Trades WebSocket
curl --request GET \
--url https://synthesis.trade/api/v1/trades/ws \
--header 'Content-Type: application/json' \
--data '
{
"type": "<string>",
"venue": "<string>",
"markets": [
"0xbd71b43bb47eb60dbcb41fa25df2a0ed4da612873d6e0447a2c730bd4cc25910",
"KXBTC-25-T100000"
],
"offset": 100,
"limit": 500
}
'import requests
url = "https://synthesis.trade/api/v1/trades/ws"
payload = {
"type": "<string>",
"venue": "<string>",
"markets": ["0xbd71b43bb47eb60dbcb41fa25df2a0ed4da612873d6e0447a2c730bd4cc25910", "KXBTC-25-T100000"],
"offset": 100,
"limit": 500
}
headers = {"Content-Type": "application/json"}
response = requests.get(url, json=payload, headers=headers)
print(response.text)const options = {
method: 'GET',
headers: {'Content-Type': 'application/json'},
body: JSON.stringify({
type: '<string>',
venue: '<string>',
markets: [
'0xbd71b43bb47eb60dbcb41fa25df2a0ed4da612873d6e0447a2c730bd4cc25910',
'KXBTC-25-T100000'
],
offset: 100,
limit: 500
})
};
fetch('https://synthesis.trade/api/v1/trades/ws', options)
.then(res => res.json())
.then(res => console.log(res))
.catch(err => console.error(err));<?php
$curl = curl_init();
curl_setopt_array($curl, [
CURLOPT_URL => "https://synthesis.trade/api/v1/trades/ws",
CURLOPT_RETURNTRANSFER => true,
CURLOPT_ENCODING => "",
CURLOPT_MAXREDIRS => 10,
CURLOPT_TIMEOUT => 30,
CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
CURLOPT_CUSTOMREQUEST => "GET",
CURLOPT_POSTFIELDS => json_encode([
'type' => '<string>',
'venue' => '<string>',
'markets' => [
'0xbd71b43bb47eb60dbcb41fa25df2a0ed4da612873d6e0447a2c730bd4cc25910',
'KXBTC-25-T100000'
],
'offset' => 100,
'limit' => 500
]),
CURLOPT_HTTPHEADER => [
"Content-Type: application/json"
],
]);
$response = curl_exec($curl);
$err = curl_error($curl);
curl_close($curl);
if ($err) {
echo "cURL Error #:" . $err;
} else {
echo $response;
}package main
import (
"fmt"
"strings"
"net/http"
"io"
)
func main() {
url := "https://synthesis.trade/api/v1/trades/ws"
payload := strings.NewReader("{\n \"type\": \"<string>\",\n \"venue\": \"<string>\",\n \"markets\": [\n \"0xbd71b43bb47eb60dbcb41fa25df2a0ed4da612873d6e0447a2c730bd4cc25910\",\n \"KXBTC-25-T100000\"\n ],\n \"offset\": 100,\n \"limit\": 500\n}")
req, _ := http.NewRequest("GET", url, payload)
req.Header.Add("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)
defer res.Body.Close()
body, _ := io.ReadAll(res.Body)
fmt.Println(string(body))
}HttpResponse<String> response = Unirest.get("https://synthesis.trade/api/v1/trades/ws")
.header("Content-Type", "application/json")
.body("{\n \"type\": \"<string>\",\n \"venue\": \"<string>\",\n \"markets\": [\n \"0xbd71b43bb47eb60dbcb41fa25df2a0ed4da612873d6e0447a2c730bd4cc25910\",\n \"KXBTC-25-T100000\"\n ],\n \"offset\": 100,\n \"limit\": 500\n}")
.asString();require 'uri'
require 'net/http'
url = URI("https://synthesis.trade/api/v1/trades/ws")
http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true
request = Net::HTTP::Get.new(url)
request["Content-Type"] = 'application/json'
request.body = "{\n \"type\": \"<string>\",\n \"venue\": \"<string>\",\n \"markets\": [\n \"0xbd71b43bb47eb60dbcb41fa25df2a0ed4da612873d6e0447a2c730bd4cc25910\",\n \"KXBTC-25-T100000\"\n ],\n \"offset\": 100,\n \"limit\": 500\n}"
response = http.request(request)
puts response.read_body{
"success": true,
"response": {
"trades": [
{
"venue": "polymarket",
"trade": {
"tx_hash": "0xa1b2c3d4e5f6a1b2c3d4e5f6a1b2c3d4e5f6a1b2c3d4e5f6a1b2c3d4e5f6a1b2",
