Package org.apache.juneau.rest.server.mcp

Interface McpRevision

All Known Implementing Classes:

McpRevision, McpRevision

public interface McpRevision

Service-provider interface implemented once per MCP protocol revision.

A consumer binds exactly one revision at compile time, by extending that revision's abstract servlet or composing its endpoint mixin. There is deliberately no ServiceLoader wiring and no priority()/isAvailable() pair: unlike the transport-provider precedent in juneau-rest-client-apache-httpclient-45, there is never a set of runtime candidates to choose between.

This interface has exactly three methods and must stay that way. default methods here are reserved for genuinely additive future protocol growth — a hook a later revision needs that earlier revisions can no-op. They are not for utility plumbing: a revision-neutral helper belongs on whichever neutral type already owns the concept (an envelope bean, McpCursor, McpParamUtils), never here.

Method Summary

Modifier and Type	Method	Description
McpDispatchResult	dispatch(McpExchange exchange, McpServerConfig config, BeanStore ctx)	Dispatches one JSON-RPC request.
int	errorCode(McpErrorKind kind)	Maps a neutral failure classification to this revision's JSON-RPC error code.
String	protocolVersion()	The MCP protocol revision string this implementation speaks.

Method Details

protocolVersion

String protocolVersion()

The MCP protocol revision string this implementation speaks.

Returns:

The revision token (e.g. "2025-06-18"). Never null.

dispatch

McpDispatchResult dispatch(McpExchange exchange,
 McpServerConfig config,
 BeanStore ctx)

Dispatches one JSON-RPC request.

Parameters:

exchange - The inbound envelope plus header access. Never null.

config - The neutral handler registry and pagination strategy. Never null.

ctx - The per-request bean store, passed through to handlers. Never null.

Returns:

A McpResponseResult for a normal request, a McpStreamResult (for example wrapping a Flow.Publisher produced by a v2-only method) for a request whose response is not a single JSON-RPC envelope, or null for a notification request (which the HTTP layer renders as an empty body).

errorCode

int errorCode(McpErrorKind kind)

Maps a neutral failure classification to this revision's JSON-RPC error code.

Parameters:

kind - The failure classification. Never null.

Returns:

The JSON-RPC error code this revision reports for that kind.