audiolla
Thirty audio engines. One port. Zero cloud. Fire-and-forget async jobs. Webhooks.
You needed Demucs for stems. Then librosa for BPM and key. Then basic-pitch for MIDI transcription. Then pyannote for speaker diarization. Then DeepFilterNet for speech enhancement. Then you spent three days debugging Python version conflicts and now you hate everything.
audiolla is what happens when you stop doing that.
Every audio processing tool worth using — wrapped in one HTTP API, running in one Docker container. POST a file. Get audio, JSON, or MIDI back. Drive it from curl, shell scripts, Python notebooks, Makefiles, or point an LLM agent at the MCP endpoint and let it rip.
No account. No subscription. No per-minute billing. No vendor lock-in. docker run and you're done.
What's in the box
| |
|---|
| 🎛️ Stem separation | Demucs — htdemucs, fine-tuned, 6-stem, MDX variants |
| 🎚️ Mastering | Reference mastering (matchering) + custom pedalboard chains |
| 📊 Analysis | BPM · key · LUFS · beats · onsets · melody · structural segments |
| 🎹 Chords + key | Chord detection + Krumhansl-Schmuckler key estimation |
| 🎵 Audio → MIDI | Polyphonic transcription via Spotify's basic-pitch (ONNX, no TF) |
| 🧹 Restoration | De-reverb · de-echo · de-noise via UVR BS-Roformer + MelBand Roformer |
| 🗣️ Speech | Enhancement (DeepFilterNet) · VAD (silero-vad) · diarization (pyannote) |
| 🖼️ Visuals | Spectrogram + waveform PNGs + 8-mode animated MP4/WebM |
| 🔍 Fingerprint | Chromaprint acoustic fingerprinting (AcoustID-compatible) |
| ✂️ Silence | Detect gaps · trim edges · strip all silence |
| 🎼 MIDI pipeline | Compose from JSON · inspect · transform · render via fluidsynth |
| 🎸 Effects | 23-effect pedalboard chain — Compressor, Reverb, PitchShift, filters… |
| 🔧 Transforms | Sox DSP — pitch, tempo, EQ, reverb, gain |
| 📢 Loudness | Measure LUFS · normalize to target |
| 🥁 HPSS | Harmonic/percussive source separation via librosa median filter |
| 🔇 Noise reduction | Spectral noise reduction via noisereduce — stationary + adaptive modes |
| ⏩ Time-stretch | Independent tempo factor + pitch shift via librosa phase vocoder |
| 🏷️ Audio tagging | Top-K AudioSet class labels via Audio Spectrogram Transformer |
| 🔗 Audio embeddings | 512-dim semantic embeddings via LAION CLAP + optional text similarity |
| 🏷️ Zero-shot classify | CLAP cosine similarity against any free-form text labels — genres, moods, instruments |
| 📋 Audio info | ffprobe metadata — duration, sample rate, channels, codec, bit depth |
| ✂️ Trim | Cut a clip by start/end seconds — any format in, any format out |
| 🎚️ Mix | Combine N staged tracks with per-track gain_db — pure ffmpeg, no model |
| 🔗 Concat | Stitch N audio files end-to-end in order |
| ⏩ Speed | Change playback speed without pitch shift (0.1× – 10×) via ffmpeg atempo |
| 🔄 Convert | Re-encode: format, sample rate, channel count in one call |
| 🔍 Similar | Cosine similarity between two audio files via CLAP embeddings |
| 🎹 MIDI quantize | Snap MIDI note timings to a rhythmic grid (16th, 8th, quarter…) |
| 🌅 Fade | Fade-in and/or fade-out with 13 curve shapes |
| ⏪ Reverse | Flip audio backwards |
| 🔁 Loop | Repeat audio N times |
| 🎯 BPM match | Auto-detect BPM then stretch to a target — no manual math |
| 📈 Loudness curve | RMS envelope over time — time-stamped dB values for gain automation |
| 🎤 Pitch correct | Auto-tune toward nearest chromatic semitone — configurable strength |
| 🔧 Repair | Declip + dehum — fix clipped peaks and remove power-line hum |
| 🔁 Loop point | Find best seamless loop boundary — score, bar count, candidates list |
| 🥁 Drum machine | Step-sequencer spec → GM drum MIDI — 16-step pattern, swing, tempo |
| 🎼 Chords to MIDI | Chord progression → MIDI file — root+3rd+5th voicings per segment |
| ↔️ Stereo width | Widen or collapse the stereo image via M/S processing |
| ✂️ Split | Split into N equal parts or on silence — returns ZIP of segments |
| 🔊 Pan | Position audio in the stereo field (-1 left → 0 center → 1 right) |
| 🎚️ EQ | Parametric EQ — JSON array of freq/gain_db/width_hz bands |
| 🎵 Key match | Detect source key then pitch-shift to a target key |
| 🎙️ Sidechain duck | Duck music when a trigger track (voice) is loud |
| 🏷️ Metadata | Read and write ID3/Vorbis/FLAC/WAV audio tags via mutagen |
| 🔴 Clip detect | Detect digital clipping — count, ratio, peak dBFS |
| ↔️ Mid/Side | Encode L/R → Mid+Side or decode Mid+Side → L/R |
| ✂️ Beat slice | Slice audio at detected beat positions — returns ZIP of segments |
| 🏟️ Conv reverb | Convolution reverb via impulse response — wet_mix control |
| 🥁 Transient shaper | Attack/sustain dual-compressor — punch up drums, cut room tail |
| 🎚️ Multiband compress | N-band compressor with zero-phase LR4 crossovers — mastering-grade dynamics |
| 🎛️ DJ prep | One call: BPM + key + Camelot wheel position + integrated LUFS |
| 📦 Batch | Run trim/convert/fade/reverse/speed/eq on staged files in sequence |
| 🧩 Presets + pipeline | Curated YAML workflows (master-for-spotify, podcast-cleanup, …) + ad-hoc op chaining server-side |
| 🗂️ Catalog | GET /v1/catalog — machine-readable endpoint list grouped by category for discovery |
| ⚡ Async jobs | Every endpoint supports async_job=true — fire-and-forget + webhook callbacks |
Table of Contents
Run it
docker run --rm -it \
-v $HOME/.audiolla-data:/data \
-p 8000:8000 \
psyb0t/audiolla:latest
docker run --rm -it --gpus all \
-v $HOME/.audiolla-data:/data \
-e AUDIOLLA_DEVICE=cuda \
-p 8000:8000 \
psyb0t/audiolla:latest-cuda
Demucs weights prefetch at container startup (for whichever variants are enabled) and cache in /data/torch_cache/. First boot downloads them; same -v mount next time and they're already there. Other engines (matchering, pedalboard, librosa, sox, fx, midi) have no weights — they're ready as soon as /healthz is green.
Migration from v0.23.x → v1.0.0
v1.0.0 is a breaking API release. Every existing client breaks. The new shape:
- Every audio endpoint takes a JSON body (no more
multipart/form-data except at /v1/files)
- Input is
file_path (FILES_DIR-relative) xor file_url (server-side fetch). Pre-stage the file via PUT /v1/files/{path} first.
- Output requires
output_path xor output_url. No more raw audio bytes in responses.
- Async path:
async_job=true auto-stages to jobs/{id}.{ext} if neither output is given.
- MCP audio-producing tools dropped
audio_base64 (and midi_base64 / image_base64 / video_base64). Same output_path xor output_url requirement.
openapi.yaml is now the contract — Pydantic models regenerate from it via make generate. Never hand-edit src/audiolla/schema/_generated.py.
- curl -X POST http://localhost:8000/v1/audio/normalize \
- -F "file=@track.wav" -F "target_lufs=-14" -o normalized.wav
+ # 1) stage the file (multipart only lives here now)
+ curl -X PUT --data-binary @track.wav \
+ -H 'Content-Type: application/octet-stream' \
+ http://localhost:8000/v1/files/uploads/track.wav
+ # 2) process via JSON body — response is JSON, not bytes
+ curl -X POST http://localhost:8000/v1/audio/normalize \
+ -H 'Content-Type: application/json' \
+ -d '{"file_path":"uploads/track.wav","target_lufs":-14,"output_path":"out/normalized.wav"}'
+ # 3) retrieve the result
+ curl -o normalized.wav http://localhost:8000/v1/files/out/normalized.wav
Why? See the v1.0.0 CHANGELOG entry for the full rationale.
Quick start
Once the container is up, this is a complete audio pipeline in six commands (every audio endpoint is JSON-body now; stage your input file at /v1/files/... first):
curl -X PUT --data-binary @song.wav \
-H 'Content-Type: application/octet-stream' \
http://localhost:8000/v1/files/uploads/song.wav
curl -X POST http://localhost:8000/v1/audio/separate \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/song.wav","engine":"htdemucs","stems":["vocals"],"output_path":"out/vocals.wav"}'
curl -o vocals.wav http://localhost:8000/v1/files/out/vocals.wav
curl -X POST http://localhost:8000/v1/audio/chords \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/song.wav"}'
curl -X PUT --data-binary @out/vocals.wav -H 'Content-Type: application/octet-stream' \
http://localhost:8000/v1/files/uploads/vocals.wav
curl -X POST http://localhost:8000/v1/audio/to_midi/basic-pitch \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/vocals.wav","output_path":"out/melody.mid"}'
curl -X POST http://localhost:8000/v1/midi/render \
-H 'Content-Type: application/json' \
-d '{"file_path":"out/melody.mid","output_path":"out/rendered.wav"}'
curl -X POST http://localhost:8000/v1/audio/noise-reduce/uvr-denoise \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/interview.wav","output_path":"out/clean.wav"}'
curl -X POST http://localhost:8000/v1/audio/diarize/pyannote \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/interview.wav"}'
Audio in. MIDI out. Chords detected. Speakers identified. De-noised. Re-synthesized. No Python environment to set up. No API keys. No account. Just HTTP.
What it can do
Output defaults to wav. Add "output_format":"mp3" to the JSON body to get mp3 instead (flac, opus, aac, pcm also work).
Every audio endpoint takes an application/json body. The only place multipart still lives is PUT /v1/files/{path} (raw bytes for staging an input file).
