Submit a transaction to the Tachyon relay network for execution across multiple blockchain networks

Submit Relay Transaction

Submit a transaction to the Tachyon relay network for execution. The relay service handles gas payments and transaction submission on your behalf, returning a unique transaction ID for tracking.

Endpoint

POST https://tachyon.rath.fi/api/submit-tx

Request Body

Parameter	Type	Required	Description
`chainId`	number	Yes	The blockchain network ID where the transaction will be executed
`to`	string	Yes	The recipient wallet address or smart contract address. Format varies by chain (hex for EVM, base58 for Solana, named for NEAR)
`callData`	string	Yes	Encoded transaction data in hexadecimal format (use '0x' for simple transfers)
`value`	string	No	Amount of native currency to send in the smallest unit (wei for EVM, lamports for Solana, yoctoNEAR for NEAR, MIST for Sui). Defaults to '0'
`label`	string	No	Optional human-readable label for easier transaction identification and tracking
`gasLimit`	string	No	Optional gas limit for the transaction. If not specified, it will be estimated automatically. Required for Aptos and Sui transactions
`gasPrice`	string	No	Gas price in wei (for legacy transactions). Cannot be used with maxFeePerGas or maxPriorityFeePerGas
`maxFeePerGas`	string	No	Maximum fee per gas for EIP-1559 transactions. Must be used together with maxPriorityFeePerGas
`maxPriorityFeePerGas`	string	No	Maximum priority fee per gas for EIP-1559 transactions. Must be used together with maxFeePerGas
`maxUSD`	number	No	Maximum cost in USD that you're willing to pay for this transaction
`shouldBatchInMulticall`	boolean	No	Whether to batch this transaction in a multicall
`retries`	number	No	Number of retries if transaction fails. Defaults to 0
`isAuthenticatedTx`	boolean	No	Enable authenticated relay mode for additional security and verification. Defaults to false
`derivationPath`	string	No	Optional HD wallet derivation path for transaction signing (useful for multi-account setups)
`transactionType`	string	No	Type of relay transaction: `"flash"` (default), `"authenticated"`, `"funding-signed"`, or `"flash-blocks"` (Base/Base Sepolia only)
`authorizationList`	array	No	Optional list of authorization entries for delegated transactions or batched operations (EIP-7702). Not allowed for flash-blocks transactions

AuthorizationListItem Object

When using authorizationList, each item should contain:

Field	Type	Required	Description
`chainId`	number	Yes	Chain ID for the authorization
`address`	string	Yes	Ethereum address (must start with "0x")
`nonce`	number	Yes	Nonce for the authorization
`r`	string	Yes	Signature r component (must start with "0x")
`s`	string	Yes	Signature s component (must start with "0x")
`yParity`	number	Yes	Signature y parity (0 or 1)
`v`	number/bigint	No	Optional signature v value

Gas Parameter Rules

Legacy transactions: Use gasPrice only
EIP-1559 transactions: Use both maxFeePerGas and maxPriorityFeePerGas together
You cannot mix gasPrice with maxFeePerGas or maxPriorityFeePerGas

Response

Success Response

{
  "success": true,
  "data": {
    "txId": "68fa3450539a3c9d28bbca33"
  },
  "timestamp": "2025-10-24T12:34:56.789Z"
}

Response Fields

Field	Type	Description
`txId`	string	Unique transaction ID that can be used to track the transaction status and execution

Error Response

{
  "success": false,
  "error": {
    "code": "INVALID_PARAMETERS",
    "message": "Missing required transaction parameters",
    "category": "VALIDATION_ERROR",
    "details": {
      "field": "chainId",
      "message": "chainId is required"
    },
    "traceId": "trace_abc123xyz789"
  },
  "timestamp": "2025-10-24T12:34:56.789Z"
}

Example Requests

EVM Chains (Ethereum, Base, Polygon, etc.)

