common

Documentation

Overview

Package common provides shared utilities for MCP tool implementations. It contains common helper functions used across all tool packages to avoid code duplication and ensure consistent behavior.

Index

• func GetAccountFromArgs(ctx context.Context, args map[string]interface{}) string
• func InstrumentedToolHandler(toolName string, sc *server.ServerContext, ...) ...
• func InstrumentedToolHandlerWithService(toolName string, serviceName string, operation string, ...) ...

Functions

func GetAccountFromArgs

func GetAccountFromArgs(ctx context.Context, args map[string]interface{}) string

GetAccountFromArgs extracts the account name from request arguments and context. For OAuth-authenticated requests, uses the authenticated user's email. Otherwise defaults to "default" or the explicitly provided account name.

Priority order:

1. OAuth user email from context (set by OAuth middleware)
2. Explicit "account" argument in request
3. "default"

func InstrumentedToolHandler

func InstrumentedToolHandler(
	toolName string,
	sc *server.ServerContext,
	handler func(ctx context.Context, request mcp.CallToolRequest) (*mcp.CallToolResult, error),
) func(ctx context.Context, request mcp.CallToolRequest) (*mcp.CallToolResult, error)

InstrumentedToolHandler wraps a tool handler with tracing, metrics and audit logging. It creates a trace span, records tool invocation metrics, and logs the invocation for audit purposes.

Usage:

s.AddTool(myTool, common.InstrumentedToolHandler("my_tool", sc, handler))

func InstrumentedToolHandlerWithService

func InstrumentedToolHandlerWithService(
	toolName string,
	serviceName string,
	operation string,
	sc *server.ServerContext,
	handler func(ctx context.Context, request mcp.CallToolRequest) (*mcp.CallToolResult, error),
) func(ctx context.Context, request mcp.CallToolRequest) (*mcp.CallToolResult, error)

InstrumentedToolHandlerWithService is like InstrumentedToolHandler but also records the Google service and operation type for more detailed metrics and tracing.

This handler creates a trace span with service attributes and records both: - MCP tool invocation metrics (mcp_tool_invocations_total, mcp_tool_duration_seconds) - Google API operation metrics (google_api_operations_total, google_api_operation_duration_seconds)

Usage:

s.AddTool(myTool, common.InstrumentedToolHandlerWithService("my_tool", "gmail", "list", sc, handler))