Authentication¶

Complete guide to authenticating with the Crypto Data Aggregator API.

Overview¶

The API supports two authentication methods:

API Keys¶

API keys provide traditional authentication with tiered rate limits.

Getting an API Key¶

1. Visit /developers
2. Enter your email address
3. Save your API key (shown only once!)

Using Your API Key¶

curl -H "X-API-Key: cda_free_xxxxx" \
  https://cryptonews.direct/api/v1/coins

curl "https://cryptonews.direct/api/v1/coins?api_key=cda_free_xxxxx"

API Key Tiers¶

Key Prefixes¶

Keys are prefixed to indicate tier:

• cda_free_ - Free tier
• cda_pro_ - Pro tier
• cda_ent_ - Enterprise tier

x402 Micropayments¶

x402 enables pay-per-request access using USDC on Base network. No subscription required.

How It Works¶

sequenceDiagram
    participant Client
    participant API as Resource Server
    participant Facilitator

    Client->>API: 1. GET /api/v1/coins
    API-->>Client: 2. 402 + X-PAYMENT-REQUIRED
    Client->>API: 3. GET /api/v1/coins + X-PAYMENT
    API->>Facilitator: 4. Verify payment
    Facilitator-->>API: 5. Verification result
    API-->>Client: 6. 200 OK + Data
    API->>Facilitator: 7. Settle on-chain

Pricing¶

Using x402 in Code¶

import { wrapFetch } from '@x402/fetch';
import { createWalletClient, http } from 'viem';
import { privateKeyToAccount } from 'viem/accounts';
import { baseSepolia } from 'viem/chains';

// Create wallet client
const account = privateKeyToAccount(process.env.PRIVATE_KEY);
const walletClient = createWalletClient({
  account,
  chain: baseSepolia,
  transport: http(),
});

// Wrap fetch with x402 support
const x402Fetch = wrapFetch(fetch, walletClient);

// Make request - payment is handled automatically
const response = await x402Fetch('https://api.example.com/api/v1/coins');
const data = await response.json();

import requests
import base64
import json

# First request to get payment requirements
response = requests.get('https://api.example.com/api/v1/coins')

if response.status_code == 402:
    payment_required = response.headers.get('X-PAYMENT-REQUIRED')
    requirements = json.loads(base64.b64decode(payment_required))

    # Sign payment with your wallet
    payment = sign_x402_payment(requirements)
    payment_header = base64.b64encode(json.dumps(payment).encode()).decode()

    # Retry with payment
    response = requests.get(
        'https://api.example.com/api/v1/coins',
        headers={'X-PAYMENT': payment_header}
    )

    data = response.json()

Rate Limits¶

Response Headers¶

All authenticated requests include rate limit headers:

X-RateLimit-Limit: 100
X-RateLimit-Remaining: 87
X-RateLimit-Reset: 1706054400000

Rate Limit by Tier¶

Error Handling¶

401 Unauthorized¶

No valid API key provided.

{
  "error": "Unauthorized",
  "message": "Valid API key required. Get one at /developers"
}

402 Payment Required¶

x402 payment needed for this endpoint.

{
  "error": "Payment Required",
  "message": "This endpoint requires payment via x402 protocol",
  "x402Version": 2
}

429 Too Many Requests¶

Rate limit exceeded.

{
  "error": "Rate limit exceeded",
  "message": "You have exceeded your Free tier limit",
  "resetAt": "2026-01-24T00:00:00.000Z"
}

Comparison: API Keys vs x402¶

Next Steps¶

• Get your API key
• API Overview
• x402 Integration