Authentication

The Zerion API supports three ways to authenticate a request:

Method	Best for	How it works
API key	Apps and services with steady traffic	HTTP Basic Auth with a key from the Dashboard. Subject to rate limits.
x402	AI agents and per-call workloads	Pay USDC on Base or Solana per request. No API key, no rate limits.
MPP	AI agents and per-call workloads	Pay USDC on Tempo per request. No API key, no rate limits.

The rest of this page covers the API key flow. For pay-per-request flows, see the dedicated x402 and MPP pages.

API key

The Zerion API uses HTTP Basic Authentication. You can get your API key from the Dashboard.

Try it from the docs

Every API reference page has an interactive playground. Click Try it, paste your API key in the Username field, leave Password empty, and hit Send to make a live request.

Using the API from your code

When calling the API from code, append a colon to your API key (your_api_key:), Base64-encode it, and pass it in the Authorization header:

Authorization: Basic BASE64_ENCODED_KEY

Go to the Dashboard Get Started section for ready-to-use code snippets with your API key pre-filled.

# Transform your API key for Basic Auth
API_KEY_TRANSFORMED=$(echo -n "YOUR_API_KEY:" | base64)

# Make the request
curl -X GET "https://api.zerion.io/v1/wallets/0x42b9df65b219b3dd36ff330a4dd8f327a6ada990/portfolio" \
  -H "Authorization: Basic $API_KEY_TRANSFORMED" \
  -H "accept: application/json"

// Transform your API key for Basic Auth
const apiKey = 'YOUR_API_KEY';
const apiKeyTransformed = btoa(apiKey + ':');

// Make the request
const response = await fetch(
  'https://api.zerion.io/v1/wallets/0x42b9df65b219b3dd36ff330a4dd8f327a6ada990/portfolio',
  {
    headers: {
      'Authorization': `Basic ${apiKeyTransformed}`,
      'accept': 'application/json'
    }
  }
);
const data = await response.json();
console.log(data);

import requests
import base64

# Transform your API key for Basic Auth
api_key = 'YOUR_API_KEY'
api_key_transformed = base64.b64encode(f'{api_key}:'.encode()).decode()

# Make the request
response = requests.get(
    'https://api.zerion.io/v1/wallets/0x42b9df65b219b3dd36ff330a4dd8f327a6ada990/portfolio',
    headers={
        'Authorization': f'Basic {api_key_transformed}',
        'accept': 'application/json'
    }
)
data = response.json()
print(data)

import (
    "encoding/base64"
    "net/http"
)

// Transform your API key for Basic Auth
apiKey := "YOUR_API_KEY"
apiKeyTransformed := base64.StdEncoding.EncodeToString([]byte(apiKey + ":"))

// Make the request
client := &http.Client{}
req, _ := http.NewRequest("GET", "https://api.zerion.io/v1/wallets/0x42b9df65b219b3dd36ff330a4dd8f327a6ada990/portfolio", nil)
req.Header.Set("Authorization", "Basic " + apiKeyTransformed)
req.Header.Set("accept", "application/json")

resp, _ := client.Do(req)
defer resp.Body.Close()

Security best practices

Never expose your API key in client-side code or public repositories.

Store your API key in environment variables
Make API requests from server-side code
Rotate your key immediately if it’s ever compromised
Use separate keys for development and production

Pay-per-request: x402 and MPP

Both x402 and MPP let you call the Zerion API by paying a small USDC fee per request instead of presenting an API key. They’re a better fit than API keys when:

You’re building an AI agent or automated pipeline that shouldn’t manage long-lived credentials
Traffic is bursty or unpredictable and you don’t want to size a rate-limited plan
You want usage-based cost accounting at the request level

The two protocols differ only in which chain they settle on:

x402 (Coinbase’s open protocol) — settles in USDC on Base or Solana. Uses the PAYMENT-SIGNATURE request header.
MPP (Machine Payments Protocol) — settles in USDC on Tempo. Uses the Authorization: Payment request header.

Both cover the same set of endpoints as API-key auth and accept the same parameters. Pick whichever chain your wallet already holds USDC on. The Zerion CLI supports both via --x402 / --mpp flags.

Get Started

Core Concepts

Migrating to Zerion API

API key

Try it from the docs

Using the API from your code

Security best practices

Pay-per-request: x402 and MPP

​API key

​Try it from the docs

​Using the API from your code

​Security best practices

​Pay-per-request: x402 and MPP

API key

Try it from the docs

Using the API from your code

Security best practices

Pay-per-request: x402 and MPP