Input — every audio endpoint requires exactly one of:
file_path — path inside the /v1/files staging area (stage with PUT /v1/files/{path} first)file_url — remote URL the server fetches (disabled by default — see Remote URLs)
Output — audio-producing endpoints require exactly one of:
output_path — server writes to /v1/files/<path>, returns JSON {"path":..., "size":..., ...}output_url — server PUTs to a presigned URL, returns JSON {"url":..., "size":..., ...}
Analysis-only endpoints (those that return JSON data, e.g. /v1/audio/analyze, /v1/audio/loudness, /v1/audio/info) don't need output_path / output_url — the response is the result.
Split stems
curl -X PUT --data-binary @track.wav \
-H 'Content-Type: application/octet-stream' \
http://localhost:8000/v1/files/uploads/track.wav
curl -X POST http://localhost:8000/v1/audio/separate \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav","engine":"htdemucs","stems":["vocals"],"output_path":"out/vocals.wav"}'
curl -o vocals.wav http://localhost:8000/v1/files/out/vocals.wav
curl -X POST http://localhost:8000/v1/audio/separate \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav","engine":"htdemucs","output_path":"out/stems.zip"}'
curl -o stems.zip http://localhost:8000/v1/files/out/stems.zip
Master
curl -X PUT --data-binary @track.wav -H 'Content-Type: application/octet-stream' \
http://localhost:8000/v1/files/uploads/track.wav
curl -X PUT --data-binary @ref.wav -H 'Content-Type: application/octet-stream' \
http://localhost:8000/v1/files/uploads/ref.wav
curl -X POST http://localhost:8000/v1/audio/master \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav","mode":"reference","reference_path":"uploads/ref.wav","output_path":"out/mastered.wav"}'
curl -o mastered.wav http://localhost:8000/v1/files/out/mastered.wav
curl -X POST http://localhost:8000/v1/audio/master \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav","mode":"chain","preset":"loud","output_path":"out/mastered.wav"}'
curl -o mastered.wav http://localhost:8000/v1/files/out/mastered.wav
Analyze
curl -X POST http://localhost:8000/v1/audio/analyze \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav","features":["bpm","key","loudness"]}'
Beats, onsets, melody, segments
curl -X POST http://localhost:8000/v1/audio/beats \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav"}'
curl -X POST http://localhost:8000/v1/audio/onsets \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav"}'
curl -X POST http://localhost:8000/v1/audio/melody \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav"}'
curl -X POST http://localhost:8000/v1/audio/segments \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav","num_segments":6}'
Beat detection also generates a click-track file when click_track=true (set output_path to receive it) — handy for aligning a mix to a grid. Pass start_bpm=140 to seed the tracker when you already know the rough tempo (faster, more accurate). Melody can be exported as a single-track MIDI file via as_midi=true + output_path.
Silence detection and trimming
curl -X POST http://localhost:8000/v1/audio/silence \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav","threshold_db":-30,"min_duration_sec":1.0}'
curl -X POST http://localhost:8000/v1/audio/silence \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav","threshold_db":-30,"min_duration_sec":0.5,"trim_mode":"all","output_path":"out/trimmed.wav"}'
curl -o trimmed.wav http://localhost:8000/v1/files/out/trimmed.wav
curl -X POST http://localhost:8000/v1/audio/silence \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav","threshold_db":-40,"min_duration_sec":0.3,"trim_mode":"edges","output_path":"processed/trimmed.wav"}'
trim_mode=edges — chop leading + trailing silence only. trim_mode=all — remove every detected gap (compress a talk recording, tighten a loop). Without trim_mode, the response is JSON only: silent_ranges, non_silent_ranges, duration — and output_path / output_url is not required.
Visual output splits into two sub-namespaces by output type:
curl -X POST http://localhost:8000/v1/audio/visualize/image/spectrogram \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav","width":1280,"height":720,"output_path":"out/spec.png"}'
curl -o spec.png http://localhost:8000/v1/files/out/spec.png
curl -X POST http://localhost:8000/v1/audio/visualize/image/waveform \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav","width":1280,"height":240,"output_path":"out/wave.png"}'
curl -o wave.png http://localhost:8000/v1/files/out/wave.png
curl -X POST http://localhost:8000/v1/audio/visualize/video/spectrum \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav","width":1280,"height":720,"fps":30,"container":"mp4","output_path":"out/viz.mp4"}'
curl -o viz.mp4 http://localhost:8000/v1/files/out/viz.mp4
/image/spectrogram: produces a PNG (staged via output_path or PUT to output_url). Params: width, height, color (default intensity), scale (log/lin).
/image/waveform: produces a PNG. Params: width, height, color (default lime).
/video/{mode}: spectrum (scrolling FFT), waves (oscilloscope), cqt (constant-Q transform), freqs (bar-graph analyzer), volume (VU meter), vectorscope (stereo X/Y scope), phasemeter, histogram. Params: width, height, fps, container (mp4 default, webm).
Acoustic fingerprint
curl -X POST http://localhost:8000/v1/audio/fingerprint \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav"}'
curl -X POST http://localhost:8000/v1/audio/fingerprint \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav","return_raw":true}'
The base64 fingerprint string is compatible with the AcoustID lookup service.
De-reverb, de-echo, de-noise
AI audio restoration via UVR ecosystem models — BS-Roformer and MelBand Roformer. All three are unified under POST /v1/audio/restore/{engine}.
curl -X POST http://localhost:8000/v1/audio/restore/uvr-dereverb \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav","output_path":"out/dry.wav"}'
curl -X POST http://localhost:8000/v1/audio/restore/uvr-deecho \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav","output_path":"out/noecho.wav"}'
curl -X POST http://localhost:8000/v1/audio/restore/uvr-deecho \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav","aggressive":true,"output_path":"out/noecho.wav"}'
curl -X POST http://localhost:8000/v1/audio/restore/uvr-denoise \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav","output_path":"out/clean.wav"}'
All support output_format, output_path, output_url. For DSP-based noise reduction (no GPU) use noise-reduce/noise-reduce.
UVR engines also work through /v1/audio/separate — uvr-vocal-bsr (BS-Roformer, SDR 13) and uvr-karaoke return vocal + instrumental stems like Demucs but often with higher quality.
Audio-to-MIDI transcription
Polyphonic audio-to-MIDI via Spotify's basic-pitch (ONNX backend, no TensorFlow). Play guitar, hum a melody, record a piano riff — get a MIDI file back with all the notes.
curl -X POST http://localhost:8000/v1/audio/to_midi/basic-pitch \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/guitar_riff.wav","output_path":"out/riff.mid"}'
curl -o riff.mid http://localhost:8000/v1/files/out/riff.mid
curl -X POST http://localhost:8000/v1/audio/to_midi/basic-pitch \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/piano.wav","onset_threshold":0.6,"frame_threshold":0.3,"minimum_note_length_ms":80,"output_path":"out/piano.mid"}'
curl -X POST http://localhost:8000/v1/audio/to_midi/basic-pitch \
-H 'Content-Type: application/json' \
-d '{"file_path":"recordings/bass.wav","output_path":"midi/bass_notes.mid"}'
Optional params: onset_threshold (0–1, default 0.5), frame_threshold (0–1, default 0.3), minimum_note_length_ms (default 58), minimum_frequency / maximum_frequency (Hz, default unconstrained), multiple_pitch_bends (bool, default false), melodia_trick (bool, default true — helps with melodic content). Default engine: basic-pitch.
The MIDI file is piped straight into /v1/midi/inspect or /v1/midi/render — audio → MIDI → audio is a complete round-trip.
Neural speech and vocal enhancement
DeepFilterNet DF3 — deep learning noise suppression trained on speech. Better than broadband de-noise for voice recordings; more surgical than UVR's de-noise on vocals specifically.
curl -X POST http://localhost:8000/v1/audio/enhance/deepfilter \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/vocal_recording.wav","output_path":"out/enhanced.wav"}'
curl -o enhanced.wav http://localhost:8000/v1/files/out/enhanced.wav
curl -X POST http://localhost:8000/v1/audio/enhance/deepfilter \
-H 'Content-Type: application/json' \
-d '{"file_path":"vocals/raw.wav","output_format":"mp3","output_path":"vocals/enhanced.mp3"}'
Supports output_format, output_path, output_url.
Generate music + SFX
Text-to-audio generation under POST /v1/audio/generate/{engine}. v1.0.0 ships five engines spanning music + sound effects, with different licence / VRAM / sound profiles — all CUDA-only.
curl -X POST http://localhost:8000/v1/audio/generate/stable-audio-open \
-H 'Content-Type: application/json' \
-d '{"prompt":"130 bpm tech house drum loop, punchy kick, crisp hats, no vocals","duration_sec":10,"seed":42,"output_path":"out/loop.wav"}'
curl -o loop.wav http://localhost:8000/v1/files/out/loop.wav
curl -X POST http://localhost:8000/v1/audio/generate/musicgen-small \
-H 'Content-Type: application/json' \
-d '{"prompt":"lo-fi hip-hop beat with vinyl crackle, 90 bpm","duration_sec":15,"output_path":"out/beat.wav"}'
curl -X POST http://localhost:8000/v1/audio/generate/riffusion \
-H 'Content-Type: application/json' \
-d '{"prompt":"ambient drone with metallic resonance","output_path":"out/drone.wav"}'
curl -X POST http://localhost:8000/v1/audio/generate/audioldm2 \
-H 'Content-Type: application/json' \
-d '{"prompt":"heavy rain on a metal roof with distant thunder","duration_sec":10,"num_inference_steps":50,"output_path":"out/rain.wav"}'
Engine details:
| Engine | Licence | Max length | VRAM (fp16) | Output |
|---|
stable-audio-open | Stability Community Licence (commercial OK below the revenue threshold) | 47 s hard cap | ~12 GB | 44.1 kHz stereo. Loops, SFX, ambient textures — instrumental only |
musicgen-small | CC-BY-NC 4.0 (non-commercial only — opt-in via AUDIOLLA_ENABLE_NONCOMMERCIAL=1) | 30 s hard cap | ~3 GB | 32 kHz mono. Meta MusicGen 300M, instrumental |
musicgen-medium | CC-BY-NC 4.0 (same opt-in) | 30 s hard cap | ~6-8 GB | 32 kHz mono. Higher quality than -small |
riffusion | CreativeML OpenRAIL-M (commercial OK with the licence's usage restrictions) | ~5 s per pass | ~3 GB | 22.05 kHz mono. SD-style spectrogram, Griffin-Lim reconstruction — lo-fi / loop-y character |
audioldm2 | CC-BY 4.0 (commercial use OK — no opt-in gate) | 30 s hard cap | ~8-10 GB (CPU offload) | 16 kHz mono. General SFX: ambience, foley, animal, mechanical, impact sounds. Slow (200-step DDIM default; pass num_inference_steps=50 for ~4x speedup) |
All engines support async_job=true, webhook_url, output_path, output_url, and seed for reproducibility. stable-audio-open and audioldm2 additionally accept num_inference_steps (trade quality for speed). Model weights download on first call to HF_HOME (default /data/hf inside the container — ~7 GB across all five). Subsequent calls are inference-only. All five are flagged cuda_only — non-CUDA hosts get HTTP 400.