"token_id": "21742633143463906290569050155826241533067272736897614950488156847949938836455",
"address": "0x742d35Cc6634C0532925a3b844Bc454e4438f44e",
"side": true,
"amount": "97.5",
"shares": "150.0",
"price": "0.65",
"username": "trader1",
"image": "",
"created_at": "2026-01-01T00:00:00"
},
"event": {
"event_id": 12345,
"title": "Will Bitcoin reach $100k by end of 2025?",
"slug": "will-bitcoin-reach-100k-by-end-of-2025",
"description": "This market resolves to Yes if spot Bitcoin trades at or above $100,000 before 2025 ends.",
"image": "https://example.com/bitcoin.png",
"tags": [
"crypto",
"bitcoin"
],
"labels": [
"crypto",
"macro"
],
"neg_risk": false,
"active": true,
"liquidity": "1500000",
"volume": "5000000",
"volume24hr": "250000",
"volume1wk": "900000",
"volume1mo": "2200000",
"volume1yr": "5000000",
"live": {
"live": false,
"ended": false
},
"created_at": "2026-01-01T00:00:00",
"updated_at": "2026-01-01T00:00:00",
"ends_at": "2026-12-31T23:59:59"
},
"market": {
"event_id": 12345,
"condition_id": "0xbd71b43bb47eb60dbcb41fa25df2a0ed4da612873d6e0447a2c730bd4cc25910",
"question_id": "0xabcd",
"question": "Will Bitcoin reach $100k?",
"outcome": "Yes",
"slug": "will-bitcoin-reach-100k-yes",
"description": "Buy Yes if you think Bitcoin will trade at or above $100,000 before market expiry.",
"image": "https://example.com/bitcoin-market.png",
"left_outcome": "Yes",
"right_outcome": "No",
"left_price": "0.65",
"right_price": "0.35",
"left_token_id": "21742633143463906290569050155826241533067272736897614950488156847949938836455",
"right_token_id": "48572956138472615938471625938471659384716593847165938471659384716593847165938",
"winner_token_id": "",
"active": true,
"resolved": false,
"fees": true,
"decimals": 6,
"liquidity": "1500000",
"volume": "5000000",
"volume24hr": "250000",
"volume1wk": "900000",
"volume1mo": "2200000",
"volume1yr": "5000000",
"rewards": {
"rewards": false
},
"created_at": "2026-01-01T00:00:00",
"updated_at": "2026-01-01T00:00:00",
"ends_at": "2026-12-31T23:59:59"
}
},
{
"venue": "kalshi",
"trade": {
"trade_id": "t_abc123",
"market_id": "KXBTC-25-T100000",
"outcome": "yes",
"side": true,
"amount": "50.0",
"shares": "100.0",
"price": "0.50",
"created_at": "2026-01-01T00:00:00"
},
"event": {
"event_id": "KXBTC-25",
"series_id": "KXBTC",
"title": "Bitcoin above $100k?",
"category": "Crypto",
"status": "active",
"yes_price": "0.65",
"no_price": "0.35",
"volume": "500000",
"volume24hr": "25000",
"open_interest": "150000",
"created_at": "2026-01-01T00:00:00",
"ends_at": "2026-12-31T23:59:59"
},
"market": {
"market_id": "KXBTC-25-T100000",
"event_id": "KXBTC-25",
"series_id": "KXBTC",
"title": "Bitcoin above $100k?",
"category": "Crypto",
"status": "active",
"yes_price": "0.65",
"no_price": "0.35",
"volume": "500000",
"volume24hr": "25000",
"open_interest": "150000",
"created_at": "2026-01-01T00:00:00",
"ends_at": "2026-12-31T23:59:59"
}
}
]
}
}WebSockets
Trades WebSocket
Connect to wss://synthesis.trade/api/v1/trades/ws and send JSON messages over the socket.
Subscription behavior:
- Returns historical trades ordered by newest first (up to
limit, default100, max10000). - If
offsetis0or omitted, the socket stays subscribed for live updates. - If
offsetis greater than0, only that historical page is returned.
Market rules:
- For Polymarket,
marketsshould contain condition IDs. - For Kalshi,
marketsshould contain market IDs.
