Verify signature and authenticate

curl --request POST \
  --url https://apimonaco.xyz/api/v1/auth/verify \
  --header 'Content-Type: application/json' \
  --data '
{
  "address": "0x742d35Cc6634C0532925a3b8D4060f31E2C3d8B5",
  "signature": "0x1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0",
  "nonce": "abc123def456",
  "sessionPublicKey": "3b6a27bcceb6a42d62a3a8d02a6f0d73653215771de243a63ac048a18b59da29",
  "clientId": "monaco-frontend",
  "chainId": "1328",
  "referralCode": "0x1234567890abcdef1234567890abcdef12345678",
  "inviteCode": "aB3dE5gH7J"
}
'

import requests

url = "https://apimonaco.xyz/api/v1/auth/verify"

payload = {
    "address": "0x742d35Cc6634C0532925a3b8D4060f31E2C3d8B5",
    "signature": "0x1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0",
    "nonce": "abc123def456",
    "sessionPublicKey": "3b6a27bcceb6a42d62a3a8d02a6f0d73653215771de243a63ac048a18b59da29",
    "clientId": "monaco-frontend",
    "chainId": "1328",
    "referralCode": "0x1234567890abcdef1234567890abcdef12345678",
    "inviteCode": "aB3dE5gH7J"
}
headers = {"Content-Type": "application/json"}

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

print(response.text)

const options = {
  method: 'POST',
  headers: {'Content-Type': 'application/json'},
  body: JSON.stringify({
    address: '0x742d35Cc6634C0532925a3b8D4060f31E2C3d8B5',
    signature: '0x1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0',
    nonce: 'abc123def456',
    sessionPublicKey: '3b6a27bcceb6a42d62a3a8d02a6f0d73653215771de243a63ac048a18b59da29',
    clientId: 'monaco-frontend',
    chainId: '1328',
    referralCode: '0x1234567890abcdef1234567890abcdef12345678',
    inviteCode: 'aB3dE5gH7J'
  })
};

fetch('https://apimonaco.xyz/api/v1/auth/verify', 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://apimonaco.xyz/api/v1/auth/verify",
  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([
    'address' => '0x742d35Cc6634C0532925a3b8D4060f31E2C3d8B5',
    'signature' => '0x1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0',
    'nonce' => 'abc123def456',
    'sessionPublicKey' => '3b6a27bcceb6a42d62a3a8d02a6f0d73653215771de243a63ac048a18b59da29',
    'clientId' => 'monaco-frontend',
    'chainId' => '1328',
    'referralCode' => '0x1234567890abcdef1234567890abcdef12345678',
    'inviteCode' => 'aB3dE5gH7J'
  ]),
  CURLOPT_HTTPHEADER => [
    "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://apimonaco.xyz/api/v1/auth/verify"

	payload := strings.NewReader("{\n  \"address\": \"0x742d35Cc6634C0532925a3b8D4060f31E2C3d8B5\",\n  \"signature\": \"0x1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0\",\n  \"nonce\": \"abc123def456\",\n  \"sessionPublicKey\": \"3b6a27bcceb6a42d62a3a8d02a6f0d73653215771de243a63ac048a18b59da29\",\n  \"clientId\": \"monaco-frontend\",\n  \"chainId\": \"1328\",\n  \"referralCode\": \"0x1234567890abcdef1234567890abcdef12345678\",\n  \"inviteCode\": \"aB3dE5gH7J\"\n}")

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

	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://apimonaco.xyz/api/v1/auth/verify")
  .header("Content-Type", "application/json")
  .body("{\n  \"address\": \"0x742d35Cc6634C0532925a3b8D4060f31E2C3d8B5\",\n  \"signature\": \"0x1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0\",\n  \"nonce\": \"abc123def456\",\n  \"sessionPublicKey\": \"3b6a27bcceb6a42d62a3a8d02a6f0d73653215771de243a63ac048a18b59da29\",\n  \"clientId\": \"monaco-frontend\",\n  \"chainId\": \"1328\",\n  \"referralCode\": \"0x1234567890abcdef1234567890abcdef12345678\",\n  \"inviteCode\": \"aB3dE5gH7J\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://apimonaco.xyz/api/v1/auth/verify")

