Add tool calls with agentic-gpt

src/agentic-gpt.ts

@@ -0,0 +1,317 @@
+import { GPT } from './gpt.js';
+import type { GPTConfig, GPTRequest, Message } from './gpt.ts';
+import type { ToolDefinition, ToolCall, MessageChunk } from './gpt-response.js';
+
+/**
+ * Function signature for tool execution
+ */
+export type ToolFunction = (args: Record<string, unknown>) => Promise<unknown> | unknown;
+
+/**
+ * Registration entry for a tool with its definition and execution function
+ */
+export type ToolRegistration = {
+  /**
+   * OpenAI-format tool definition
+   */
+  definition: ToolDefinition;
+  
+  /**
+   * Function to execute when the tool is called
+   */
+  fn: ToolFunction;
+};
+
+/**
+ * Options for agentic tool execution
+ */
+export type AgenticOptions = {
+  /**
+   * Maximum number of tool execution loops to prevent infinite loops
+   * @default 10
+   */
+  maxLoops?: number;
+
+  /**
+   * Whether to emit events for tool calls
+   * @default true
+   */
+  emitEvents?: boolean;
+};
+
+/**
+ * AgenticGPT extends the base GPT class to provide automatic tool execution.
+ * 
+ * This class:
+ * - Registers tools with their execution functions
+ * - Automatically executes tools when the LLM requests them
+ * - Loops until the LLM provides a final response without tool calls
+ * - Yields all chunks (content, reasoning, tool calls) during iteration
+ * - Emits events for monitoring tool execution
+ * 
+ * @example
+ * ```typescript
+ * const agenticGPT = new AgenticGPT(config, [
+ *   {
+ *     definition: {
+ *       type: 'function',
+ *       function: {
+ *         name: 'get_weather',
+ *         description: 'Get current weather for a location',
+ *         parameters: {
+ *           type: 'object',
+ *           properties: {
+ *             location: { type: 'string', description: 'City name' }
+ *           },
+ *           required: ['location']
+ *         }
+ *       }
+ *     },
+ *     fn: async (args) => {
+ *       return { temperature: 22, condition: 'sunny' };
+ *     }
+ *   }
+ * ]);
+ * 
+ * // Automatic tool execution with streaming
+ * for await (const chunk of agenticGPT.sendWithTools({ 
+ *   messages: [{ role: 'user', content: 'What is the weather in Paris?' }]
+ * })) {
+ *   console.log(chunk);
+ * }
+ * ```
+ */
+export class AgenticGPT extends GPT {
+  /**
+   * Registry mapping tool names to their execution functions
+   */
+  private toolRegistry: Map<string, ToolFunction> = new Map();
+  
+  /**
+   * Tool definitions to send with requests
+   */
+  private toolDefinitions: ToolDefinition[] = [];
+
+  /**
+   * Default options for agentic execution
+   */
+  private options: Required<AgenticOptions>;
+
+  /**
+   * Creates a new AgenticGPT instance
+   * 
+   * @param config - GPT configuration (API key, URL, model)
+   * @param tools - Array of tool registrations with definitions and execution functions
+   * @param options - Optional configuration for agentic behavior
+   */
+  constructor(
+    config: GPTConfig,
+    tools: ToolRegistration[] = [],
+    options: AgenticOptions = {}
+  ) {
+    super(config);
+    
+    // Set default options
+    this.options = {
+      maxLoops: options.maxLoops ?? 10,
+      emitEvents: options.emitEvents ?? true,
+    };
+    
+    // Register tools
+    for (const tool of tools) {
+      this.registerTool(tool);
+    }
+  }
+
+  /**
+   * Registers a tool with its definition and execution function
+   * 
+   * @param tool - Tool registration with definition and execution function
+   */
+  registerTool(tool: ToolRegistration): void {
+    const toolName = tool.definition.function.name;
+    this.toolRegistry.set(toolName, tool.fn);
+    this.toolDefinitions.push(tool.definition);
+  }
+
+  /**
+   * Unregisters a tool by name
+   * 
+   * @param toolName - Name of the tool to unregister
+   */
+  unregisterTool(toolName: string): void {
+    this.toolRegistry.delete(toolName);
+    this.toolDefinitions = this.toolDefinitions.filter(
+      def => def.function.name !== toolName
+    );
+  }
+
+  /**
+   * Sends a request with automatic tool execution.
+   * 
+   * This method:
+   * 1. Sends the request to the GPT API with registered tools
+   * 2. Yields all chunks (content, reasoning, tool calls) as they arrive
+   * 3. When tool calls are detected, executes them automatically
+   * 4. Adds tool results to the conversation and continues
+   * 5. Repeats until the LLM provides a final response or max loops reached
+   * 
+   * @param request - GPT request with messages and optional tool configuration
+   * @param options - Optional overrides for agentic options
+   * @returns Async iterator of message chunks
+   * 
+   * @example
+   * ```typescript