Licence opt-in for MusicGen. MusicGen weights are CC-BY-NC 4.0. The engine code ships with the image but refuses to load the model unless the operator explicitly sets AUDIOLLA_ENABLE_NONCOMMERCIAL=1 in the server's environment. Same pattern matchering (GPL v3) follows — licence-encumbered code in the image, conscious opt-in to actually use it. Read the MusicGen weights licence before opting in. AudioLDM 2 is CC-BY 4.0 (commercial use allowed, no opt-in gate) — it's the only generator in this set that's commercial-safe without flipping any flags.
Deferred to a future release (researched but not shipped in v1.0.0):
- ACE-Step v1 (3.5B, Apache 2.0, full songs with vocals up to 4 min) — requires
AceStepPipeline from diffusers>=0.38, which itself requires a pre-release safetensors. Doesn't pass the project's hash-locked supply-chain gate. Revisit when safetensors 0.8.x ships stable, or vendor ACE-Step's pipeline directly.
- DiffRhythm full v1.2 (Apache 2.0) — unpackaged research repo (no
setup.py / PyPI release). Revisit when upstream ships a package or we vendor under thirdparty/.
- Stable Audio Open Small (Stability Community Licence, 11 s SFX-specialist) — requires
stable-audio-tools which pins python >=3.10, <3.11; audiolla is on Python 3.12, hard incompatibility. Revisit when stable-audio-tools widens the Python constraint or diffusers grows a pipeline for it.
- TangoFlux (ICLR 2026, 44.1 kHz, 30 s, fast) — git-only install (no PyPI package). Could be SHA-pinned in the hash-locked supply chain; deferred for now to keep the heavy-deps stack PyPI-only.
- AudioGen (Meta, CC-BY-NC) —
audiocraft==1.3.0 pins transformers<=4.31.0, hard conflict with audiolla's 4.51.3. Would require an isolated subprocess / sidecar container.
- YuE 7B (Apache 2.0, full songs with vocals) — needs 16-24 GB VRAM at fp16, doesn't fit 12 GB GPUs without int4 quant tooling.
Chord and key detection
Krumhansl-Schmuckler key estimation + chroma-template chord segmentation via librosa. No extra deps beyond the librosa stack.
curl -X POST http://localhost:8000/v1/audio/chords \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav"}'
curl -X POST http://localhost:8000/v1/audio/chords \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav","hop_length":256}'
Optional params: hop_length (default 512), segment_min_duration_sec (default 0.5 — merge very short chord segments).
Voice activity detection
silero-vad — ONNX-based VAD, fast and accurate on both speech and music. Returns timestamped speech and non-speech segments.
curl -X POST http://localhost:8000/v1/audio/vad \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/interview.wav"}'
curl -X POST http://localhost:8000/v1/audio/vad \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/podcast.wav","threshold":0.7,"min_speech_duration_ms":300,"min_silence_duration_ms":200}'
Optional params: threshold (0–1, default 0.5), min_speech_duration_ms (default 250), min_silence_duration_ms (default 100).
Speaker diarization
pyannote/speaker-diarization-3.1 — state-of-the-art speaker diarization from HuggingFace Hub. Returns per-speaker timestamped segments and speaker count.
Note: This engine requires a HuggingFace account. You must accept the model terms at
https://huggingface.co/pyannote/speaker-diarization-3.1
and then set HF_TOKEN (or the older alias HUGGINGFACE_TOKEN — the entrypoint mirrors them both ways) when starting the container. A read-only token with model access is enough. The same token also unlocks the gated text-to-audio engines (stable-audio-open, musicgen-small, musicgen-medium) provided you've accepted their licences on huggingface.co.
docker run ... \
-e HF_TOKEN=hf_your_token_here \
psyb0t/audiolla:latest
curl -X POST http://localhost:8000/v1/audio/diarize/pyannote \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/interview.wav"}'
curl -X POST http://localhost:8000/v1/audio/diarize/pyannote \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/roundtable.wav","num_speakers":4}'
curl -X POST http://localhost:8000/v1/audio/diarize/pyannote \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/panel.wav","min_speakers":2,"max_speakers":6}'
Optional params: num_speakers (exact count hint), min_speakers, max_speakers.
curl -X POST http://localhost:8000/v1/audio/transform \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav","operations":[{"op":"pitch","params":{"n_semitones":2}},{"op":"reverb","params":{"reverberance":50}}],"output_format":"mp3","output_path":"out/out.mp3"}'
curl -o out.mp3 http://localhost:8000/v1/files/out/out.mp3
Loudness measurement
curl -X POST http://localhost:8000/v1/audio/loudness \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav"}'
Loudness curve
RMS envelope over time — returns a list of {time_sec, rms_db} points. Useful for generating gain automation curves, finding loud and quiet sections, or visualising dynamic range before mastering.
curl -X POST http://localhost:8000/v1/audio/loudness/curve \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav"}' | jq '.curve[:5]'
curl -X POST http://localhost:8000/v1/audio/loudness/curve \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav","hop_length":2048}' | jq '{duration, sample_rate, points}'
Response fields: curve (array of {time_sec, rms_db}), duration (seconds), sample_rate, points (total curve length). Optional param: hop_length (default 512).
Loudness normalization
curl -X POST http://localhost:8000/v1/audio/normalize \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav","target_lufs":-14,"output_path":"out/normalized.wav"}'
curl -o normalized.wav http://localhost:8000/v1/files/out/normalized.wav
curl -X POST http://localhost:8000/v1/audio/normalize \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav","target_lufs":-23,"output_path":"mastered/norm.wav"}'
target_lufs is required. The response JSON carries loudness_lufs with the measured pre-normalization level alongside path / url / size.
HPSS (harmonic/percussive split)
Median-filter harmonic/percussive source separation via librosa. Harmonic = tonal content (pitched instruments, pads); percussive = transients (drums, percussion). No ML — pure DSP, fast, no GPU needed.
curl -X POST http://localhost:8000/v1/audio/separate/hpss \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav","output_path":"out/stems.zip"}'
curl -o stems.zip http://localhost:8000/v1/files/out/stems.zip
curl -X POST http://localhost:8000/v1/audio/separate/hpss \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav","margin":3.0,"output_path":"out/stems.zip"}'
curl -X POST http://localhost:8000/v1/audio/separate/hpss \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav","output_path":"hpss/stems.zip"}'
Params: margin (default 1.0 — ≥1.0, higher = more aggressive), kernel_size (default 31 — odd int, median filter width), output_format (default wav).
Spectral noise reduction
Noise reduction with two engine options under the same endpoint — pick DSP for no-GPU fast cleanup or ML for higher-quality removal.
curl -X POST http://localhost:8000/v1/audio/noise-reduce/noise-reduce \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/recording.wav","output_path":"out/clean.wav"}'
curl -X POST http://localhost:8000/v1/audio/noise-reduce/noise-reduce \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/recording.wav","stationary":true,"output_path":"out/clean.wav"}'
curl -X POST http://localhost:8000/v1/audio/noise-reduce/noise-reduce \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/recording.wav","prop_decrease":0.5,"output_path":"out/clean.wav"}'
curl -X POST http://localhost:8000/v1/audio/noise-reduce/uvr-denoise \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/recording.wav","output_path":"out/clean.wav"}'
DSP params (only apply to noise-reduce engine): stationary (bool, default false), prop_decrease (0–1, default 1.0). Both engines accept output_format, output_path, output_url.
Time-stretch and pitch-shift
Independent tempo factor and semitone offset via librosa phase vocoder. Slow a track down to learn it; shift a vocal up 3 semitones for a different key; transpose a MIDI melody to a different register first, then render.
curl -X POST http://localhost:8000/v1/audio/stretch \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav","tempo_factor":0.8,"output_path":"out/slow.wav"}'
curl -X POST http://localhost:8000/v1/audio/stretch \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/vocal.wav","pitch_semitones":3,"output_path":"out/pitched.wav"}'
curl -X POST http://localhost:8000/v1/audio/stretch \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav","tempo_factor":0.5,"pitch_semitones":6,"output_format":"mp3","output_path":"out/stretched.mp3"}'
Params: tempo_factor (default 1.0 — 0.5 = half speed), pitch_semitones (default 0.0 — ±semitones), output_format, output_path.
Pitch correct
Auto-tune audio toward the nearest chromatic semitone using librosa's phase vocoder. Full strength=1.0 snaps hard to pitch; lower values blend the corrected and original signal.
curl -X POST http://localhost:8000/v1/audio/pitch-correct \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/vocal.wav","output_path":"out/tuned.wav"}'
curl -X POST http://localhost:8000/v1/audio/pitch-correct \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/vocal.wav","strength":0.5,"output_format":"mp3","output_path":"out/tuned.mp3"}'
curl -X POST http://localhost:8000/v1/audio/pitch-correct \
-H 'Content-Type: application/json' \
-d '{"file_path":"sessions/take1.wav","strength":1.0,"async_job":true,"output_path":"sessions/take1_tuned.wav"}'
Params: strength (0.0–1.0, default 1.0), output_format, output_path, async_job, webhook_url. Requires librosa-analyze engine.
