# build_setlist

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.

Agent View of the PolicyLayer registry record for `build_setlist`. HTML page: https://policylayer.com/tools/com-freqblog-music-metadata/build-setlist

## Facts

- Tool: `build_setlist`
- Server: FreqBlog Music Metadata (`https://mcp.freqblog.com/mcp`) — https://policylayer.com/tools/com-freqblog-music-metadata.md
- Homepage: https://github.com/https://mcp.freqblog.com/mcp
- Risk category: Read (Low risk)
- Registry record: grade D, identity unverified
- Server auth posture: open
- Server rate-limited: no
- Parameters: 3 (1 required)
- Recommended policy verdict: Allowed

## Parameters

| Parameter | Type | Required | Description |
| --- | --- | --- | --- |
| `arc` | string | no | Energy arc: 'peak_time' (default), 'warmup', 'cooldown', or 'flat'. |
| `track_ids` | array | yes | The crate to order — 2 to 100 catalog itunes_track_ids. |
| `start_track_id` | object | no | Optional fixed opener — must be one of track_ids. |

Parameters from the server's own tool schema.

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "build_setlist",
    "arguments": {
      "track_ids": []
    }
  }
}
```

## Why build_setlist is rated Low

The tool takes a list of track IDs and computes an optimized ordering with transition scores. It reads from the catalog and returns a structured result (ordered list, scores, omitted IDs). No data is created, modified, deleted, or executed — it is purely a read/query/computation operation against existing catalog data.

From the tool's own definition: "Order a crate of 2-100 catalog tracks into a beat-matched DJ set... Returns the `arc`, `count`, an overall `flow_score`... the `tracks` in play order, the per-step `transitions`"

## Use case

AI agents call build_setlist to retrieve information from FreqBlog Music Metadata without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

## Recommended policy (PolicyLayer)

Verdict: **Allowed**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches FreqBlog Music Metadata:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "build_setlist": {}
  }
}
```

## Other tools on FreqBlog Music Metadata (11)

- `find_compatible_keys` — Read — https://policylayer.com/tools/com-freqblog-music-metadata/find-compatible-keys.md
- `find_tracks_by_bpm` — Read — https://policylayer.com/tools/com-freqblog-music-metadata/find-tracks-by-bpm.md
- `find_tracks_by_key` — Read — https://policylayer.com/tools/com-freqblog-music-metadata/find-tracks-by-key.md
- `get_audio_features` — Read — https://policylayer.com/tools/com-freqblog-music-metadata/get-audio-features.md
- `get_audio_features_batch` — Read — https://policylayer.com/tools/com-freqblog-music-metadata/get-audio-features-batch.md
- `get_recommendations` — Read — https://policylayer.com/tools/com-freqblog-music-metadata/get-recommendations.md
- `get_related_artists` — Read — https://policylayer.com/tools/com-freqblog-music-metadata/get-related-artists.md
- `score_transition` — Read — https://policylayer.com/tools/com-freqblog-music-metadata/score-transition.md
- `search_catalog` — Read — https://policylayer.com/tools/com-freqblog-music-metadata/search-catalog.md
- `suggest_next_track` — Read — https://policylayer.com/tools/com-freqblog-music-metadata/suggest-next-track.md
- `tag_track` — Write — https://policylayer.com/tools/com-freqblog-music-metadata/tag-track.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

---

Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=com-freqblog-music-metadata · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/com-freqblog-music-metadata