curl -X POST "https://tachyon.rath.fi/api/submit-tx" \
  -H "Content-Type: application/json" \
  -H "api-key: YOUR_API_KEY" \
  -d '{
    "chainId": 8453,
    "to": "0x3dbE34f2C21b3B2980d4dc53f3c7E51e39663F49",
    "value": "1000000000000000",
    "callData": "0x",
    "label": "My Base Transaction"
  }'

With Gas Parameters:

curl -X POST "https://tachyon.rath.fi/api/submit-tx" \
  -H "Content-Type: application/json" \
  -H "api-key: YOUR_API_KEY" \
  -d '{
    "chainId": 8453,
    "to": "0x3dbE34f2C21b3B2980d4dc53f3c7E51e39663F49",
    "value": "1000000000000000",
    "callData": "0x",
    "gasLimit": "21000",
    "label": "My Transaction with Gas Limit"
  }'

With EIP-1559 Gas Parameters:

curl -X POST "https://tachyon.rath.fi/api/submit-tx" \
  -H "Content-Type: application/json" \
  -H "api-key: YOUR_API_KEY" \
  -d '{
    "chainId": 8453,
    "to": "0x3dbE34f2C21b3B2980d4dc53f3c7E51e39663F49",
    "value": "1000000000000000",
    "callData": "0x",
    "maxFeePerGas": "2000000000",
    "maxPriorityFeePerGas": "1000000000",
    "label": "EIP-1559 Transaction"
  }'

Aptos

curl -X POST "https://tachyon.rath.fi/api/submit-tx" \
  -H "Content-Type: application/json" \
  -H "api-key: YOUR_API_KEY" \
  -d '{
    "chainId": 88888888,
    "to": "0x09ebf332aa3e4edad203aff521bd8a47597119de1956885711223ec157eac219",
    "value": "1",
    "callData": "0x",
    "gasLimit": "100",
    "label": "My Aptos Transaction"
  }'

Note: Gas limit is required for Aptos transactions.

Solana

curl -X POST "https://tachyon.rath.fi/api/submit-tx" \
  -H "Content-Type: application/json" \
  -H "api-key: YOUR_API_KEY" \
  -d '{
    "chainId": 10100000,
    "to": "BSNsLtDDM1wN8rjEJQaZreVqRhibsUtsEq9m1G2deAm",
    "value": "1000000",
    "callData": "0x",
    "label": "My Solana Transaction"
  }'

Sui

curl -X POST "https://tachyon.rath.fi/api/submit-tx" \
  -H "Content-Type: application/json" \
  -H "api-key: YOUR_API_KEY" \
  -d '{
    "chainId": 897796746,
    "to": "0xf78da4499004aa2d594143d69a7804f6f989ab8152de59d3726def827c9fe1f0",
    "value": "100000000",
    "callData": "0x",
    "gasLimit": "3000000",
    "label": "send-native-sui"
  }'

Note: Gas limit is required for Sui transactions. Value is denominated in MIST (1 SUI = 10^9 MIST).

NEAR

curl -X POST "https://tachyon.rath.fi/api/submit-tx" \
  -H "Content-Type: application/json" \
  -H "api-key: YOUR_API_KEY" \
  -d '{
    "chainId": 7777777,
    "to": "deeprice6887.near",
    "value": "1000000000000000000000000",
    "callData": "0x",
    "label": "My NEAR Transaction"
  }'

NEAR

curl -X POST "https://tachyon.rath.fi/api/submit-tx" \
  -H "Content-Type: application/json" \
  -H "api-key: YOUR_API_KEY" \
  -d '{
    "to": "0x021Af6FEc4753c4C7C248Dc68d1B43ed721f0246e9dC8A9e5b7d74Ff3373764B",
    "callData": "0x",
    "value": "1",
    "chainId": 23448594291968334,
    "label": "send strk",
    "retries": 0
  }'