Repair
Declip clipped peaks and/or remove power-line hum. Declipping uses cubic interpolation to reconstruct flattened waveform tops and bottoms. Dehumming applies a notch filter at hum_freq (and harmonics).
curl -X POST http://localhost:8000/v1/audio/repair \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/overdriven.wav","output_path":"out/repaired.wav"}'
curl -X POST http://localhost:8000/v1/audio/repair \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/recording.wav","declip":false,"dehum":true,"hum_freq":60.0,"output_path":"out/clean.wav"}'
curl -X POST http://localhost:8000/v1/audio/repair \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/problem_track.wav","declip":true,"dehum":true,"hum_freq":50.0,"output_format":"flac","output_path":"out/repaired.flac"}'
Params: declip (bool, default true), dehum (bool, default false), hum_freq (Hz, default 50.0), output_format, output_path, async_job, webhook_url.
Audio tagging
Top-K AudioSet class label classification via Audio Spectrogram Transformer (MIT/ast-finetuned-audioset-10-10-0.4593). Identifies what's in a recording — music, speech, specific instruments, environmental sounds, etc.
curl -X POST http://localhost:8000/v1/audio/tag \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/recording.wav"}'
curl -X POST http://localhost:8000/v1/audio/tag \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/soundscape.wav","top_k":20}'
Requires the HF model cache. First run downloads the weights to /data/hf/. Optional: top_k (default 10).
The image defaults to HF_HUB_OFFLINE=0 so first call lazy-downloads the weights into /data/hf/. For locked-down deployments (no egress), prefetch the model with huggingface-cli download <model> into a mounted /data/hf volume, then start the container with -e HF_HUB_OFFLINE=1.
Audio embeddings
512-dimensional L2-normalized audio embeddings via LAION CLAP (laion/larger_clap_music_and_speech). Useful for semantic audio search, similarity scoring, and clustering.
curl -X POST http://localhost:8000/v1/audio/embed \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav"}'
curl -X POST http://localhost:8000/v1/audio/embed \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav","query_text":"energetic rock guitar riff"}'
similarity is cosine similarity in [-1, 1]. Requires HF model cache — same first-run download caveat as audio tagging.
Zero-shot classification
Given audio and a list of free-form text labels, return cosine similarity scores for each using the existing CLAP model. No extra model download — uses the same clap-embed engine. Works for genres, moods, instruments, sonic descriptors — anything CLAP understands.
curl -X POST http://localhost:8000/v1/audio/classify \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav","labels":["jazz","hip-hop","classical","electronic","rock"]}'
curl -X POST http://localhost:8000/v1/audio/classify \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav","labels":["energetic","calm","melancholic","aggressive","uplifting"]}'
curl -X POST http://localhost:8000/v1/audio/classify \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/interview.wav","labels":["male voice","female voice","child voice","multiple speakers"]}'
Results are sorted by descending score. Scores are cosine similarities in [-1, 1] — higher = more similar. Requires clap-embed model cache.
Audio info
Probe any audio file for metadata without loading it into memory for processing. Uses ffprobe — handles any format.
curl -X POST http://localhost:8000/v1/audio/info \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav"}'
curl -X POST http://localhost:8000/v1/audio/info \
-H 'Content-Type: application/json' \
-d '{"file_path":"recordings/interview.mp3"}'
Trim
Cut a precise time range out of any audio file. Common use: extract a chorus, clip a sample, chop a stem at bar boundaries.
curl -X POST http://localhost:8000/v1/audio/trim \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav","start_sec":30.0,"end_sec":90.0,"output_path":"out/chorus.wav"}'
curl -X POST http://localhost:8000/v1/audio/trim \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/stem.wav","start_sec":0.0,"end_sec":8.0,"output_format":"mp3","output_path":"out/loop.mp3"}'
curl -X POST http://localhost:8000/v1/audio/trim \
-H 'Content-Type: application/json' \
-d '{"file_path":"sessions/full.wav","start_sec":120.5,"end_sec":180.0,"output_path":"clips/verse.wav"}'
start_sec defaults to 0. end_sec is required and must be greater than start_sec. Supports all standard output_format values.
Mix
Combine multiple staged or URL-accessible tracks into one. Per-track gain_db lets you balance levels before mixing. Useful for bouncing separated stems back together at custom levels, layering synth parts, or combining click-track + music.
curl -X POST http://localhost:8000/v1/audio/mix \
-H 'Content-Type: application/json' \
-d '{"tracks":[{"file_path":"stems/drums.wav"},{"file_path":"stems/bass.wav"}],"output_path":"out/rhythm.wav"}'
curl -X POST http://localhost:8000/v1/audio/mix \
-H 'Content-Type: application/json' \
-d '{"tracks":[
{"file_path":"stems/drums.wav","gain_db":-3},
{"file_path":"stems/bass.wav","gain_db":0},
{"file_path":"stems/vocals.wav","gain_db":2}
],"output_format":"wav","output_path":"out/custom_mix.wav"}'
curl -X POST http://localhost:8000/v1/audio/mix \
-H 'Content-Type: application/json' \
-d '{"tracks":[{"file_path":"stems/harmonic.wav"},{"file_path":"stems/percussive.wav","gain_db":-6}],"output_path":"mixed/recombined.wav"}'
tracks is a required JSON array. Each entry needs file_path or file_url and an optional gain_db (default 0.0). Requires at least 2 tracks. Shorter tracks are padded with silence to match the longest.
Concat
Stitch N audio files together in order. Handles different sample rates and channel counts automatically (ffmpeg resamples on the fly).
curl -X POST http://localhost:8000/v1/audio/concat \
-H 'Content-Type: application/json' \
-d '{"files":[{"file_path":"intro.wav"},{"file_path":"verse.wav"},{"file_path":"outro.wav"}],"output_path":"out/full_track.wav"}'
curl -X POST http://localhost:8000/v1/audio/concat \
-H 'Content-Type: application/json' \
-d '{"files":[{"file_path":"a.wav"},{"file_path":"b.wav"}],"output_format":"mp3","output_path":"concat/result.mp3"}'
files is a required JSON array of {file_path?, file_url?} objects. Requires at least 2 entries.
Speed
Change playback speed without pitch shifting — useful for auditioning at half/double speed, or creating slow-motion effects. Uses ffmpeg atempo filter chained for extreme multipliers.
curl -X POST http://localhost:8000/v1/audio/speed \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav","speed":0.5,"output_path":"out/slow.wav"}'
curl -X POST http://localhost:8000/v1/audio/speed \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav","speed":2.0,"output_path":"out/fast.wav"}'
curl -X POST http://localhost:8000/v1/audio/speed \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav","speed":4.0,"output_format":"mp3","output_path":"out/fast.mp3"}'
speed is required. Range: 0.1–10.0. Note: this changes duration but not pitch. For pitch-preserving tempo changes use /v1/audio/stretch.
Convert
Re-encode audio to a different format, sample rate, or channel count in a single call.
curl -X POST http://localhost:8000/v1/audio/convert \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/recording.wav","output_format":"flac","sample_rate":16000,"channels":1,"output_path":"out/prepared.flac"}'
curl -X POST http://localhost:8000/v1/audio/convert \
-H 'Content-Type: application/json' \
-d '{"file_path":"stereo.wav","channels":1,"output_path":"out/mono.wav"}'
curl -X POST http://localhost:8000/v1/audio/convert \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/audio.mp3","output_format":"opus","sample_rate":48000,"output_path":"out/out.opus"}'
output_format defaults to wav. sample_rate and channels are optional; if omitted, the source values are preserved.
Similar
Compute cosine similarity between two audio files using CLAP embeddings. Returns a score in [-1, 1] — 1 = identical sound, 0 = unrelated, negative = acoustically opposite. Useful for duplicate detection, cover matching, or finding the closest sample in a library.
curl -X POST http://localhost:8000/v1/audio/similar \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/original.wav","reference_file_path":"uploads/remix.wav"}'
curl -X POST http://localhost:8000/v1/audio/similar \
-H 'Content-Type: application/json' \
-d '{"file_path":"stems/vocals.wav","reference_file_path":"stems/vocals_ref.wav"}'
Primary file: file_path / file_url. Reference file: reference_file_path / reference_file_url. Requires clap-embed engine.
MIDI quantize
Snap all note timings in a MIDI file to the nearest rhythmic grid. Cleaner dedicated endpoint than /v1/midi/transform's quantize_grid_beats param.
curl -X POST http://localhost:8000/v1/midi/quantize \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/sloppy.mid","grid_beats":0.25,"output_path":"out/tight.mid"}'
curl -X POST http://localhost:8000/v1/midi/quantize \
-H 'Content-Type: application/json' \
-d '{"file_path":"recorded.mid","grid_beats":0.5,"output_path":"midi/quantized.mid"}'
grid_beats: grid size in beats — 0.25 = 16th note, 0.5 = 8th, 1.0 = quarter note. Default: 0.25.
Fade
Apply fade-in, fade-out, or both. 13 curve shapes: tri, qsin, esin, hsin, log, ipar, qua, cub, squ, cbr, par, exp, lin.
curl -X POST http://localhost:8000/v1/audio/fade \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav","fade_in":2.0,"output_path":"out/faded.wav"}'
curl -X POST http://localhost:8000/v1/audio/fade \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav","fade_out":3.0,"curve":"exp","output_path":"out/faded.wav"}'
curl -X POST http://localhost:8000/v1/audio/fade \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav","fade_in":1.0,"fade_out":2.0,"output_path":"out/faded.wav"}'
At least one of fade_in / fade_out must be > 0.
