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

# core::starknet::syscalls::send_message_to_l1_syscall

Sends a message to L1.

## Signature

```rust theme={null}
pub extern fn send_message_to_l1_syscall(to_address: felt252, payload: Span) -> Result> implicits(GasBuiltin, System) nopanic;
```

#### Arguments

* `to_address` - The recipient's L1 address.
* `payload` - The content of the message.