Execute ERC-20 Permit

curl --request POST \
  --url https://api.mrdn.finance/v1/permit \
  --header 'Authorization: <api-key>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "network": "base-sepolia",
  "owner": "0x742d35Cc6634C0532925a3b8D0c4E5e6C2aE7A3e",
  "spender": "0x8e633dBf31adCc7D41BE3e95B7c8DD3526B5235A",
  "value": "1000000",
  "deadline": "1893456000",
  "recipient": "0x742d35Cc6634C0532925a3b8D0c4E5e6C2aE7A3e",
  "tokenAddress": "0x036CbD53842c5426634e7929541eC2318f3dCF7e",
  "signature": "0x...",
  "v": 127,
  "r": "<string>",
  "s": "<string>"
}
'

import requests

url = "https://api.mrdn.finance/v1/permit"

payload = {
    "network": "base-sepolia",
    "owner": "0x742d35Cc6634C0532925a3b8D0c4E5e6C2aE7A3e",
    "spender": "0x8e633dBf31adCc7D41BE3e95B7c8DD3526B5235A",
    "value": "1000000",
    "deadline": "1893456000",
    "recipient": "0x742d35Cc6634C0532925a3b8D0c4E5e6C2aE7A3e",
    "tokenAddress": "0x036CbD53842c5426634e7929541eC2318f3dCF7e",
    "signature": "0x...",
    "v": 127,
    "r": "<string>",
    "s": "<string>"
}
headers = {
    "Authorization": "<api-key>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {Authorization: '<api-key>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    network: 'base-sepolia',
    owner: '0x742d35Cc6634C0532925a3b8D0c4E5e6C2aE7A3e',
    spender: '0x8e633dBf31adCc7D41BE3e95B7c8DD3526B5235A',
    value: '1000000',
    deadline: '1893456000',
    recipient: '0x742d35Cc6634C0532925a3b8D0c4E5e6C2aE7A3e',
    tokenAddress: '0x036CbD53842c5426634e7929541eC2318f3dCF7e',
    signature: '0x...',
    v: 127,
    r: '<string>',
    s: '<string>'
  })
};

fetch('https://api.mrdn.finance/v1/permit', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.mrdn.finance/v1/permit",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'network' => 'base-sepolia',
    'owner' => '0x742d35Cc6634C0532925a3b8D0c4E5e6C2aE7A3e',
    'spender' => '0x8e633dBf31adCc7D41BE3e95B7c8DD3526B5235A',
    'value' => '1000000',
    'deadline' => '1893456000',
    'recipient' => '0x742d35Cc6634C0532925a3b8D0c4E5e6C2aE7A3e',
    'tokenAddress' => '0x036CbD53842c5426634e7929541eC2318f3dCF7e',
    'signature' => '0x...',
    'v' => 127,
    'r' => '<string>',
    's' => '<string>'
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: <api-key>",
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://api.mrdn.finance/v1/permit"