Reverse
Flip audio backwards via ffmpeg areverse.
curl -X POST http://localhost:8000/v1/audio/reverse \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/sample.wav","output_path":"out/reversed.wav"}'
curl -X POST http://localhost:8000/v1/audio/reverse \
-H 'Content-Type: application/json' \
-d '{"file_path":"stems/vocals.wav","output_format":"mp3","output_path":"out/reversed.mp3"}'
Loop
Repeat audio N times. Uses ffmpeg aloop filter — no re-encoding overhead per iteration.
curl -X POST http://localhost:8000/v1/audio/loop \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/beat.wav","count":4,"output_path":"out/looped.wav"}'
curl -X POST http://localhost:8000/v1/audio/loop \
-H 'Content-Type: application/json' \
-d '{"file_path":"stems/drums.wav","count":4,"output_path":"loops/drums32.wav"}'
count must be ≥ 2 (total plays, not extra loops).
BPM match
Detect the source BPM via librosa, then time-stretch to the target — no manual math.
curl -X POST http://localhost:8000/v1/audio/bpm-match \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/loop.wav","target_bpm":128,"output_path":"out/matched.wav"}'
curl -X POST http://localhost:8000/v1/audio/bpm-match \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/loop.wav","target_bpm":140,"pitch_semitones":2,"output_path":"out/matched.wav"}'
Response JSON includes source_bpm, target_bpm, and tempo_factor alongside the staged path / url. Requires both librosa-analyze and stretch engines.
Stereo width
Widen or collapse the stereo image via M/S processing. width=0.0 → mono, 1.0 → original, >1.0 → wider. Works on mono input too (upmixes first).
curl -X POST http://localhost:8000/v1/audio/stereo-width \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/mix.wav","width":1.5,"output_path":"out/wide.wav"}'
curl -X POST http://localhost:8000/v1/audio/stereo-width \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/mix.wav","width":0.0,"output_path":"out/mono.wav"}'
curl -X POST http://localhost:8000/v1/audio/stereo-width \
-H 'Content-Type: application/json' \
-d '{"file_path":"master/mix.wav","width":0.8,"output_path":"master/narrow.wav"}'
Range: [0.0, 3.0].
Split
Split a file into segments. Two modes: equal (N equal time parts) or silence (split on quiet gaps). Returns a ZIP of numbered files.
curl -X POST http://localhost:8000/v1/audio/split \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav","mode":"equal","count":4,"output_path":"out/segments.zip"}'
curl -X POST http://localhost:8000/v1/audio/split \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/djmix.wav","mode":"silence","threshold_db":-40,"min_duration_sec":1.0,"output_path":"out/tracks.zip"}'
curl -X POST http://localhost:8000/v1/audio/split \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/album.flac","mode":"equal","count":10,"output_format":"mp3","output_path":"out/parts.zip"}'
mode=equal requires count >= 2. mode=silence uses threshold_db (default -30) and min_duration_sec (default 0.5); requires the silence-detect engine.
Pan
Position audio in the stereo field. Works on mono and stereo input.
curl -X POST http://localhost:8000/v1/audio/pan \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/vocal.wav","position":-1.0,"output_path":"out/left.wav"}'
curl -X POST http://localhost:8000/v1/audio/pan \
-H 'Content-Type: application/json' \
-d '{"file_path":"stems/guitar.wav","position":0.4,"output_path":"out/guitar_panned.wav"}'
curl -X POST http://localhost:8000/v1/audio/pan \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/mono.wav","position":0.0,"output_path":"out/stereo.wav"}'
position: -1.0 = hard left, 0.0 = center, 1.0 = hard right.
EQ
Parametric EQ via ffmpeg equalizer filter. Pass any number of bands — each with a center frequency, gain, and optional bandwidth.
curl -X POST http://localhost:8000/v1/audio/eq \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/vocal.wav","bands":[{"freq":100,"gain_db":-6,"width_hz":80},{"freq":3000,"gain_db":3,"width_hz":500}],"output_path":"out/eq.wav"}'
curl -X POST http://localhost:8000/v1/audio/eq \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/recording.wav","bands":[{"freq":60,"gain_db":-20,"width_hz":30}],"output_path":"out/clean.wav"}'
Each band: freq (Hz, required), gain_db (dB, required, range ±30), width_hz (optional, default 100).
Key match
Detect the source key via CLAP chord analysis, then pitch-shift to a target key — one call instead of two.
curl -X POST http://localhost:8000/v1/audio/key-match \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/loop.wav","target_key":"C","output_path":"out/matched.wav"}'
curl -X POST http://localhost:8000/v1/audio/key-match \
-H 'Content-Type: application/json' \
-d '{"file_path":"stems/melody.wav","target_key":"F#","output_path":"matched/melody_fsharp.wav"}'
target_key: root note, e.g. C, F#, Bb, D#. Mode suffix (major/minor/m) is ignored — only the root matters for pitch. Requires chord-detect and stretch engines.
Sidechain duck
Duck a primary track (music) whenever a trigger track (voice) is loud — the classic voiceover-over-music effect. Pure ffmpeg sidechaincompress, no model required.
curl -X POST http://localhost:8000/v1/audio/sidechain-duck \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/music.wav","trigger_file_path":"uploads/voice.wav","threshold_db":-20,"ratio":4,"attack_ms":10,"release_ms":200,"output_path":"out/ducked.wav"}'
curl -X POST http://localhost:8000/v1/audio/sidechain-duck \
-H 'Content-Type: application/json' \
-d '{"file_path":"music/bed.wav","trigger_file_path":"voice/narration.wav","threshold_db":-30,"ratio":10,"release_ms":400,"output_path":"final/mix.wav"}'
Primary track is compressed whenever the trigger exceeds threshold_db. ratio sets compression intensity. Files must be the same duration for best results; shorter trigger is padded with silence.
Effects chain
Apply an ordered chain of pedalboard effects — full catalog, you pick the order and params. Different from /v1/audio/master (which runs preset mastering chains).
curl -X POST http://localhost:8000/v1/audio/fx \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav","effects":[
{"type":"Compressor","params":{"threshold_db":-18,"ratio":4.0}},
{"type":"Reverb","params":{"room_size":0.5,"wet_level":0.3}},
{"type":"Gain","params":{"gain_db":-3.0}}
],"output_path":"out/out.wav"}'
Allowed effects: Compressor, Limiter, NoiseGate, Gain, Clipping, Distortion, Bitcrush, Reverb, Chorus, Delay, Phaser, PitchShift, HighShelfFilter, LowShelfFilter, PeakFilter, HighpassFilter, LowpassFilter, LadderFilter, IIRFilter, GSMFullRateCompressor, MP3Compressor, Resample, Invert, Convolution.
VST3 / AudioUnit / external plugins are NOT in the allowlist — they load arbitrary native code.
Loop point
Find the best seamless loop boundary in an audio file — audiolla analyses the beat grid and returns the start and end positions where a loop will repeat without a click or gap.
curl -X POST http://localhost:8000/v1/audio/loop-point \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/beat.wav"}' | jq '{loop_start_sec, loop_end_sec, bars, score, tempo_bpm}'
curl -X POST http://localhost:8000/v1/audio/loop-point \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/long_track.wav","min_loop_bars":8,"num_candidates":3}'
Response fields: loop_start_sec, loop_end_sec, bars, score (0–1, higher = tighter loop), tempo_bpm, candidates (array of ranked alternatives). Optional params: min_loop_bars (default 4), num_candidates (default 5). Requires librosa-analyze engine.
Compose MIDI
POST a JSON song spec, get Standard MIDI File bytes back. Write the spec by hand, generate it from a tracker / DAW / sequencer, script it out of a Python notebook, or have an LLM produce it — audiolla doesn't care. No AI runs server-side; the spec is the music.
curl -X POST http://localhost:8000/v1/midi/compose \
-H 'Content-Type: application/json' \
-d '{
"tempo_bpm": 120,
"tracks": [
{"name":"Lead","program":0,"channel":0,"notes":[
{"pitch":60,"start_beats":0.0,"duration_beats":0.5,"velocity":100},
{"pitch":64,"start_beats":0.5,"duration_beats":0.5,"velocity":100},
{"pitch":67,"start_beats":1.0,"duration_beats":0.5,"velocity":100},
{"pitch":72,"start_beats":1.5,"duration_beats":0.5,"velocity":100}
]},
{"name":"Kick","program":0,"channel":9,"notes":[
{"pitch":36,"start_beats":0.0,"duration_beats":0.1,"velocity":110},
{"pitch":36,"start_beats":1.0,"duration_beats":0.1,"velocity":110},
{"pitch":36,"start_beats":2.0,"duration_beats":0.1,"velocity":110},
{"pitch":36,"start_beats":3.0,"duration_beats":0.1,"velocity":110}
]}
],
"output_path": "midi/song.mid"
}'
curl -o song.mid http://localhost:8000/v1/files/midi/song.mid
curl -X POST http://localhost:8000/v1/midi/compose \
-H 'Content-Type: application/json' \
-d @spec.json
Spec fields: tempo_bpm (default 120), time_signature (default [4,4]), key_signature (optional, e.g. "C", "Am"), ticks_per_beat (default 480), tracks[].{name, program, channel, volume, pan, notes[].{pitch, start_beats, duration_beats, velocity}}. Time is in beats. program is GM program 0-127. Channel 9 is the GM drum channel — pitches there map to the drum kit (36 = kick, 38 = snare, 42 = closed hi-hat, etc.).
Inspect MIDI
curl -X POST http://localhost:8000/v1/midi/inspect \
-H 'Content-Type: application/json' \
-d '{"file_path":"midi/song.mid"}'
curl -X POST http://localhost:8000/v1/midi/transform \
-H 'Content-Type: application/json' \
-d '{"file_path":"midi/song.mid","transpose_semitones":12,"output_path":"midi/transposed.mid"}'
curl -X POST http://localhost:8000/v1/midi/transform \
-H 'Content-Type: application/json' \
-d '{"file_path":"midi/song.mid","tempo_bpm":140,"output_path":"midi/fast.mid"}'
curl -X POST http://localhost:8000/v1/midi/transform \
-H 'Content-Type: application/json' \
-d '{"file_path":"midi/song.mid","drop_channels":[9],"output_path":"midi/no-drums.mid"}'
curl -X POST http://localhost:8000/v1/midi/transform \
-H 'Content-Type: application/json' \
-d '{"file_path":"midi/song.mid","keep_channels":[0,1],"output_path":"midi/two-ch.mid"}'
curl -X POST http://localhost:8000/v1/midi/transform \
-H 'Content-Type: application/json' \
-d '{"file_path":"midi/song.mid","quantize_grid_beats":0.25,"output_path":"midi/quantized.mid"}'
transpose_semitones ±48. quantize_grid_beats is in beats (0.25 = 1/16th at 4/4). keep_channels and drop_channels take a JSON array of channel numbers; only one can be set per request.
