Registration

{
  "iss": "YOUR_CLIENT_ID",
  "sub": "YOUR_CLIENT_ID",
  "aud": "https://pmx-preprod.us.auth0.com/oauth/token",
  "iat": 1703270400,
  "exp": 1703270700,
  "jti": "unique-random-uuid"
}

curl --request POST \
  --url "https://pmx-preprod.us.auth0.com/oauth/token" \
  --header "content-type: application/json" \
  --data '{
    "client_id": "YOUR_CLIENT_ID",
    "client_assertion_type": "urn:ietf:params:oauth:client-assertion-type:jwt-bearer",
    "client_assertion": "YOUR_SIGNED_JWT_ASSERTION",
    "audience": "https://api.preprod.polymarketexchange.com",
    "grant_type": "client_credentials"
  }'

{
  "access_token": "eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCIs...",
  "token_type": "Bearer",
  "expires_in": 180
}

import jwt
import uuid
import time
import requests
from cryptography.hazmat.primitives import serialization

class AuthClient:
    def __init__(self, domain: str, client_id: str, audience: str, private_key_path: str):
        self.domain = domain
        self.client_id = client_id
        self.audience = audience
        self.private_key_path = private_key_path
        self.token = None
        self.token_expiry = None

    def _load_private_key(self):
        """Load the RSA private key from file."""
        with open(self.private_key_path, 'rb') as f:
            return serialization.load_pem_private_key(f.read(), password=None)

    def _create_client_assertion(self) -> str:
        """Create a signed JWT for client authentication."""
        private_key = self._load_private_key()
        now = int(time.time())

        claims = {
            "iss": self.client_id,
            "sub": self.client_id,
            "aud": f"https://{self.domain}/oauth/token",
            "iat": now,
            "exp": now + 300,  # 5 minutes
            "jti": str(uuid.uuid4()),
        }

        return jwt.encode(claims, private_key, algorithm="RS256")

    def get_token(self) -> str:
        """Get a valid access token, refreshing if necessary."""
        if self._is_token_valid():
            return self.token

        # Create client assertion
        assertion = self._create_client_assertion()

        # Request access token
        response = requests.post(
            f"https://{self.domain}/oauth/token",
            json={
                "client_id": self.client_id,
                "client_assertion_type": "urn:ietf:params:oauth:client-assertion-type:jwt-bearer",
                "client_assertion": assertion,
                "audience": self.audience,
                "grant_type": "client_credentials"
            },
            headers={"content-type": "application/json"}
        )
        response.raise_for_status()

        data = response.json()
        self.token = data["access_token"]
        # Set expiry with 30-second buffer
        self.token_expiry = time.time() + data["expires_in"] - 30

        return self.token

    def _is_token_valid(self) -> bool:
        """Check if current token is still valid."""
        if not self.token or not self.token_expiry:
            return False
        return time.time() < self.token_expiry


# Usage
auth_client = AuthClient(
    domain="pmx-preprod.us.auth0.com",
    client_id="YOUR_CLIENT_ID",
    audience="https://api.preprod.polymarketexchange.com",
    private_key_path="/path/to/my_private_key.pem"
)

token = auth_client.get_token()

pip install PyJWT cryptography requests

package main

import (
    "crypto/rsa"
    "crypto/x509"
    "encoding/json"
    "encoding/pem"
    "fmt"
    "net/http"
    "os"
    "time"

    "github.com/golang-jwt/jwt/v5"
    "github.com/google/uuid"
)

func getAccessToken(domain, clientID, audience, privateKeyPath string) (string, error) {
    // Load private key
    keyData, err := os.ReadFile(privateKeyPath)
    if err != nil {
        return "", fmt.Errorf("read key file: %w", err)
    }

    block, _ := pem.Decode(keyData)
    privateKey, err := x509.ParsePKCS1PrivateKey(block.Bytes)
    if err != nil {
        return "", fmt.Errorf("parse private key: %w", err)
    }

    // Create client assertion JWT
    now := time.Now()
    claims := jwt.MapClaims{
        "iss": clientID,
        "sub": clientID,
        "aud": fmt.Sprintf("https://%s/oauth/token", domain),
        "iat": now.Unix(),
        "exp": now.Add(5 * time.Minute).Unix(),
        "jti": uuid.New().String(),
    }

    token := jwt.NewWithClaims(jwt.SigningMethodRS256, claims)
    assertion, err := token.SignedString(privateKey)
    if err != nil {
        return "", fmt.Errorf("sign assertion: %w", err)
    }

    // Request access token
    // (implement HTTP POST to token endpoint)
    // ...

    return accessToken, nil
}

curl -X GET "https://api.preprod.polymarketexchange.com/v1/whoami" \
  -H "Authorization: Bearer YOUR_ACCESS_TOKEN"

import grpc

# Create metadata with token
metadata = [
    ('authorization', f'Bearer {access_token}')
]

# Make gRPC call with metadata
response = stub.SomeMethod(request, metadata=metadata)

{
  "iss": "YOUR_CLIENT_ID",
  "sub": "YOUR_CLIENT_ID",
  "aud": "https://pmx-preprod.us.auth0.com/oauth/token",
  "iat": 1703270400,
  "exp": 1703270700,
  "jti": "550e8400-e29b-41d4-a716-446655440000"
}

import base64
import json

# Decode the payload (middle part of JWT)
payload = access_token.split('.')[1]
payload += '=' * (4 - len(payload) % 4)  # Add padding
claims = json.loads(base64.urlsafe_b64decode(payload))

print("Granted scopes:", claims.get("scope", ""))