mcp

Documentation

Overview

Package mcp implements a native Model Context Protocol (MCP) server for Argus.

The server communicates over JSON-RPC 2.0 via stdio and exposes Argus's 30-rule database hygiene engine as autonomous AI agent tools.

Index

• Constants
• Variables
• func NegotiateProtocolVersion(requested string) string
• func Serve(r io.Reader, w io.Writer, opts ...ServerOption) error
• func ServeStdio() error
• type Dispatcher
• type JSONRPCError
• type JSONRPCResponse
• type ParsedRequest
• type RequestMeta
• type RequestTracker
• type ResourceCost
• type ServerOption
  • func WithStrictLifecycle(strict bool) ServerOption
• type SynchronizedWriter
• type Tool
• type ToolDef

Constants

const (
	CostCheap     = transport.CostCheap
	CostExpensive = transport.CostExpensive

	DefaultMaxConcurrentCheap     = transport.DefaultMaxConcurrentCheap
	DefaultMaxConcurrentExpensive = transport.DefaultMaxConcurrentExpensive
	DefaultShutdownTimeout        = transport.DefaultShutdownTimeout

	CodeParseError                 = errorspkg.CodeParseError
	CodeInvalidRequest             = errorspkg.CodeInvalidRequest
	CodeMethodNotFound             = errorspkg.CodeMethodNotFound
	CodeInvalidParams              = errorspkg.CodeInvalidParams
	CodeInternalError              = errorspkg.CodeInternalError
	CodeServerNotInitialized       = errorspkg.CodeServerNotInitialized
	CodeUnsupportedProtocolVersion = errorspkg.CodeUnsupportedProtocolVersion
	CodeCancelled                  = errorspkg.CodeCancelled
)

const LatestProtocolVersion = "2026-07-28"

LatestProtocolVersion is the canonical protocol version offered by Argus.

const (
	// MaxMessageSize is the maximum allowed size (in bytes) of a single newline-delimited
	// JSON-RPC message on the stdio transport. Messages exceeding this limit cause
	// immediate connection termination — no partial execution, no partial stdout.
	MaxMessageSize = 10 * 1024 * 1024 // 10 MiB
)

Variables

var (
	ProtocolError                   = errorspkg.ProtocolError
	InvalidParamsError              = errorspkg.InvalidParamsError
	MethodNotFoundError             = errorspkg.MethodNotFoundError
	UnsupportedProtocolVersionError = errorspkg.UnsupportedProtocolVersionError
	CancelledError                  = errorspkg.CancelledError
	ToolSuccess                     = errorspkg.ToolSuccess
	ToolError                       = errorspkg.ToolError

	ValidateJSONRPC       = transport.ValidateJSONRPC
	NewDispatcher         = transport.NewDispatcher
	NewSynchronizedWriter = transport.NewSynchronizedWriter
	NewRequestTracker     = transport.NewRequestTracker
	IDKey                 = transport.IDKey
	ErrShutdownTimeout    = transport.ErrShutdownTimeout

	RegisterTool   = tools.RegisterTool
	UnregisterTool = tools.UnregisterTool

	NewPathAuthority = security.NewPathAuthority
	SubmitViaURL     = telemetry.SubmitViaURL
)

var ErrOversizedMessage = errors.New("mcp: message exceeds maximum allowed size")

ErrOversizedMessage is returned when a client sends a message exceeding MaxMessageSize. This is a connection-fatal transport violation: the server terminates the connection without sending a JSON-RPC error response, because the message framing itself is broken.

var SupportedProtocolVersions = map[string]bool{
	"2024-11-05": true,
	"2025-03-26": true,
	"2025-06-18": true,
	"2025-11-25": true,
	"2026-07-28": true,
}

SupportedProtocolVersions contains the set of MCP protocol versions supported by Argus.

Functions

func NegotiateProtocolVersion

func NegotiateProtocolVersion(requested string) string

NegotiateProtocolVersion negotiates an MCP protocol version according to the MCP specification: If the requested version is supported, it is selected; otherwise, the latest supported version is returned as the fallback.

func Serve

func Serve(r io.Reader, w io.Writer, opts ...ServerOption) error

Serve starts the MCP server reading from r and writing to w with optional configuration.

func ServeStdio

func ServeStdio() error

ServeStdio starts the MCP server reading from stdin and writing to stdout with strict lifecycle enforcement.

Types

type Dispatcher

type Dispatcher = transport.Dispatcher

type JSONRPCError

type JSONRPCError = errorspkg.JSONRPCError

type JSONRPCResponse

type JSONRPCResponse = errorspkg.JSONRPCResponse

type ParsedRequest

type ParsedRequest = transport.ParsedRequest

type RequestMeta

type RequestMeta = transport.RequestMeta

type RequestTracker

type RequestTracker = transport.RequestTracker

type ResourceCost

type ResourceCost = transport.ResourceCost

type ServerOption

type ServerOption func(*serverConfig)

ServerOption configures server runtime policies.

func WithStrictLifecycle

func WithStrictLifecycle(strict bool) ServerOption

WithStrictLifecycle configures whether the server enforces the standard MCP lifecycle state machine.

type SynchronizedWriter

type SynchronizedWriter = transport.SynchronizedWriter

type Tool

type Tool = tools.Tool

type ToolDef

type ToolDef = tools.ToolDef