Render MIDI to audio
curl -X POST http://localhost:8000/v1/midi/render \
-H 'Content-Type: application/json' \
-d '{"file_path":"midi/song.mid","output_format":"wav","output_path":"out/song.wav"}'
curl -o song.wav http://localhost:8000/v1/files/out/song.wav
curl -X PUT --data-binary @my.sf2 \
-H 'Content-Type: application/octet-stream' \
http://localhost:8000/v1/files/sf/orchestral.sf2
curl -X POST http://localhost:8000/v1/midi/render \
-H 'Content-Type: application/json' \
-d '{"file_path":"midi/song.mid","soundfont_path":"sf/orchestral.sf2","output_format":"flac","output_path":"out/orch.flac"}'
Generate music from a spec
Compose + render in one call — spec in, audio file staged.
curl -X POST http://localhost:8000/v1/midi/generate \
-H 'Content-Type: application/json' \
-d @spec.json
curl -o song.wav http://localhost:8000/v1/files/out/song.wav
Drum pattern
Step-sequencer spec → GM drum MIDI. Define a rhythmic pattern as arrays of 0/1 step values for each drum voice; the server maps them to GM channel 9 pitches and bakes a MIDI file. Optional swing shifts even-numbered 16th steps for a shuffled feel.
curl -X POST http://localhost:8000/v1/midi/drum \
-H "Content-Type: application/json" \
-d '{
"tempo_bpm": 120,
"steps": 16,
"bars": 2,
"swing": 0.0,
"pattern": {
"kick": [1,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0],
"snare": [0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0],
"hihat": [1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1]
},
"output_path": "midi/beat.mid"
}'
curl -o beat.mid http://localhost:8000/v1/files/midi/beat.mid
curl -X POST http://localhost:8000/v1/midi/drum \
-H "Content-Type: application/json" \
-d '{
"tempo_bpm": 95,
"steps": 16,
"bars": 1,
"swing": 0.2,
"pattern": {
"kick": [1,0,0,1,0,0,1,0,1,0,0,1,0,0,1,0],
"snare": [0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0],
"hihat": [1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0]
},
"output_path": "midi/groove.mid"
}'
Body fields: tempo_bpm (default 120), steps (steps per bar, default 16), bars (default 1), swing (0.0–0.5, default 0.0), pattern (object — keys are drum voice names, values are arrays of 0/1). Supported voices: kick, snare, hihat, open_hihat, ride, crash, clap, tom_hi, tom_mid, tom_low, rim, cowbell. Requires midi-compose engine.
Chords to MIDI
Detect the chord progression from an audio file and convert each segment to a MIDI chord (root + 3rd + 5th). Useful for exporting a detected chord chart as playable MIDI, re-harmonising an arrangement, or seeding a DAW session.
curl -X POST http://localhost:8000/v1/audio/chords-to-midi \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav","output_path":"out/chords.mid"}'
curl -X POST http://localhost:8000/v1/audio/chords-to-midi \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/song.wav","tempo_bpm":120,"velocity":90,"octave":3,"output_path":"out/chords.mid"}'
curl -X POST http://localhost:8000/v1/audio/chords-to-midi \
-H 'Content-Type: application/json' \
-d '{"file_path":"sessions/song.wav","output_path":"midi/song_chords.mid"}'
Optional params: tempo_bpm (default: detected from audio), velocity (1–127, default 80), octave (0–8, default 4), output_path. Requires chord-detect engine. Each chord segment becomes a MIDI chord event (root + major 3rd/minor 3rd + perfect 5th, duration = segment length).
Read and write ID3 (MP3), Vorbis (OGG/FLAC), and WAV/M4A tags via mutagen. Requires the metadata engine.
curl -X POST http://localhost:8000/v1/audio/metadata \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.mp3"}' | jq '{title, artist, bpm, key, duration_sec}'
curl -X POST http://localhost:8000/v1/audio/metadata \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.mp3","tags":{"title":"My Track","artist":"DJ Audiolla","bpm":"128","year":"2026"}}'
Clip detection
Detect digital clipping. No engine required — pure numpy arithmetic.
curl -X POST http://localhost:8000/v1/audio/clip-detect \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/loud_master.wav"}' | jq '{clipped, clip_count, clip_ratio, peak_db}'
Mid/Side encode and decode
Encode L/R stereo to Mid+Side or decode back. Useful for stereo width surgery without touching the pedalboard chain.
curl -X POST http://localhost:8000/v1/audio/mid-side \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/stereo.wav","mode":"encode","output_path":"out/ms_encoded.wav"}'
curl -X POST http://localhost:8000/v1/audio/mid-side \
-H 'Content-Type: application/json' \
-d '{"file_path":"out/ms_encoded.wav","mode":"decode","output_path":"out/restored.wav"}'
Beat slice
Detect beat positions with librosa and return a ZIP of numbered WAV/MP3 slices — one file per beat interval.
curl -X POST http://localhost:8000/v1/audio/beat-slice \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/loop.wav","output_format":"wav","output_path":"out/slices.zip"}'
curl -o slices.zip http://localhost:8000/v1/files/out/slices.zip
curl -X POST http://localhost:8000/v1/audio/beat-slice \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/loop.wav","output_path":"beats/loop_slices.zip"}'
Convolution reverb
Apply an impulse response (IR) to audio via pedalboard's Convolution. Any WAV file can be used as the IR.
curl -X PUT --data-binary @plate_reverb.wav \
-H 'Content-Type: application/octet-stream' \
http://localhost:8000/v1/files/ir/plate.wav
curl -X POST http://localhost:8000/v1/audio/conv-reverb \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/dry_vocal.wav","ir_file_path":"ir/plate.wav","wet_mix":0.25,"output_format":"wav","output_path":"out/reverbed.wav"}'
Transient shaper
Attack/sustain dual-compressor blending. Positive attack_gain_db makes drums punchier; negative sustain_gain_db cuts room tail.
curl -X POST http://localhost:8000/v1/audio/transient \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/drums.wav","attack_gain_db":6,"sustain_gain_db":-4,"output_path":"out/punchy_drums.wav"}'
curl -X POST http://localhost:8000/v1/audio/transient \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/synth.wav","attack_gain_db":-6,"sustain_gain_db":0,"output_path":"out/softened.wav"}'
Multiband compression
Split the signal into N+1 frequency bands and compress each one independently. Bands are split with zero-phase LR4-equivalent crossovers, so a bypassed chain reconstructs the original. Mastering-engineer staple — tame bass thump without squashing vocal sibilance, level out a busy mid-range, etc.
curl -X POST http://localhost:8000/v1/audio/multiband-compress \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/mixdown.wav","crossovers_hz":[200,3000],"bands":[
{"threshold_db":-18,"ratio":4,"attack_ms":15,"release_ms":150,"makeup_db":1.5},
{"threshold_db":-14,"ratio":3,"attack_ms":8, "release_ms":80, "makeup_db":1.0},
{"threshold_db":-10,"ratio":2,"attack_ms":3, "release_ms":40, "makeup_db":0.5}
],"output_path":"out/mastered.wav"}'
crossovers_hz length is N, bands length is N+1. Each band: required threshold_db + ratio, optional attack_ms (default 10), release_ms (default 100), makeup_db (default 0).
DJ prep
One call returns everything a DJ needs about a track. Requires librosa-analyze + chord-detect. LUFS is reported when a loudness engine is available.
curl -X POST http://localhost:8000/v1/audio/dj-prep \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/track.wav"}' | jq .
Camelot wheel positions let you quickly find harmonically compatible tracks for mixing.
De-ess
Split-band high-frequency de-esser — attenuates sibilance above frequency_hz without affecting the rest of the signal. Implemented with a Butterworth HPF, envelope follower, and per-channel gain reduction. No engine required.
curl -X POST http://localhost:8000/v1/audio/deess \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/vocal.wav","output_path":"out/deessed.wav"}'
curl -X POST http://localhost:8000/v1/audio/deess \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/mix.wav","threshold_db":-15,"frequency_hz":7000,"ratio":2.5,"output_path":"out/mix_deessed.wav"}'
curl -X POST http://localhost:8000/v1/audio/deess \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/vocal.wav","output_path":"sessions/vocal_deessed.wav"}'
Optional params: threshold_db (≤ 0, default -20), frequency_hz (2000–15000, default 6000), ratio (1.0–20.0, default 4.0), output_format (wav/mp3/flac…), output_path.
Stereo field analysis
Measure stereo width, phase correlation, mid/side balance, and mono compatibility. No engine required — pure numpy.
curl -X POST http://localhost:8000/v1/audio/stereo-field \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/stereo_mix.wav"}' | jq .
curl -X POST http://localhost:8000/v1/audio/stereo-field \
-H 'Content-Type: application/json' \
-d '{"file_path":"masters/track.wav"}' | jq '{correlation, width, mono_compatible}'
Mono files return correlation=1.0, width=0.0, mono_compatible=true. Use correlation < 0 as a red flag for phase-cancelled material that will collapse on mono playback.
Audio thumbnail
Extract the most energetic segment of an audio file — the passage with the highest onset density in a given window. Useful for generating preview clips, podcast teasers, or DJ cue points. Requires librosa-analyze.
curl -X POST http://localhost:8000/v1/audio/thumbnail \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/long_track.wav","output_path":"out/preview.wav"}'
curl -X POST http://localhost:8000/v1/audio/thumbnail \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/podcast.wav","duration_sec":10,"output_format":"mp3","output_path":"out/teaser.mp3"}'
curl -X POST http://localhost:8000/v1/audio/thumbnail \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/album_track.wav","duration_sec":20,"output_path":"previews/track_thumb.wav"}'
Optional params: duration_sec (1–300, default 30), output_format, output_path. When output_path is set the response JSON includes start_sec and end_sec so you know exactly where in the source the thumbnail was extracted.
