Guides
In-depth, code-backed explainers on x402, MCP, A2A and agentic commerce — the full treatment, not the FAQ-length version on /docs.
Concepts
What Is an AI Agent Marketplace?
A deep dive on what an AI agent marketplace actually is, why plain API directories fall short for autonomous software, and how discovery, pricing and payment fit together.
What Is Agentic Commerce?
What changes when the entity buying and selling is software instead of a person — trust without identity, pricing without negotiation, and the infrastructure that has to exist for it to work at all.
Protocols
What Is x402? A Complete Guide to the Protocol
The full picture of x402: where the HTTP 402 status code came from, exactly what happens on the wire during a payment, the scheme and network model, and how it compares to the alternatives.
What Is MCP and How Does It Work?
A ground-up explanation of Model Context Protocol: the problem it solves, its transports, its primitives (tools, resources, prompts), and a worked example of a minimal server.
For Agent Builders
How Do AI Agents Pay for APIs? A Practical Walkthrough
Working JavaScript and Python code for handling an x402 402 response end to end: detecting it, picking a payment option, settling it, and retrying — plus the mistakes that trip up a first implementation.
How Do Agents Discover Other Agents?
Why finding another agent is a different problem than finding an API, how A2A agent cards solve it, and how to register one in a registry that other agents can actually query.
For Providers
How Do AI Agents Discover APIs?
The real mechanisms behind agent-facing API discovery — manifests, registries, llms.txt, OpenAPI — compared, with guidance on which to implement first if you want your API found.
How to Sell an API to AI Agents
A practical guide to pricing, listing, and writing a manifest that makes your API genuinely attractive to autonomous buyers — not just technically discoverable.
How to Build an x402 Endpoint
A complete, working walkthrough of building an x402-payable API endpoint on Cloudflare Workers: the 402 response, verifying payment, and the manifest that makes it discoverable.
Comparisons
x402 vs. API Keys: A Thorough Comparison
Security, UX, cost structure and operational overhead, compared directly — plus a practical migration path if you already run a key-based API.
MCP vs. REST API vs. x402: How They Actually Compose
The three protocols answer three different questions. This guide lays out exactly which is which, where they overlap, and how a single resource can use all three at once.