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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": 500
}
'
{
  "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"
        }
      }
    ]
  }
}

Documentation Index

Fetch the complete documentation index at: https://api.synthesis.trade/docs/llms.txt

Use this file to discover all available pages before exploring further.

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 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"
]
​
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 500.

Example:

500

Response

101 - application/json

WebSocket connection established