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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": 1000
}
'
{ "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
​
type
string
required

WebSocket message type. Supported values: subscribe or unsubscribe.

​
venue
string

Optional venue filter. Supported values: polymarket or kalshi. If omitted, the all-venues stream is only supported when markets is also omitted.

​
markets
string[]

Optional list of market IDs. Maximum 1000 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"
]
​
offset
integer
default:0

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

​
limit
integer
default:100

Maximum historical trades to return per query. Capped at 10000.

Example:

1000

Response

101 - application/json

WebSocket connection established