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Tutorials and deep dives on APIs, agentic commerce, and integrations.

Agentic Commerce in 2026: The Complete Developer Guide

Guides

4/16/2026

Agentic Commerce in 2026: The Complete Developer Guide

Agentic commerce lets AI agents buy on your behalf. Here's the 3-layer stack, the protocols powering it, and what's actually live in production today.

How to Build an AI Shopping Agent: Step-by-Step Guide

Guides

4/16/2026

How to Build an AI Shopping Agent: Step-by-Step Guide

Build an AI shopping agent that actually completes purchases, not just suggests them. Full walkthrough with Claude, MCP tools, Zinc for order execution, and MPP for payments.

What Is HTTP 402 Payment Required? A Complete Guide

Guides

4/16/2026

What Is HTTP 402 Payment Required? A Complete Guide

HTTP 402 was reserved in 1997 and unused for 30 years. Here's the history, the current revival via x402 and MPP, and why it's becoming the foundation of agentic commerce.

MPP vs x402: Which Agent Payment Protocol to Use?

Guides

4/16/2026

MPP vs x402: Which Agent Payment Protocol to Use?

MPP (Stripe + Tempo) and x402 (Coinbase) both revive HTTP 402 for agent payments. Here is a technical comparison and when to use each, with code.

What Is ACP? The Agentic Commerce Protocol Explained

Guides

4/16/2026

What Is ACP? The Agentic Commerce Protocol Explained

ACP is the open protocol for agent-to-merchant checkout from Stripe and OpenAI. Here's how it works, its four endpoints, Shared Payment Tokens, and what it can't do.

What Is AP2? The Agent Payments Protocol Explained

Guides

4/16/2026

What Is AP2? The Agent Payments Protocol Explained

AP2 is Google's open protocol for authorizing AI agent payments with cryptographically signed mandates. Here's how it works, its three mandate types, and when to use it.

What Is MPP? A Developer's Guide to Machine Payments

Guides

4/16/2026

What Is MPP? A Developer's Guide to Machine Payments

MPP lets AI agents pay for anything over HTTP without an account. Here's how the Machine Payments Protocol actually works, how it compares to x402 and ACP, and real production code.

Amazon Shopping API: The Ultimate Guide (2026)

Guides

3/16/2026

Amazon Shopping API: The Ultimate Guide (2026)

Everything you need to know about Amazon APIs, their limitations, and how to use Zinc as a complete Amazon Shopping API for your business.

Walmart Shopping API: The Ultimate Guide to Programmatic Buying (2026)

Guides

3/16/2026

Walmart Shopping API: The Ultimate Guide to Programmatic Buying (2026)

Everything you need to know about Walmart APIs, their limitations for developers, and how to use Zinc as a complete Walmart Shopping API.