Model Context Protocol (MCP)
Build, secure, verify, and operate stateless MCP systems from JSON-RPC envelopes through conformance release gates.
#LessonPhaseTimeRequirementOpen
01MCP Fundamentals: Stateless Requests and JSON-RPCModern MCP has no handshake and no protocol session. Each request must carry enough metadata to be understood, authorized, routed, and retried on its own.Phase 1355 minRequired↗ Official lesson02Building an MCP Server: Stateless Python and TypeScriptA modern MCP server does not remember a handshake. It validates the metadata on every request, runs one handler, and returns one typed result.Phase 1385 minRequired↗ Official lesson03Building an MCP Client: Discovery, Routing, and Dual-Era FallbackA 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.Phase 1385 minRequired↗ Official lesson04MCP Transports: stdio and Stateless Streamable HTTPTransport 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.Phase 1365 minRequired↗ Official lesson05MCP Resources and Prompts: Addressable Context for Stateless ServersTools perform operations. Resources expose addressable content. Prompts package user-selected message templates. A good MCP server keeps those contracts separate and predictable.Phase 1360 minRequired↗ Official lesson06MCP Model Input: Sampling Migration and Stateless MRTRMCP 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 `input_required` result and the client retries the original request with the model output. The reasoning loop becomes explicit, bounded, and stateless at the protocol layer.Phase 1375 minRequired↗ Official lesson07Explicit Scope and Stateless ElicitationRoots are deprecated in MCP 2026-07-28 and were never a security sandbox. Put scope in visible tool arguments or resource URIs, authorize it on the server, and use MRTR when a tool genuinely needs user input. The user sees the decision, the model sees the handle, and any server instance can process the retry.Phase 1360 minRequired↗ Official lesson08MCP Tasks Extension: Durable Work on a Stateless CoreStateless MCP does not mean every operation must finish in one request. The official Tasks extension gives long-running work an explicit durable handle. A server can return that handle from `tools/call`, any instance can answer `tasks/get`, and client input arrives through `tasks/update` without reviving protocol sessions.Phase 1390 minRequired↗ Official lesson09MCP Apps on the Stateless ProtocolAn 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.Phase 1375 minRequired↗ Official lesson10MCP Security: Poisoned Metadata, Routing, and MRTR StateStateless does not mean trustless. It means every request exposes the evidence a server and gateway need to validate the call independently.Phase 1360 minRequired↗ Official lesson11MCP Authorization: CIMD, Issuer Binding, PKCE, and Step-UpA remote MCP request is stateless, but its authorization is not anonymous. Bind every credential to the issuer that created it and every token to the resource that receives it.Phase 1390 minRequired↗ Official lesson12MCP Auth in Production: Issuer-Bound Enrollment and TokensLesson 16 built the OAuth 2.1 state machine. This lesson hardens its production boundaries for MCP 2026-07-28: Client ID Metadata Documents first, deprecated dynamic registration only for compatibility, authorization-response issuer validation, issuer-keyed client credentials, JWKS refresh, and audience-pinned tokens on every stateless request.Phase 1390 minRequired↗ Official lesson13Stateless MCP Gateways and Registry AdmissionA gateway should make every route explicit. The 2026-07-28 protocol gives it method, name, version, capability, identity, cache, and trace boundaries without a transport session.Phase 1375 minRequired↗ Official lesson14MCP Tool Contracts and ContentA tool is safe to automate only when discovery, arguments, results, pagination, and transport metadata agree on one contract.Phase 13120 minRequired↗ Official lesson15MCP Reliability, Cancellation, and Flow ControlA request ID correlates a message. It does not make a side effect safe, stop a worker, or protect a stream from a slow consumer.Phase 13120 minRequired↗ Official lesson16MCP Registry Supply Chain: Admission, Drift, and RollbackA registry entry tells you what a publisher declared. Production admission proves what you fetched, what you observed, what you approved, and what you can safely restore.Phase 1390 minRequired↗ Official lesson17MCP Conformance Engineering: Versioning, Evidence, and OperationsA server is not conformant because its happy path worked through one SDK. Conformance lives at the wire, at version boundaries, through intermediaries, and during rollback.Phase 13100 minRequired↗ Official lesson