Fingerprint API

Distributed copyright detection via listener-side audio fingerprinting. Listeners compute 64-bit spectral hashes from received audio and report them to the relay server, which aggregates reports and identifies tracks through consensus.

Listener Device Relay Server Rights DB Audio RX POST /api/fingerprint FFT 8 bands x 32 windows ────────────────────→ Aggregation 64-bit hash │ Consensus (hamming ≤ 8, N ≥ 2) │ Match → Royalty 70% rights holder 20% DJ cashback 10% platform

Base URL: https://relay.solun.art (or your self-hosted relay)

POST /api/fingerprint

Submit a fingerprint report from a listener device. The relay server aggregates reports from multiple listeners and runs consensus every 10 seconds.

Request Body

Field	Type	Required	Description
hash	string	required	64-bit fingerprint hash as hex string (16 chars)
channel	string	required	Channel / group name the listener is receiving from
device_id	string	required	Unique identifier for the reporting device
timestamp	integer	optional	Unix timestamp (seconds). Server uses current time if omitted.

Request Example

// POST /api/fingerprint
// Content-Type: application/json

{
  "hash": "abcdef0123456789",
  "channel": "dj-set-tokyo",
  "device_id": "iphone-abc123",
  "timestamp": 1710000000
}

Responses

200 Report accepted

{
  "ok": true
}

400 Missing required fields

{
  "error": "missing required field: hash"
}

cURL Example

curl -X POST https://relay.solun.art/api/fingerprint \
  -H "Content-Type: application/json" \
  -d '{
    "hash": "abcdef0123456789",
    "channel": "dj-set-tokyo",
    "device_id": "iphone-abc123"
  }'

GET /api/fingerprint/matches

Retrieve current copyright detection matches for a channel. Returns the active consensus result and matched track information.

Query Parameters

Parameter	Type	Required	Description
channel	string	required	Channel name to query matches for

Request Example

// GET /api/fingerprint/matches?channel=dj-set-tokyo

Responses

200 Match found

{
  "channel": "dj-set-tokyo",
  "match": true,
  "track": {
    "title": "Summer Vibes",
    "artist": "DJ Example",
    "isrc": "US-XXX-24-00001"
  },
  "confidence": 0.95,
  "consensus_count": 3,
  "since": 1710000000
}

200 No match

{
  "channel": "dj-set-tokyo",
  "match": false,
  "consensus_count": 0
}

cURL Example

curl "https://relay.solun.art/api/fingerprint/matches?channel=dj-set-tokyo"

Algorithm Details

Hash Computation

The 64-bit fingerprint is computed from 5 seconds of audio at 48kHz:

Parameter	Value	Description
Sample rate	48,000 Hz	Standard audio sample rate
Window count	32	Audio divided into 32 time windows
Frequency bands	8	Spectral energy split into 8 bands
Hash size	64 bits	8 bands x 8 comparison bits per band
Extract interval	5 seconds	New fingerprint every 5s

Consensus Protocol

The relay server aggregates fingerprint reports from multiple listeners and determines matches:

Parameter	Value	Description
Hamming threshold	≤ 8 bits	Max bit difference to consider two hashes matching
Min cluster size	≥ 2 reports	Minimum agreeing listeners for consensus
Window	60 seconds	Reports older than 60s are pruned
Check interval	10 seconds	Consensus evaluated every 10s

Revenue Split

Recipient	Share	Description
Rights Holder	70%	Copyright owner / label
DJ Cashback	20%	Incentive for the broadcaster
Platform	10%	Soluna operations