AI agent, MCP server and skill categories

SDKs, CLIs and frameworks for building with AI.

Agents and tools that write, review and refactor code.

Everything else worth a look.

Guides, curated lists, courses and examples.

Automate tasks, email, calendars and docs.

Design, diagrams, images and video.

Deep research, reports and insight generation.

SQL, vector stores and data access.

Scanners, pentest helpers and test automation.

Models, RAG pipelines, embeddings and datasets.

CI/CD, containers and infrastructure.

Agents that drive real browsers.

Chat, voice, Slack, Discord and messaging.

AWS, Azure, GCP and cloud ops.

Stock and crypto trading, market data, payments and finance agents.

Writing, docs and content pipelines.

Posting, scheduling and research on X, LinkedIn, Instagram, TikTok, YouTube and Reddit.

Crawl, scrape and extract structured data.

Game engines, modding and game-playing agents.

Keyword research, site audits, rank tracking and visibility in AI answers.

Ads, email, growth and marketing workflows.

Home Assistant, ESP32 and Raspberry Pi devices, sensors and hardware agents.

Wallets, DeFi, on-chain data and blockchain agents.

Stores, product listings, Shopify, Amazon and online selling.

Job hunting, resume tailoring, cover letters and interview prep.

Lead generation, outreach, CRM data and sales agents.

A2A (Agent2Agent)

A2A (Agent2Agent) is an open standard for communication between AI agents. It covers agent-to-agent interaction, while MCP covers connections from agents to tools. Google originally developed it and donated it to the Linux Foundation.

ACP (Agent Client Protocol)

The Agent Client Protocol (ACP) standardizes communication between code editors and coding agents, much as the Language Server Protocol did for language servers. Local agents run as editor sub-processes using JSON-RPC over stdio, and remote agents use HTTP or WebSocket. It is a different project from the Agent Communication Protocol, which shares the ACP abbreviation.

AP2 (Agent Payments Protocol)

AP2 (Agent Payments Protocol) is an open protocol for payments made by AI agents. It extends the Agent2Agent protocol and integrates with the Universal Commerce Protocol. The current version supports credit and debit card pull payments, with e-wallets, real-time bank transfers and digital currencies on its roadmap.

x402

x402 is an open standard for internet-native payments built on the HTTP 402 Payment Required status code. A server can require payment for a request, and a client that receives a 402 response pays and retries. Coinbase created the protocol and contributed it to the x402 Foundation at the Linux Foundation, announced on April 2, 2026.

MCP Apps

MCP Apps are an extension to the Model Context Protocol that lets servers return interactive HTML interfaces rendered inside the chat. A tool declares a ui:// resource, the host renders it in a sandboxed iframe, and the app talks to the host over JSON-RPC through postMessage. Host support varies by client.

MCP Gateways

An MCP gateway is a proxy that sits between MCP clients and MCP servers, usually to aggregate servers behind one endpoint, bridge transports or apply access policy. It is a product category and not a protocol of its own. The MCP specification defines hosts, clients and servers, and does not define a gateway role.

Mobile Agents

Mobile agents are AI agents that run on a phone, control a phone, or act as personal assistants through messaging apps such as WhatsApp and Telegram. They typically read the screen and tap through apps, or connect to devices through tools such as ADB. This is a group of independent projects and not a single protocol.