CrossChain Sandbox

Generate structurally valid mock Flare Data Connector proofs for local tests. Pick an attestation type, fill in the request body, and get a response JSON you can paste into a Foundry or Hardhat test fixture. Real FDCVerification will reject these because the merkle root is not attested on-chain.

Attestation type

Payment request

Flare docs →

Source chain

transactionIdbytes32

Hash or id of the payment transaction on the source chain.

inUtxouint256

Index of the source address in UTXO inputs (UTXO chains only, else 0).

utxouint256

Index of the receiving UTXO output (UTXO chains only, else 0).