+   * for await (const chunk of agenticGPT.sendWithTools({ 
+   *   messages: [{ role: 'user', content: 'Tell me a joke and the weather' }]
+   * })) {
+   *   if (chunk.type === 'content') {
+   *     process.stdout.write(chunk.content);
+   *   } else if (chunk.type === 'tool_call') {
+   *     console.log('Calling tool:', chunk.toolCall.function.name);
+   *   }
+   * }
+   * ```
+   */
+  async *sendWithTools(
+    request: GPTRequest,
+    options?: AgenticOptions
+  ): AsyncIterableIterator<MessageChunk> {
+    // Merge options
+    const effectiveOptions: Required<AgenticOptions> = {
+      maxLoops: options?.maxLoops ?? this.options.maxLoops,
+      emitEvents: options?.emitEvents ?? this.options.emitEvents,
+    };
+
+    // Start with the initial messages
+    let messages: Message[] = [...request.messages];
+    let loopCount = 0;
+    let continueLoop = true;
+
+    while (continueLoop && loopCount < effectiveOptions.maxLoops) {
+      loopCount++;
+      
+      // Build the request with tools
+      const gptRequest: GPTRequest = {
+        messages,
+        tools: request.tools || this.toolDefinitions,
+        tool_choice: request.tool_choice || 'auto',
+      };
+
+      // Send to GPT and collect tool calls
+      const response = this.send(gptRequest);
+      const toolCalls: ToolCall[] = [];
+      let hasContent = false;
+
+      // Stream and collect chunks
+      for await (const chunk of response) {
+        yield chunk;
+
+        if (chunk.type === 'tool_call') {
+          toolCalls.push(chunk.toolCall);
+        } else if (chunk.type === 'content' && chunk.content) {
+          hasContent = true;
+        }
+      }
+
+      // If no tool calls, we're done
+      if (toolCalls.length === 0) {
+        continueLoop = false;
+        break;
+      }
+
+      // Add the assistant message with tool calls to the conversation
+      messages.push({
+        role: 'assistant',
+        content: hasContent ? null : null, // Content is null when tool calls are present
+        tool_calls: toolCalls,
+      });
+
+      // Execute tools and add results to messages
+      for (const toolCall of toolCalls) {
+        try {
+          const result = await this.executeTool(toolCall);
+          
+          // Add tool result to messages
+          messages.push({
+            role: 'tool',
+            tool_call_id: toolCall.id,
+            name: toolCall.function.name,
+            content: typeof result === 'string' ? result : JSON.stringify(result),
+          });
+
+          // Emit event if enabled
+          if (effectiveOptions.emitEvents) {
+            this.emit('toolCalled', {
+              toolName: toolCall.function.name,
+              arguments: JSON.parse(toolCall.function.arguments),
+              result,
+            });
+          }
+        } catch (error) {
+          // If tool execution fails, add error message
+          const errorMessage = error instanceof Error ? error.message : String(error);
+          
+          messages.push({
+            role: 'tool',
+            tool_call_id: toolCall.id,
+            name: toolCall.function.name,
+            content: JSON.stringify({ error: errorMessage }),
+          });
+
+          console.error(`Error executing tool ${toolCall.function.name}:`, error);
+        }
+      }
+    }
+
+    // Check if we hit max loops
+    if (loopCount >= effectiveOptions.maxLoops) {
+      console.warn(`AgenticGPT: Reached maximum loop count (${effectiveOptions.maxLoops})`);
+    }
+  }
+
+  /**
+   * Executes a tool call with the provided arguments
+   * 
+   * @param toolCall - The tool call to execute
+   * @returns The result of the tool execution
+   * @throws Error if the tool is not found or execution fails
+   */
+  private async executeTool(toolCall: ToolCall): Promise<unknown> {
+    const toolName = toolCall.function.name;
+    const fn = this.toolRegistry.get(toolName);
+
+    if (!fn) {
+      throw new Error(`Tool "${toolName}" not found in registry`);
+    }
+
+    let args: Record<string, unknown>;
+    
+    try {
+      args = JSON.parse(toolCall.function.arguments);
+    } catch (error) {
+      throw new Error(`Invalid JSON arguments for tool "${toolName}": ${toolCall.function.arguments}`);
+    }
+
+    return await fn(args);
+  }
+
+  /**
+   * Gets all registered tool definitions
+   * 
+   * @returns Array of tool definitions
+   */
+  getToolDefinitions(): ToolDefinition[] {
+    return [...this.toolDefinitions];
+  }
+
+  /**
+   * Checks if a tool is registered
+   * 
+   * @param toolName - Name of the tool to check
+   * @returns True if the tool is registered
+   */
+  hasTool(toolName: string): boolean {
+    return this.toolRegistry.has(toolName);
+  }
+}

