> ## Documentation Index > Fetch the complete documentation index at: https://docs.modulate.ai/llms.txt > Use this file to discover all available pages before exploring further. # AI Music Detection Streaming > Real-time AI music detection over WebSocket. Per-window vocal AI verdicts are emitted progressively as audio arrives, followed by a final clip-level summary that includes instrumental AI detection. Real-time AI music detection over WebSocket. The client streams audio and receives per-window vocal AI verdicts as they become available, followed by a final clip-level summary - including instrumental AI detection - on completion. ## Endpoint ```text theme={null} wss://platform.modulate.ai/api/velma-2-ai-music-detection-streaming ``` ## Authentication Pass your API key as a query parameter on the connection URL: ```text theme={null} wss://.../velma-2-ai-music-detection-streaming?api_key=YOUR_API_KEY&audio_format=mp3 ``` ## Connection parameters | Parameter | Required | Description | | -------------- | ------------ | ------------------------------------------ | | `api_key` | Yes | Your API key | | `audio_format` | Yes | Audio format - see supported formats below | | `sample_rate` | Raw PCM only | Sample rate in Hz | | `num_channels` | Raw PCM only | Number of channels (1-8) | ## Supported audio formats **Container formats** - `sample_rate` and `num_channels` must not be specified (the headers already carry this metadata): `wav`, `mp3`, `ogg`, `flac`, `webm`, `aac`, `aiff` **Raw PCM formats** - `sample_rate` and `num_channels` are required: `s8`, `s16le`, `s16be`, `s24le`, `s24be`, `s32le`, `s32be`, `u8`, `u16le`, `u16be`, `u24le`, `u24be`, `u32le`, `u32be`, `f32le`, `f32be`, `f64le`, `f64be`, `mulaw`, `alaw` **Valid sample rates:** 8000, 11025, 16000, 22050, 32000, 44100, 48000, 96000 ## Protocol ### Client -> server | Message | Description | | --------------------- | ------------------------------------------------------ | | Binary frame | Chunk of audio bytes in the declared format (any size) | | Empty text frame `""` | Signals end of stream | ### Server -> client | Message | Description | | ------------------------------------- | ------------------------------------------------------------------------ | | `{"type": "window", "window": {...}}` | Per-window result - emitted for each completed 4-second window, in order | | `{"type": "done", ...}` | Stream complete - clip-level verdict plus instrumental AI detection | | `{"type": "error", "error": "..."}` | An error occurred - connection will close | Vocal AI detection runs on each 4-second window as audio arrives and is reported in `window` messages. Instrumental AI detection runs on the accumulated audio at end-of-stream, so `instrumental_ai_percentage` and `instrumental_ai_confidence` appear only in the final `done` message. ### Window object | Field | Type | Description | | ------------------------- | ------- | --------------------------------------------------------------------------------------------------------------------- | | `start_time_ms` | integer | Window start time in milliseconds | | `end_time_ms` | integer | Window end time in milliseconds | | `vocal_percentage` | float | Percentage of the window containing vocal content (0-100) | | `vocal_ai_percentage` | float | `100` if the window is classified as AI-generated vocals, `0` otherwise (always `0` without sufficient vocal content) | | `vocal_ai_confidence` | float | Confidence the window contains AI-generated vocals (0-1); `0` without sufficient vocal content | | `instrumental_percentage` | float | Percentage of the window containing instrumental music content (0-100) | | `silence_percentage` | float | Percentage of the window containing neither vocal nor instrumental content (0-100) | ### Done object | Field | Type | Description | | ---------------------------- | ------- | ----------------------------------------------------------------------------------------------------------------------------------------------------- | | `duration_ms` | integer | Total duration of the streamed audio in milliseconds | | `window_count` | integer | Total number of windows analysed during the session | | `primary_verdict` | string | Clip-level classification: `"ai-vocal-music"`, `"ai-instrumental"`, or `"not-ai-music"` | | `vocal_percentage` | float | Average percentage of audio with vocal content, across all windows (0-100) | | `vocal_ai_percentage` | float | Percentage of clip duration classified as AI-generated vocals (0-100). A clip-level measure — it may differ from what the per-window messages suggest | | `vocal_ai_confidence` | float | Average confidence that vocal windows contain AI-generated vocals (0-1) | | `instrumental_percentage` | float | Average percentage of audio with instrumental content, across all windows (0-100) | | `instrumental_ai_percentage` | float | AI detection score for the clip's instrumental content (0-100) | | `instrumental_ai_confidence` | float | Confidence in the instrumental AI assessment for the full clip (0-1) | | `silence_percentage` | float | Average percentage of audio with neither vocal nor instrumental content (0-100) | ## WebSocket close codes | Code | Meaning | | ------ | --------------------------------------------------------------------------------------------- | | `1000` | Normal closure after the `done` message, or after the connection completes | | `1003` | Invalid or missing query parameters (unknown format, bad sample rate, missing `audio_format`) | | `4002` | Audio could not be decoded, or does not match the declared raw `audio_format` | | `4003` | The request could not be validated, or the request is not permitted | | `4029` | The request could not be completed due to insufficient credits | An `error` message is sent before the connection closes for the `1003`, `4002`, `4003`, and `4029` cases. ## Rate limits * Concurrent connection limits apply per organization * Monthly usage limits (in audio hours) apply per organization