# getNextTxn

Retrieves the raw transaction data for the next pending step in the transaction sequence. The response format varies based on the blockchain network:

```typescript
interface TransactionDataParams {
  routeId: string; // Route ID from createTransaction
  stepId: string; // Step ID from the transaction steps array
}

//Example implementation
const nextTxn = await getNextTxn({
  routeId: transaction.routeId,
  stepId: transaction.steps[0].id,
});

// Example Response (shortened)
{
  "status": "success",
  "data": {
    "routeId": "01J2WB1NY6MD3F25CJTTB01D8F",
    "stepId": "01J2WB1NY64MKVCM8FM994WMZV",
    "networkType": "evm",
    "txnData": {
      "txnType": "on-chain" | "sign-typed" | "sign-untyped"
      "txnEvm": {
        "to": "0x...",
        "value": "420000000000000000",
        // ... other transaction details
      }
    }
  }
}
```

**Transaction Types**

The SDK supports multiple transaction types that are automatically handled based on the protocol and requirements:

1. **On-chain Transactions** (`txnType: "on-chain"`):

   * Regular blockchain transactions that require gas fees
   * Used for standard token transfers and swaps

   ```typescript
   // Example response for on-chain transaction
   {
     "txnType": "on-chain",
     "txnEvm": {
       "from": "0x17e7c3DD600529F34eFA1310f00996709FfA8d5c",
       "to": "0x1234567890abcdef1234567890abcdef12345678",
       "value": "420000000000000000",
       "data": "0x095ea7b3...",
       "gasPrice": "30000000000",
       "gasLimit": "250000"
     }
   }

   // Execute using wagmi/viem
   import { getWalletClient } from "wagmi";
   const client = await getWalletClient();
   const hash = await client.sendTransaction({
     to: txnEvm.to as `0x${string}`,
     data: txnEvm.data as `0x${string}`,
     value: BigInt(txnEvm.value),
     gas: BigInt(txnEvm.gasLimit),
     gasPrice: BigInt(txnEvm.gasPrice),
   });

   // Execute using ethers.js
   import { BrowserProvider } from "ethers";
   const provider = new BrowserProvider(window.ethereum);
   const signer = await provider.getSigner();
   const transaction = await signer.sendTransaction({
     from: txnEvm.from,
     to: txnEvm.to,
     data: txnEvm.data,
     gasLimit: txnEvm.gasLimit,
     gasPrice: txnEvm.gasPrice,
     value: txnEvm.value,
   });
   const hash = transaction.hash;
   ```
2. **EIP-712 Typed Data Signing** (`txnType: "sign-typed"`):

   * Implements EIP-712 for structured data signing on EVM chains
   * Used for permit-style approvals and meta-transactions (for gasless)

   ```typescript
   // Example response for typed data signing
   {
     "txnType": "sign-typed",
     "txnEvm": {
       "domain": {
         "name": "Permit2",
         "version": "1",
         "chainId": 1,
         "verifyingContract": "0x000000000022D473030F116dDEE9F6B43aC78BA3"
       },
       "types": {
         "PermitSingle": [
           { "name": "details", "type": "PermitDetails" },
           { "name": "spender", "type": "address" },
           { "name": "sigDeadline", "type": "uint256" }
         ],
         "PermitDetails": [
           { "name": "token", "type": "address" },
           { "name": "amount", "type": "uint160" },
           { "name": "expiration", "type": "uint48" },
           { "name": "nonce", "type": "uint48" }
         ]
       },
       "message": {
         "details": {
           "token": "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48",
           "amount": "1461501637330902918203684832716283019655932542975",
           "expiration": "1747836789",
           "nonce": "0"
         },
         "spender": "0x1234567890123456789012345678901234567890",
         "sigDeadline": "1747836789"
       },
       "primaryType": "PermitSingle"
     }
   }

   // Execute using wagmi/viem
   import { getWalletClient } from "wagmi";
   const client = await getWalletClient();
   const signature = await client.signTypedData({
     account, // userWalletAddress
     domain: txnEvm.domain,
     types: txnEvm.types,
     primaryType: txnEvm.primaryType,
     message: txnEvm.message,
   });

   // Execute using ethers.js
   import { BrowserProvider } from "ethers";
   const provider = new BrowserProvider(window.ethereum);
   const signer = await provider.getSigner();
   // Remove EIP712Domain from types before signing
   delete txnEvm.types.EIP712Domain;
   const signature = await signer.signTypedData(
     txnEvm.domain,
     {
       [txnEvm.primaryType]: txnEvm.types[txnEvm.primaryType],
       ...txnEvm.types,
     },
     txnEvm.message
   );
   ```
3. **Untyped Message Signing** (`txnType: "sign-untyped"`):

   * Used for protocols like Meson.fi that require message signing
   * Supports cross-chain message verification

   ```typescript
   // Example response for untyped message signing
   {
     "txnType": "sign-untyped",
     "txnEvm": {
       "message": "0x1901c02aaa39b223fe8d0a0e5c4f27ead9083c756cc20001f4fc3",
     }
   }

   // Execute using wagmi/viem
   import { getWalletClient } from "wagmi";
   const client = await getWalletClient();
   const signature = await client.request({
     method: "personal_sign",
     params: [txnEvm.message, account],
   });

   // Execute using ethers.js
   import { BrowserProvider } from "ethers";
   const provider = new BrowserProvider(window.ethereum);
   const signer = await provider.getSigner();
   const signature = await provider.send("personal_sign", [
     txnEvm.message,
     account,
   ]);
   ```

The transaction type is automatically determined based on the quote and protocol being used. The SDK handles all the necessary signing logic internally, including:

* Proper formatting of typed and untyped data
* Chain-specific signature requirements
* Protocol-specific message formatting
* Gasless transaction handling

**Transaction Data Response Examples**

Send txnEvm or txnSol or txnCosmos to the appropriate wallet/provider based on the networkType and get the transaction hash to monitor the status of the transaction.

**EVM Chain Response**

```typescript
{
  "status": "success",
  "data": {
    "routeId": "01J2WB1NY6MD3F25CJTTB01D8F",
    "stepId": "01J2WB1NY64MKVCM8FM994WMZV",
    "networkType": "evm",
    "txnData": {
      "txnEvm": {
        "from": "0x17e7c3DD600529F34eFA1310f00996709FfA8d5c",
        "to": "0x1234567890abcdef1234567890abcdef12345678",
        "value": "420000000000000000",
        "data": "0x095ea7b3...",
        "gasPrice": "30000000000",
        "gasLimit": "250000"
      }
    }
  }
}
```

**Solana Chain Response**

```typescript
{
  "status": "success",
  "data": {
    "routeId": "01J2WB1NY6MD3F25CJTTB01D8F",
    "stepId": "01J2WB1NY64MKVCM8FM994WMZV",
    "networkType": "sol",
    "txnData": {
      "txnSol": {
        "data": "base64EncodedTransactionData...",
      }
    }
  }
}
```

**Cosmos Chain Response**

```typescript
{
  "status": "success",
  "data": {
    "routeId": "01J2WB1NY6MD3F25CJTTB01D8F",
    "stepId": "01J2WB1NY64MKVCM8FM994WMZV",
    "networkType": "cosmos",
    "txnData": {
      "txnCosmos": {
        "data": "{"typeUrl":"/ibc.applications.trans"}",
        "value": "0",
        "gasLimit": "250000",
        "gasPrice": "0.025",
      }
    }
  }
}
```

[View full getNextTxn response example](https://docs.blockend.com/compass-api/api-reference/get-raw-transaction-to-execute)