MR::Mcp::Server Class Reference

Owns a HTTP MCP server (using the SSE protocol). More...

#include <MRMcp/MRMcp.h>

Classes
struct	Params

Public Types
using	ToolFunc = std::function<nlohmann::json( const nlohmann::json& args )>
	Those functions are allowed to throw, that's how you report errors to the MCP.
using	ToolValidator = std::function<Expected<void>( const std::string& toolId )>

Public Member Functions
MRMCP_API	Server ()
MRMCP_API	Server (Server &&)
MRMCP_API Server &	operator= (Server &&)
MRMCP_API	~Server ()
MRMCP_API bool	addTool (std::string id, std::string name, std::string desc, Schema::Base inputSchema, Schema::Base outputSchema, ToolFunc func)
MRMCP_API const Params &	getParams () const
MRMCP_API void	setParams (Params params)
	This restarts the server if necessary.
MRMCP_API bool	isRunning () const
MRMCP_API bool	setRunning (bool enable)
MRMCP_API void	shutdown ()
MRMCP_API nlohmann::json	dumpToolsAsJson () const
MRMCP_API Expected< void >	saveToolsCache (const std::filesystem::path &path) const
MRMCP_API void	setToolValidator (ToolValidator validator)

Detailed Description

Owns a HTTP MCP server (using the SSE protocol).

Member Typedef Documentation

ToolFunc

using MR::Mcp::Server::ToolFunc = std::function<nlohmann::json( const nlohmann::json& args )>

Those functions are allowed to throw, that's how you report errors to the MCP.

ToolValidator

using MR::Mcp::Server::ToolValidator = std::function<Expected<void>( const std::string& toolId )>

Optional predicate consulted before every tool dispatch, given the tool's id. Return {} to allow; return unexpected("reason") to block — the reason surfaces to the MCP client as the tool-call error. Evaluated per call, so changes (e.g. user sign-in) take effect immediately.

Constructor & Destructor Documentation

Server() [1/2]

MRMCP_API MR::Mcp::Server::Server

(

)

Server() [2/2]

MRMCP_API MR::Mcp::Server::Server

(

Server &&

)

~Server()

MRMCP_API MR::Mcp::Server::~Server

(

)

Member Function Documentation

addTool()

MRMCP_API bool MR::Mcp::Server::addTool	(	std::string	id,
		std::string	name,
		std::string	desc,
		Schema::Base	inputSchema,
		Schema::Base	outputSchema,
		ToolFunc	func )

Registers a new tool.

Parameters

id	An arbitrary function name, e.g. foo.bar.
name	A human/ai-readable name.
desc	A human/ai-readable explanation of what the tool does.
inputSchema	Describes the arguments. Normally it should be Schema::Object{} with some fields added.
outputSchema	Describes the returned JSON. Fails if the tool with this id already exists. Must be called early, before setRunning(true) is called for the first time, otherwise fails. Returns true on success. Asserts when returning false, so you don't have to check the return value. NOTE: Consult docs/testing_mcp.md for how to test your tool.

dumpToolsAsJson()

MRMCP_API nlohmann::json MR::Mcp::Server::dumpToolsAsJson ( ) const

nodiscard

Returns the list of currently-registered tools as a JSON array of MCP tool entries (name, optional title/description, inputSchema, outputSchema). Suitable for splicing into a tools/list response or persisting to a cache file.

getParams()

MRMCP_API const Params & MR::Mcp::Server::getParams ( ) const

nodiscard

isRunning()

MRMCP_API bool MR::Mcp::Server::isRunning ( ) const

nodiscard

operator=()

MRMCP_API Server & MR::Mcp::Server::operator=

(

Server &&

)

saveToolsCache()

MRMCP_API Expected< void > MR::Mcp::Server::saveToolsCache

(

const std::filesystem::path &

path

)

const

Atomically writes { "tools": dumpToolsAsJson() } to path, creating parent directories as needed. Returns an error message on I/O failure.

setParams()

MRMCP_API void MR::Mcp::Server::setParams

(

Params

params

)

This restarts the server if necessary.

setRunning()

MRMCP_API bool MR::Mcp::Server::setRunning

(

bool

enable

)

Returns true on success, including if the server is already running and you're trying to start it again. Stopping always returns true.

setToolValidator()

MRMCP_API void MR::Mcp::Server::setToolValidator

(

ToolValidator

validator

)

shutdown()

MRMCP_API void MR::Mcp::Server::shutdown

(

)

Tears down the running asio server (if any) and clears all registered tools. Use before unloading DLLs whose translation units called addTool — their captured std::function deleters dangle once those DLLs are unmapped, so a later ~Server would segfault. Idempotent. Safe to call when nothing was registered.

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The documentation for this class was generated from the following file:

• MRMcp/MRMcp.h