MIDI humanize
Add subtle timing and velocity variations to a MIDI file to make it sound less mechanical. Jitter is uniformly distributed and, when a seed is provided, fully deterministic. Requires midi-compose.
curl -X POST http://localhost:8000/v1/midi/humanize \
-H 'Content-Type: application/json' \
-d '{"file_path":"midi/rigid.mid","output_path":"midi/human.mid"}'
curl -X POST http://localhost:8000/v1/midi/humanize \
-H 'Content-Type: application/json' \
-d '{"file_path":"midi/drums.mid","timing_ms":20,"velocity_pct":15,"seed":42,"output_path":"midi/drums_human.mid"}'
curl -X POST http://localhost:8000/v1/midi/humanize \
-H 'Content-Type: application/json' \
-d '{"file_path":"midi/pattern.mid","timing_ms":8,"output_path":"midi/pattern_human.mid"}'
Optional params: timing_ms (0–500, default 10), velocity_pct (0–50, default 10), seed (any int, optional), output_path. Non-MIDI input returns 400. Requires midi-compose.
Batch operations
Run multiple operations on staged files in one HTTP call. Operations run sequentially; each gets an independent result entry even if earlier ops fail.
Supported ops: convert, normalize, trim, fade, reverse, speed, eq.
curl -X PUT http://localhost:8000/v1/files/work/track.wav --data-binary @track.wav
curl -X POST http://localhost:8000/v1/batch \
-H "Content-Type: application/json" \
-d '[
{"op":"trim","file_path":"work/track.wav","output_path":"work/chorus.wav","start_sec":30,"end_sec":60},
{"op":"convert","file_path":"work/track.wav","output_path":"work/track.mp3","output_format":"mp3"},
{"op":"reverse","file_path":"work/track.wav","output_path":"work/reversed.wav"}
]' | jq '.results[].status'
Async jobs and webhooks
Every audio endpoint accepts async_job=true — the request returns immediately with a job ID and the work happens in the background. Poll for status or register a webhook.
curl -X PUT --data-binary @track.wav \
-H 'Content-Type: application/octet-stream' \
http://localhost:8000/v1/files/uploads/track.wav
curl -X POST http://localhost:8000/v1/audio/separate \
-H 'Content-Type: application/json' \
-d '{
"file_path":"uploads/track.wav",
"engine":"htdemucs",
"stems":["vocals"],
"async_job":true,
"webhook_url":"https://my-server.com/hooks/audio",
"output_path":"stems/track-vocals.wav"
}'
curl -X POST http://localhost:8000/v1/audio/master \
-H 'Content-Type: application/json' \
-d '{
"file_path":"uploads/track.wav",
"mode":"chain",
"preset":"transparent",
"async_job":true,
"output_url":"https://bucket.s3.amazonaws.com/result.wav?X-Amz-..."
}'
curl http://localhost:8000/v1/jobs/abc123 | jq '{status, duration_sec, result}'
curl http://localhost:8000/v1/jobs
curl -X DELETE http://localhost:8000/v1/jobs/abc123
Webhook payload (POST to your URL when the job completes):
{
"id": "abc123",
"endpoint": "/v1/audio/separate",
"status": "completed",
"duration_sec": 12.4,
"result": {"path": "stems/track-vocals.wav", "size": 3145728, ...}
}
Delivery has 4 attempts with exponential backoff (0 s, 1 s, 2 s, 4 s). Completed jobs stay in memory for AUDIOLLA_JOB_TTL seconds (default 1 hour) then are swept.
Stage files
A simple server-side file store under /v1/files. Upload, list, download, delete.
curl -X PUT http://localhost:8000/v1/files/mytrack.wav \
--data-binary @track.wav
curl http://localhost:8000/v1/files
curl http://localhost:8000/v1/files/mytrack.wav -o copy.wav
curl -X DELETE http://localhost:8000/v1/files/mytrack.wav
Once staged, reference the file by path on any audio endpoint via file_path:
curl -X POST http://localhost:8000/v1/audio/analyze \
-H 'Content-Type: application/json' \
-d '{"file_path":"mytrack.wav","features":["bpm"]}'
curl -X POST http://localhost:8000/v1/audio/separate \
-H 'Content-Type: application/json' \
-d '{
"file_path":"mytrack.wav",
"engine":"htdemucs",
"stems":["vocals"],
"output_path":"stems/mytrack-vocals.wav"
}'
Remote URLs
Disabled by default. To allow the server to fetch file_url or PUT to
output_url, set the policy at container start:
docker run ... \
-e AUDIOLLA_FETCH_MODE=allowlist \
-e AUDIOLLA_FETCH_HOSTS="*.s3.amazonaws.com,*.r2.cloudflarestorage.com" \
psyb0t/audiolla:latest
Then:
curl -X POST http://localhost:8000/v1/audio/master \
-H 'Content-Type: application/json' \
-d '{
"file_url":"https://my-bucket.s3.amazonaws.com/in.wav",
"reference_url":"https://my-bucket.s3.amazonaws.com/ref.wav",
"mode":"reference",
"output_url":"https://my-bucket.s3.amazonaws.com/out.wav?X-Amz-Signature=..."
}'
Policy modes:
disabled (default) — file_url / output_url rejected with 400allowlist — only hosts matching AUDIOLLA_FETCH_HOSTS alloweddenylist — anything except listed hosts allowed (pair with AUDIOLLA_FETCH_ALLOW_PRIVATE=false to block private IPs / metadata services)
Always-on protections:
- DNS-resolved private / loopback / link-local IPs rejected (toggleable)
- Only
https by default; http opt-in via AUDIOLLA_FETCH_SCHEMES
- Redirects re-validated through the same policy
- Hard timeout + size cap =
AUDIOLLA_MAX_UPLOAD_BYTES
- Every fetch / upload URL logged
See Configuration for all AUDIOLLA_FETCH_* env vars.
Engines
| Slug | What it does |
|---|
htdemucs | 4-stem separation: drums, bass, other, vocals. Best speed/quality tradeoff. |
htdemucs_ft | Same 4 stems, fine-tuned weights. Higher quality, ~4x slower. CUDA-only — rejected with 400 on the CPU image. |
htdemucs_6s | 6 stems — also splits guitar and piano. Experimental. |
mdx_extra | Strong on vocal isolation. MUSDB-trained, different architecture. |
matchering | Reference-based mastering: EQ + loudness matched to a reference track. |
pedalboard-chain | Preset mastering chains via pedalboard — transparent (light) or loud (4:1 squash). Backs /v1/audio/master with mode=chain. For arbitrary chains use fx-chain / /v1/audio/fx. |
librosa-analyze | BPM, key, LUFS, duration, spectral features, beat grid, onset detection, melody (pyin), structural segmentation via librosa. |
sox-transform | Gain, EQ, compression, reverb, pitch shift, tempo via pysox. |
fx-chain | Arbitrary pedalboard effects chain — full catalog, your order and params. Backs /v1/audio/fx. |
midi-compose | JSON spec → MIDI bytes. Also inspects and transforms existing MIDI files. Backs /v1/midi/{compose,inspect,transform,generate}. |
midi-render | MIDI → audio via fluidsynth + SoundFont. Backs /v1/midi/render and /v1/midi/generate. |
silence-detect | Locate silent gaps via ffmpeg silencedetect. Optional auto-trim. Backs /v1/audio/silence. |
ffmpeg-render | Static PNG spectrogram/waveform + 8-mode animated MP4/WebM video via ffmpeg filters. Backs /v1/audio/visualize/image/* and /v1/audio/visualize/video/{mode}. |
audio-fingerprint | Chromaprint acoustic fingerprint via fpcalc. Backs /v1/audio/fingerprint. |
uvr-dereverb | BS-Roformer de-reverb — removes room reverb; primary_stem=No Reverb. |
uvr-deecho | VR Architecture de-echo — normal and aggressive modes; pass aggressive=true for harder suppression. |
uvr-denoise | MelBand Roformer de-noise (SDR 28) — removes broadband background noise. |
uvr-karaoke | MelBand Roformer karaoke — remove lead vocals, keep backing; works via /v1/audio/separate. |
uvr-vocal-bsr | BS-Roformer vocal/instrumental (SDR 13) — highest-quality vocal separation; works via /v1/audio/separate. |
basic-pitch | Polyphonic audio-to-MIDI via Spotify basic-pitch (ONNX backend). Backs /v1/audio/to_midi. |
deepfilter | Neural speech and vocal enhancement via DeepFilterNet DF3. Backs /v1/audio/enhance. |
chord-detect | Chord and key detection via librosa — Krumhansl-Schmuckler key estimation + chroma template chord segmentation. Backs /v1/audio/chords. |
silero-vad | Voice activity detection via silero-vad (ONNX) — returns speech/non-speech segments with timestamps and speech ratio. Backs /v1/audio/vad. |
pyannote | Speaker diarization via pyannote/speaker-diarization-3.1 — returns per-speaker timestamped segments. Requires HUGGINGFACE_TOKEN. Backs /v1/audio/diarize. |
stretch | Time-stretch + pitch-shift via librosa phase vocoder — independent tempo factor and semitone offset. Backs /v1/audio/stretch. |
ast-tag | Audio tagging via Audio Spectrogram Transformer (MIT/ast-finetuned-audioset-10-10-0.4593) — top-K AudioSet class labels. Requires HF model cache. Backs /v1/audio/tag. |
clap-embed | 512-dim L2-normalized audio embeddings via LAION CLAP (laion/larger_clap_music_and_speech) — semantic audio search. Requires HF model cache. Backs /v1/audio/embed. |
hpss | Harmonic/percussive source separation via librosa HPSS median filter — returns harmonic + percussive stems as a ZIP. Backs /v1/audio/separate/hpss. |
noise-reduce | Spectral noise reduction via noisereduce — stationary (constant hum/hiss) and non-stationary (adaptive) modes, no GPU required. Backs /v1/audio/noise-reduce/noise-reduce. |
metadata | Read/write audio tags (ID3 for MP3, Vorbis for OGG/FLAC, INFO for WAV, MP4 for M4A) via mutagen. No ML weights. Backs /v1/audio/metadata. |
stable-audio-open | Text-to-audio — Stability Stable Audio Open 1.0. Stability Community Licence (commercial use OK below the revenue threshold; read the license). 47-second hard cap; best for loops, riffs, ambient textures, SFX, drum beats. No vocals. ~12 GB VRAM at fp16 — CUDA-only. Backs /v1/audio/generate/stable-audio-open. |
musicgen-small | Text-to-music — Meta MusicGen 300M. CC-BY-NC 4.0 (non-commercial only; opt-in via AUDIOLLA_ENABLE_NONCOMMERCIAL=1 in the server env). 30 s hard cap; instrumental only. ~3 GB VRAM at fp16 — CUDA-only. Backs /v1/audio/generate/musicgen-small. |
musicgen-medium | Text-to-music — Meta MusicGen 1.5B. CC-BY-NC 4.0 (same opt-in). 30 s hard cap; higher quality than -small. ~6-8 GB VRAM at fp16 — CUDA-only. Backs /v1/audio/generate/musicgen-medium. |
riffusion | Text-to-music — Riffusion-v1, a Stable Diffusion fine-tune that generates spectrograms (converted to audio via Griffin-Lim). CreativeML OpenRAIL-M (commercial use OK with the licence's usage restrictions). ~5 s per pass, lo-fi character, 22.05 kHz mono. ~3 GB VRAM at fp16 — CUDA-only. Backs /v1/audio/generate/riffusion. |
audioldm2 | Text-to-audio / SFX — AudioLDM 2 (cvssp/audioldm2). CC-BY 4.0 (commercial use OK — no opt-in gate, the only commercial-safe generator in this set). General-purpose SFX: environmental ambience, animal sounds, foley, mechanical / impact sounds. 16 kHz mono, up to 30 s. Slow (200-step DDIM by default — pass num_inference_steps=50 to trade quality for ~4x speed). ~8-10 GB VRAM at fp16 with CPU offload. CUDA-only. Backs /v1/audio/generate/audioldm2. |
Each Demucs variant is its own checkpoint (hosted on dl.fbaipublicfiles.com). The entrypoint prefetches every enabled variant into /data/torch_cache/ at startup so the first separation request doesn't sit there downloading.
