x402 Pay-Per-Request: No API Key, No Sign-Up, Just Pay and Fetch

March 11, 2026·4 min read·StripFeed Team

StripFeed Meets x402

StripFeed is the first content extraction API to support the x402 payment protocol. Starting today, you can hit our new v2 endpoint and pay per request with USDC on Base. No API key. No sign-up. No subscription. Just send a request, pay $0.01, and get clean Markdown back.

This is a big deal for autonomous AI agents. An agent can discover the endpoint, pay for exactly what it needs, and move on. No human has to create an account, generate a key, or manage billing. The agent handles everything on its own.

What is x402?

The x402 protocol is an open payment standard created by Coinbase. It brings the HTTP 402 Payment Required status code to life. When a client requests a paid resource, the server responds with a 402 containing payment instructions. The client signs a payment, resends the request, and the server delivers the content after a facilitator verifies the transaction.

Payments settle in USDC on Base mainnet. A facilitator service handles verification and on-chain settlement, so neither the client nor the server needs to manage blockchain transactions directly. Since launching in May 2025, the protocol has processed over 100 million transactions across the ecosystem.

How It Works

The flow is simple and fully automated:

Agent sends a request to GET /api/v2/fetch?url=https://example.com
Server responds with HTTP 402 including payment instructions: price ($0.01), wallet address, network (Base), and facilitator URL
Agent signs a $0.01 USDC payment and resends the request with a X-PAYMENT header containing the signed transaction
Facilitator verifies the payment, the server returns clean Markdown, and the payment settles on-chain

The entire round-trip adds only a few hundred milliseconds. From the agent's perspective, it is just one extra step before getting the content.

Why x402 for AI Agents

Traditional API access requires human setup. Someone has to create an account, pick a plan, generate an API key, store it securely, and monitor usage. That works fine for human developers, but it creates friction for autonomous agents.

With x402, the barriers disappear:

No sign-up required. The agent does not need an account on StripFeed.
No API key management. There is nothing to generate, rotate, or revoke.
No subscription. Pay only for what you use, one request at a time.
No monthly limits. Every request is independently paid for, so there is no quota to track.
Self-service for agents. An autonomous agent can discover the endpoint, understand the payment requirements from the 402 response, pay, and receive content. No human in the loop.

This is the model that internet-native AI agents need. They should be able to pay for services the same way they call APIs: programmatically, instantly, and without prior arrangement.

Pricing

Every request costs $0.01 USDC on Base mainnet. That is it. No tiers, no overages, no hidden fees.

All features are available on every x402 request:

All output formats (Markdown, JSON, text, HTML)
CSS selector extraction
Content caching
Token counting
Truncation control

How to Use It

Using x402-cli

The simplest way to test it from the command line:

x402 https://www.stripfeed.dev/api/v2/fetch?url=https://example.com

The CLI handles wallet management, payment signing, and the 402 handshake automatically.

Using @x402/fetch in TypeScript

import { fetchWithPayment } from "@x402/fetch";

const response = await fetchWithPayment(
  "https://www.stripfeed.dev/api/v2/fetch?url=https://example.com",
  {},
  { wallet }
);

const markdown = await response.text();
console.log(markdown);

Inspecting the 402 Response with curl

You can see the payment requirements without paying:

curl -i "https://www.stripfeed.dev/api/v2/fetch?url=https://example.com"

The response includes headers with the price, accepted currency, network, and facilitator endpoint. Any x402-compatible client can parse these and complete the payment automatically.

Your Existing API Keys Still Work

The v1 API with API key authentication is not going anywhere. If you are on the Free or Pro plan with API keys, nothing changes. The v2 x402 endpoint is a parallel option, not a replacement.

Choose what fits your use case:

v1 with API keys is ideal for applications with predictable usage where you want dashboard analytics, usage tracking, and team management.
v2 with x402 is ideal for autonomous agents, one-off requests, and situations where you want zero setup.

Both endpoints use the same extraction pipeline and return identical output.