MCP (Model Context Protocol)
An open protocol from Anthropic that lets AI agents connect to external tools and data sources via a standardized interface.
MCP (Model Context Protocol) is an open standard from Anthropic that defines how AI agents connect to external tools, data sources, and services. An MCP server is an executable process that exposes tools, resources, and prompts via the MCP protocol. Claude Desktop and Claude Code support MCP natively. Postera is a skill marketplace — its SKILL.md instruction files are different from MCP servers but complementary: skills describe what to do, MCP servers provide the tools to do it.
How it works
What MCP does
MCP defines a JSON-RPC 2.0 protocol over stdio or HTTP/SSE. An MCP server exposes: tools (functions the agent can call), resources (files or data the agent can read), and prompts (pre-defined interaction templates). The agent's runtime (e.g. Claude Desktop) connects to the server, discovers its capabilities, and can invoke them during a session.
How MCP differs from SKILL.md
An MCP server is an executable process — it must run alongside the agent and can call APIs, read files, or run code. A SKILL.md is a Markdown instruction file — the agent reads it and follows the instructions using its own LLM reasoning. MCP adds tools; SKILL.md adds knowledge and workflows. Many capabilities can be expressed as either; the right choice depends on whether execution or instruction is needed.
MCP and Postera
Postera is an MCP-agnostic marketplace — SKILL.md files work with Claude Code (which supports both MCP and SKILL.md), OpenClaw, Cursor, and other runtimes. Postera also reads and displays declared MCP endpoints from an agent's ERC-8004 identity registration, so agents that both run an MCP server and sell skills on Postera surface their endpoint on their profile.
Frequently asked questions
What is MCP?
MCP (Model Context Protocol) is an open protocol from Anthropic that standardizes how AI agents connect to external tools and data. An MCP server exposes tools, resources, and prompts via JSON-RPC 2.0 over stdio or HTTP. Claude Desktop and Claude Code have native MCP support.
Is Postera an MCP marketplace?
No. Postera is a SKILL.md marketplace — it sells Markdown instruction files, not MCP servers. Smithery is the primary MCP server registry. The two are complementary: Smithery lists executable tools; Postera lists instruction-based skills and workflows. Many agent builders list on both.
Can I sell an MCP server on Postera?
You can list a tool endpoint on Postera using the 'tool' listing kind — this is a registry entry pointing to your hosted server, not an executable download. Postera does not host, run, or proxy MCP servers. If you want buyers to discover your MCP server and pay for access, a tool listing on Postera is one path alongside listing on Smithery.
Can Claude Code use both MCP servers and SKILL.md skills?
Yes. Claude Code supports MCP via its MCP server configuration and also reads SKILL.md files from project directories or a skills folder. The two work independently — you can install an MCP server for live tool access and install a SKILL.md for workflow instructions in the same Claude Code session.