> ## Documentation Index > Fetch the complete documentation index at: https://docs.caldera.xyz/llms.txt > Use this file to discover all available pages before exploring further. # API Reference > Type definitions and data structures for the Metalayer SDK # Core Types Complex data structures used throughout the Metalayer SDK for transaction execution, order tracking, and cross-chain operations. ## Chain Comprehensive blockchain network information including configuration and metadata. | Property | Type | Description | | ----------------- | --------------------------------------- | ------------------------------------------------------------------------ | | `identifier` | **[ChainIdentifier](#chainidentifier)** | Unique identifier for the blockchain network | | `name` | `string` | Human-readable name of the blockchain (e.g., "Ethereum", "Arbitrum One") | | `isTestnet` | `boolean` | Whether this is a testnet chain used for development and testing | | `imageUrl` | `string` | URL to the chain's logo or icon image | | `parentChain` | **[ChainIdentifier](#chainidentifier)** | Parent chain identifier with both ID and architecture | | `stack` | `RollupStack` | Stack used by this chain (Nitro, ZkSync, Optimism) | | `nativeCurrency` | `NativeCurrency` | Native currency information for this chain | | `defaultRpc` | `ChainRpc` | Default RPC for this chain | | `alternativeRpcs` | `ChainRpc[]` | Alternative RPCs for this chain | | `blockExplorer` | `ChainBlockExplorer` | Block explorer information for this chain | | `contracts` | `Record` | Known deployed contracts on this chain | | `lastUpdatedAt` | `Date` | Timestamp for when this chain was last updated | ## ChainIdentifier Minimal chain identifier containing ID and architecture information. | Property | Type | Description | | -------------- | ------------------------------------------- | ------------------------------------------------------ | | `id` | `number` | Unique numerical identifier for the blockchain network | | `architecture` | **[ChainArchitecture](#chainarchitecture)** | Blockchain architecture (Ethereum, Solana) | ## ExecutionStep A transaction execution step containing the specific action data for EVM transactions, EIP-712 signatures, or Solana transactions. | Property | Type | Description | | -------- | ----------------------------------------------- | ---------------------------------------------------- | | `action` | **[ExecutionStepAction](#executionstepaction)** | Union type containing the specific action to execute | ### ExecutionStepAction The `action` property is a union type with `case` and `value` properties: | Property | Type | Description | | -------- | ----------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------- | | `case` | `"transactionRequest"` \| `"eip712Data"` \| `"solanaTransaction"` | Discriminator indicating which type of action this is | | `value` | **[TransactionRequest](#transactionrequest)** \| **[EIP712Data](#eip712data)** \| **[SolanaTransaction](#solanatransaction)** | The actual action data based on the case | ### Action Types | Case | Value Type | Description | | ---------------------- | --------------------------------------------- | ------------------------------------------- | | `"transactionRequest"` | **[TransactionRequest](#transactionrequest)** | Standard EVM transactions | | `"eip712Data"` | **[EIP712Data](#eip712data)** | EIP-712 typed data for gasless transactions | | `"solanaTransaction"` | **[SolanaTransaction](#solanatransaction)** | Solana blockchain transactions | ```typescript theme={null} // Example: Processing ExecutionStep for (const step of quote.steps) { switch (step.action.case) { case 'transactionRequest': // Handle EVM transaction const txRequest = step.action.value; break; case 'eip712Data': // Handle EIP-712 signature const typedData = step.action.value; break; case 'solanaTransaction': // Handle Solana transaction const solanaTransaction = step.action.value; break; } } ``` ## TransactionRequest Standard EVM transaction request for on-chain operations. | Property | Type | Description | | --------- | ----------------- | ----------------------------------------------------------------- | | `to` | `string` | Target contract address | | `data` | `string` | Encoded function call data | | `value` | `string` | ETH value in wei | | `chainId` | `number` | Execution chain ID | | `type` | `TransactionType` | Transaction type (`ERC20_APPROVAL`, `CONTRACT_WRITE`, `TRANSFER`) | ## EIP712Data EIP-712 typed data structure for gasless transactions and meta-transactions. | Property | Type | Description | | ------------- | -------------------------------------- | ------------------------------------------------------- | | `account` | `string` | Account address that will sign this typed data | | `domain` | `EIP712Domain` | Domain separator information for signature verification | | `types` | `Record` | Type definitions for structured data | | `primaryType` | `string` | Primary type name being signed | | `message` | `object` | The structured data to be signed | ## SolanaTransaction Solana blockchain transaction containing multiple instructions. | Property | Type | Description | | -------------- | ---------------------------------- | ------------------------------------------ | | `instructions` | **[Instruction](#instruction)\[]** | List of instructions to execute atomically | ### Instruction Individual instruction within a Solana transaction. | Property | Type | Description | | ----------- | ---------------------------------- | ------------------------------------------------ | | `accounts` | **[AccountMeta](#accountmeta)\[]** | Accounts involved with their access permissions | | `programId` | `string` | Public key of the Solana program to invoke | | `data` | `string` | Encoded instruction data specific to the program | ### AccountMeta Account metadata specifying permissions for Solana transactions. | Property | Type | Description | | ------------ | --------- | ---------------------------------------------- | | `pubkey` | `string` | Public key of the account | | `isSigner` | `boolean` | Whether this account must sign the transaction | | `isWritable` | `boolean` | Whether this account's data may be modified | ## Token Token information including metadata and chain-specific details. | Property | Type | Description | | ---------- | -------- | ---------------------------------------------- | | `address` | `string` | Contract address of the token | | `symbol` | `string` | Token symbol (e.g., "ETH", "USDC") | | `name` | `string` | Full token name (e.g., "Ethereum", "USD Coin") | | `decimals` | `number` | Number of decimal places for the token | | `chainId` | `number` | Chain ID where this token exists | | `imageUrl` | `string` | URL to the token's logo or icon | ## TokenList Container for a list of tokens on a specific chain. | Property | Type | Description | | -------- | ---------------------- | -------------------------------------- | | `tokens` | **[Token](#token)\[]** | Array of tokens available on the chain | ## Quote Bridge quote containing execution steps and fee information. | Property | Type | Description | | ----------------------- | -------------------------------------- | ----------------------------------------- | | `quoteId` | `string` | Unique identifier for tracking | | `steps` | **[ExecutionStep](#executionstep)\[]** | Transaction steps to execute | | `amountOut` | `bigint` | Expected output amount | | `totalFees` | `bigint` | Total fees in source token | | `provider` | **[QuoteProvider](#quoteprovider)** | Bridge provider | | `estimatedFillTimeSecs` | `number` | Completion time (seconds) | | `deadline` | `Date` | Quote expiration time | | `fees` | `TokenFee[]` | Detailed fee breakdown by token and chain | ## Order A cross-chain bridge order that tracks transaction status and details. | Property | Type | Description | | ---------------------------- | --------------------------------------- | ----------------------------------------------------------- | | `quoteId` | `string` | Unique identifier linking this order to the original quote | | `provider` | **[QuoteProvider](#quoteprovider)** | Provider that processed this order | | `status` | **[OrderStatus](#orderstatus)** | Current status of the cross-chain order | | `sourceTransactionHash` | `string` | Transaction hash on the source chain | | `destinationTransactionHash` | `string` | Transaction hash on the destination chain | | `sourceChain` | **[ChainIdentifier](#chainidentifier)** | Source chain with id and architecture | | `destinationChain` | **[ChainIdentifier](#chainidentifier)** | Destination chain with id and architecture | | `senderAddress` | `string` | Address that initiated the order | | `receiverAddress` | `string` | Address that will receive the tokens | | `amountIn` | `string` | Input amount sent in source token's smallest unit | | `amountOut` | `string` | Output amount received in destination token's smallest unit | | `sourceTokenAddress` | `string` | Contract address of the source token | | `destinationTokenAddress` | `string` | Contract address of the destination token | | `timestamp` | `Date` | Block timestamp of the source transaction | | `lastUpdated` | `Date` | Block timestamp of the last update to the order | | `nextSteps` | **[ExecutionStep](#executionstep)\[]** | Required user actions to complete the order | | `deadline` | `Date \| undefined` | Expiration time when the order becomes eligible for refund | # Enums Enumeration types that define specific sets of values used across the SDK. ## ChainArchitecture Blockchain architecture types supported by the Metalayer SDK. | Architecture | Description | | ------------- | ---------------------------------- | | `UNSPECIFIED` | Unspecified architecture | | `ETHEREUM` | Ethereum and EVM-compatible chains | | `SOLANA` | Solana blockchain | ## QuoteProvider Bridge providers that can process cross-chain transactions. | Provider | Description | | ----------------------- | ---------------------------- | | `UNSPECIFIED` | Unspecified provider | | `NITRO_BRIDGE` | Arbitrum Nitro native bridge | | `BEDROCK_BRIDGE` | OP Stack native bridge | | `ZKSYNC_BRIDGE` | zkSync native bridge | | `ACROSS` | Across protocol bridge | | `ECO` | Eco protocol bridge | | `RELAY` | Relay protocol bridge | | `METATOKEN` | MetaToken bridge | | `LAYER_ZERO_OFT` | LayerZero OFT bridge | | `HYPERLANE_WARP_ROUTES` | Hyperlane Warp Routes bridge | ## OrderStatus Order status values indicating the current state of a cross-chain transaction. | Status | Description | | ------------------- | ----------------------------------------------------------- | | `PENDING` | Order is in progress, waiting for completion | | `WAITING_TO_PROVE` | Withdrawal is waiting for proof submission (native bridges) | | `WITHDRAWAL_PROVEN` | Withdrawal proof has been submitted | | `FULFILLED` | Order completed successfully | | `REFUNDED` | Order was refunded to the source address | | `FAILED` | Order failed and cannot be completed | | `READY_TO_REFUND` | Order deadline passed, eligible for refund | ```typescript theme={null} import { OrderStatus } from '@metalayer/sdk'; const { order } = await client.getOrder({ sourceTransactionHash: '0xTxHash', sourceChainId: 1, }); // Check specific status if (order.status === OrderStatus.FULFILLED) { console.log('Bridge transaction completed!'); } ```