	payload := strings.NewReader("{\n  \"network\": \"base-sepolia\",\n  \"owner\": \"0x742d35Cc6634C0532925a3b8D0c4E5e6C2aE7A3e\",\n  \"spender\": \"0x8e633dBf31adCc7D41BE3e95B7c8DD3526B5235A\",\n  \"value\": \"1000000\",\n  \"deadline\": \"1893456000\",\n  \"recipient\": \"0x742d35Cc6634C0532925a3b8D0c4E5e6C2aE7A3e\",\n  \"tokenAddress\": \"0x036CbD53842c5426634e7929541eC2318f3dCF7e\",\n  \"signature\": \"0x...\",\n  \"v\": 127,\n  \"r\": \"<string>\",\n  \"s\": \"<string>\"\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Authorization", "<api-key>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://api.mrdn.finance/v1/permit")
  .header("Authorization", "<api-key>")
  .header("Content-Type", "application/json")
  .body("{\n  \"network\": \"base-sepolia\",\n  \"owner\": \"0x742d35Cc6634C0532925a3b8D0c4E5e6C2aE7A3e\",\n  \"spender\": \"0x8e633dBf31adCc7D41BE3e95B7c8DD3526B5235A\",\n  \"value\": \"1000000\",\n  \"deadline\": \"1893456000\",\n  \"recipient\": \"0x742d35Cc6634C0532925a3b8D0c4E5e6C2aE7A3e\",\n  \"tokenAddress\": \"0x036CbD53842c5426634e7929541eC2318f3dCF7e\",\n  \"signature\": \"0x...\",\n  \"v\": 127,\n  \"r\": \"<string>\",\n  \"s\": \"<string>\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.mrdn.finance/v1/permit")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Authorization"] = '<api-key>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"network\": \"base-sepolia\",\n  \"owner\": \"0x742d35Cc6634C0532925a3b8D0c4E5e6C2aE7A3e\",\n  \"spender\": \"0x8e633dBf31adCc7D41BE3e95B7c8DD3526B5235A\",\n  \"value\": \"1000000\",\n  \"deadline\": \"1893456000\",\n  \"recipient\": \"0x742d35Cc6634C0532925a3b8D0c4E5e6C2aE7A3e\",\n  \"tokenAddress\": \"0x036CbD53842c5426634e7929541eC2318f3dCF7e\",\n  \"signature\": \"0x...\",\n  \"v\": 127,\n  \"r\": \"<string>\",\n  \"s\": \"<string>\"\n}"

response = http.request(request)
puts response.read_body

{
  "success": true,
  "transaction": "<string>",
  "network": "<string>"
}

{
  "success": true,
  "transaction": "<string>",
  "network": "<string>"
}

{
  "success": true,
  "transaction": "<string>",
  "network": "<string>"
}

POST

permit

Execute ERC-20 Permit

curl --request POST \
  --url https://api.mrdn.finance/v1/permit \
  --header 'Authorization: <api-key>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "network": "base-sepolia",
  "owner": "0x742d35Cc6634C0532925a3b8D0c4E5e6C2aE7A3e",
  "spender": "0x8e633dBf31adCc7D41BE3e95B7c8DD3526B5235A",
  "value": "1000000",
  "deadline": "1893456000",
  "recipient": "0x742d35Cc6634C0532925a3b8D0c4E5e6C2aE7A3e",
  "tokenAddress": "0x036CbD53842c5426634e7929541eC2318f3dCF7e",
  "signature": "0x...",
  "v": 127,
  "r": "<string>",
  "s": "<string>"
}
'

import requests

url = "https://api.mrdn.finance/v1/permit"

payload = {
    "network": "base-sepolia",
    "owner": "0x742d35Cc6634C0532925a3b8D0c4E5e6C2aE7A3e",
    "spender": "0x8e633dBf31adCc7D41BE3e95B7c8DD3526B5235A",
    "value": "1000000",
    "deadline": "1893456000",
    "recipient": "0x742d35Cc6634C0532925a3b8D0c4E5e6C2aE7A3e",
    "tokenAddress": "0x036CbD53842c5426634e7929541eC2318f3dCF7e",
    "signature": "0x...",
    "v": 127,
    "r": "<string>",
    "s": "<string>"
}
headers = {
    "Authorization": "<api-key>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {Authorization: '<api-key>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    network: 'base-sepolia',
    owner: '0x742d35Cc6634C0532925a3b8D0c4E5e6C2aE7A3e',
    spender: '0x8e633dBf31adCc7D41BE3e95B7c8DD3526B5235A',
    value: '1000000',
    deadline: '1893456000',
    recipient: '0x742d35Cc6634C0532925a3b8D0c4E5e6C2aE7A3e',
    tokenAddress: '0x036CbD53842c5426634e7929541eC2318f3dCF7e',
    signature: '0x...',
    v: 127,
    r: '<string>',
    s: '<string>'
  })
};