src/gpt-response.ts

@@ -1,14 +1,82 @@
 import type { SSEvent } from './sse-session.js';
 
-export type MessageChunk = {
-  type: 'reasoning' | 'content';
-  reasoning_details?: string;
-  content: string;
-}
+/**
+ * JSON Schema type for tool parameter definitions
+ */
+export type JSONSchema = {
+  type: 'object' | 'string' | 'number' | 'boolean' | 'array' | 'null';
+  properties?: Record<string, JSONSchema>;
+  items?: JSONSchema;
+  required?: string[];
+  enum?: (string | number)[];
+  description?: string;
+  additionalProperties?: boolean;
+  [key: string]: unknown;
+};
 
+/**
+ * OpenAI-format tool definition using JSON Schema
+ */
+export type ToolDefinition = {
+  type: 'function';
+  function: {
+    name: string;
+    description: string;
+    parameters: JSONSchema;
+    strict?: boolean;
+  };
+};
+
+/**
+ * Represents a complete tool call from the LLM
+ */
+export type ToolCall = {
+  id: string;
+  type: 'function';
+  function: {
+    name: string;
+    arguments: string; // JSON string
+  };
+};
+
+/**
+ * Delta format for streaming tool calls
+ */
+export type ToolCallDelta = {
+  index: number;
+  id?: string;
+  type?: 'function';
+  function?: {
+    name?: string;
+    arguments?: string;
+  };
+};
+
+/**
+ * Message chunk types that can be yielded during streaming
+ */
+export type MessageChunk = 
+  | {
+      type: 'reasoning';
+      reasoning_details?: string;
+      content: string;
+    }
+  | {
+      type: 'content';
+      content: string;
+    }
+  | {
+      type: 'tool_call';
+      toolCall: ToolCall;
+    };
+
+/**
+ * Final result after consuming all chunks
+ */
 export type FinalResult = {
   reasoning: string;
   content: string;
+  toolCalls: ToolCall[];
 }
 
