> For the complete documentation index, see [llms.txt](/llms.txt)

# Global Variables

Similar to Solidity's global `block` variable, Aztec exposes contextual values within each function via the `context` object.

Aztec has two execution environments—Private and Public—each with different available globals.

## Private Global Variables

Private functions access transaction context via [`TxContext`](/aztec-nr-api/mainnet/noir_aztec/protocol/abis/transaction/tx_context/struct.TxContext.md). The following fields are accessible via `context` methods:

### Chain Id

The unique identifier for the Aztec network instance (not the Ethereum chain the rollup settles to).

```rust
self.context.chain_id();
```

### Version

The Aztec protocol version number. The genesis block has version 1.

```rust
self.context.version();
```

### Gas Settings

The gas limits, max fees per gas, and inclusion fee set by the user for the transaction.

```rust
self.context.gas_settings();
```

## Public Global Variables

Public functions access block-level context via [`GlobalVariables`](/aztec-nr-api/mainnet/noir_aztec/protocol/abis/global_variables/struct.GlobalVariables.md).

note

Not all fields in `GlobalVariables` are exposed via context methods. The `coinbase`, `fee_recipient`, and `slot_number` fields are used internally by the protocol.

Public functions have access to `chain_id()` and `version()` (same syntax as private), plus the following block-level values:

### Timestamp

The unix timestamp when the block is executed. Provided by the block proposer, so it may have slight variance. Always increases monotonically.

```rust
self.context.timestamp();
```

### Block Number

The sequential block identifier. Genesis block is 1, incrementing by 1 for each subsequent block.

```rust
self.context.block_number();
```

### Gas Fees

The current L2 and DA gas prices for the block. You can access gas-related information via:

```rust
self.context.l2_gas_left();       // Remaining L2 gas
self.context.da_gas_left();       // Remaining DA gas
self.context.min_fee_per_l2_gas(); // L2 gas price
self.context.min_fee_per_da_gas(); // DA gas price
self.context.transaction_fee();   // Final tx fee (only available in teardown phase)
```

Why do available globals differ between environments?

Private functions execute on the user's device before the transaction is submitted, so they cannot know which block will include the transaction. Therefore, `timestamp` and `block_number` are unavailable in private context.

Public functions execute on a sequencer who knows the current block's timestamp and number, making these values accessible.