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

Interface McpEndpointMixin

All Known Subinterfaces:

McpEndpoint, McpEndpoint

All Known Implementing Classes:

SpringExampleMcpServer, SpringMcpRestServlet, SpringMcpRestServlet

public interface McpEndpointMixin

Mixin interface that exposes an MCP JSON-RPC endpoint at POST /mcp on any Juneau REST resource.

Implementing classes supply their McpServerConfig via getMcpConfig() and their protocol revision via revision(). In practice a consumer implements a revision-specific sub-interface (for example org.apache.juneau.rest.server.mcp.v20250618.McpEndpoint), which supplies revision() for them.

Example:

Method Summary

Modifier and Type	Method	Description
McpServerConfig	getMcpConfig()	Returns the McpServerConfig backing this endpoint.
default Object	handleMcpRequest(JsonRpcRequest req, RestRequest restReq)	Default MCP JSON-RPC endpoint handler.
McpRevision	revision()	The MCP protocol revision this endpoint speaks.
default McpSubscriptionBroker	subscriptionBroker()	Optional subscription broker backing this endpoint's subscriptions/listen support.

Method Details

getMcpConfig

McpServerConfig getMcpConfig()

Returns the McpServerConfig backing this endpoint.

Returns:

The config. Never null.

revision

McpRevision revision()

The MCP protocol revision this endpoint speaks.

Returns:

The bound revision. Never null.

subscriptionBroker

default McpSubscriptionBroker subscriptionBroker()

Optional subscription broker backing this endpoint's subscriptions/listen support.

Returning null (the default) means this endpoint does not support subscriptions: no McpSubscriptionBroker or McpSubscriptions bean is added to the request-scoped BeanStore that handleMcpRequest(org.apache.juneau.bean.jsonrpc.JsonRpcRequest, org.apache.juneau.rest.server.RestRequest) builds.

A revision binding that implements subscriptions/listen (for example org.apache.juneau.rest.server.mcp.v20260728.McpEndpoint) overrides this to return a binding-owned broker instance (its own per-binding vs. shared-instance semantics are that revision's own choice — see its Javadoc).

Returns:

The subscription broker, or null if this endpoint does not support subscriptions.

handleMcpRequest

default Object handleMcpRequest(@Content
 JsonRpcRequest req,
 RestRequest restReq)

Default MCP JSON-RPC endpoint handler.

Implementations may override this method to customize routing (path / annotations) but must still dispatch through revision().

Applies the same serializer policy as AbstractMcpRestServlet (addBeanTypes and uriResolution="NONE"), so the two neutral HTTP entrypoints stay at parity.

Parameters:

req - JSON-RPC request envelope.

restReq - The current REST request.

Returns:

The response, or null for notifications.