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htlc-create-transaction

Create a transaction with an HTLC (Hashed TimeLock Contract) output without broadcasting it.

An HTLC locks funds that can be claimed in two ways:

  • Spend path: the recipient provides the correct secret whose hash matches <SECRET_HASH> before the timelock expires.
  • Refund path: the sender reclaims the funds after the refund timelock expires, without needing the secret.

Usage​

htlc-create-transaction <CURRENCY> <AMOUNT> <SECRET_HASH> <SPEND_ADDRESS> <REFUND_TIMELOCK> <REFUND_ADDRESS>

Arguments​

  • <CURRENCY>: The currency to lock. Use a token id or coin for ML coins. For NFTs, use the token id.

  • <AMOUNT>: The amount to lock. For NFTs, use 1.

  • <SECRET_HASH>: Hex-encoded hash of the HTLC secret. Generate a secret with htlc-generate-secret and hash it with htlc-calc-secret-hash.

  • <SPEND_ADDRESS>: The address that can spend the HTLC by revealing the secret.

  • <REFUND_TIMELOCK>: When the sender can reclaim funds if the HTLC is not spent. One of:

    • block_count(N), N blocks from now
    • seconds(N), N seconds from now
    • until_height(N), until block height N
    • until_time(RFC3339), until a specific datetime, e.g. until_time(2026-06-01T00:00:00Z)

  • <REFUND_ADDRESS>: The address that can reclaim the funds after the timelock expires.

Examples​

# Lock 10 ML coins, claimable with a secret, refundable after 720 blocks (~12 hours)
htlc-create-transaction coin 10 <secret_hash> <spend_address> block_count(720) <refund_address>

# Lock tokens, refundable after a specific date
htlc-create-transaction <token_id> 500 <secret_hash> <spend_address> until_time(2026-06-01T00:00:00Z) <refund_address>

Notes​

This command creates the transaction but does not broadcast it. Use node-submit-transaction to broadcast it after signing if needed.

Use htlc-generate-secret to generate a random secret and htlc-calc-secret-hash to compute its hash before creating the HTLC.