_relationships(entity_type: str, entity_id: str) -> str:
      """
      Get relationships for any entity type (e.g., band members, producers,
      recording studios, Wikipedia links).
      Args:
          entity_type: artist, release, release-group, recording, work, label, area,
                       place, event, instrument, series
          entity_id: The MBID (must match the entity_type)
      """
      valid_types = {
          "artist": (musicbrainzngs.get_artist_by_id, ["artist-rels", "url-rels"]),
          "release": (musicbrainzngs.get_release_by_id, ["artist-rels", "url-rels"]),
          "release-group": (
              musicbrainzngs.get_release_group_by_id,
              ["artist-rels", "url-rels"],
          ),
          "recording": (
              musicbrainzngs.get_recording_by_id,
              ["artist-rels", "work-rels", "url-rels"],
          ),
          "work": (musicbrainzngs.get_work_by_id, ["artist-rels", "url-rels"]),
          "label": (musicbrainzngs.get_label_by_id, ["artist-rels", "url-rels"]),
          "area": (musicbrainzngs.get_area_by_id, ["area-rels", "url-rels"]),
          "place": (musicbrainzngs.get_place_by_id, ["place-rels", "url-rels"]),
          "event": (musicbrainzngs.get_event_by_id, ["artist-rels", "url-rels"]),
          "instrument": (
              musicbrainzngs.get_instrument_by_id,
              ["instrument-rels", "url-rels"],
          ),
          "series": (musicbrainzngs.get_series_by_id, ["series-rels", "url-rels"]),
      }
  
      if entity_type not in valid_types:
          return f"Invalid entity type. Choose from: {', '.join(valid_types.keys())}"
  
      func, includes = valid_types[entity_type]
      res = func(entity_id, includes=includes)
      entity = res.get(entity_type)
      if not entity:
          return f"No data found for {entity_type} {entity_id}."
  
      lines = [f"Relationships for {entity_type} {entity_id}:"]
      found = False
  
      # Standardize relation list keys (artist-relation-list, url-relation-list, etc.)
      for key, value in entity.items():
          if key.endswith("-relation-list") and isinstance(value, list):
              for rel in value:
                  rtype = rel.get("type", "Unknown")
                  target = (
                      rel.get("artist", {}).get("name")
                      or rel.get("work", {}).get("title")
                      or rel.get("release", {}).get("title")
                      or rel.get("label", {}).get("name")
                      or rel.get("target", "Unknown")
                  )
                  lines.append(f"  - {rtype.capitalize()}: {target}")
                  found = True
  
      if not found:
          return f"No relationships found for this {entity_type}."
  
      return "\n".join(lines)