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

request = Net::HTTP::Post.new(url)
request["Content-Type"] = 'application/json'
request.body = "{\n  \"address\": \"0x742d35Cc6634C0532925a3b8D4060f31E2C3d8B5\",\n  \"signature\": \"0x1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0\",\n  \"nonce\": \"abc123def456\",\n  \"sessionPublicKey\": \"3b6a27bcceb6a42d62a3a8d02a6f0d73653215771de243a63ac048a18b59da29\",\n  \"clientId\": \"monaco-frontend\",\n  \"chainId\": \"1328\",\n  \"referralCode\": \"0x1234567890abcdef1234567890abcdef12345678\",\n  \"inviteCode\": \"aB3dE5gH7J\"\n}"

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

{
  "expiresAt": 1699876543,
  "user": {
    "id": "123e4567-e89b-12d3-a456-426614174000",
    "address": "0x742d35Cc6634C0532925a3b8D4060f31E2C3d8B5",
    "username": "trader123"
  },
  "isNewUser": true,
  "referralApplied": true,
  "referralNotAppliedReason": "REFERRAL_NOT_APPLIED_REASON_UNSPECIFIED"
}

Auth

Verify signature and authenticate

Verify signature and authenticate.

Verify the signed challenge message and create an authenticated session. Binds the caller-provided ed25519 session public key to the new session; subsequent requests are signed with the matching private key.

How the signature is checked depends on the address. Almost every address is verified by recovering the signing key, exactly as before. EIP-1271 verification applies only to an address that is BOTH eligible for contract-signature login AND has contract code deployed on chain: an eligible payout wallet that is an ordinary EOA is still verified by recovery. The two are mutually exclusive, and the request is identical either way — signature carries whatever the wallet produced, and no field changes. The one bound is length: a contract signature over 8192 decoded bytes is refused as invalid rather than forwarded to the chain, which is far above any realistic owner set.

Because deciding that requires reading the chain, this adds one client-visible outcome the recovery path does not have: UNAVAILABLE (REST 503). It is retryable and is NOT a verdict on the signature. It covers three cases, and an eligible address can see any of them even when it turns out to be an EOA, because the code lookup happens first: the chain did not answer, it did not answer within the deadline, or the server declined to ask because its own concurrent-verification capacity was full. That last one is local saturation rather than a chain fault, so an operator diagnosing it should check this service before the RPC endpoint.

A rejected signature is 401, and so is a contract that rejects by REVERTING: that is the wallet answering “no”, not a failure to ask.

POST

api

auth

verify

Verify signature and authenticate

curl --request POST \
  --url https://apimonaco.xyz/api/v1/auth/verify \
  --header 'Content-Type: application/json' \
  --data '
{
  "address": "0x742d35Cc6634C0532925a3b8D4060f31E2C3d8B5",
  "signature": "0x1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0",
  "nonce": "abc123def456",
  "sessionPublicKey": "3b6a27bcceb6a42d62a3a8d02a6f0d73653215771de243a63ac048a18b59da29",
  "clientId": "monaco-frontend",
  "chainId": "1328",
  "referralCode": "0x1234567890abcdef1234567890abcdef12345678",
  "inviteCode": "aB3dE5gH7J"
}
'

import requests

url = "https://apimonaco.xyz/api/v1/auth/verify"

payload = {
    "address": "0x742d35Cc6634C0532925a3b8D4060f31E2C3d8B5",
    "signature": "0x1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0",
    "nonce": "abc123def456",
    "sessionPublicKey": "3b6a27bcceb6a42d62a3a8d02a6f0d73653215771de243a63ac048a18b59da29",
    "clientId": "monaco-frontend",
    "chainId": "1328",
    "referralCode": "0x1234567890abcdef1234567890abcdef12345678",
    "inviteCode": "aB3dE5gH7J"
}
headers = {"Content-Type": "application/json"}

