Withdraw funds

Pull collateral back out with the single-call withdraw flow.

Withdrawals are a single call, but two things make them different from a normal transaction: they need a separate fee payer, and the funds settle asynchronously.

1. Build the withdrawal

curl -X POST $FLASH_API_URL/transaction-builder/withdraw -d '{
  "owner": "<WALLET>", "tokenSymbol": "USDC", "amount": "12.5", "feePayer": "<FEE_PAYER>"
}'

• feePayer must differ from owner — the delegation program rejects owner == feePayer. The client holds this keypair and co-signs the transaction.

• Optionally pass feePayerTopUpLamports to prepend an owner → feePayer transfer that covers the escrow rent.

2. Handle the response

The response includes receipt, custodySettlementRequired, and isNativeSol.

• custodySettlementRequired: true → the trade vault can't cover the amount yet. Settle first, then retry withdraw:

  curl -X POST $FLASH_API_URL/transaction-builder/custody-settlement -d '{
    "owner": "<WALLET>", "tokenSymbol": "USDC"
  }'

3. Submit and wait

Sign (owner + fee payer), submit to your Solana RPC, then poll until the escrow receipt account closes — that means the funds landed in your ATA.

• isNativeSol: true → the funds arrive as WSOL; unwrap the WSOL account back to native SOL.

• If the withdrawal doesn't finalize on its own, resume it:

  curl -X POST $FLASH_API_URL/transaction-builder/withdrawal-settle -d '{
    "owner": "<WALLET>", "tokenMint": "<MINT>"
  }'

A lower-level request-withdrawal performs just the request step (also requires feePayer ≠ owner). Most integrations should use withdraw.

→ Full fields: API reference › Account & funds · Background: Funds lifecycle