Trades WebSocket
curl --request GET \
--url https://synthesis.trade/api/v1/trades/ws \
--header 'Content-Type: application/json' \
--data '
{
"type": "<string>",
"venue": "<string>",
"markets": [
"0xbd71b43bb47eb60dbcb41fa25df2a0ed4da612873d6e0447a2c730bd4cc25910",
"KXBTC-25-T100000"
],
"offset": 100,
"limit": 500
}
'import requests
url = "https://synthesis.trade/api/v1/trades/ws"
payload = {
"type": "<string>",
"venue": "<string>",
"markets": ["0xbd71b43bb47eb60dbcb41fa25df2a0ed4da612873d6e0447a2c730bd4cc25910", "KXBTC-25-T100000"],
"offset": 100,
"limit": 500
}
headers = {"Content-Type": "application/json"}
response = requests.get(url, json=payload, headers=headers)
print(response.text)const options = {
method: 'GET',
headers: {'Content-Type': 'application/json'},
body: JSON.stringify({
type: '<string>',
venue: '<string>',
markets: [
'0xbd71b43bb47eb60dbcb41fa25df2a0ed4da612873d6e0447a2c730bd4cc25910',
'KXBTC-25-T100000'
],
offset: 100,
limit: 500
})
};
fetch('https://synthesis.trade/api/v1/trades/ws', options)
.then(res => res.json())
.then(res => console.log(res))
.catch(err => console.error(err));<?php
$curl = curl_init();
curl_setopt_array($curl, [
CURLOPT_URL => "https://synthesis.trade/api/v1/trades/ws",
CURLOPT_RETURNTRANSFER => true,
CURLOPT_ENCODING => "",
CURLOPT_MAXREDIRS => 10,
CURLOPT_TIMEOUT => 30,
CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
CURLOPT_CUSTOMREQUEST => "GET",
CURLOPT_POSTFIELDS => json_encode([
'type' => '<string>',
'venue' => '<string>',
'markets' => [
'0xbd71b43bb47eb60dbcb41fa25df2a0ed4da612873d6e0447a2c730bd4cc25910',
'KXBTC-25-T100000'
],
'offset' => 100,
'limit' => 500
]),
CURLOPT_HTTPHEADER => [
"Content-Type: application/json"
],
]);
$response = curl_exec($curl);
$err = curl_error($curl);
curl_close($curl);
if ($err) {
echo "cURL Error #:" . $err;
} else {
echo $response;
}package main
import (
"fmt"
"strings"
"net/http"
"io"
)
func main() {
url := "https://synthesis.trade/api/v1/trades/ws"
payload := strings.NewReader("{\n \"type\": \"<string>\",\n \"venue\": \"<string>\",\n \"markets\": [\n \"0xbd71b43bb47eb60dbcb41fa25df2a0ed4da612873d6e0447a2c730bd4cc25910\",\n \"KXBTC-25-T100000\"\n ],\n \"offset\": 100,\n \"limit\": 500\n}")
req, _ := http.NewRequest("GET", url, payload)
req.Header.Add("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)
defer res.Body.Close()
body, _ := io.ReadAll(res.Body)
fmt.Println(string(body))
}HttpResponse<String> response = Unirest.get("https://synthesis.trade/api/v1/trades/ws")
.header("Content-Type", "application/json")
.body("{\n \"type\": \"<string>\",\n \"venue\": \"<string>\",\n \"markets\": [\n \"0xbd71b43bb47eb60dbcb41fa25df2a0ed4da612873d6e0447a2c730bd4cc25910\",\n \"KXBTC-25-T100000\"\n ],\n \"offset\": 100,\n \"limit\": 500\n}")
.asString();require 'uri'
require 'net/http'
url = URI("https://synthesis.trade/api/v1/trades/ws")
http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true
request = Net::HTTP::Get.new(url)
request["Content-Type"] = 'application/json'
request.body = "{\n \"type\": \"<string>\",\n \"venue\": \"<string>\",\n \"markets\": [\n \"0xbd71b43bb47eb60dbcb41fa25df2a0ed4da612873d6e0447a2c730bd4cc25910\",\n \"KXBTC-25-T100000\"\n ],\n \"offset\": 100,\n \"limit\": 500\n}"
response = http.request(request)
puts response.read_body{
"success": true,
"response": {
"trades": [
{
"venue": "polymarket",
"trade": {
"tx_hash": "0xa1b2c3d4e5f6a1b2c3d4e5f6a1b2c3d4e5f6a1b2c3d4e5f6a1b2c3d4e5f6a1b2",
"token_id": "21742633143463906290569050155826241533067272736897614950488156847949938836455",
"address": "0x742d35Cc6634C0532925a3b844Bc454e4438f44e",