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

print(response.text)

const options = {
  method: 'POST',
  headers: {'Content-Type': 'application/json'},
  body: JSON.stringify({
    address: '0x742d35Cc6634C0532925a3b8D4060f31E2C3d8B5',
    signature: '0x1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0',
    nonce: 'abc123def456',
    sessionPublicKey: '3b6a27bcceb6a42d62a3a8d02a6f0d73653215771de243a63ac048a18b59da29',
    clientId: 'monaco-frontend',
    chainId: '1328',
    referralCode: '0x1234567890abcdef1234567890abcdef12345678',
    inviteCode: 'aB3dE5gH7J'
  })
};

fetch('https://apimonaco.xyz/api/v1/auth/verify', 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://apimonaco.xyz/api/v1/auth/verify",
  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([
    'address' => '0x742d35Cc6634C0532925a3b8D4060f31E2C3d8B5',
    'signature' => '0x1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0',
    'nonce' => 'abc123def456',
    'sessionPublicKey' => '3b6a27bcceb6a42d62a3a8d02a6f0d73653215771de243a63ac048a18b59da29',
    'clientId' => 'monaco-frontend',
    'chainId' => '1328',
    'referralCode' => '0x1234567890abcdef1234567890abcdef12345678',
    'inviteCode' => 'aB3dE5gH7J'
  ]),
  CURLOPT_HTTPHEADER => [
    "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://apimonaco.xyz/api/v1/auth/verify"

	payload := strings.NewReader("{\n  \"address\": \"0x742d35Cc6634C0532925a3b8D4060f31E2C3d8B5\",\n  \"signature\": \"0x1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0\",\n  \"nonce\": \"abc123def456\",\n  \"sessionPublicKey\": \"3b6a27bcceb6a42d62a3a8d02a6f0d73653215771de243a63ac048a18b59da29\",\n  \"clientId\": \"monaco-frontend\",\n  \"chainId\": \"1328\",\n  \"referralCode\": \"0x1234567890abcdef1234567890abcdef12345678\",\n  \"inviteCode\": \"aB3dE5gH7J\"\n}")

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

	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://apimonaco.xyz/api/v1/auth/verify")
  .header("Content-Type", "application/json")
  .body("{\n  \"address\": \"0x742d35Cc6634C0532925a3b8D4060f31E2C3d8B5\",\n  \"signature\": \"0x1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0\",\n  \"nonce\": \"abc123def456\",\n  \"sessionPublicKey\": \"3b6a27bcceb6a42d62a3a8d02a6f0d73653215771de243a63ac048a18b59da29\",\n  \"clientId\": \"monaco-frontend\",\n  \"chainId\": \"1328\",\n  \"referralCode\": \"0x1234567890abcdef1234567890abcdef12345678\",\n  \"inviteCode\": \"aB3dE5gH7J\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://apimonaco.xyz/api/v1/auth/verify")

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

request = Net::HTTP::Post.new(url)
request["Content-Type"] = 'application/json'
request.body = "{\n  \"address\": \"0x742d35Cc6634C0532925a3b8D4060f31E2C3d8B5\",\n  \"signature\": \"0x1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0\",\n  \"nonce\": \"abc123def456\",\n  \"sessionPublicKey\": \"3b6a27bcceb6a42d62a3a8d02a6f0d73653215771de243a63ac048a18b59da29\",\n  \"clientId\": \"monaco-frontend\",\n  \"chainId\": \"1328\",\n  \"referralCode\": \"0x1234567890abcdef1234567890abcdef12345678\",\n  \"inviteCode\": \"aB3dE5gH7J\"\n}"

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

{
  "expiresAt": 1699876543,
  "user": {
    "id": "123e4567-e89b-12d3-a456-426614174000",
    "address": "0x742d35Cc6634C0532925a3b8D4060f31E2C3d8B5",
    "username": "trader123"
  },
  "isNewUser": true,
  "referralApplied": true,
  "referralNotAppliedReason": "REFERRAL_NOT_APPLIED_REASON_UNSPECIFIED"
}

Body

application/json

address

string

required

Ethereum wallet address

Required string length: 42

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

Example:

"0x742d35Cc6634C0532925a3b8D4060f31E2C3d8B5"

signature

string

required

Wallet authorization of the challenge message, hex with an optional 0x prefix. An EOA sends a 65-byte EIP-191 signature; a contract wallet verified under EIP-1271 sends whatever its own contract accepts, which is usually longer and need not be 65 bytes. Capped at 8192 decoded bytes (16386 characters with the prefix) — enough for well over a hundred owner slots — and a longer value is rejected as an invalid signature rather than forwarded to the chain.