 export type GPTResponse = {
@@ -20,18 +88,20 @@ export type GPTResponse = {
   choices: {
     index: number;
     delta: {
-      role: 'user' | 'assistant' | 'system';
-      content: string;
-      reasoning: string;
-      reasoning_details: {
+      role?: 'user' | 'assistant' | 'system';
+      content?: string | null;
+      reasoning?: string;
+      reasoning_details?: {
         type: string;
         summary: string;
-      }
+      };
+      tool_calls?: ToolCallDelta[];
     };
+    finish_reason?: 'stop' | 'tool_calls' | 'length' | 'content_filter' | null;
   }[];
-  finish_reason: 'stop' | 'tool_calls' | 'length' | 'content_filter' | null;
-  native_finish_reason: string | null;
-  usage: {
+  finish_reason?: 'stop' | 'tool_calls' | 'length' | 'content_filter' | null;
+  native_finish_reason?: string | null;
+  usage?: {
     prompt_tokens: number;
     completion_tokens: number;
     total_tokens: number;
@@ -57,6 +127,12 @@ export class MessageResponse implements PromiseLike<FinalResult> {
   private resolveResult!: (value: FinalResult) => void;
   private resultPromise: Promise<FinalResult>;
   private iterator: AsyncIterable<SSEvent>;
+  
+  /**
+   * Accumulates tool calls as they stream in from the API
+   * Key is the tool call index, value is the partially completed tool call
+   */
+  private toolCallsInProgress: Map<number, Partial<ToolCall>> = new Map();
 
   constructor(iterator: AsyncIterable<SSEvent>) {
     this.iterator = iterator;
@@ -73,9 +149,13 @@ export class MessageResponse implements PromiseLike<FinalResult> {
     this.iteratorConsumed = true;
 
     for await (const rawChunk of this.iterator) {
-      const chunk = this.parseChunk(rawChunk);
-      this.chunks.push(chunk);
-      yield chunk;
+      const chunks = this.parseChunk(rawChunk);
+      
+      // parseChunk may return multiple chunks (e.g., when tool calls complete)
+      for (const chunk of chunks) {
+        this.chunks.push(chunk);
+        yield chunk;
+      }
     }
 
     this.resolveResult(this.buildResult());
@@ -91,8 +171,12 @@ export class MessageResponse implements PromiseLike<FinalResult> {
 
       (async () => {
         for await (const rawChunk of this.iterator) {
-          const chunk = this.parseChunk(rawChunk);
-          this.chunks.push(chunk);
+          const chunks = this.parseChunk(rawChunk);
+          
+          // parseChunk may return multiple chunks
+          for (const chunk of chunks) {
+            this.chunks.push(chunk);
+          }
         }
 
         this.resolveResult(this.buildResult());
@@ -114,22 +198,37 @@ export class MessageResponse implements PromiseLike<FinalResult> {
     return {
       reasoning: this.chunks
         .filter(c => c.type === 'reasoning')
-        .map(c => c.content)
+        .map(c => 'content' in c ? c.content : '')
         .join(''),
       content: this.chunks
         .filter(c => c.type === 'content')
-        .map(c => c.content)
+        .map(c => 'content' in c ? c.content : '')
         .join(''),
+      toolCalls: this.chunks
+        .filter(c => c.type === 'tool_call')
+        .map(c => 'toolCall' in c ? c.toolCall : null)
+        .filter((tc): tc is ToolCall => tc !== null),
     };
   }
 
-  private parseChunk(rawChunk: SSEvent) {
+  /**
+   * Parses a raw SSE chunk and returns one or more MessageChunks
+   * May return multiple chunks when tool calls complete
+   */
+  private parseChunk(rawChunk: SSEvent): MessageChunk[] {
     // console.log('Raw Chunk:', rawChunk);
     if (rawChunk.data === '[DONE]') {
-      return {
+      // When stream ends, flush any pending tool calls
+      const completedToolCalls = this.flushToolCalls();
+      
+      if (completedToolCalls.length > 0) {
+        return completedToolCalls;
+      }
+      
+      return [{
         type: 'content',
         content: '',
-      } as const;
+      }];
     }
     
     const data = JSON.parse(rawChunk.data) as GPTResponse;
@@ -140,18 +239,104 @@ export class MessageResponse implements PromiseLike<FinalResult> {
     }
     
     const delta = choice.delta;
+    const finishReason = choice.finish_reason || data.finish_reason;
     