"side": true,
"amount": "97.5",
"shares": "150.0",
"price": "0.65",
"username": "trader1",
"image": "",
"created_at": "2026-01-01T00:00:00"
},
"event": {
"event_id": 12345,
"title": "Will Bitcoin reach $100k by end of 2025?",
"slug": "will-bitcoin-reach-100k-by-end-of-2025",
"description": "This market resolves to Yes if spot Bitcoin trades at or above $100,000 before 2025 ends.",
"image": "https://example.com/bitcoin.png",
"tags": [
"crypto",
"bitcoin"
],
"labels": [
"crypto",
"macro"
],
"neg_risk": false,
"active": true,
"liquidity": "1500000",
"volume": "5000000",
"volume24hr": "250000",
"volume1wk": "900000",
"volume1mo": "2200000",
"volume1yr": "5000000",
"live": {
"live": false,
"ended": false
},
"created_at": "2026-01-01T00:00:00",
"updated_at": "2026-01-01T00:00:00",
"ends_at": "2026-12-31T23:59:59"
},
"market": {
"event_id": 12345,
"condition_id": "0xbd71b43bb47eb60dbcb41fa25df2a0ed4da612873d6e0447a2c730bd4cc25910",
"question_id": "0xabcd",
"question": "Will Bitcoin reach $100k?",
"outcome": "Yes",
"slug": "will-bitcoin-reach-100k-yes",
"description": "Buy Yes if you think Bitcoin will trade at or above $100,000 before market expiry.",
"image": "https://example.com/bitcoin-market.png",
"left_outcome": "Yes",
"right_outcome": "No",
"left_price": "0.65",
"right_price": "0.35",
"left_token_id": "21742633143463906290569050155826241533067272736897614950488156847949938836455",
"right_token_id": "48572956138472615938471625938471659384716593847165938471659384716593847165938",
"winner_token_id": "",
"active": true,
"resolved": false,
"fees": true,
"decimals": 6,
"liquidity": "1500000",
"volume": "5000000",
"volume24hr": "250000",
"volume1wk": "900000",
"volume1mo": "2200000",
"volume1yr": "5000000",
"rewards": {
"rewards": false
},
"created_at": "2026-01-01T00:00:00",
"updated_at": "2026-01-01T00:00:00",
"ends_at": "2026-12-31T23:59:59"
}
},
{
"venue": "kalshi",
"trade": {
"trade_id": "t_abc123",
"market_id": "KXBTC-25-T100000",
"outcome": "yes",
"side": true,
"amount": "50.0",
"shares": "100.0",
"price": "0.50",
"created_at": "2026-01-01T00:00:00"
},
"event": {
"event_id": "KXBTC-25",
"series_id": "KXBTC",
"title": "Bitcoin above $100k?",
"category": "Crypto",
"status": "active",
"yes_price": "0.65",
"no_price": "0.35",
"volume": "500000",
"volume24hr": "25000",
"open_interest": "150000",
"created_at": "2026-01-01T00:00:00",
"ends_at": "2026-12-31T23:59:59"
},
"market": {
"market_id": "KXBTC-25-T100000",
"event_id": "KXBTC-25",
"series_id": "KXBTC",
"title": "Bitcoin above $100k?",
"category": "Crypto",
"status": "active",
"yes_price": "0.65",
"no_price": "0.35",
"volume": "500000",
"volume24hr": "25000",
"open_interest": "150000",
"created_at": "2026-01-01T00:00:00",
"ends_at": "2026-12-31T23:59:59"
}
}
]
}
}Body
application/json
WebSocket message type. Supported values: subscribe or unsubscribe.
Optional venue filter. Supported values: polymarket or kalshi. If omitted, the all-venues stream is only supported when markets is also omitted.
Optional list of market IDs. Maximum 100 items. For Polymarket, use condition IDs. For Kalshi, use market IDs. Mixed-venue lists are supported when you provide the matching IDs for each venue.
Example:
[
"0xbd71b43bb47eb60dbcb41fa25df2a0ed4da612873d6e0447a2c730bd4cc25910",
"KXBTC-25-T100000"
]
Historical pagination offset. Historical queries return trades up to limit per venue/query shape. Live subscription is only attached when offset is 0 or omitted.
Example:
100
Maximum historical trades to return per query. Capped at 500.
Example:
500
Response
101 - application/json
WebSocket connection established
⌘I