fetch('https://api.mrdn.finance/v1/permit', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.mrdn.finance/v1/permit",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'network' => 'base-sepolia',
    'owner' => '0x742d35Cc6634C0532925a3b8D0c4E5e6C2aE7A3e',
    'spender' => '0x8e633dBf31adCc7D41BE3e95B7c8DD3526B5235A',
    'value' => '1000000',
    'deadline' => '1893456000',
    'recipient' => '0x742d35Cc6634C0532925a3b8D0c4E5e6C2aE7A3e',
    'tokenAddress' => '0x036CbD53842c5426634e7929541eC2318f3dCF7e',
    'signature' => '0x...',
    'v' => 127,
    'r' => '<string>',
    's' => '<string>'
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: <api-key>",
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://api.mrdn.finance/v1/permit"

	payload := strings.NewReader("{\n  \"network\": \"base-sepolia\",\n  \"owner\": \"0x742d35Cc6634C0532925a3b8D0c4E5e6C2aE7A3e\",\n  \"spender\": \"0x8e633dBf31adCc7D41BE3e95B7c8DD3526B5235A\",\n  \"value\": \"1000000\",\n  \"deadline\": \"1893456000\",\n  \"recipient\": \"0x742d35Cc6634C0532925a3b8D0c4E5e6C2aE7A3e\",\n  \"tokenAddress\": \"0x036CbD53842c5426634e7929541eC2318f3dCF7e\",\n  \"signature\": \"0x...\",\n  \"v\": 127,\n  \"r\": \"<string>\",\n  \"s\": \"<string>\"\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Authorization", "<api-key>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://api.mrdn.finance/v1/permit")
  .header("Authorization", "<api-key>")
  .header("Content-Type", "application/json")
  .body("{\n  \"network\": \"base-sepolia\",\n  \"owner\": \"0x742d35Cc6634C0532925a3b8D0c4E5e6C2aE7A3e\",\n  \"spender\": \"0x8e633dBf31adCc7D41BE3e95B7c8DD3526B5235A\",\n  \"value\": \"1000000\",\n  \"deadline\": \"1893456000\",\n  \"recipient\": \"0x742d35Cc6634C0532925a3b8D0c4E5e6C2aE7A3e\",\n  \"tokenAddress\": \"0x036CbD53842c5426634e7929541eC2318f3dCF7e\",\n  \"signature\": \"0x...\",\n  \"v\": 127,\n  \"r\": \"<string>\",\n  \"s\": \"<string>\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.mrdn.finance/v1/permit")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Authorization"] = '<api-key>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"network\": \"base-sepolia\",\n  \"owner\": \"0x742d35Cc6634C0532925a3b8D0c4E5e6C2aE7A3e\",\n  \"spender\": \"0x8e633dBf31adCc7D41BE3e95B7c8DD3526B5235A\",\n  \"value\": \"1000000\",\n  \"deadline\": \"1893456000\",\n  \"recipient\": \"0x742d35Cc6634C0532925a3b8D0c4E5e6C2aE7A3e\",\n  \"tokenAddress\": \"0x036CbD53842c5426634e7929541eC2318f3dCF7e\",\n  \"signature\": \"0x...\",\n  \"v\": 127,\n  \"r\": \"<string>\",\n  \"s\": \"<string>\"\n}"

response = http.request(request)
puts response.read_body

{
  "success": true,
  "transaction": "<string>",
  "network": "<string>"
}

{
  "success": true,
  "transaction": "<string>",
  "network": "<string>"
}

{
  "success": true,
  "transaction": "<string>",
  "network": "<string>"
}

Execute a gasless ERC-20 token transfer using a signed EIP-2612 permit. The user signs off-chain; the facilitator pays the gas and settles on-chain.

This endpoint is for ERC-2612 permit() transfers. Permit2 payments use POST /v1/settle with the Permit2 payment payload.

Authentication

Requires an API key passed as Authorization: Bearer <api-key>.

