Firehose

Synthient streams every data feed in real time as newline-delimited JSON (NDJSON) over a long-lived HTTP connection. Each line of the response is one complete JSON event. Connections stay open for up to 30 minutes before the server cleanly closes them; clients should reconnect immediately on disconnect. The server also emits a blank-line heartbeat every 15 seconds so intermediaries don't drop idle connections.

The stream identifiers covered on this page are:

proxies, anonymizers, torrents, ja4t.

Authentication

All endpoints are served from https://api.synthient.com under /api/v4 and require your API key in the x-api-key header. Each stream requires its own scope (PROXY_FIREHOSE, ANONYMIZERS_STREAM, TORRENTS_STREAM, JA4T_STREAM).

curl -N https://api.synthient.com/api/v4/feeds/proxies/stream \
  -H "x-api-key: $SYNTHIENT_API_KEY"

Common response codes

A successful stream returns 200 with an NDJSON body, one JSON object per line, held open for up to 30 minutes. 403 means the key lacks the per-stream feed scope. 429 can indicate a team request-rate limit, exhausted key monthly budget, or too many concurrent streams. Retry only when it carries a valid Retry-After. See Errors for the full reference.

Stream proxies

Real-time stream of proxy IP observations.

curl -N https://api.synthient.com/api/v4/feeds/proxies/stream \
  -H "x-api-key: $SYNTHIENT_API_KEY"

{
  "ip": "38.238.45.9",
  "provider": "DATAIMPULSE",
  "type": "RESIDENTIAL_PROXY",
  "timestamp": 1762605697,
  "country_code": "US",
  "asn": 174
}

Stream anonymizers

Real-time stream of anonymizer observations: VPNs, Tor exits, and relay-class detections. Anonymizer events emit IP ranges rather than individual addresses.

curl -N https://api.synthient.com/api/v4/feeds/anonymizers/stream \
  -H "x-api-key: $SYNTHIENT_API_KEY"

{
  "range_start": "2.56.252.0",
  "range_end": "2.56.252.255",
  "provider": "NORDVPN",
  "type": "COMMERCIAL_VPN",
  "country_code": "NL",
  "asn": 9009,
  "timestamp": 1762605697000
}

Stream torrents

Real-time stream of torrent peer sightings from the DHT network and trackers, with info hash, metadata, and observed peers.

curl -N https://api.synthient.com/api/v4/feeds/torrents/stream \
  -H "x-api-key: $SYNTHIENT_API_KEY"

{
  "info_hash": "abcdef0123456789abcdef0123456789abcdef01",
  "name": "ubuntu-26.04-desktop-amd64.iso",
  "magnet_uri": "magnet:?xt=urn:btih:abcdef0123456789abcdef0123456789abcdef01&dn=ubuntu-26.04-desktop-amd64.iso",
  "total_size": 4831838208,
  "piece_length": 2097152,
  "file_count": 1,
  "files": [
    { "path": "ubuntu-26.04-desktop-amd64.iso", "length": 4831838208 }
  ],
  "peers": [
    { "ip": "203.0.113.42", "port": 51413, "source": "DHT", "encrypted": true },
    { "ip": "198.51.100.17", "port": 6881, "source": "PEX", "encrypted": false }
  ],
  "timestamp": 1762605697
}

Stream JA4T fingerprints

Real-time stream of JA4T TCP fingerprints observed from proxy addresses. Requires the JA4T_STREAM scope; Parquet exports use JA4T_FEED.

curl -N https://api.synthient.com/api/v4/feeds/ja4t/stream \
  -H "x-api-key: $SYNTHIENT_API_KEY"

{
  "ip": "109.176.45.49",
  "ja4t": "43080_2-4-8-1-3_1436_9",
  "provider": "PROXYJET_DATACENTER",
  "type": "DATACENTER_PROXY",
  "timestamp": 1779818967,
  "country_code": "US",
  "asn": 16276
}

Consuming streams

A raw NDJSON consumer reads the response body line by line, skips blank heartbeat lines, and parses each remaining line as JSON. The SDKs handle this framing and retry transient connection-establishment failures with bounded backoff and Retry-After handling.

These consumers reconnect immediately after the server's clean close, normally every ~30 minutes. Any error that remains after the SDK's connection retries, or occurs while reading an established stream, is surfaced to the application. This also stops a 429 without Retry-After from becoming an endless reconnect loop. There is no resume cursor, so events sent while disconnected are missed. See Rate Limits for the retry policy.

from synthient import Client

with Client() as client:
    while True:
        with client.proxies.stream() as events:
            for event in events:
                print(event.ip, event.provider, event.type)