Agents & tools · Glossary term
What is MCP (Model Context Protocol)?
An open JSON-RPC protocol for a host to connect to servers that expose tools, resources, prompts, and extensions through defined request, result, discovery, and transport contracts. In revision 2026-07-28, every request carries its protocol version and client capabilities instead of relying on an initialization handshake or protocol session.
“A standard way for AI applications to connect to tools and context.”
What is the common confusion about MCP (Model Context Protocol)?
MCP standardizes discovery and exchange. It does not decide which tool is safe to call, grant permission, or forbid an application from using explicit state handles.
Learn MCP (Model Context Protocol) in the course
Start with
- Model Context Protocol (MCP)
MCP gives an AI host one protocol for discovering and invoking tools, resources, and prompts. The 2026-07-28 revision makes that protocol stateless: capability and version context travels with every…
Lessons that name MCP (Model Context Protocol) in a title or section
- MCP Fundamentals: Stateless Requests and JSON-RPC
Modern MCP has no handshake and no protocol session. Each request must carry enough metadata to be understood, authorized, routed, and retried on its own.
- Building an MCP Server: Stateless Python and TypeScript
A modern MCP server does not remember a handshake. It validates the metadata on every request, runs one handler, and returns one typed result. Implement mandatory server/discover for MCP 2026-07-28.
- Building an MCP Client: Discovery, Routing, and Dual-Era Fallback
A modern MCP client repeats its contract on every request. Its hardest compatibility decision is knowing when an old server is truly old and when a modern server is reporting a correctable error.
- MCP Transports: stdio and Stateless Streamable HTTP
Transport carries MCP messages. It does not supply missing protocol state. In 2026-07-28, local stdio and remote Streamable HTTP both carry self-describing requests.
- MCP Resources and Prompts: Addressable Context for Stateless Servers
Tools perform operations. Resources expose addressable content. Prompts package user-selected message templates. A good MCP server keeps those contracts separate and predictable.
- MCP Model Input: Sampling Migration and Stateless MRTR
MCP 2026-07-28 deprecates Sampling for new designs and removes the server-to-client request channel. If an existing workflow still needs the client's model, the server returns an inputrequired…
- MCP Tasks Extension: Durable Work on a Stateless Core
Stateless MCP does not mean every operation must finish in one request. The official Tasks extension gives long-running work an explicit durable handle.
- MCP Apps on the Stateless Protocol
An interactive result is still an MCP tool and resource exchange. The 2026-07-28 core makes that exchange self-contained, while the Apps extension adds the sandboxed browser surface.
Taught in Phase 11: LLM Engineering.
Also covered in Phase 13: Tools & Protocols, Phase 16: Multi-Agent & Swarms and Phase 19: Capstone Projects.
Related terms
- Stateless MCPThe MCP 2026-07-28 request model in which every request carries the protocol version and client capabilities in `params._meta`, while…
- Multi Round-Trip Request (MRTR)An MCP request pattern in which an operation returns `resultType: input_required` with one or more `inputRequests`, then the client…
- Function CallingA provider or application interface through which a model emits a structured request naming a tool and its arguments.
- Tool ContractThe complete agreement for a tool boundary: purpose, typed inputs, outputs, validation, permissions, side effects, errors, timeouts,…
- Least PrivilegeGiving a model, agent, tool, or user only the permissions required for the current task, for only as long as those permissions are needed.
- Agent SkillA discoverable directory of procedural instructions whose entry point is `SKILL.md`, with optional references, scripts, and assets that a…
Sources
More terms in Agents & tools
- Agent
- Agent Harness
- Agent Memory
- Agent State
- Agent Skill
- Approval Gate
- Checkpoint
- Compensating Action
- Delegation
- Durable Execution
- Function Calling
- Human-in-the-Loop (HITL)
- Multi Round-Trip Request (MRTR)
- Orchestration
- Planning
- ReAct
- Sandbox
- Skill Bundle
- Skill Catalog
- Skill Discovery
- Skill Invocation
- Stateless MCP
- Structured Output
- Swarm
- Termination Condition
- Tool Contract
This entry comes from glossary/terms.md on GitHub. Browse all 250 glossary terms.