> Aztec.nr API reference, v6.0.0 (mainnet and testnet). Index: https://docs.aztec.network/aztec-nr-api/mainnet/llms.txt

# Function compute_tx_effects_tree_leaf

Module: `noir_aztec::protocol::blob_data`

```rust
pub fn compute_tx_effects_tree_leaf(
    tx_effect: TxEffect,
    array_lengths: TxEffectArrayLengths,
) -> Field
```

This tx's leaf of the block's tx effects tree: a hash binding the tx hash to the hash of the tx's effects.

A holder of the block header can verify "tx X was included in this block and produced exactly effects E" with a membership proof against `BlockHeader.tx_effects_tree_root`. The verifier must recompute this leaf from the tx effect (or otherwise validate the leaf preimage under `DOM_SEP__TX_EFFECTS_TREE_LEAF`): because the tree has variable-depth paths, accepting a bare untrusted leaf could let an internal node be presented as a leaf.