# GlacisRouter **Your gateway to cross-chain activity.** The GlacisRouter smart contract acts as the on-chain interface for all cross-chain activity with Glacis. You can discover the source smart contract [`GlacisRouter.sol`](https://github.com/glacislabs/v1-core/blob/main/contracts/routers/GlacisRouter.sol) in this repository. ## The Route Function The main function in GlacisRouter is route, which sends a cross-chain message. It returns a `bytes32` messageId and a `uint256` nonce: ```solidity route( uint256 chainId, bytes32 to, bytes memory payload, address[] memory adapters, GlacisRouter.CrossChainGas[] memory fees, address refundAddress, bool retryable) payable returns(bytes32 messageId, uint256 nonce) ```
Parameter NameParameter Description
uint256 chainIdThe Glacis ID of the blockchain that you wish to send a message to
address toThe address of the destination contract that you are sending a message to
bytes memory payloadThe payload of data that you wish to send to the destination contract
address[] memory adaptersAn array of adapters to send the message over, such as an Axelar adapter. Can be an address if you wish to use an adapter that Glacis does not use, otherwise it can be a GMP ID stored as an address
GlacisRouter.CrossChainGas[] memory feesAn array of fees that correspond to the amount provided to each adapter. This is a parallel array to the adapters parameter. The sum of the "nativeCurrencyValue" must be equal to the value sent with this function
address refundAddressThe address to which excess native currency is sent to if an adapter deems that the user overpaid
bool retriableWhether to allow the message to be retried (stores owner of the message ID on-chain, slightly more gas expensive)
### CrossChainGas To represent how adapters require gas, we have created the CrossChainGas struct, located within the [GlacisCommons](https://github.com/glacislabs/v1-core/blob/main/contracts/commons/GlacisCommons.sol) contract. ```solidity struct CrossChainGas { uint128 gasLimit; uint128 nativeCurrencyValue; } ``` | Parameter Name | Parameter Description | | ------------------------------- | ----------------------------------------------------------------------------------------------------- | | **uint128** gasLimit | A desired destination chain gas limit. Required by some adapters, and ignored by others | | **uint128** nativeCurrencyValue | The amount of source chain value to be forwarded to an adapter. Different GMPs require different fees | ## The Retry Route There is an additional route function variant: ```solidity routeRetry( uint256 chainId, address to, bytes memory payload, address[] memory adapters, GlacisRouter.CrossChainGas[] memory fees, address refundAddress, bytes32 messageId, uint256 nonce) payable returns(bytes32, uint256) ``` This route cannot be used for original cross-chain messages. Instead, it is used to retry a cross-chain message with an identical message ID and identical data (but potentially through a different GMP). For example, an original message was sent through Axelar but is now being retried via Wormhole. This can be helpful in cases where a message is somehow lost by a GMP's consensus mechanism or its relayers. An identical message would be sent, and whichever message arrives after the first will revert. Two additional parameters are required with this function: | Parameter Name | Parameter Description | | ----------------- | ------------------------------------------------------------------------------------ | | bytes32 messageId | The Glacis message ID of the original message | | uint256 nonce | The nonce of the message, which can be retrieved in the original message's event log | {% hint style="info" %} Only the original message sender can retry a message, no other address can do it on their behalf. The original message must have been sent with its "retryable" parameter as true. Identical data **must** be provided. {% endhint %} ## Read-Only These are the read-only functions in GlacisRouter, but most developers won't use them: | Function Signature | Function Description | | ------------------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | glacisAdapters(uint8) returns(address) | Returns the address of the adapter contract for the specific GMP ID input | | sourceAdapterToGMP(address) returns(uint8) | Returns the GMP ID of the adapter at the specified address. Returns 0 if no such adapter exists | | validateGlacisMessageId(bytes32 messageId, uint256 toChainId, address to, uint256 nonce) returns(bool) | Returns true if the combination of chain ID, address, msg.sender, and message nonce result in the same messageId **You can use the JSON-RPC method eth\_call to simulate any msg.sender if you wish to use this in your application** | | messageSenders(bytes32) | Returns the message sender of a specific message ID | ## Errors It also includes the following errors, some of which you may encounter: | Error Name | Error Description | | ------------------------------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------ | | GlacisRouter\_\_GMPNotSupported | Occurs when routing, and the GMP ID provided is not supported on this chain | | GlacisRouter\_\_RouteDoesNotExist | Occurs when routing, and the adapter of the GMP ID does not exist | | GlacisRouter\_\_NotOwnerOfMessageToRetry | Occurs when retrying a message route, when the message ID that is attempting to be retried was not originally sent by the current message sender | | GlacisRouter\_\_OnlyAdaptersAllowed | Occurs when trying to call a function that only a Glacis GMP Adapter can call | | GlacisRouter\_\_MessageInputNotIdenticalForRetry | Occurs when retrying a message route, when the message input was not identical to the original | | GlacisRouter\_\_ClientDeniedRoute | Occurs when a message is received, and the client contract does not accept messages from the sender address, origin chain, and/or GMP | | GlacisRouter\_\_ImpossibleGMPId(uint8 gmpId) | Occurs when a message is received, and the GMP ID is not supported | | GlacisRouter\_\_MessageAlreadyReceivedFromGMP | Occurs when a message is received, and the same message has already been received from that GMP | | GlacisRouter\_\_MessageIdNotValid | Occurs when a message is received, and the Glacis message ID contained in the header does not pass verification | | \`\`\` | |