This page provides practical integration instructions for using Kite's Stablecoin Gasless Transfer service. It is intended for developers who want to implement gasless token transfers using signed authorizations (EIP-3009).

Design & Architecture - For protocol rationale, trust model, and design considerations, refer to Stablecoin Gasless Transfer – Design Guide Kite Stablecoin

Overview

Kite's Gasless Transfer service allows users to transfer supported stablecoins without holding native gas tokens. Instead, transactions are authorized off-chain using EIP-3009 signed messages, and executed on-chain by Kite's relayer infrastructure.

This model enables:

Gasless UX for users
Secure, replay-protected transfers
Wallet and agent-based payment flows
Enterprise-friendly stablecoin payments

Supported Networks

Testnet
Mainnet

Network selection is done via the request path:

Service endpoint - https://gasless.gokite.ai

Testnet Token Claim

For testnet integration and end-to-end testing, developers can mint testnet PYUSD themselves before submitting gasless transfer requests.

The PYUSD token on Kite Testnet includes built-in claim and claimTo functions. The contract has been verified on Testnet Kitescan, so builders can:

Use the Kitescan contract page to call the write methods directly
Create and send claim or claimTo transactions from their own scripts or wallets

Testnet PYUSD contract: 0x8E04D099b1a8Dd20E6caD4b2Ab2B405B98242ec9

API Reference

List Supported Tokens

Retrieve the list of tokens enabled for gasless transfers on each network.

Endpoint - GET /supported_tokens

Example Request:

curl https://gasless.gokite.ai/supported_tokens | jq .

Example Response:

{
  "mainnet": [
    {
      "address": "0x7aB6f3ed87C42eF0aDb67Ed95090f8bF5240149e",
      "balance_threshold": "0",
      "decimals": 6,
      "eip712_name": "Bridged USDC (Kite AI)",
      "eip712_version": "2",
      "minimum_transfer_amount": "10000",
      "name": "Bridged USDC (Kite AI)",
      "symbol": "USDC.e"
    }
  ],
  "testnet": [
    {
      "address": "0x8E04D099b1a8Dd20E6caD4b2Ab2B405B98242ec9",
      "balance_threshold": "0",
      "decimals": 18,
      "eip712_name": "PYUSD",
      "eip712_version": "1",
      "minimum_transfer_amount": "10000000000000000",
      "name": "PYUSD",
      "symbol": "PYUSD"
    }
  ]
}

Response Fields:

address: The contract address of the token
balance_threshold: The minimum balance required for the sender to use this service (in token's smallest unit)
decimals: The number of decimals used by the token
eip712_name: The EIP-712 domain name used for signature generation
eip712_version: The EIP-712 domain version used for signature generation
minimum_transfer_amount: The minimum transfer amount allowed (in token's smallest unit, e.g., wei)
name: The display name of the token
symbol: The token symbol

Submit Transfer Request

Submit a gasless transfer request using EIP-3009 signed authorization.

Endpoint: POST /testnet or POST /mainnet

Request Path:

Use /testnet for testnet network transfers
Use /mainnet for mainnet network transfers

Request Method: POST

Request Body Example:

{
  "from": "0x570DEDa407f5fC26Fc2016E19FD4B65Cb8446914F",
  "to": "0x2Ba214b0AfCa4Cad5A6A9b8AF05032cE574F16e6",
  "value": "1000",
  "validAfter": "1768925639",
  "validBefore": "1768925888",
  "tokenAddress": "0x7aB6f3ed87C42eF0aDb67Ed95090f8bF5240149e",
  "nonce": "0x55ce4241653a0efe60c6272d39dd7b13eba92b482bf46e101b3af92af6443a2c",
  "v": 27,
  "r": "0x82cf40577c6520f48a57f089c9ea48bdeb7cb3f687b5fdbaf495a582d137c12e",
  "s": "0x06be1848101880d34337cebb5fc535ffa2d462b8cca92e9784b62835bbc46d17"
}

Request Parameters:

All parameters follow the EIP-3009 specification:

Network Path: Use /testnet or /mainnet according to your target network
tokenAddress: Must be a token address listed in the /supported_tokens API response
value: The transfer amount in the token's smallest unit (e.g., wei for 18-decimal tokens)
validAfter: The timestamp after which the transfer is valid. Must be greater than the latest block timestamp of the associated Kite network, otherwise the transaction simulation will fail
validBefore: The timestamp before which the transfer must be executed. Currently, transfers are only accepted within 30 seconds from the current time
nonce: A unique nonce for this transfer. Each nonce can only be used once
v, r, s: ECDSA signature components. See EIP-3009 for detailed signature generation instructions

Response Fields:

txHash: The transaction hash for the gasless transfer.

Implementation Reference

For a complete TypeScript implementation example demonstrating how to generate the EIP-3009 signature and submit the request, refer to: GitHub EIP-3009 example

Stablecoin Gasless Transfer: Integration Guide