Request Body

{
  "network": "base-sepolia",
  "tokenAddress": "0x036CbD53842c5426634e7929541eC2318f3dCF7e",
  "owner": "0x742d35Cc6634C0532925a3b8D0c4E5e6C2aE7A3e",
  "spender": "0x8e633dBf31adCc7D41BE3e95B7c8DD3526B5235A",
  "value": "1000000",
  "deadline": "1893456000",
  "v": 27,
  "r": "0x...",
  "s": "0x...",
  "recipient": "0x742d35Cc6634C0532925a3b8D0c4E5e6C2aE7A3e"
}

Field	Required	Notes
`network`	yes	EVM network identifier (e.g. `base`, `avalanche`, `arbitrum`, `bsc`, `bot-chain`, `base-sepolia`, `arc-testnet`, `bot-chain-testnet`, `optimism`, `polygon`, `unichain`, `ink`, `sei`, `tempo`, `monad`, `robinhood`)
`tokenAddress`	yes	ERC-20 token contract address
`owner`	yes	Token owner address; must have signed the EIP-2612 permit
`spender`	yes	Spender address authorized in the permit signature
`value`	yes	Amount in the token’s smallest unit as a decimal string (`1000000` = 1 USDC)
`deadline`	yes	Unix timestamp after which the permit expires, as a decimal string
`v`	yes*	Signature recovery byte (27 or 28). Provide `v/r/s` OR `signature`, not both.
`r`	yes*	32-byte hex signature component
`s`	yes*	32-byte hex signature component
`recipient`	yes	Address that receives the transferred tokens

Facilitator contract addresses

Network	Contract
`arc-testnet`	`0x8e633dBf31adCc7D41BE3e95B7c8DD3526B5235A`
`bot-chain-testnet`	`0x8e633dBf31adCc7D41BE3e95B7c8DD3526B5235A`
`bot-chain`	`0x8E7769D440b3460b92159Dd9C6D17302b036e2d6`
`base`	`0x8E7769D440b3460b92159Dd9C6D17302b036e2d6`
`bsc`	`0x8E7769D440b3460b92159Dd9C6D17302b036e2d6`
`base-sepolia`	`0x8e633dBf31adCc7D41BE3e95B7c8DD3526B5235A`
`avalanche`	`0x8E7769D440b3460b92159Dd9C6D17302b036e2d6`
`optimism`	`0x8E7769D440b3460b92159Dd9C6D17302b036e2d6`
`optimism-sepolia`	`0x8e633dBf31adCc7D41BE3e95B7c8DD3526B5235A`
`arbitrum`	`0x8E7769D440b3460b92159Dd9C6D17302b036e2d6`
`polygon`	`0x8E7769D440b3460b92159Dd9C6D17302b036e2d6`
`unichain`	`0x8E7769D440b3460b92159Dd9C6D17302b036e2d6`
`ink`	`0x8E7769D440b3460b92159Dd9C6D17302b036e2d6`
`worldchain`	`0x8E7769D440b3460b92159Dd9C6D17302b036e2d6`
`sei`	`0x8E7769D440b3460b92159Dd9C6D17302b036e2d6`
`hyperevm`	`0x8E7769D440b3460b92159Dd9C6D17302b036e2d6`
`megaeth`	`0x8E7769D440b3460b92159Dd9C6D17302b036e2d6`
`tempo`	`0x8E7769D440b3460b92159Dd9C6D17302b036e2d6`
`monad`	`0x8E7769D440b3460b92159Dd9C6D17302b036e2d6`
`robinhood`	`0x8E7769D440b3460b92159Dd9C6D17302b036e2d6`
`fluent-testnet`	`0xB3Ac1B7871942bCdCD0bD6C65765272bBE70B8Da`

Response

Success

{
  "success": true,
  "transaction": "0x1234567890abcdef...",
  "network": "base-sepolia"
}

Error

{
  "success": false,
  "transaction": "",
  "network": "base-sepolia",
  "errorReason": "invalid_request"
}

Error Codes

`errorReason`	HTTP	Description
`invalid_request`	400	Missing or malformed fields in the request body
`unsupported_network`	400	`network` is not a supported EVM network
`network_not_configured`	400	The facilitator has no private key configured for this network
`invalid_signature`	400	Could not resolve a valid `v`, `r`, `s` from the provided inputs
`permit_execution_failed`	500	On-chain transaction failed (RPC error, revert, bad permit, etc.)

