cosign.eth_lock_htlc

workflowcross-chain-swap·step 4 of 7Workflow: cross-chain-swap · step 4 of 7

cosign.eth_lock_htlc "htlc_address" "swap_id" "recipient" "secret_hash" timelock "amount_wei" "signing_key" ( "token_address" gas_limit max_fee_gwei max_priority_fee_gwei ) Lock ETH or ERC-20 tokens into the HTLC contract. Arguments: 1. htlc_address (string, required) HTLC contract address 2. swap_id (string, required) 32-byte swap ID (hex) 3. recipient (string, required) Recipient address 4. secret_hash (string, required) sha256(secret) (hex) 5. timelock (numeric, required) Refund-eligible unix timestamp 6. amount_wei (string, required) Amount in wei (hex) 7. signing_key (string, required) 32-byte private key (hex) 8. token_address (string, optional) ERC-20 token address (null for native ETH) 9. gas_limit (numeric, optional) Gas limit (default 200000) 10. max_fee_gwei (numeric, optional) Max fee in gwei (default 50) 11. max_priority_fee_gwei (numeric, optional) Max priority fee in gwei (default 2) Result: { (json object) "success" : true|false, (boolean) Whether broadcast succeeded "tx_hash" : "str", (string) Transaction hash "from" : "str", (string) Sender address "nonce" : n (numeric) Transaction nonce } Examples: > bitcoin-cli cosign.eth_lock_htlc "0xHTLC" "0xSWAPID" "0xRECIPIENT" "0xSECRETHASH" 1234567890 "0xAMOUNT" "0xKEY"

Signature

cosign.eth_lock_htlc(htlc_address: string, swap_id: string, recipient: string, secret_hash: string, timelock: number, amount_wei: string, signing_key: string, token_address?: string, gas_limit?: number, max_fee_gwei?: number, max_priority_fee_gwei?: number) → any

Code samples

curl --user "$RPC_USER:$RPC_PASS" \
  --data-binary '{"jsonrpc":"1.0","id":"docs","method":"cosign.eth_lock_htlc","params":["\"<htlc_address>\"","\"<swap_id>\"","\"<recipient>\"","\"<secret_hash>\"",0,"\"<amount_wei>\"","\"<signing_key>\"","\"<token_address>\"",0,0,0]}' \
  -H 'content-type: text/plain;' \
  http://127.0.0.1:8332/

bitcoin-cli cosign.eth_lock_htlc "0xHTLC" "0xSWAPID" "0xRECIPIENT" "0xSECRETHASH" 1234567890 "0xAMOUNT" "0xKEY"

import requests
r = requests.post(
    "http://127.0.0.1:8332/",
    auth=("$RPC_USER", "$RPC_PASS"),
    json={
        "jsonrpc": "1.0",
        "id": "docs",
        "method": "cosign.eth_lock_htlc",
        "params": ["\"<htlc_address>\"", "\"<swap_id>\"", "\"<recipient>\"", "\"<secret_hash>\"", 0, "\"<amount_wei>\"", "\"<signing_key>\"", "\"<token_address>\"", 0, 0, 0],
    },
    timeout=30,
)
print(r.json())

const res = await fetch("http://127.0.0.1:8332/", {
  method: "POST",
  headers: {
    "content-type": "application/json",
    "authorization": "Basic " + btoa(`${process.env.RPC_USER}:${process.env.RPC_PASS}`),
  },
  body: JSON.stringify({
    jsonrpc: "1.0",
    id: "docs",
    method: "cosign.eth_lock_htlc",
    params: ["\"<htlc_address>\"","\"<swap_id>\"","\"<recipient>\"","\"<secret_hash>\"",0,"\"<amount_wei>\"","\"<signing_key>\"","\"<token_address>\"",0,0,0],
  }),
});
console.log(await res.json());

Parameters

Name	Type	Req.	Description
htlc_address	`string`	yes	HTLC contract address
swap_id	`string`	yes	32-byte swap ID (hex)
recipient	`string`	yes	Recipient address
secret_hash	`string`	yes	sha256(secret) (hex)
timelock	`number`	yes	Refund-eligible unix timestamp
amount_wei	`string`	yes	Amount in wei (hex)
signing_key	`string`	yes	32-byte private key (hex)
token_address	`string`	—	ERC-20 token address (null for native ETH)
gas_limit	`number`	—	Gas limit (default 200000)
max_fee_gwei	`number`	—	Max fee in gwei (default 50)
max_priority_fee_gwei	`number`	—	Max priority fee in gwei (default 2)

Result

Type: any

{ (json object) "success" : true|false, (boolean) Whether broadcast succeeded "tx_hash" : "str", (string) Transaction hash "from" : "str", (string) Sender address "nonce" : n (numeric) Transaction nonce }

Source: services/core-node/bcore/src/rpc/cosign.cpp:3375

C++ symbol: cosign_eth_lock_htlc

Code samples

curl --user "$RPC_USER:$RPC_PASS" \
  --data-binary '{"jsonrpc":"1.0","id":"docs","method":"cosign.eth_lock_htlc","params":["\"<htlc_address>\"","\"<swap_id>\"","\"<recipient>\"","\"<secret_hash>\"",0,"\"<amount_wei>\"","\"<signing_key>\"","\"<token_address>\"",0,0,0]}' \
  -H 'content-type: text/plain;' \
  http://127.0.0.1:8332/

bitcoin-cli cosign.eth_lock_htlc "0xHTLC" "0xSWAPID" "0xRECIPIENT" "0xSECRETHASH" 1234567890 "0xAMOUNT" "0xKEY"

import requests
r = requests.post(
    "http://127.0.0.1:8332/",
    auth=("$RPC_USER", "$RPC_PASS"),
    json={
        "jsonrpc": "1.0",
        "id": "docs",
        "method": "cosign.eth_lock_htlc",
        "params": ["\"<htlc_address>\"", "\"<swap_id>\"", "\"<recipient>\"", "\"<secret_hash>\"", 0, "\"<amount_wei>\"", "\"<signing_key>\"", "\"<token_address>\"", 0, 0, 0],
    },
    timeout=30,
)
print(r.json())

const res = await fetch("http://127.0.0.1:8332/", {
  method: "POST",
  headers: {
    "content-type": "application/json",
    "authorization": "Basic " + btoa(`${process.env.RPC_USER}:${process.env.RPC_PASS}`),
  },
  body: JSON.stringify({
    jsonrpc: "1.0",
    id: "docs",
    method: "cosign.eth_lock_htlc",
    params: ["\"<htlc_address>\"","\"<swap_id>\"","\"<recipient>\"","\"<secret_hash>\"",0,"\"<amount_wei>\"","\"<signing_key>\"","\"<token_address>\"",0,0,0],
  }),
});
console.log(await res.json());