> ## Documentation Index > Fetch the complete documentation index at: https://docs.agentfront.dev/llms.txt > Use this file to discover all available pages before exploring further. # ToolContext > ToolContext is the base class for all tool implementations. It extends ExecutionContextBase and provides tool-specific features like notifications, progress reporting, and elicitation. ## Class Definition ```typescript theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} export abstract class ToolContext< InSchema extends ToolInputType = ToolInputType, OutSchema extends ToolOutputType = ToolOutputType, In = ToolInputOf<{ inputSchema: InSchema }>, Out = ToolOutputOf<{ outputSchema: OutSchema }>, > extends ExecutionContextBase ``` ## Type Parameters | Parameter | Description | | ----------- | ----------------------------- | | `InSchema` | Input schema type (Zod shape) | | `OutSchema` | Output schema type | | `In` | Inferred input type | | `Out` | Inferred output type | ## Properties | Property | Type | Description | | ------------ | ------------------------- | --------------------------------------- | | `metadata` | `ToolMetadata` | Tool metadata (name, description, etc.) | | `input` | `In` | Parsed and validated input | | `output` | `Out \| undefined` | Tool output (after execution) | | `toolName` | `string` | Tool name | | `toolId` | `string` | Tool ID (or name if not specified) | | `platform` | `AIPlatformType` | Detected AI platform | | `clientInfo` | `ClientInfo \| undefined` | Client information | ## Abstract Method ### execute(input) The main execution method that must be implemented. ```typescript theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} abstract execute(input: In): Promise ``` ```typescript theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} @Tool({ name: 'my_tool', inputSchema: { value: z.number() }, outputSchema: z.object({ result: z.number() }), }) class MyTool extends ToolContext { async execute(input: { value: number }) { return { result: input.value * 2 }; } } ``` ## Methods ### Response Methods #### respond(value) Set output and end execution immediately. ```typescript theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} respond(value: Out): never ``` ```typescript theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} async execute(input) { if (cached) { this.respond(cached); // Ends execution here } // This code won't run if cached return processInput(input); } ``` ### Notification Methods (MCP 2025-11-25) #### notify(message, level?) Send a log message notification to the client. ```typescript theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} protected notify( message: string | Record, level?: 'debug' | 'info' | 'warning' | 'error' ): Promise ``` ```typescript theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} await this.notify('Processing started', 'info'); await this.notify({ step: 1, status: 'validating' }, 'debug'); ``` #### progress(progress, total?, message?) Send a progress notification to the client. ```typescript theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} protected progress( progress: number, total?: number, message?: string ): Promise ``` ```typescript theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} await this.progress(0, 100, 'Starting...'); await this.progress(50, 100, 'Halfway done'); await this.progress(100, 100, 'Complete'); ``` ### Elicitation Methods #### elicit\(message, requestedSchema, options?) Request interactive user input during execution. ```typescript theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} protected elicit( message: string, requestedSchema: S, options?: ElicitOptions ): Promise>> ``` **Options:** | Option | Type | Description | | ------ | ----------------- | ----------------------- | | `mode` | `'form' \| 'url'` | Input mode | | `ttl` | `number` | Timeout in milliseconds | **Result:** ```typescript theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} interface ElicitResult { status: 'accept' | 'reject' | 'timeout'; content?: T; validationErrors?: string[]; } ``` **Usage:** ```typescript theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} async execute(input) { const result = await this.elicit( 'Please confirm this action', z.object({ confirmed: z.boolean(), reason: z.string().optional(), }), { mode: 'form', ttl: 300000 } ); if (result.status !== 'accept' || !result.content?.confirmed) { return { cancelled: true }; } // Proceed with action return { success: true }; } ``` ### Platform Detection #### get platform Detect the AI platform making the request. ```typescript theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} get platform(): AIPlatformType ``` Values: `'openai' | 'claude' | 'gemini' | 'langchain' | 'vercel-ai' | 'unknown'` ```typescript theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} if (this.platform === 'claude') { // Claude-specific formatting } ``` #### get clientInfo Get client information. ```typescript theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} get clientInfo(): ClientInfo | undefined ``` ```typescript theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} const client = this.clientInfo; if (client) { console.log(client.name); // 'claude' console.log(client.version); // '1.0.0' } ``` ### History #### inputHistory History of input changes during execution. ```typescript theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} get inputHistory(): ReadonlyArray ``` #### outputHistory History of output changes during execution. ```typescript theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} get outputHistory(): ReadonlyArray ``` ## Full Example ```typescript theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}} import { Tool, ToolContext } from '@frontmcp/sdk'; import { z } from 'zod'; const inputSchema = { action: z.enum(['create', 'update', 'delete']), resourceId: z.string(), data: z.any().optional(), }; const outputSchema = z.object({ success: z.boolean(), resourceId: z.string(), message: z.string(), }); @Tool({ name: 'manage_resource', description: 'Create, update, or delete a resource', inputSchema, outputSchema, annotations: { destructiveHint: true, }, }) class ManageResourceTool extends ToolContext< typeof inputSchema, typeof outputSchema > { async execute(input) { // Log start await this.notify(`Starting ${input.action} operation`, 'info'); await this.progress(0, 100, 'Initializing...'); // For destructive actions, confirm with user if (input.action === 'delete') { const confirmation = await this.elicit( `Are you sure you want to delete resource ${input.resourceId}?`, z.object({ confirmed: z.boolean() }), { mode: 'form', ttl: 60000 } ); if (confirmation.status !== 'accept' || !confirmation.content?.confirmed) { return { success: false, resourceId: input.resourceId, message: 'Delete cancelled by user', }; } } await this.progress(25, 100, 'Validating...'); // Get service const resourceService = this.get(ResourceServiceToken); // Perform action await this.progress(50, 100, `Executing ${input.action}...`); let message: string; switch (input.action) { case 'create': await resourceService.create(input.resourceId, input.data); message = 'Resource created successfully'; break; case 'update': await resourceService.update(input.resourceId, input.data); message = 'Resource updated successfully'; break; case 'delete': await resourceService.delete(input.resourceId); message = 'Resource deleted successfully'; break; } await this.progress(100, 100, 'Complete'); await this.notify({ action: input.action, resourceId: input.resourceId }, 'info'); return { success: true, resourceId: input.resourceId, message, }; } } ``` ## Related Tool decorator Base class Tool registry Tool errors