Music Playlist Generation (PlaylistGen)

# Music Playlist Generation (PlaylistGen)

LLM-powered playlist generation for your local music library that contains music audio files such as mp3, flac, m4a, etc. Integrate this skill with your Agents (e.g., OpenClaw) to enable natural language music discovery and playlist curation through conversation. Point it at your music folder, run the indexer once, and get a natural language playlist generator — accessible via web browser or API.

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What it does

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Setup

Work through these steps with the user. Each step requires user input or confirmation before proceeding.

Step 0 — Install the skill

Clone or install PlaylistGen into the OpenClaw skills directory:

git clone https://github.com/asriverwang/playlistgen ~/.openclaw/skills/playlistgen
cd ~/.openclaw/skills/playlistgen

All subsequent commands assume PlaylistGen is located at `~/.openclaw/skills/playlistgen`.

Step 1 — Gather requirements

Ask the user:

1. Where is their music directory? (e.g. `/home/user/Music`, `/media/data/Music`)

2. Do they have an Anthropic API key, MiniMax API key, or both? (Anthropic Haiku preferred)

3. What IP/port should playlist links use? (default `http://localhost:5678` works for local use; set `MUSIC_SERVER_URL` to a LAN/Tailscale IP if they want links to work on other devices)

Step 2 — Create the virtual environment

cd ~/.openclaw/skills/playlistgen
python3 -m venv venv
venv/bin/pip install requests openai anthropic mutagen

Also check that `ffprobe` is available:

ffprobe -version
# If missing: sudo apt install ffmpeg   (Linux) or brew install ffmpeg (macOS)

Step 3 — Create .env

Copy `env.sample.md` to `.env` and fill in the values from Step 1:

cp env.sample.md .env

Required keys:

Optional:

Step 4 — Present MUSIC_RULES.md for review

**Read `MUSIC_RULES.md` and summarize the two sections to the user:**

**Ask the user:** "Do you want to use the default rules, or customize them before we start?"

If they want to customize:

If they use defaults: proceed.

Step 5 — Index the music library

This enriches every song with LLM-generated tags (genre, subgenre, mood, energy, language, region, usage context). It runs once and is safe to resume if interrupted.

source .env
venv/bin/python3 smart_indexer.py \
  --path "$MUSIC_DIR" \
  --llm haiku \
  --key "$ANTHROPIC_API_KEY" \
  --db "${DB_PATH:-music.db}" \
  --batch 40 \
  --workers 1

> **Note:** When using haiku, always set `--workers 1`. Haiku is efficient enough for single-worker throughput, but will throw 429 (rate limit) errors if batches are sent in parallel.

Use `--llm minimax --key "$MINIMAX_API_KEY"` if using MiniMax instead (MiniMax supports higher worker counts).

**Timing heads-up to give the user:** indexing takes roughly 1–3 hours per 5,000 songs depending on the response time and quality of the LLM model. Progress is saved after every batch so they can stop and resume without losing work. By default the indexer prints a live progress line with rate, ETA, and error counts:

Phase 2 (LLM): 2057 songs in 103 batches | haiku / claude-haiku | workers=1 | timeout=120s
Phase 2 (LLM): 45/103 (43.7%) [2.3 songs/s] | avg 8.7s/batch | ETA 4m12s

Errors, retries, and dropped batches are always printed (even without `--verbose`) so the agent can diagnose issues. Add `--verbose` for full per-batch detail including raw LLM response snippets.

> **Warning:** Playlist generation quality depends directly on how many songs have been enriched. Advise the user to wait until at least 500 songs have been indexed by the LLM before starting the server and using the service. They can monitor progress via the live `Phase 2 (LLM): N/M (X%)` output and resume at any time if they need to pause.

When done, tell the user:

Step 6 — Start the server

bash start.sh

Verify it's up:

curl -s http://localhost:5678/api/stats | python3 -m json.tool | head -5

Tell the user: "PlaylistGen is running at http://localhost:5678 — open it in a browser to search your library."

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Day-to-day operations

Generate a playlist (API)

POST http://localhost:5678/api/generate
{"prompt": "obscure 80s synth for late night driving", "max_count": 30}
→ {"title": "...", "url": "http://.../player?saved=XXXX", "count": 28}

Share only the returned `url`. Do not construct player URLs manually.

Search the library

GET http://localhost:5678/api/search?q=radiohead

Re-index after adding new music

source .env
venv/bin/python3 smart_indexer.py --path "$MUSIC_DIR" --llm haiku --key "$ANTHROPIC_API_KEY" --db "${DB_PATH:-music.db}" --workers 1

Skips already-indexed songs automatically.

