joshi-chinmay-016/AgentProof

使用時機

在實作 NitroStack 工具方法的請求驗證、授權檢查、回應映射、日誌記錄、錯誤處理或效能追蹤時，請使用此技能。

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1. Guards（守衛）（Guard 與 @UseGuards）

Guards 根據驗證、授權或其他條件，決定請求是否應由工具處理器處理。

介面：

import { Guard, ExecutionContext } from '@nitrostack/core';

export interface Guard {
  canActivate(context: ExecutionContext): boolean | Promise<boolean>;
}

範例：

import { Guard, ExecutionContext, Injectable } from '@nitrostack/core';

@Injectable()
export class RolesGuard implements Guard {
  async canActivate(context: ExecutionContext): Promise<boolean> {
    const userRoles = context.clientMetadata?.roles || [];
    return userRoles.includes('admin');
  }
}

使用 @UseGuards(...) 套用守衛：

import { Tool, UseGuards, z } from '@nitrostack/core';
import { RolesGuard } from './roles.guard.js';

export class AdminTools {
  @Tool({
    name: 'delete_system_logs',
    description: 'Delete all system logs from the server.',
    inputSchema: z.object({}),
  })
  @UseGuards(RolesGuard)
  async deleteLogs() {
    return { success: true };
  }
}

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2. Interceptors（攔截器）（InterceptorInterface 與 @UseInterceptors）

Interceptors 可以轉換/攔截工具方法執行過程中的輸入引數或映射後的輸出。

介面：

import { ExecutionContext } from '@nitrostack/core';

export interface InterceptorInterface {
  intercept(context: ExecutionContext, next: () => Promise<unknown>): Promise<unknown>;
}

範例：

import { InterceptorInterface, ExecutionContext, Injectable } from '@nitrostack/core';

@Injectable()
export class TimingInterceptor implements InterceptorInterface {
  async intercept(context: ExecutionContext, next: () => Promise<unknown>): Promise<unknown> {
    const start = Date.now();
    const result = await next();
    const duration = Date.now() - start;
    context.logger.info(`Execution took ${duration}ms`);
    return {
      ...result,
      _meta: { durationMs: duration }
    };
  }
}

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3. Exception Filters（異常過濾器）（ExceptionFilterInterface 與 @UseFilters）

Exception Filters 會捕捉在 guards、interceptors 或工具處理器本身中拋出的任何錯誤，並將其對應到使用者友善的 JSON 負載。

介面：

import { ExecutionContext } from '@nitrostack/core';

export interface ExceptionFilterInterface {
  catch(exception: unknown, context: ExecutionContext): unknown | Promise<unknown>;
}

範例：

import { ExceptionFilterInterface, ExecutionContext, Injectable } from '@nitrostack/core';

@Injectable()
export class CustomExceptionFilter implements ExceptionFilterInterface {
  catch(exception: unknown, context: ExecutionContext) {
    const message = exception instanceof Error ? exception.message : 'Unknown error';
    return {
      error: true,
      message,
      timestamp: new Date().toISOString()
    };
  }
}

在工具方法上使用 @UseFilters(...) 套用過濾器：

import { Tool, UseFilters, z } from '@nitrostack/core';
import { CustomExceptionFilter } from './custom-exception.filter.js';

export class LoggingTools {
  @Tool({
    name: 'generate_report',
    description: 'Generates system usage reports.',
    inputSchema: z.object({}),
  })
  @UseFilters(CustomExceptionFilter)
  async generateReport() {
    throw new Error('Report generation is not implemented yet.');
  }
}

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4. Middleware（中介軟體）（MiddlewareInterface、@Middleware 與 @UseMiddleware）

Middleware 在請求到達工具處理器之前執行，並可透過呼叫 next() 包覆處理器的執行。

介面：

import { ExecutionContext } from '@nitrostack/core';

export interface MiddlewareInterface {
  use(context: ExecutionContext, next: () => Promise<unknown>): Promise<unknown>;
}

範例：

import { Middleware, MiddlewareInterface, ExecutionContext } from '@nitrostack/core';

@Middleware()
export class LoggingMiddleware implements MiddlewareInterface {
  async use(context: ExecutionContext, next: () => Promise<unknown>): Promise<unknown> {
    context.logger.info(`Entering tool: ${context.toolName}`);
    try {
      const result = await next();
      context.logger.info(`Exiting tool: ${context.toolName}`);
      return result;
    } catch (error) {
      context.logger.error(`Error in tool: ${error}`);
      throw error;
    }
  }
}

在工具方法上使用 @UseMiddleware(...) 套用中介軟體：

import { Tool, UseMiddleware, z } from '@nitrostack/core';
import { LoggingMiddleware } from './logging.middleware.js';

export class StationTools {
  @Tool({
    name: 'fetch_logs',
    description: 'Fetch station operations logs.',
    inputSchema: z.object({}),
  })
  @UseMiddleware(LoggingMiddleware)
  async fetchLogs() {
    return { status: 'operational' };
  }
}

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5. Pipes（管道）（PipeInterface、@Pipe 與 @UsePipes）

Pipes 用於在輸入引數到達工具處理器方法之前對其進行轉換或驗證。

介面：

import { ArgumentMetadata } from '@nitrostack/core';

export interface PipeInterface<T = unknown, R = unknown> {
  transform(value: T, metadata: ArgumentMetadata): R | Promise<R>;
}

範例：

import { Pipe, PipeInterface, ArgumentMetadata } from '@nitrostack/core';

@Pipe()
export class TrimPipe implements PipeInterface<Record<string, unknown>, Record<string, unknown>> {
  transform(value: Record<string, unknown>, metadata: ArgumentMetadata) {
    const trimmed: Record<string, unknown> = {};
    for (const [key, val] of Object.entries(value)) {
      trimmed[key] = typeof val === 'string' ? val.trim() : val;
    }
    return trimmed;
  }
}

在工具方法上使用 @UsePipes(...) 套用管道：

import { Tool, UsePipes, z } from '@nitrostack/core';
import { TrimPipe } from './trim.pipe.js';

export class MessagingTools {
  @Tool({
    name: 'send_message',
    description: 'Send a message to other stations.',
    inputSchema: z.object({ text: z.string() }),
  })
  @UsePipes(TrimPipe)
  async sendMessage(input: { text: string }) {
    return { sentText: input.text };
  }
}