# CCIP v1.6.0 Aptos Messages API Reference Source: https://docs.chain.link/ccip/api-reference/aptos/v1.6.0/messages > For the complete documentation index, see [llms.txt](/llms.txt). ## Messages This section details the data structures used for sending and receiving CCIP messages on Aptos. ### Any2AptosTokenAmount The `Any2AptosTokenAmount` struct represents a specific token and amount being delivered to the Aptos chain as part of a cross-chain message. ```rust // As defined in ccip::client struct Any2AptosTokenAmount has store, drop, copy { token: address, amount: u64 } ``` **Parameters** | Field | Type | Description | | -------- | --------- | -------------------------------------------------------------------------------------------------------------- | | `token` | `address` | The address of the token on Aptos. | | `amount` | `u64` | The number of tokens transferred, represented in the token's smallest unit (e.g., Octas for APT-based tokens). | **Where it's used**: - As part of the `dest_token_amounts` vector in the `Any2AptosMessage` struct when receiving a message on Aptos. ### Aptos2AnyMessage (Conceptual) This isn't a formal struct but represents the parameters passed to the `onramp::ccip_send` entry function to initiate a cross-chain message from Aptos. **Parameters** | Field | Type | Description | | ----------------------- | ----------------- | ---------------------------------------------------------------------------------------------------------------------------------------------- | | `receiver` | `vector` | The destination address in its native byte format (e.g., 20 bytes for EVM addresses, 32 for Aptos). | | `data` | `vector` | The arbitrary data payload to be processed by the receiver on the destination chain. | | `token_addresses` | `vector
` | A vector of Aptos token type addresses to transfer. | | `token_amounts` | `vector` | A vector of amounts for each corresponding token, in the token's smallest denomination. | | `token_store_addresses` | `vector
` | A vector of Fungible Asset store addresses from which tokens are withdrawn. Use `0x0` to default to the primary store of the sender's account. | | `fee_token` | `address` | The type address of the token used to pay CCIP fees. Use `0xa` if paying with native APT. | | `fee_token_store` | `address` | The Fungible Asset store address for the fee token. Use `0x0` to default to the primary store. | | `extra_args` | `vector` | Serialized byte vector containing additional arguments for the destination chain, such as gas limits. | ### Any2AptosMessage ```rust // As defined in ccip::client struct Any2AptosMessage has store, drop, copy { message_id: vector, source_chain_selector: u64, sender: vector, data: vector, dest_token_amounts: vector } ``` **Parameters** | Field | Type | Description | | ----------------------- | ------------------------------ | ------------------------------------------------------------------------------------------------------------- | | `message_id` | `vector` | The unique 32-byte identifier for this cross-chain message. | | `source_chain_selector` | `u64` | The unique identifier of the blockchain where the message originated. | | `sender` | `vector` | The sender's address on the source blockchain, in its native byte format. | | `data` | `vector` | The arbitrary data payload sent from the source chain for your module to process. | | `dest_token_amounts` | `vector` | A list of tokens and their amounts that were bridged and are being delivered to the receiver module on Aptos. | ### Aptos2AnyRampMessage ```rust // As defined in the OnRamp module struct Aptos2AnyRampMessage has store, drop, copy { header: RampMessageHeader, sender: address, data: vector, receiver: vector, extra_args: vector, fee_token: address, fee_token_amount: u64, fee_value_juels: u256, token_amounts: vector } ``` **Parameters** | Field | Type | Description | | ------------------ | -------------------------------- | ------------------------------------------------------------------------------------------------------------------------- | | `header` | `RampMessageHeader` | Metadata about the message: `message_id`, `source_chain_selector`, `dest_chain_selector`, `sequence_number`, and `nonce`. | | `sender` | `address` | The sender's 32-byte Aptos account address on the source chain. | | `data` | `vector` | The arbitrary payload data. | | `receiver` | `vector` | The destination address in its native byte format. | | `extra_args` | `vector` | The serialized "extra arguments" relevant to the destination, such as gas limits. | | `fee_token` | `address` | The type address of the token used to pay CCIP fees. | | `fee_token_amount` | `u64` | The amount of the `fee_token` (in its native denomination) that was charged. | | `fee_value_juels` | `u256` | The total fee value converted to LINK Juels (1e18 decimals) for standardized value reporting. | | `token_amounts` | `vector` | A list of tokens locked or burned on Aptos as part of the message. | ## Extra Args ### Tags | Constant | Value (Hex) | Purpose | | ----------------------- | ------------ | ----------------------------------------------------------------------- | | `EVM_EXTRA_ARGS_V2_TAG` | `0x181dcf10` | Denotes `GenericExtraArgsV2` for Aptos → EVM or Aptos → Aptos messages. | | `SVM_EXTRA_ARGS_V1_TAG` | `0x1f3b3aba` | Denotes `SVMExtraArgsV1` for Aptos → SVM messages. | *** ### GenericExtraArgsV2 ```rust // Conceptual representation of data to be encoded struct GenericExtraArgsV2 { gas_limit: u256, allow_out_of_order_execution: bool, } ``` **Parameters** | Field | Type | Description | | ------------------------------ | ------ | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `gas_limit` | `u256` | The gas limit for calling the receiver on the destination chain. For EVM, this is the gas for `ccipReceive`. For Aptos, it's the gas for your `ccip_receive` function. | | `allow_out_of_order_execution` | `bool` | If `true`, the message can be processed by the CCIP network in a different order than it was sent. It is recommended to set this to `true`. | *** ### SVMExtraArgsV1 ```rust // Conceptual representation of data to be encoded struct SVMExtraArgsV1 { compute_units: u32, account_is_writable_bitmap: u64, allow_out_of_order_execution: bool, token_receiver: [u8; 32], accounts: vector>, } ``` **Parameters** | Field | Type | Description | | ------------------------------ | -------------------- | ------------------------------------------------------------------------------------------------------------------------------------- | | `compute_units` | `u32` | The number of compute units allocated to the SVM program. | | `account_is_writable_bitmap` | `u64` | Bitmap indicating which accounts are writable during program execution. | | `allow_out_of_order_execution` | `bool` | If `true`, allows the message to be processed out of order by the CCIP network. | | `token_receiver` | `[u8; 32]` | A 32-byte Solana address that will receive any bridged tokens. If input is shorter than 32 bytes, it will be zero-padded on the left. | | `accounts` | `vector>` | A list of serialized SVM accounts passed to the program. |