Self-Submit On-Chain

For integrators who sign and broadcast transactions with their own wallet or custodian.

Workflow

Steps

1. Call /calldata for the operation:

   • Orders: POST /api/v1/orders/calldata

   • Deposits: POST /api/v1/cash/deposits/calldata

   • Withdrawals: POST /api/v1/cash/withdrawals/calldata

2. Submit toAddress, value, and callData on-chain.

3. Call the matching /tx endpoint with txHash.

4. Indexer backfills orderId or operationId.

5. Poll status endpoints until settled.

Use a reliable RPC node. estimateGas, eth_call, and waitForTransactionReceipt hit your RPC provider, not the Synfutures API. Free/public endpoints (including viem's default http() transport and free-tier providers) may rate-limit or reject eth_call and gas estimation, failing before the API is involved. Pass your own node URL to http("<url>").

Add a gas buffer. Default estimateGas can under-estimate router calls on some chains (e.g. Monad) and the tx reverts out-of-gas. Multiply the estimate (e.g. × 1.5–2) before submitting.

Record tx endpoints

Operation	Endpoint
Place order	POST /api/v1/orders/tx
Deposit	POST /api/v1/cash/deposits/tx
Withdraw	POST /api/v1/cash/withdrawals/tx

Status queries

Operation	Endpoints
Order	GET /api/v1/orders/tx/{txHash}, GET /api/v1/orders/{orderId}
Deposit	GET /api/v1/cash/deposits/{operationId}
Withdraw	GET /api/v1/cash/withdrawals/{operationId}

Same txHash from the same API key is idempotent. A txHash already recorded by another API key returns an error.

Deposit prerequisite

Complete ERC-20 approve before deposit calldata execution. See cash/deposits.md and demo-code.md.