Advanced Examples

Transaction with Max USD Limit

curl -X POST "https://tachyon.rath.fi/api/submit-tx" \
  -H "Content-Type: application/json" \
  -H "api-key: YOUR_API_KEY" \
  -d '{
    "chainId": 8453,
    "to": "0x3dbE34f2C21b3B2980d4dc53f3c7E51e39663F49",
    "value": "1000000000000000",
    "callData": "0x",
    "maxUSD": 5.0,
    "label": "Transaction with USD Cap"
  }'

Authenticated Transaction

curl -X POST "https://tachyon.rath.fi/api/submit-tx" \
  -H "Content-Type: application/json" \
  -H "api-key: YOUR_API_KEY" \
  -d '{
    "chainId": 8453,
    "to": "0x3dbE34f2C21b3B2980d4dc53f3c7E51e39663F49",
    "value": "1000000000000000",
    "callData": "0x",
    "transactionType": "authenticated",
    "isAuthenticatedTx": true,
    "label": "Authenticated Transaction"
  }'

Flash-Blocks Transaction

curl -X POST "https://tachyon.rath.fi/api/submit-tx" \
  -H "Content-Type: application/json" \
  -H "api-key: YOUR_API_KEY" \
  -d '{
    "chainId": 8453,
    "to": "0x3dbE34f2C21b3B2980d4dc53f3c7E51e39663F49",
    "value": "1000000000000000",
    "callData": "0x",
    "transactionType": "flash-blocks",
    "label": "Flash-Blocks Transaction"
  }'

Note: Flash-blocks transaction type is only supported on Base (8453) and Base Sepolia (84532). Authorization lists cannot be used with flash-blocks transactions.

Transaction with Authorization List (EIP-7702)

curl -X POST "https://tachyon.rath.fi/api/submit-tx" \
  -H "Content-Type: application/json" \
  -H "api-key: YOUR_API_KEY" \
  -d '{
    "chainId": 8453,
    "to": "0x3dbE34f2C21b3B2980d4dc53f3c7E51e39663F49",
    "value": "1000000000000000",
    "callData": "0x",
    "authorizationList": [
      {
        "chainId": 8453,
        "address": "0x1234567890abcdef1234567890abcdef12345678",
        "nonce": 1,
        "r": "0xabcdef1234567890abcdef1234567890abcdef1234567890abcdef1234567890",
        "s": "0x1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef",
        "yParity": 1
      }
    ],
    "label": "Delegated Transaction"
  }'

With Custom Derivation Path

curl -X POST "https://tachyon.rath.fi/api/submit-tx" \
  -H "Content-Type: application/json" \
  -H "api-key: YOUR_API_KEY" \
  -d '{
    "chainId": 8453,
    "to": "0x3dbE34f2C21b3B2980d4dc53f3c7E51e39663F49",
    "value": "1000000000000000",
    "callData": "0x",
    "derivationPath": "m/44'\''/60'\''/0'\''/0/1",
    "label": "Transaction from Custom Account"
  }'

Transaction with Multicall Batching

curl -X POST "https://tachyon.rath.fi/api/submit-tx" \
  -H "Content-Type: application/json" \
  -H "api-key: YOUR_API_KEY" \
  -d '{
    "chainId": 8453,
    "to": "0x3dbE34f2C21b3B2980d4dc53f3c7E51e39663F49",
    "value": "0",
    "callData": "0xa9059cbb000000000000000000000000...",
    "shouldBatchInMulticall": true,
    "label": "Batched Transaction"
  }'

Transaction with Retries

curl -X POST "https://tachyon.rath.fi/api/submit-tx" \
  -H "Content-Type: application/json" \
  -H "api-key: YOUR_API_KEY" \
  -d '{
    "chainId": 8453,
    "to": "0x3dbE34f2C21b3B2980d4dc53f3c7E51e39663F49",
    "value": "1000000000000000",
    "callData": "0x",
    "retries": 3,
    "label": "Transaction with Auto-Retry"
  }'

Relay Transaction

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