Authorizations

Authorization

string

header

required

Body

application/json

network

string

required

EVM network identifier. Must be one of the facilitator's configured EVM networks (e.g. base, arbitrum, bsc, bot-chain, base-sepolia, bot-chain-testnet, optimism, optimism-sepolia, polygon, unichain, ink, tempo, monad, robinhood, worldchain, hyperevm, megaeth, fluent-testnet, etc.).

Example:

"base-sepolia"

owner

string

required

Token owner address (the signer of the EIP-2612 permit). Tokens are pulled from this address.

Pattern: ^0x[a-fA-F0-9]{40}$

Example:

"0x742d35Cc6634C0532925a3b8D0c4E5e6C2aE7A3e"

spender

string

required

Spender address authorized by the permit signature. Required by the request schema. The on-chain transferWithPermit call uses the facilitator contract as the spender; this field is forwarded for signing-side compatibility.

Pattern: ^0x[a-fA-F0-9]{40}$

Example:

"0x8e633dBf31adCc7D41BE3e95B7c8DD3526B5235A"

value

string

required

uint256 token amount as a decimal string in the token's smallest unit (e.g. 1000000 = 1 USDC at 6 decimals). Numbers and bigints are accepted and coerced to a decimal string.

Pattern: ^\d+$

Example:

"1000000"

deadline

string

required

uint256 permit deadline as a decimal Unix timestamp string. Numbers and bigints are accepted and coerced to a decimal string.

Pattern: ^\d+$

Example:

"1893456000"

recipient

string

required

Address that receives the transferred tokens after the permit is applied.

Pattern: ^0x[a-fA-F0-9]{40}$

Example:

"0x742d35Cc6634C0532925a3b8D0c4E5e6C2aE7A3e"

tokenAddress

string

ERC-20 token address. Documented as optional with a fallback to the network's USDC, but the actual transferWithPermit call uses this value directly. Provide it explicitly to avoid permit_execution_failed.

Pattern: ^0x[a-fA-F0-9]{40}$

Example:

"0x036CbD53842c5426634e7929541eC2318f3dCF7e"

signature

string

Optional 65-byte EIP-2612 permit signature, hex-encoded. Schema accepts ^0x[a-fA-F0-9]+$. WARNING: this field is broken at runtime in the current handler (viem returns r/s as 0x-prefixed and the assembler re-wraps them, producing malformed bytes); use the split (v, r, s) form instead. Provide this OR (v, r, s), but not both.

Pattern: ^0x[a-fA-F0-9]+$

Example:

"0x..."

integer

Optional v byte of the signature. The exclusivity check uses Boolean(data.v), so v = 0 is treated as missing; use 27 or 28.

Required range: 0 <= x <= 255

string

Optional r component. The schema accepts any string (no regex). In practice, send a 32-byte hex value (with or without leading 0x); only the first occurrence of 0x is stripped when assembling the final signature.

string

Optional s component. The schema accepts any string (no regex). In practice, send a 32-byte hex value (with or without leading 0x); only the first occurrence of 0x is stripped when assembling the final signature.

Response

Permit transaction submitted

success

boolean

required

true only when the on-chain transaction was submitted successfully.

transaction

string

required

Transaction hash on success. Empty string ("") on every error response.

network

string

required

Echoes the network from the request (or "" if the request body could not be parsed).

errorReason

enum<string>

Present on error responses only.

Available options:

invalid_request,

unsupported_network,

network_not_configured,

invalid_signature,

permit_execution_failed

Settle x402 Payment Get Supported Payment Kinds

Overview

x402 Payments

x402 Inference

Merchant Top-ups

Nanopayments Gateway

Execute ERC-20 Permit

Authentication

Request Body

Facilitator contract addresses

Response

Success

Error

Error Codes

Authorizations

Body

Response

​Authentication

​Request Body

​Facilitator contract addresses

​Response

​Success

​Error

​Error Codes

Authorizations

Body

Response

Authentication

Request Body

Facilitator contract addresses

Response

Success

Error

Error Codes