Send Swap Transaction

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Overview

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Request Body

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Single Mode

• chainId (required) — The blockchain identifier. Examples: solana:solana, evm:1 (Ethereum), evm:42161 (Arbitrum), evm:8453 (Base), evm:137 (Polygon), evm:56 (BNB Chain)
• signedTransaction (required) — Base64-encoded signed transaction bytes
• awaitLanding (optional, boolean) — When true, the endpoint blocks until the transaction is confirmed on-chain and returns detailed confirmation data including landing time and swap amounts. Default: false

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Batch Mode (Solana MEV)

• chainId (required) — The blockchain identifier
• candidates (required) — Array of candidate transactions targeting different block engines (landers)
  • lander (string) — Lander identifier (e.g. jito, nozomi, zeroslot)
  • signedTransaction (string) — Base64-encoded signed transaction
• awaitLanding (optional, boolean) — Same as single mode

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Usage Examples

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Fire-and-Forget (Default)

curl -X POST "https://api.mobula.io/api/2/swap/send" \
  -H "Content-Type: application/json" \
  -d '{
    "chainId": "solana:solana",
    "signedTransaction": "<base64-signed-tx>"
  }'

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Await Landing (Solana)

curl -X POST "https://api.mobula.io/api/2/swap/send" \
  -H "Content-Type: application/json" \
  -d '{
    "chainId": "solana:solana",
    "signedTransaction": "<base64-signed-tx>",
    "awaitLanding": true
  }'

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Await Landing (EVM)

curl -X POST "https://api.mobula.io/api/2/swap/send" \
  -H "Content-Type: application/json" \
  -d '{
    "chainId": "evm:42161",
    "signedTransaction": "<base64-signed-tx>",
    "awaitLanding": true
  }'

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Batch Mode (Solana MEV)

curl -X POST "https://api.mobula.io/api/2/swap/send" \
  -H "Content-Type: application/json" \
  -d '{
    "chainId": "solana:solana",
    "candidates": [
      { "lander": "jito", "signedTransaction": "<base64-jito-tx>" },
      { "lander": "nozomi", "signedTransaction": "<base64-nozomi-tx>" }
    ],
    "awaitLanding": true
  }'

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Response Format

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Response Fields

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Data Object

• success (boolean) — Whether the transaction was successfully broadcast
• transactionHash (string, optional) — Transaction hash/signature on the blockchain
• requestId (string) — Unique identifier for the request
• status (string, optional) — Landing status, present when awaitLanding is used:
  • broadcasted — Transaction sent to the network (default when awaitLanding is false)
  • processed — Transaction processed by a Solana validator (fast, ~500ms, not yet confirmed by supermajority)
  • confirmed — Transaction fully confirmed on-chain (EVM receipt or Solana RPC fallback)
  • failed — Transaction landed on-chain but reverted/failed
  • timeout — Confirmation not received within the timeout period (30s Solana, 60s EVM)
• onchainLandingTimeMs (number, optional) — Time in milliseconds from broadcast to on-chain confirmation
• lander (string, optional) — Which block engine landed the transaction (batch mode only, e.g. jito, nozomi)
• landingTimeMs (number, optional) — Time in milliseconds from send to first RPC acceptance
• swap (object, optional) — Parsed swap data from the confirmed transaction (Solana only):
  • tokenIn — { address: string, amount: string } — Token sent
  • tokenOut — { address: string, amount: string } — Token received

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Error Field

• error (string, optional) — Error message if the transaction failed

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Example Responses

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Broadcasted (fire-and-forget)

{
  "data": {
    "success": true,
    "transactionHash": "5VERv8NMvzbJMEkV8xnrLkEaWRtSz9CosKDYjCJjBRnbJLgp8uirBgmQpjKhoR4tjF3ZpRzrFmBV6UjKdiSZkQUW",
    "requestId": "550e8400-e29b-41d4-a716-446655440000",
    "status": "broadcasted"
  }
}

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Processed (Solana with awaitLanding)

{
  "data": {
    "success": true,
    "transactionHash": "563cifbEg4NXUmChZ8mPmXWcHYsSCQFE3nCZPuH8DPjT6TD8z425qoJvuyTwrEUAEveYqMnkZEaGnnLxELe2paGu",
    "requestId": "a0f6d6ad-8b1a-4156-8efa-5ec634cc83e5",
    "status": "processed",
    "onchainLandingTimeMs": 535,
    "swap": {
      "tokenIn": {
        "address": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
        "amount": "100000"
      },
      "tokenOut": {
        "address": "So11111111111111111111111111111111111111112",
        "amount": "1116467"
      }
    }
  }
}

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Confirmed (EVM with awaitLanding)

{
  "data": {
    "success": true,
    "transactionHash": "0xb1c87a9045eeed21b63071f31b3ec3e51543aac6b1ca823e2d984d717c27db96",
    "requestId": "8ab08aeb-ddb6-4fd8-aa0f-4fa7bd5b24c7",
    "status": "confirmed",
    "onchainLandingTimeMs": 1518
  }
}

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Failed On-Chain

{
  "data": {
    "success": false,
    "transactionHash": "0x...",
    "requestId": "770e8400-e29b-41d4-a716-446655440002",
    "status": "failed",
    "onchainLandingTimeMs": 2100
  },
  "error": "Transaction failed on-chain"
}

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Broadcast Error

{
  "data": {
    "success": false,
    "requestId": "880e8400-e29b-41d4-a716-446655440003",
    "status": "broadcasted"
  },
  "error": "Transaction simulation failed: insufficient funds"
}

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Transaction Flow

1. Get Quote: Call the Swap Quoting endpoint to get a serialized transaction
2. Sign Transaction: Use your wallet to sign the transaction
   • For Solana: Use @solana/web3.js to deserialize, sign, and re-serialize
   • For EVM: Use viem, ethers.js, or web3.js to sign with gas estimation
3. Encode to Base64: Convert the signed transaction bytes to base64
4. Broadcast: Send the encoded transaction using this endpoint
5. Track: Either use awaitLanding: true to get immediate confirmation, or track using the returned transaction hash on blockchain explorers

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Status Semantics

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Important Notes

• awaitLanding latency: Solana ~500ms (PROCESSED), EVM ~1-3s depending on chain block time
• Timeouts: Solana gRPC timeout is 30s with RPC fallback, EVM polling timeout is 60s
• Transaction Validity: Transactions may expire if not sent within a certain timeframe
• Slippage: If market conditions change significantly, the transaction may fail
• Batch Mode: Only supported for Solana. All candidates share a durable nonce so only one can land

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Error Handling

• Insufficient Funds: Wallet doesn’t have enough balance to cover the swap + fees
• Slippage Exceeded: Market moved beyond acceptable slippage tolerance
• Invalid Signature: Transaction was not properly signed
• Expired Transaction: Transaction validity period has passed
• Network Congestion: Blockchain network is experiencing high load

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Use Cases

• Automated Trading: Execute swaps programmatically with confirmation tracking
• Trading Bots: Use awaitLanding for real-time execution feedback
• MEV Protection: Use batch mode with multiple landers for optimal landing
• DeFi Integration: Complete swap flows with on-chain confirmation in your application