Zerion API Now Supports x402 Payments on Base

Zerion API integrated the x402 protocol. Any AI agent with a crypto wallet can now make an API call, pay 0.01 USDC on Base, and get back structured wallet data: portfolio balances, DeFi positions, token prices, PnL, and more. It's the first step toward an API economy where agents pay for data the same way humans pay for software.

The x402 protocol brings the long-dormant HTTP 402 (Payment Required) status code to life. When a client makes an API request, the server responds with payment instructions. The client sends an onchain payment on Base, the server verifies it, and the data comes back.

Zerion used the Coinbase Developer Platform to start accepting x402 payments for its data. Payments are done in USDC on Base, an Ethereum Layer-2 network incubated by Coinbase.

For Zerion API, this supplements the traditional human-centered onboarding flow (signup, API key, billing setup) with a single AI-native step: pay and receive data.

"Most API providers assume there's a human signing up with a credit card. That doesn't work when your user is an AI agent. x402 lets us meet agents where they are. They pay and immediately get a response back with the data. Same portfolio, positions, and PnL data that powers the Zerion app, is now available to any agent on Base for a cent per call." — Abi Dharshan, Product Lead, Zerion API

"Agents need to spend money, and right now that's harder than it should be. x402 on Base gives agents a way to pay for services like Zerion's API without a human in the loop. In turn, Zerion API gives agents a way to take part in the onchain economy. They can use this API to watch their own trading wallets, generate value-added analysis, or provide other services." — Kevin Leffew, GTM Lead, Coinbase Developer Platform

Why Zerion data

Raw blockchain data is hard to use. A token transfer on Ethereum looks nothing like a Solana swap. Neither comes with human-readable labels, USD values, or protocol context. Building that normalization layer from scratch takes months.

Zerion API returns interpreted, normalized data. It’s the same data that powers the Zerion portfolio tracker app. Token names, prices, and other metadata are included in every response. This makes the data directly usable in dashboards, reports, and agent workflows without additional processing.

For AI agents, this matters because LLMs work best with structured data. An agent that receives a clean JSON response with token symbols, USD values, and position types can immediately reason about it. An agent that receives raw calldata cannot.

Built for autonomous agents

Traditional API access models assume a human on the other end. Someone creates an account, enters a credit card, and manages a subscription. AI agents can't do that. 

x402 enables a better agent-first payment experience., An agent discovers a Zerion endpoint, pays from its own wallet, and receives structured data. The flat pricing gives agents a clear budget constraint, so they can reason about the marginal cost before making requests.

Agents need structured wallet state, portfolio truth, and reliable pricing to act autonomously. With x402 access to Zerion's data, an agent can check its own portfolio, track PnL on positions it holds, and layer Zerion queries into more complex workflows.

Already powering AI agents at scale

Zerion API already powers leading AI agents, which collectively making millions of API calls. x402 support extends this access to any agent with a wallet, no contract or integration required.

Available data

Zerion for agents offers the same onchain wallet data available in Zerion:

• Wallet portfolio and token balances across chains
• DeFi positions (staking, lending, LP, and more)
• Token prices and historical charts
• PnL for any token
• Transaction history

How to get started

Fast path: try it in 10 seconds

You can test x402 access with any wallet that supports Base. No setup required: just call a pay-gated endpoint and see the response.

Try this live endpoint to fetch all transactions for vitalik.eth: api.zerion.io/v1/wallets/0xd8da.../transactions/

Production path: set up your AI agent

This setup gives your agent a wallet and teaches it how to call Zerion:

1. Give your agent a wallet. Install Coinbase Agentic Wallet or CDP Server Wallet to create a crypto wallet on Base.
2. Add the Zerion API CLI. This gives your agent structured descriptions of available endpoints and data types, so it knows what to call and when. 
3. Prompt. Ask the agent to fetch portfolio for any wallet address. The agent will pay $0.01 per request via x402 on Base and receive structured JSON responses.

For full instructions and a complete list of available endpoints, visit the dedicated GitHub repository for Zerion API with AI.

Part of Zerion's agent infrastructure

x402 support is one piece of a broader effort to make Zerion's data accessible to autonomous systems. Three layers are coming together:

• x402 payments — permissionless, pay-per-request access (live now)
• Zerion CLI — structured access to Zerion endpoints that agents can discover and use
• MCP server — a standardized way for AI to access Zerion API data

Together, these let agents discover, understand, and pay for blockchain data without human setup.