What Is MCP (Model Context Protocol)? A Plain Guide and the Most Popular MCP Servers

The Model Context Protocol (MCP) is an open standard for connecting AI agents to tools and data. Instead of every agent building its own integration with GitHub, a database or a browser, a developer writes one MCP server for that tool, and any agent that speaks MCP (an MCP client) can use it. Anthropic introduced the protocol in late 2024; it has since been adopted across the industry, and the official MCP Registry now lists 40,867 servers, which AgentGid tracks in its MCP catalog.

How it works, in three parts

The client is the agent or app you use: a coding agent, a desktop assistant, an IDE. It decides when to call a tool.
The server is a small program that exposes tools ("create an issue", "run this SQL query"), resources (files, records) and prompts. It can run on your machine or as a remote service.
The protocol is the shared language between them, so a server written once works in every client that supports MCP.

In practice you add a server to your agent's configuration, the agent discovers the tools it offers, and from then on it can call them when a task needs them, usually asking for your approval first.

Which agents support MCP

82 of the agents AgentGid tracks list MCP support, including:

#	Agent	Gid Score	Downloads 7d	7d	30d	Stars	Latest release
1	OpenAI CodexOpenAI	85	21.4M	down 18.4%	up 35.2%	128K+148/day	0.162.02d ago
3	Claude CodeAnthropic	81	12.2M	down 15.4%	down 24.3%	150K+170/day	2.1.296yesterday
4	LangChainLangChain	78	41.1M	down 7.8%	down 16.9%	148K+46/day	1.4.42d ago
8	PiEarendil Inc. (created by Mario Zechner)	76	4.4M	down 8.4%	up 77.6%	114K+334/day	1.1.03d ago
9	OpenCodeAnomaly (SST team)	75	3M	down 0.8%	up 24.8%	212K+184/day	1.18.354d ago
12	CursorAnysphere (owned by SpaceX)	72	—	—	—	33.3K+3/day	—
13	GitHub CopilotGitHub (Microsoft)	71	—	—	—	—	—
14	LangGraphLangChain	70	15.9M	up 1.3%	down 9.4%	43K+52/day	1.2.144d ago
16	AI SDKVercel	68	29.8M	down 11.6%	up 44.6%	27.2K+20/day	6.0.303yesterday
21	Strands AgentsAWS	63	8.7M	down 0.4%	up 6.3%	8,751+20/day	0.2.02d ago
22	Claude Agent SDKAnthropic	63	19.7M	down 5.1%	up 11.4%	8,237+5/day	0.2.1652d ago
27	LovableLovable	60	—	—	—	—	—
No agents match that filter.

Every client keeps its server list in its own config file and format. The config file library shows where each one expects it, with copy-ready templates.

The most popular MCP servers

Ranked by GitHub stars of the server's repository (counting only repositories that are MCP servers by name), one entry per repository, as of Oct 10, 2026:

Server	What it connects to	GitHub stars
Scrapling MCP Server	Browser and web scraping	86.1K
Chrome DevTools MCP	Browser and web scraping	53.1K
Codebase Memory	Search and knowledge	46K
mcp-server	Files and documents	43.7K
PostHog MCP Server	Commerce and payments	40.2K
mcp-server-browser	Browser and web scraping	39.2K
playwright-mcp	Browser and web scraping	37.9K
GitHub	Git, GitHub and code review	33.4K
AIHawk	Browser and web scraping	31.8K
Serena MCP: the IDE for your agent	Search and knowledge	30.1K
OpenWork MCP Gateway	Security	23.9K
MCP Toolbox for Databases	Databases	16.6K

Stars measure attention, not quality or safety. Some very popular projects (browser automation libraries, analytics platforms) also ship an MCP server; they are in the catalog but left out of this list.

Servers by category

Category	Servers listed
Finance and crypto	3,874
Search and knowledge	3,803
Memory and agent tools	3,464
Data and analytics	3,013
Commerce and payments	2,042
Developer tools	1,894
Messaging and social	1,836
Design, images and media	1,677
Files and documents	1,451
Browser and web scraping	1,236
Productivity and workspace	1,216
Cloud and DevOps	1,072
Databases	935
Security	869
AI models and prompts	672
Git, GitHub and code review	459

The categories are assigned automatically from each server's name and description, so expect a few servers in the wrong drawer.

Installing an MCP server safely

An MCP server runs with the permissions you give it, and the agent will act on whatever the server returns. A few habits avoid most problems:

Prefer official servers from the vendor of the tool (GitHub's server for GitHub, your database vendor's for your database) or well-maintained open-source ones. Check the repository's recent activity.
Use least privilege. Give a database server a read-only user, give a GitHub server a token scoped to the repositories it needs.
Keep approvals on for tools that write, send or delete, at least until you know how the agent uses them.
Treat tool output as untrusted. A web page or an issue comment fetched through MCP can contain instructions aimed at the agent ("prompt injection"). Good clients flag this; a cautious setup limits what the agent can do right after reading outside content.
Store secrets in environment variables, not inline in a config file you might commit.

MCP compared with other ways to give agents tools

Function calling in a model API is how a single application wires its own tools. MCP is a layer above it that makes tools portable between applications.
Plugins and extensions of a particular agent work only in that agent; an MCP server works in any client.
Agent-to-agent protocols such as A2A connect agents to other agents, while MCP connects an agent to tools and data. The two are complementary.

Where to go next

Browse the MCP catalog to search all servers with install commands, see the glossary for related terms, or pick a client from the coding agents ranking.