Refresh catalog vocabulary (after re-indexing)

GET http://localhost:5678/api/catalog/vocab/refresh

Or just restart the server — it rebuilds on startup.

Update playlist rules

Edit `MUSIC_RULES.md` directly. Changes take effect on next server start. Restart:

bash start.sh

Check server status

curl -s http://localhost:5678/api/stats
tail -f playlist_server.log

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API Reference

Base URL: `http://localhost:5678` (or whatever `PORT` and `MUSIC_SERVER_URL` are set to).

**Never construct player URLs manually. Always use the `url` field returned by the server.**

Generating a playlist — try automated first, fall back to manual

**Always try the automated endpoint first:**

POST /api/generate
{"prompt": "obscure 80s synth for late night driving", "max_count": 30}

→ {"title": "...", "url": "http://<host>:5678/player?saved=XXXX", "count": 28, "tags": {...}}

Share only the returned `url`. Do not modify it. One call handles everything (interpret → fetch → curate → save).

**If `/api/generate` returns `{"error": ...}`, switch to the manual workflow below.**

Manual workflow (fallback)

Use this only when `/api/generate` fails. You participate in the pipeline directly.

**Step 1 — Interpret prompt → structured tags**

Fetch valid tags first: `GET /api/catalog/vocab`

Pick tags following these field rules:

**Step 2 — Fetch candidates**

Language is a hard filter. Region and popularity are NOT filtered here — pass them to Step 3.

GET /api/songs?genre=Rock,Indie&subgenre=Shoegaze,Dream+Pop&mood=Melancholic,Dreamy&usage_context=night&language=&limit=300
→ {"songs": [...], "count": N}

All params are substring-matched, comma-separated for multiple values. Returns up to 300 songs with full metadata.

**Step 3 — Curate: select and order final playlist**

Each song has: `path` (use as ID), `artist`, `title`, `genre`, `subgenre`, `mood`, `energy`, `language`, `region`, `year`, `popularity`. Select and order them yourself, then pass the paths to Step 4.

**Step 4 — Save and get player URL**

POST /api/playlist/save
{"title": "My Playlist", "songs": ["path1", "path2", ...]}
→ {"url": "http://<host>:5678/player?saved=XXXX", "title": "...", "count": N}

Share only the returned `url`. Do not modify it.

Other endpoints

| Endpoint | Description |

|---|---|

| `GET /api/stats` | Library stats: total songs, top artists/albums |

| `GET /api/search?q=<text>` | Keyword search on title/artist/album (50 results) |

| `GET /api/interpret?q=<prompt>&provider=claude\|minimax` | LLM prompt → structured tags (default: claude) |

| `GET /api/catalog/vocab` | Full tag→count dict for all fields |

| `GET /api/catalog/vocab/refresh` | Rebuild vocab from DB, rewrite catalog JSON file |

| `GET /` | Web search UI |

| `GET /player?saved=<key>` | Playlist player page |

Song fields

| Field | Type | Notes |

|---|---|---|

| `path` | string | Absolute filesystem path — use as song ID in all API calls |

| `url` | string | Relative path — use as audio `src` in browser |

| `title` | string | |

| `artist` | string | |

| `album` | string | |

| `year` | string | |

| `genre` | string | e.g. `"Rock"`, `"Electronic"` |

| `subgenre` | string | e.g. `"Shoegaze"`, `"Synthpop"` |

| `mood` | string | Comma-separated, e.g. `"Melancholic, Dreamy"` |

| `usage_context` | string | e.g. `"night"`, `"driving"` |

| `energy` | string | `"low"`, `"medium"`, or `"high"` |

| `language` | string | e.g. `"English"`, `"Mandarin"` |

| `region` | string | e.g. `"UK"`, `"USA"`, `"Taiwan"` |

| `popularity` | string | `"mainstream"`, `"indie"`, `"niche"`, `"obscure"` |

| `duration` | float | Seconds |

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Architecture summary

| Component | Role |

|---|---|

| `playlist_server.py` | HTTP server: all API endpoints, web UI, player |

| `smart_indexer.py` | One-time LLM enrichment — run standalone |

| `MUSIC_RULES.md` | Editable rules for interpret and curate LLM prompts |

| `music.db` | SQLite: songs table + playlists table |

| `music_catalog_vocab.json` | Auto-generated tag→count snapshot (written at server start) |

**Playlist generation pipeline (inside `/api/generate`):**

1. Interpret prompt → structured tags (LLM, guided by `MUSIC_RULES.md`)

2. Fetch candidates from DB — language is a hard filter; region/popularity are not

3. Curate: LLM selects and orders final playlist (guided by `MUSIC_RULES.md`)

4. Save playlist to DB → return player URL

**Key design principles:**