AUDIOLLA_ENABLED_ENGINES — restrict which engines are available. AUDIOLLA_PRELOAD — load specific engines into memory at startup instead of waiting for the first request.
Workflows — presets + pipeline
Two ways to chain operations server-side without re-uploading the audio between calls:
Curated presets — server-side YAML workflows shipped in presets/. Run one with a single POST:
curl -X PUT --data-binary @mix.wav \
-H 'Content-Type: application/octet-stream' \
http://localhost:8000/v1/files/uploads/mix.wav
curl -X POST http://localhost:8000/v1/presets/master-for-spotify \
-H 'Content-Type: application/json' \
-d '{"file_path":"uploads/mix.wav","output_path":"out/mastered.wav"}'
curl -o mastered.wav http://localhost:8000/v1/files/out/mastered.wav
curl http://localhost:8000/v1/presets | jq '.data[] | {name, description}'
curl http://localhost:8000/v1/presets/podcast-cleanup | jq '.steps'
Shipped presets: master-for-spotify (3-band master + -14 LUFS), podcast-cleanup (DeepFilterNet + de-ess + -16 LUFS), vocal-cleanup (UVR dereverb + denoise + de-ess + light comp). Add your own as a YAML file in presets/.
Ad-hoc pipeline — chain any registered ops in a single call:
curl -X POST http://localhost:8000/v1/pipeline \
-H 'Content-Type: application/json' \
-d '{
"file_path":"uploads/track.wav",
"output_path":"out/pipelined.wav",
"steps":[
{"op":"restore","params":{"engine":"uvr-denoise"}},
{"op":"multiband_compress","params":{
"crossovers_hz":[200,3000],
"bands":[
{"threshold_db":-18,"ratio":3},
{"threshold_db":-14,"ratio":2.5},
{"threshold_db":-10,"ratio":2}
]
}},
{"op":"normalize","params":{"target_lufs":-14}}
]
}'
curl http://localhost:8000/v1/ops | jq .
The response of pipeline + preset endpoints includes a steps log so you can audit what ran. Both endpoints support async_job=true, output_path, output_url like every other audio-producing endpoint.
API catalog
GET /v1/catalog returns the machine-readable list of every endpoint grouped by category (separation, restoration, dynamics, eq-spatial, mastering, time-pitch, editing, analysis, effects-creative, visualize, midi, metadata, workflow, speech, files, jobs, management). Use it for discovery; LLM agents and codegen scripts both consume it.
curl http://localhost:8000/v1/catalog | jq '.categories[] | {name, endpoint_count: (.endpoints | length)}'
Endpoints
Full wire contract: openapi.yaml.
Audio processing
Every endpoint takes a JSON body. Inputs pick exactly one of file_path
(pre-staged file under FILES_DIR) xor file_url (HTTPS URL the server
fetches). Audio-producing endpoints additionally require exactly one of
output_path (server writes the result under FILES_DIR) xor
output_url (presigned PUT — server uploads the encoded bytes). Both
missing → 400; both set → 400. Responses are always JSON — no raw audio
bytes, no Content-Disposition: attachment, no *_base64 fields.
| Method | Path | Default returns |
|---|
POST | /v1/audio/separate | JSON {path|url, size, ...} — one stem; multi-stem (or all) returns ZIP stream of stems via output_path/output_url |
POST | /v1/audio/master | JSON {path|url, size, output_format, ...} |
POST | /v1/audio/analyze | JSON — BPM, key, LUFS, spectral features |
POST | /v1/audio/beats | JSON — BPM + beat timestamps; optional click-track WAV |
POST | /v1/audio/onsets | JSON — onset timestamps |
POST | /v1/audio/melody | JSON — dominant melody contour; optional MIDI export |
POST | /v1/audio/segments | JSON — structural segment labels (A, B, C…) |
POST | /v1/audio/silence | JSON — silent/non-silent ranges; optional trimmed audio |
POST | /v1/audio/visualize/image/spectrogram | JSON {path|url, size, ...} — static PNG spectrogram (color, scale params) |
POST | /v1/audio/visualize/image/waveform | JSON {path|url, size, ...} — static PNG waveform (color param) |
POST | /v1/audio/visualize/video/{mode} | JSON {path|url, size, ...} — animated MP4/WebM video (8 modes: spectrum, waves, cqt, …) |
POST | /v1/audio/fingerprint | JSON — Chromaprint fingerprint string |
POST | /v1/audio/restore/{engine} | JSON {path|url, size, output_format, ...} — reverb/echo/noise removed; aggressive=true for uvr-deecho hard mode |
POST | /v1/audio/to_midi/{engine} | JSON {path|url, size, ...} — polyphonic transcription (MIDI) |
POST | /v1/audio/enhance/{engine} | JSON {path|url, size, output_format, ...} — neural speech/vocal enhancement |
POST | /v1/audio/generate/{engine} | JSON {path|url, size, output_format, ...} — text-to-audio (engine = stable-audio-open / musicgen-small / musicgen-medium / riffusion / audioldm2); prompt required, optional duration_sec / seed / lyrics / num_inference_steps |
POST | /v1/audio/chords | JSON — detected key and chord progression |
POST | /v1/audio/vad | JSON — speech/non-speech segments with timestamps and speech ratio |
POST | /v1/audio/diarize/{engine} | JSON — per-speaker timestamped segments |
POST | /v1/audio/transform | JSON {path|url, size, output_format, ...} |
POST | /v1/audio/loudness | JSON — {loudness_lufs} (measure only, no audio) |
POST | /v1/audio/loudness/curve | JSON — {curve:[{time_sec,rms_db}],duration,sample_rate,points}; hop_length param |
POST | /v1/audio/normalize | JSON {path|url, size, measured_lufs, ...} — requires target_lufs; pre-normalization LUFS reported in measured_lufs field |
POST | /v1/audio/separate/hpss | JSON {path|url, size, ...} — ZIP stream containing harmonic.<fmt> + percussive.<fmt> |
POST | /v1/audio/noise-reduce/{engine} | JSON {path|url, size, output_format, ...} — engine=noise-reduce (DSP, stationary/prop_decrease) or uvr-denoise (ML) |
POST | /v1/audio/stretch | JSON {path|url, size, output_format, ...} |
POST | /v1/audio/pitch-correct | JSON {path|url, size, output_format, ...} — strength [0.0–1.0]; requires librosa-analyze |
POST | /v1/audio/repair | JSON {path|url, size, output_format, ...} — declip bool, dehum bool, hum_freq Hz |
POST | /v1/audio/tag | JSON — top-K AudioSet labels with confidence scores |
POST | /v1/audio/embed | JSON — 512-dim embedding; with query_text also returns cosine similarity |
POST | /v1/audio/classify | JSON — {results: [{label, score}]} sorted descending; requires clap-embed |
POST | /v1/audio/info | JSON — duration, sample_rate, channels, codec, bit_depth, format |
POST | /v1/audio/trim | JSON {path|url, size, output_format, ...} — start_sec + end_sec required |
POST | /v1/audio/mix | JSON {path|url, size, output_format, ...} — tracks JSON array required (≥2 entries) |
POST | /v1/audio/concat | JSON {path|url, size, output_format, ...} — files JSON array required (≥2 entries) |
POST | /v1/audio/speed | JSON {path|url, size, output_format, ...} — speed float required (0.1–10.0) |
POST | /v1/audio/convert | JSON {path|url, size, output_format, ...} — format/sample_rate/channels conversion |
POST | /v1/audio/similar | JSON — {similarity, dim}; requires clap-embed |
POST | /v1/audio/fade | JSON {path|url, size, output_format, ...} — fade_in/fade_out seconds, 13 curve options |
POST | /v1/audio/reverse | JSON {path|url, size, output_format, ...} — flips playback direction |
POST | /v1/audio/loop | JSON `{path|url, size, output |