# Module `iota::tx_context` - [Struct `TxContext`](#iota_tx_context_TxContext) - [Function `sender`](#iota_tx_context_sender) - [Function `digest`](#iota_tx_context_digest) - [Function `epoch`](#iota_tx_context_epoch) - [Function `epoch_timestamp_ms`](#iota_tx_context_epoch_timestamp_ms) - [Function `fresh_object_address`](#iota_tx_context_fresh_object_address) - [Function `ids_created`](#iota_tx_context_ids_created) - [Function `derive_id`](#iota_tx_context_derive_id)

## Struct `TxContext` Information about the transaction currently being executed. This cannot be constructed by a transaction. It is a privileged object created by the VM and passed in to the entrypoint of the transaction as &mut TxContext.

public struct TxContext has drop

Fields

sender: address: The address of the user that signed the current transaction
tx_hash: vector<u8>: Hash of the current transaction
epoch: u64: The current epoch number
epoch_timestamp_ms: u64: Timestamp that the epoch started at
ids_created: u64: Counter recording the number of fresh id's created while executing this transaction. Always 0 at the start of a transaction

## Function `sender` Return the address of the user that signed the current transaction

public fun sender(self: &iota::tx_context::TxContext): address

Implementation

public fun sender(self: &TxContext): address {
    self.sender
}

## Function `digest` Return the transaction digest (hash of transaction inputs). Please do not use as a source of randomness.

public fun digest(self: &iota::tx_context::TxContext): &vector<u8>

Implementation

public fun digest(self: &TxContext): &vector<u8> {
    &self.tx_hash
}

## Function `epoch` Return the current epoch

public fun epoch(self: &iota::tx_context::TxContext): u64

Implementation

public fun epoch(self: &TxContext): u64 {
    self.epoch
}

## Function `epoch_timestamp_ms` Return the epoch start time as a unix timestamp in milliseconds.

public fun epoch_timestamp_ms(self: &iota::tx_context::TxContext): u64

Implementation

public fun epoch_timestamp_ms(self: &TxContext): u64 {
    self.epoch_timestamp_ms
}

## Function `fresh_object_address` Create an address that has not been used. As it is an object address, it will never occur as the address for a user. In other words, the generated address is a globally unique object ID.

public fun fresh_object_address(ctx: &mut iota::tx_context::TxContext): address

Implementation

public fun fresh_object_address(ctx: &mut TxContext): address {
    let ids_created = ctx.ids_created;
    let id = derive_id(*&ctx.tx_hash, ids_created);
    ctx.ids_created = ids_created + 1;
    id
}

## Function `ids_created` Return the number of id's created by the current transaction. Hidden for now, but may expose later

fun ids_created(self: &iota::tx_context::TxContext): u64

Implementation

fun ids_created(self: &TxContext): u64 {
    self.ids_created
}

## Function `derive_id` Native function for deriving an ID via hash(tx_hash || ids_created)

fun derive_id(tx_hash: vector<u8>, ids_created: u64): address

Implementation

native fun derive_id(tx_hash: vector<u8>, ids_created: u64): address;