> ## Documentation Index
> Fetch the complete documentation index at: https://docs.modular.cloud/llms.txt
> Use this file to discover all available pages before exploring further.

# Get transaction by hash

> Look up a transaction by its hash. This is the same hash that is returned
by the API when submitting a transaction (see PendingTransaction).

When given a transaction hash, the server first looks for the transaction
in storage (on-chain, committed). If no on-chain transaction is found, it
looks the transaction up by hash in the mempool (pending, not yet committed).

To create a transaction hash by yourself, do the following:
1. Hash message bytes: "RawTransaction" bytes + BCS bytes of [Transaction](https://aptos-labs.github.io/aptos-core/aptos_types/transaction/enum.Transaction.html).
2. Apply hash algorithm `SHA3-256` to the hash message bytes.
3. Hex-encode the hash bytes with `0x` prefix.