fetchReversedTxid

Calls the pox-5 get-reversed-txid read-only and returns the double SHA-256 of a raw Bitcoin transaction: its txid in internal byte order, the reverse of the txid block explorers show.

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Usage

import { bytesToHex } from '@stacks/common';
import { fetchReversedTxid } from '@stacks/bitcoin-staking';

// The Bitcoin genesis block's coinbase transaction
const tx =
  '01000000010000000000000000000000000000000000000000000000000000000000000000ffffffff4d04ffff001d0104455468652054696d65732030332f4a616e2f32303039204368616e63656c6c6f72206f6e206272696e6b206f66207365636f6e64206261696c6f757420666f722062616e6b73ffffffff0100f2052a01000000434104678afdb0fe5548271967f1a67130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef38c4f35504e51ec112de5c384df7ba0b8d578a4c702b6bf11d5fac00000000';

const reversed = await fetchReversedTxid({ tx, network: 'mainnet' });

bytesToHex(reversed); // '3ba3edfd7a7b12b27ac72c3e67768f617fc81bc3888a51323a9fb8aa4b1e5e4a'
// Displayed txid: 4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2127b7afdeda33b

Notes

• Wraps get-reversed-txid, which returns (sha256 (sha256 tx)). Reverse the result, for example with fetchReverseBuff32, to get the displayed txid.

• Pass the serialization without witness data. For a SegWit transaction, hashing the witness serialization gives the wtxid, not the txid.

• The transaction is at most 100,000 bytes, the contract's (buff 100000) argument type.

• Throws an Error if the node returns a non-2xx status (the message starts with Error calling read-only function.) or answers okay: false (the message is the node's cause).

Reference Link

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Signature

function fetchReversedTxid(
  opts: { tx: Uint8Array | string } & NetworkClientParam
): Promise<Uint8Array>;

opts is a NetworkClientParam plus tx.

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Returns

Promise<Uint8Array>

The 32-byte txid in internal (little-endian) byte order.

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Parameters

opts.tx (required)

• Type: Uint8Array | string

The raw transaction, as raw bytes or hex, without witness data.

opts.network (optional)

• Type: StacksNetworkName | StacksNetwork

The network to query: a name such as 'mainnet' or 'testnet', or a StacksNetwork object. Defaults to 'mainnet'.

opts.client (optional)

• Type: { baseUrl?: string; fetch?: FetchFn }

Overrides the API base URL or the fetch function, for example to query your own node. Fields you set replace the network's defaults.