Protocol·8 min
What is x402? The HTTP Payment Protocol Explained
A deep dive into x402 — the open protocol that turns HTTP 402 Payment Required into a native payment rail for AI agents and APIs.
Blog
Guides, tutorials, and insights on AI agent payments, the x402 protocol, and building agents that can spend.
Guide·12 min
How AI Agents Make Payments: A Developer's Guide
Everything you need to know about giving autonomous agents the ability to spend money — wallets, credit lines, spending controls, and security.
Analysis·7 min
x402 vs API Keys vs Subscriptions: How Should Agents Pay for APIs?
A comparison of payment models for AI agent API consumption. Why pay-per-call with x402 beats traditional API key authentication.
Tutorial·5 min
Give Your AI Agent a Credit Line in 5 Minutes
Step-by-step tutorial: sign up, create a wallet, set spending limits, and make your first x402 payment with the TypeScript SDK.
Tutorial·10 min
Building a Research Agent with Exa Search + Mithril
Build an autonomous research agent that searches the web, summarizes findings, and pays for every API call — no API keys required.
Security·6 min
Agent Wallet Security: Spending Limits, Monitoring, and Controls
How to secure autonomous agent spending with per-wallet limits, transaction caps, freeze controls, and real-time monitoring.
Guide·7 min
SKILL.md: Teaching Any AI Agent New Capabilities
How the SKILL.md file format lets you give any LLM-based agent — Claude, GPT, or open-source — full API access with a single markdown file.
Architecture·9 min
Managing Spend Across 100 Agents: A Practical Architecture
Architecture patterns for deploying fleets of autonomous agents with individual wallets, shared credit lines, and centralized billing.
Tutorial·8 min
Building an Autonomous Web Scraping Agent with Firecrawl
Step-by-step: build an agent that crawls websites, extracts structured data, and pays per page — all with x402 and Mithril.
Thesis·11 min
The Future of Agent Commerce: When Machines Have Wallets
A thesis on why autonomous agents need their own financial infrastructure, and how x402 creates a machine-to-machine economy.
Tutorial·7 min
Smart LLM Routing: Using OpenRouter with Mithril for Cost-Optimized AI
How to build agents that automatically pick the cheapest or fastest LLM for each task, paid per-call through x402.
Report·10 min
State of the x402 Ecosystem: Services, Volume, and Growth
Data-driven analysis of the x402 ecosystem — how many services support it, transaction volumes, most popular endpoints, and growth trends.
Tutorial·9 min
Autonomous Sales: Building an AI Outreach Agent with Apollo + AgentMail
Build a sales agent that prospects with Apollo, writes personalized emails, and sends via AgentMail — fully autonomous, pay-per-action.
Thesis·6 min
Why AI Agents Need Credit, Not Prepaid Balances
Prepaid wallets break agent autonomy. Here's why credit lines with post-pay billing are the right financial primitive for AI agents.
Comparison·8 min
Mithril vs Stripe Agent Toolkit: Which Is Right for Your Agents?
An honest comparison of Mithril and Stripe's agent toolkit — pricing, features, x402 support, and when to use each.