+    // Handle tool calls
+    if (delta.tool_calls) {
+      this.processToolCallDeltas(delta.tool_calls);
+      
+      // If finish_reason is 'tool_calls', all tool calls are complete
+      if (finishReason === 'tool_calls') {
+        return this.flushToolCalls();
+      }
+      
+      // Otherwise, don't yield anything yet (still accumulating)
+      return [];
+    }
+    
+    // Handle reasoning chunks
     if (delta.reasoning) {
-      return {
+      const chunk: MessageChunk = {
         type: 'reasoning',
         content: delta.reasoning,
-        reasoning_details: delta.reasoning_details.summary,
-      } as const;
-    } else {
-      return {
+      };
+      
+      // Add reasoning_details if present
+      if (delta.reasoning_details?.summary) {
+        chunk.reasoning_details = delta.reasoning_details.summary;
+      }
+      
+      return [chunk];
+    }
+    
+    // Handle content chunks
+    if (delta.content !== undefined && delta.content !== null) {
+      return [{
         type: 'content',
         content: delta.content,
-      } as const;
+      }];
+    }
+    
+    // Empty chunk (e.g., role assignment)
+    return [];
+  }
+
+  /**
+   * Processes tool call deltas and accumulates them
+   */
+  private processToolCallDeltas(deltas: ToolCallDelta[]): void {
+    for (const delta of deltas) {
+      const index = delta.index;
+      
+      if (!this.toolCallsInProgress.has(index)) {
+        // Start a new tool call
+        this.toolCallsInProgress.set(index, {
+          id: delta.id || '',
+          type: 'function',
+          function: {
+            name: delta.function?.name || '',
+            arguments: delta.function?.arguments || '',
+          },
+        });
+      } else {
+        // Accumulate arguments for existing tool call
+        const existing = this.toolCallsInProgress.get(index)!;
+        
+        if (delta.function?.arguments) {
+          existing.function!.arguments += delta.function.arguments;
+        }
+        
+        // Update other fields if provided
+        if (delta.id) {
+          existing.id = delta.id;
+        }
+        if (delta.function?.name) {
+          existing.function!.name = delta.function.name;
+        }
+      }
     }
   }
+
+  /**
+   * Flushes all accumulated tool calls and returns them as chunks
+   */
+  private flushToolCalls(): MessageChunk[] {
+    const chunks: MessageChunk[] = [];
+    
+    // Convert accumulated tool calls to chunks
+    for (const [index, toolCall] of this.toolCallsInProgress.entries()) {
+      // Validate that the tool call is complete
+      if (toolCall.id && toolCall.function?.name && toolCall.function?.arguments !== undefined) {
+        chunks.push({
+          type: 'tool_call',
+          toolCall: toolCall as ToolCall,
+        });
+      }
+    }
+    
+    // Clear the accumulator
+    this.toolCallsInProgress.clear();
+    
+    return chunks;
+  }
 }

src/gpt.ts

@@ -1,6 +1,7 @@
 import { SSESession } from './sse-session.js';
 import { EventEmitter } from './utils/event-emitter.js';
 import { MessageResponse } from './gpt-response.js';
+import type { ToolDefinition, ToolCall } from './gpt-response.js';
 
 
 export type GPTEventMap = {
@@ -42,11 +43,47 @@ export type GPTConfig = {
   model: string;
 }
 
