Get Transaction Quote

Before submitting a transaction, you can request a quote to estimate the cost in USD and the minimum balance required. This helps you understand the transaction cost upfront and ensure your account has sufficient balance.

Endpoint


POST https://api.tachyon.rath.fi/api/quote

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)
`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’
`callData`	string	Yes	Encoded transaction data in hexadecimal format (use ‘0x’ for simple transfers)
`label`	string	No	Optional human-readable label for tracking
`gasLimit`	string	No	Optional gas limit for the transaction. 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	Whether to use authenticated relay mode for additional security. Defaults to false
`derivationPath`	string	No	Optional HD wallet derivation path for transaction signing
`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

response.json


{
  "success": true,
  "data": {
    "costUSD": 0.0009221670934825817,
    "minBalanceRequired": "223171904787"
  },
  "timestamp": "2025-10-24T12:34:56.789Z"
}

Response Fields

Field	Type	Description
`costUSD`	number	Estimated transaction cost in USD. This includes gas fees and relay service charges
`minBalanceRequired`	string	Minimum balance required in the smallest unit to execute the transaction. Unit varies by chain (wei for EVM, lamports for Solana, yoctoNEAR for NEAR, octas for Aptos, MIST for Sui)

Error Response

error-response.json


{
  "success": false,
  "error": {
    "code": "INVALID_PARAMETERS",
    "message": "Missing required transaction parameters for quote",
    "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.)

api-request.sh


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

With Gas Limit:

api-request.sh


curl -X POST "https://api.tachyon.rath.fi/api/quote" \
  -H "Content-Type: application/json" \
  -H "apikey: 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:

api-request.sh


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

Aptos

api-request.sh


curl -X POST "https://api.tachyon.rath.fi/api/quote" \
  -H "Content-Type: application/json" \
  -H "apikey: 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

api-request.sh


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

Sui

api-request.sh


curl -X POST "https://api.tachyon.rath.fi/api/quote" \
  -H "Content-Type: application/json" \
  -H "apikey: 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

api-request.sh


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

Advanced Examples

Quote with Max USD Limit

api-request.sh


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

Authenticated Transaction Quote

api-request.sh


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

Flash-Blocks Transaction Quote

api-request.sh


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

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

Quote with Authorization List (EIP-7702)

api-request.sh


curl -X POST "https://api.tachyon.rath.fi/api/quote" \
  -H "Content-Type: application/json" \
  -H "apikey: 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 Quote"
  }'

Quote with Custom Derivation Path

api-request.sh


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

Quote with Multicall Batching

api-request.sh


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

Understanding Units

The minBalanceRequired field uses different units depending on the blockchain:

Network	Unit	Conversion
EVM Chains	Wei	1 ETH = 10¹⁸ wei
Solana	Lamports	1 SOL = 10⁹ lamports
NEAR	yoctoNEAR	1 NEAR = 10²⁴ yoctoNEAR
Aptos	Octas	1 APT = 10⁸ octas
Sui	MIST	1 SUI = 10⁹ MIST

Use Cases

Pre-transaction validation: Check if users have sufficient balance before attempting a transaction
Cost transparency: Display estimated costs to users in your application UI
Budget planning: Help users understand the financial impact of their transactions with maxUSD limits
Multi-chain comparison: Compare costs across different blockchain networks for the same operation
Gas optimization: Test different gas parameters to find the optimal transaction cost