Required string length: 1 - 16386

Example:

"0x1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0"

nonce

string

required

Challenge nonce

Minimum string length: 1

Example:

"abc123def456"

sessionPublicKey

string

required

Lowercase hex (64 chars) ed25519 public key generated locally by the SDK. Subsequent authenticated requests are signed with the matching private key. The wallet's signature on the challenge message proves the user authorized this specific public key.

Required string length: 64

Pattern: ^[0-9a-f]{64}$

Example:

"3b6a27bcceb6a42d62a3a8d02a6f0d73653215771de243a63ac048a18b59da29"

clientId

string | null

Optional application identifier

Example:

"monaco-frontend"

chainId

string | null

Optional EVM chain ID supplied by SDK clients, as a JSON number or a decimal string (for example 1329 or "1329")

Example:

"1328"

referralCode

string | null

Optional TraderCode captured at signup (e.g. from a ?ref=CODE link). When a user verifies for the very first time with a valid code, a referral relationship is recorded atomically. Ignored for users who already exist. A code that does not apply (unknown, the wallet's own, or a different referrer than the one the wallet already has) never blocks sign-in; VerifyResponse.referral_not_applied_reason says why.

Example:

"0x1234567890abcdef1234567890abcdef12345678"

inviteCode

string | null

Optional Mainnet invite code. Exactly 10 case-sensitive ASCII letters or digits. Required while Mainnet Invite Mode is enabled for any wallet without a Mainnet access grant, including existing accounts that never received one; ignored while Invite Mode is off and unnecessary once the wallet has access. A missing code is refused with 403 and code INVITE_CODE_REQUIRED; a wrong, redeemed or revoked code, or an unused code whose issuer is deactivated, with 403 and code INVITE_CODE_INVALID. A deactivated signing account is refused with 403 and code ACCOUNT_DEACTIVATED.

Required string length: 10

Pattern: ^[A-Za-z0-9]{10}$

Example:

"aB3dE5gH7J"

Response

expiresAt

integer<int32> | null

Unix timestamp when the session expires

Example:

1699876543

user

object

Show child attributes

isNewUser

boolean | null

True when this verify created the user row — the wallet's first sign-in to THIS application. Identity is per (wallet, application), so a wallet already registered on another application is still is_new_user on its first sign-in to a new one. Use it to gate first-time UX (e.g. showing the optional "have a referral code?" input only to new users) and to confirm a fresh sign-up. False for every returning verify on this application.

Example:

true

referralApplied

boolean | null

True when a TraderCodes referral relationship was recorded on this verify: a valid, non-self TraderCode presented on the wallet's first sign-in to THIS application resolved to a known referrer. Scoped like is_new_user (per (wallet, application)), so a wallet already registered on another application can still see this on its first sign-in to a new one. False for a returning user of this application, an absent or unknown code, a self-referral, or a wallet that already has a different referrer (see referral_not_applied_reason). Confirms the referral landed for the signup success screen.

Example:

true

referralNotAppliedReason

enum<string> | null

Why the TraderCode presented on this sign-up did not apply. Absent when it applied, when no code was presented, and for a returning user of this application.

Available options:

REFERRAL_NOT_APPLIED_REASON_UNSPECIFIED,

REFERRAL_NOT_APPLIED_REASON_ALREADY_REFERRED,

REFERRAL_NOT_APPLIED_REASON_UNKNOWN_CODE,

REFERRAL_NOT_APPLIED_REASON_SELF_REFERRAL

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Verify signature and authenticate

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Response