+/**
+ * Message types that can be sent to the GPT API
+ */
+export type Message = 
+  | {
+      role: 'user' | 'system';
+      content: string;
+    }
+  | {
+      role: 'assistant';
+      content: string | null;
+      tool_calls?: ToolCall[];
+    }
+  | {
+      role: 'tool';
+      tool_call_id: string;
+      name: string;
+      content: string;
+    };
+
+/**
+ * Request configuration for GPT API calls
+ */
 export type GPTRequest = {
   /**
    * The messages to send to the GPT API
    */
-  messages: { role: 'user' | 'assistant' | 'system'; content: string }[];
+  messages: Message[];
+
+  /**
+   * Optional tool definitions for function calling
+   */
+  tools?: ToolDefinition[];
+
+  /**
+   * Controls which (if any) tool is called by the model
+   * - 'auto' (default): model decides whether to call a tool
+   * - 'none': model will not call any tools
+   * - { type: 'function', function: { name: 'tool_name' } }: forces a specific tool call
+   */
+  tool_choice?: 'auto' | 'none' | { type: 'function'; function: { name: string } };
 }
 
 export class GPT extends EventEmitter<GPTEventMap> {
@@ -56,23 +93,36 @@ export class GPT extends EventEmitter<GPTEventMap> {
 
   /**
    * Sends a message to the GPT API
-   * @param message - The message to send
+   * @param request - The request configuration including messages and optional tools
    * @returns The response from the GPT API
    */
   send(request: GPTRequest): MessageResponse {
     const config = this.config;
   
     const lazyIterator = (async function* () {
+      // Build the API request body
+      const requestBody: Record<string, unknown> = {
+        model: config.model,
+        messages: request.messages,
+        stream: true,
+      };
+
+      // Add tools if provided
+      if (request.tools && request.tools.length > 0) {
+        requestBody.tools = request.tools;
+      }
+
+      // Add tool_choice if provided
+      if (request.tool_choice) {
+        requestBody.tool_choice = request.tool_choice;
+      }
+
       const session = await SSESession.from(config.apiUrl, {
         headers: {
           Authorization: `Bearer ${config.apiKey}`,
         },
         method: 'POST',
-        body: JSON.stringify({
-          model: config.model,
-          messages: request.messages,
-          stream: true,
-        }),
+        body: JSON.stringify(requestBody),
       });
   
       if (!session.messages) {

src/index.ts

@@ -1,39 +1,275 @@
+/**
+ * Export all public types and classes
+ */
+export { GPT } from './gpt.js';
+export type { GPTConfig, GPTRequest, Message, GPTEventMap } from './gpt.js';
+export { AgenticGPT } from './agentic-gpt.js';
+export type { ToolFunction, ToolRegistration, AgenticOptions } from './agentic-gpt.js';
+export { MessageResponse } from './gpt-response.js';
+export type { 
+  MessageChunk, 
+  FinalResult, 
+  ToolDefinition, 
+  ToolCall, 
+  ToolCallDelta,
+  JSONSchema,
+  GPTResponse 
+} from './gpt-response.js';
+
 import { GPT } from './gpt.js';
-
-const gptConfig = {
-  apiKey: process.env.OPENROUTER_API_KEY || '',
-  apiUrl: 'https://openrouter.ai/api/v1/chat/completions',
-  model: 'x-ai/grok-4.1-fast',
-}
-
-const gpt = new GPT(gptConfig);
-
-const request = gpt.send({ messages: [{ role: 'user', content: 'Hello, how are you?' }] });
-
-let lastChunk = { type: 'reasoning' } as { type: 'reasoning' | 'content'; reasoning?: string; reasoning_details?: string; content: string };
-
-for await (const chunk of request) {
-  if (lastChunk.type === 'reasoning' && chunk.type === 'content') {
-    process.stdout.write('\n')
-  }
-
-  process.stdout.write(chunk.content);
-
-  lastChunk = chunk;
-}
-
-console.log('\n');
-console.log('--------------------------------');
-console.log('Streaming Results Completed');
-console.log('--------------------------------\n\n');
+import { AgenticGPT } from './agentic-gpt.js';
+import type { ToolDefinition } from './gpt-response.js';
 
 /**
- * Generate the full response and get the final result
+ * Examples demonstrating the different usage patterns
+ * Uncomment the example you want to run
  */
-const response = await gpt.send({ messages: [{ role: 'user', content: 'Hello, how are you?' }] });
-console.log(response);
 
