> ## 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. # 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`, default `100`, max `10000`). - If `offset` is `0` or omitted, the socket stays subscribed for live updates. - If `offset` is greater than `0`, only that historical page is returned. Market rules: - For Polymarket, `markets` should contain condition IDs. - For Kalshi, `markets` should contain market IDs. ## OpenAPI ````yaml /openapi.json get /api/v1/trades/ws openapi: 3.1.0 info: title: Synthesis API version: 1.0.0 description: Unified prediction market API for Polymarket and Kalshi. servers: - url: https://synthesis.trade security: [] tags: - name: Projects description: Create and manage project accounts, sessions, and account API keys. - name: Accounts description: >- Authenticate and manage account-level sessions, account API keys, and public account preferences. - name: Markets description: Unified market discovery and analytics across Polymarket and Kalshi. - name: Polymarket description: Polymarket market data, prices, orderbooks, trades, and holders endpoints. - name: Kalshi description: Kalshi market data, events, history, leaderboard, and profile endpoints. - name: Wallets description: Wallet management routes. Each wallet supports multiple chains. - name: Polygon description: >- Polygon wallet routes for balances, orders, minting, redemption, withdrawals, and swaps. - name: Polygon Copytrades description: Polymarket copytrade configuration and management for Polygon wallets. - name: Solana description: >- Solana wallet routes used for Kalshi balances, KYC, orders, redemption, and withdrawals. - name: News description: News endpoints with market and event matching. - name: WebSockets description: >- Real-time streaming endpoints for orderbooks, trades, balances, and live data feeds. paths: /api/v1/trades/ws: get: tags: - WebSockets summary: Trades WebSocket description: >- 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`, default `100`, max `10000`). - If `offset` is `0` or omitted, the socket stays subscribed for live updates. - If `offset` is greater than `0`, only that historical page is returned. Market rules: - For Polymarket, `markets` should contain condition IDs. - For Kalshi, `markets` should contain market IDs. operationId: trades-ws requestBody: required: true content: application/json: schema: type: object required: - type properties: type: type: string description: >- WebSocket message type. Supported values: `subscribe` or `unsubscribe`. venue: type: string description: >- Optional venue filter. Supported values: `polymarket` or `kalshi`. If omitted, the all-venues stream is only supported when `markets` is also omitted. markets: type: array items: type: string description: >- 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: type: integer description: >- 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. default: 0 example: 100 limit: type: integer description: >- Maximum historical trades to return per query. Capped at `500`. default: 100 example: 500 responses: '101': description: WebSocket connection established content: application/json: examples: Historical Trades: summary: Initial historical trades returned on subscribe value: 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' Polymarket Trade: summary: Live Polymarket trade streamed after subscribe value: success: true response: venue: polymarket trade: tx_hash: >- 0xc3d4e5f6a7b8c3d4e5f6a7b8c3d4e5f6a7b8c3d4e5f6a7b8c3d4e5f6a7b8c3d4 token_id: >- 21742633143463906290569050155826241533067272736897614950488156847949938836455 address: '0x742d35Cc6634C0532925a3b844Bc454e4438f44e' side: true amount: '97.5' shares: '150.0' price: '0.65' username: trader1 image: '' created_at: '2026-01-01T00:00:01' 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' Kalshi Trade: summary: Live Kalshi trade streamed after subscribe value: success: true response: venue: kalshi trade: trade_id: t_def456 market_id: KXBTC-25-T100000 outcome: 'yes' side: true amount: '50.0' shares: '100.0' price: '0.50' created_at: '2026-01-01T00:00:01' 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' Unsubscribed: summary: Unsubscribe acknowledgment value: success: true response: Unsubscribed Error: summary: Error response value: success: false response: Invalid markets security: [] ````