-console.log('\n');
-console.log('--------------------------------');
-console.log('Final Result Generated');
-console.log('--------------------------------\n\n');
+// =============================================================================
+// Example 1: Basic GPT streaming (no tools)
+// =============================================================================
+async function basicStreamingExample() {
+  
+  const gptConfig = {
+    apiKey: process.env.OPENROUTER_API_KEY || '',
+    apiUrl: 'https://openrouter.ai/api/v1/chat/completions',
+    model: 'x-ai/grok-4.1-fast',
+  };
+
+  const gpt = new GPT(gptConfig);
+
+  console.log('=== Basic Streaming Example ===\n');
+
+  const request = gpt.send({ 
+    messages: [{ role: 'user', content: 'Tell me a short joke about programming.' }] 
+  });
+
+  let lastChunk = { type: 'reasoning' } as { type: 'reasoning' | 'content' | 'tool_call' };
+
+  for await (const chunk of request) {
+    // Handle different chunk types
+    if (chunk.type === 'reasoning') {
+      process.stdout.write(chunk.content);
+    } else if (chunk.type === 'content') {
+      if (lastChunk.type === 'reasoning') {
+        process.stdout.write('\n');
+      }
+      process.stdout.write(chunk.content);
+    }
+
+    lastChunk = chunk;
+  }
+
+  console.log('\n\n=== Streaming Completed ===\n');
+}
+
+// =============================================================================
+// Example 2: Manual tool call handling (streaming with tools)
+// =============================================================================
+async function manualToolHandlingExample() {
+  const gptConfig = {
+    apiKey: process.env.OPENROUTER_API_KEY || '',
+    apiUrl: 'https://openrouter.ai/api/v1/chat/completions',
+    model: 'x-ai/grok-4.1-fast',
+  };
+
+  const gpt = new GPT(gptConfig);
+
+  console.log('=== Manual Tool Handling Example ===\n');
+
+  // Define a weather tool
+  const weatherTool: ToolDefinition = {
+    type: 'function' as const,
+    function: {
+      name: 'get_weather',
+      description: 'Get the current weather for a location',
+      parameters: {
+        type: 'object',
+        properties: {
+          location: {
+            type: 'string',
+            description: 'City name, e.g., "Paris" or "New York"',
+          },
+          units: {
+            type: 'string',
+            enum: ['celsius', 'fahrenheit'],
+            description: 'Temperature units',
+          },
+        },
+        required: ['location', 'units'],
+        additionalProperties: false,
+      },
+    },
+  };
+
+  const response = gpt.send({
+    messages: [{ role: 'user', content: 'What is the weather like in Paris?' }],
+    tools: [weatherTool],
+  });
+
+  console.log('Streaming response:\n');
+
+  for await (const chunk of response) {
+    if (chunk.type === 'content' && chunk.content) {
+      process.stdout.write(chunk.content);
+    } else if (chunk.type === 'tool_call') {
+      console.log('\n\nTool called:', chunk.toolCall.function.name);
+      console.log('Arguments:', chunk.toolCall.function.arguments);
+      console.log('(In a real app, you would execute the tool here and continue the conversation)');
+    }
+  }
+
+  console.log('\n\n=== Manual Tool Handling Completed ===\n');
+}
+
+// =============================================================================
+// Example 3: Automatic tool execution with AgenticGPT
+// =============================================================================
+async function agenticToolExecutionExample() {
+  const gptConfig = {
+    apiKey: process.env.OPENROUTER_API_KEY || '',
+    apiUrl: 'https://openrouter.ai/api/v1/chat/completions',
+    model: 'x-ai/grok-4.1-fast',
+  };
+
+  console.log('=== Agentic Tool Execution Example ===\n');
+
+  // Define tools with their execution functions
+  const weatherTool: ToolDefinition = {
+    type: 'function' as const,
+    function: {
+      name: 'get_weather',
+      description: 'Get the current weather for a location',
+      parameters: {
+        type: 'object',
+        properties: {
+          location: {
+            type: 'string',
+            description: 'City name',
+          },
+          units: {
+            type: 'string',
+            enum: ['celsius', 'fahrenheit'],
+            description: 'Temperature units',
+          },
+        },
+        required: ['location', 'units'],
+        additionalProperties: false,
+      },
+    },
+  };
+
+  // Create weather function
+  const getWeather = async (args: Record<string, unknown>) => {
+    const location = args.location as string;
+    const units = args.units as string;
+    
+    console.log(`\n[Executing get_weather(${location}, ${units})]`);
+    
+    // Simulate API call
+    await new Promise(resolve => setTimeout(resolve, 500));
+    
+    return {
+      location,
+      temperature: units === 'celsius' ? 22 : 72,
+      condition: 'sunny',
+      units,
+    };
+  };
+
+  // Create AgenticGPT with tools
+  const agenticGPT = new AgenticGPT(gptConfig, [
+    { definition: weatherTool, fn: getWeather }
+  ]);
+
+  // Listen for tool execution events
+  agenticGPT.on('toolCalled', (event) => {
+    console.log(`\n[Tool executed: ${event.toolName}]`);
+    console.log('[Result:', JSON.stringify(event.result), ']');
+  });
+
+  console.log('User: What is the weather in Paris and London?\n');
+  console.log('Assistant: ');
+
+  // Send request with automatic tool execution
+  for await (const chunk of agenticGPT.sendWithTools({
+    messages: [{ 
+      role: 'user', 
+      content: 'What is the weather in Paris and London? Use celsius for Paris and fahrenheit for London.' 
+    }],
+  })) {
+    if (chunk.type === 'content' && chunk.content) {
+      process.stdout.write(chunk.content);
+    } else if (chunk.type === 'tool_call') {
+      console.log(`\n[Calling tool: ${chunk.toolCall.function.name}]`);
+    }
+  }
+
+  console.log('\n\n=== Agentic Tool Execution Completed ===\n');
+}
+
+// =============================================================================
+// Example 4: Thenable pattern with tool history
+// =============================================================================
+async function thenableWithToolHistoryExample() {
+  const gptConfig = {
+    apiKey: process.env.OPENROUTER_API_KEY || '',
+    apiUrl: 'https://openrouter.ai/api/v1/chat/completions',
+    model: 'x-ai/grok-4.1-fast',
+  };
+
+  console.log('=== Thenable Pattern with Tool History Example ===\n');
+
+  const calculatorTool: ToolDefinition = {
+    type: 'function' as const,
+    function: {
+      name: 'calculate',
+      description: 'Perform mathematical calculations',
+      parameters: {
+        type: 'object',
+        properties: {
+          expression: {
+            type: 'string',
+            description: 'Mathematical expression to evaluate, e.g., "2 + 2"',
+          },
+        },
+        required: ['expression'],
+        additionalProperties: false,
+      },
+    },
+  };
+
+  // For this example, we'll use the base GPT class with thenable pattern
+  const gpt = new GPT(gptConfig);
+
+  console.log('Requesting response without streaming...\n');
+
+  // Use thenable pattern (await the response directly)
+  // This will consume the stream automatically and return the final result
+  const result = await gpt.send({
+    messages: [{ 
+      role: 'user', 
+      content: 'Use the calculator tool to calculate 2 + 2' 
+    }],
+    tools: [calculatorTool],
+  });
+
+  console.log('\n=== Final Result ===');
+  console.log('Content:', result.content);
+  console.log('Reasoning:', result.reasoning || '(none)');
+  console.log('\nTool Calls Made:', result.toolCalls.length);
+  result.toolCalls.forEach((tc, i) => {
+    console.log(`  ${i + 1}. ${tc.function.name}(${tc.function.arguments})`);
+  });
+  console.log('\n=== Thenable Example Completed ===\n');
+}
+
+// =============================================================================
+// Run examples
+// =============================================================================
+
+// Uncomment the example you want to run:
+await basicStreamingExample();
+await manualToolHandlingExample();
+await agenticToolExecutionExample();
+await thenableWithToolHistoryExample();