Tool use

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// 1. User asks what the weather is in New York
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{
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  "type": "user_message",
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  "message": {
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    "role": "user",
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    "content": "What's the weather in New York?"
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  },
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  // ...etc
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}
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// 2. EVI infers it is time to make a function call
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{
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  "type": "tool_call",
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  "tool_type": "function",
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  "response_required": true,
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  "tool_call_id": "call_m7PTzGxrD0i9oCHiquKIaibo",
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  "name": "get_current_weather",
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  "parameters": "{\"location\":\"New York\",\"format\":\"fahrenheit\"}"
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}
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// 3. User communicates sudden disinterested in the weather
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{
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  "type": "user_message",
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  "message": {
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    "role": "user",
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    "content": "Actually, never mind."
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  }
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}
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// 4. EVI infers the function call should be canceled
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{
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    "type": "assistant_message",
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    "message": {
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      "role": "assistant",
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      "content": "If you change your mind or need any weather information in the future, feel free to let me know."
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    },
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    // ...etc
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  }

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// 1. User asks EVI what the weather is in New York
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{
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  "type": "user_message",
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  "message": {
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    "role": "user",
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    "content": "What's the weather in New York?"
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  },
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  // ...etc
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}
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// 2. EVI infers it is time to make a function call
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{
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  "type": "tool_call",
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  "tool_type": "function",
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  "response_required": true,
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  "tool_call_id": "call_m7PTzGxrD0i9oCHiquKIaibo",
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  "name": "get_current_weather",
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  "parameters": "{\"location\":\"New York\",\"format\":\"fahrenheit\"}"
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}
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// 3. User communicates to EVI they want the weather in Los Angeles instead
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{
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  "type": "user_message",
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  "message": {
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    "role": "user",
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    "content": "Actually, Los Angeles."
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  }
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}
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// 4. EVI infers the parameters to function call should be updated
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{
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  "type": "tool_call",
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  "response_required": true,
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  "tool_call_id": "call_5RWLt3IMQyayzGdvMQVn5AOQ",
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  "name": "get_current_weather",
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  "parameters": "{\"location\":\"Los Angeles\",\"format\":\"celsius\"}"
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}
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// 5. User sends results of function call to EVI
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{
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  "type": "tool_response",
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  "tool_call_id":"call_5RWLt3IMQyayzGdvMQVn5AOQ",
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  "content":"72F"
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}
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// 6. EVI sends response container function call result
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{
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  "type": "assistant_message",
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  "message": {
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    "role": "assistant",
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    "content": "The current weather in Los Angeles is 72F."
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  },
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  // ...etc
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}

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{
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  "version_description": "Adds fallback content",
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  "description": "This tool is for getting the current weather.",
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  "parameters": "{ \"type\": \"object\", \"properties\": { \"location\": { \"type\": \"string\", \"description\": \"The city and state, e.g. San Francisco, CA\" }, \"format\": { \"type\": \"string\", \"enum\": [\"celsius\", \"fahrenheit\"], \"description\": \"The temperature unit to use. Infer this from the users location.\" } }, \"required\": [\"location\", \"format\"] }",
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  "fallback_content": "Something went wrong. Failed to get the weather."
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}

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{
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  "tool_type": "FUNCTION",
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  "id": "36f09fdc-4630-40c0-8afa-6a3bdc4eb4b1",
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  "version": 1,
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  "version_type": "FIXED",
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  "version_description": "Adds fallback content",
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  "name": "get_current_weather",
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  "created_on": 1714421925626,
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  "modified_on": 1714425632084,
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  "fallback_content": "Something went wrong. Failed to get the weather.",
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  "description": null,
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  "parameters": "{ \"type\": \"object\", \"properties\": { \"location\": { \"type\": \"string\", \"description\": \"The city and state, e.g. San Francisco, CA\" }, \"format\": { \"type\": \"string\", \"enum\": [\"celsius\", \"fahrenheit\"], \"description\": \"The temperature unit to use. Infer this from the user's location.\" } }, \"required\": [\"location\", \"format\"] }"
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}

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// 1. User asks EVI what the weather is in New York
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{
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  "type": "user_message",
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  "message": {
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    "role": "user",
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    "content": "What's the weather in New York?"
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  },
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  // ...etc
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}
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// 2. EVI infers it is time to make a function call
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{
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  "type": "tool_call",
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  "tool_type": "function",
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  "response_required": true,
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  "tool_call_id": "call_m7PTzGxrD0i9oCHiquKIaibo",
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  "name": "get_current_weather",
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  "parameters": "{\"location\":\"New York\",\"format\":\"fahrenheit\"}"
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}
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// 3. User sends results of function call to EVI (result not formatted correctly)
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{
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  "type": "tool_response",
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  "tool_call_id":"call_5RWLt3IMQyayzGdvMQVn5AOQ",
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  "content":"MALFORMED RESPONSE"
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}
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// 4. EVI sends response communicating it failed to process the tool_response
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{
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  "type": "tool_error",
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  "tool_call_id": "call_m7PTzGxrD0i9oCHiquKIaibo",
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  "error": "Malformed tool response: <error message here>",
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  "fallback_content": "Something went wrong. Failed to get the weather.",
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  "level": "warn"
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}
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// 5. EVI generates a response based on the failure
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{
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  "type": "assistant_message",
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  "message": {
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    "role": "assistant",
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    "content": "It looks like there was an issue retrieving the weather information for New York."
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  },
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  // ...etc
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}

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// 1. User asks EVI what the weather is in New York
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{
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  "type": "user_message",
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  "message": {
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    "role": "user",
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    "content": "What's the weather in New York?"
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  },
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  // ...etc
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}
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// 2. EVI infers it is time to make a function call
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{
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  "type": "tool_call",
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  "tool_type": "function",
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  "response_required": true,
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  "tool_call_id": "call_m7PTzGxrD0i9oCHiquKIaibo",
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  "name": "get_current_weather",
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  "parameters": "{\"location\":\"New York\",\"format\":\"fahrenheit\"}"
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}
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// 3. Function failed, so we send EVI a message communicating the failure on our end
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{
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  "type": "tool_error",
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  "tool_call_id": "call_m7PTzGxrD0i9oCHiquKIaibo",
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  "error": "Malformed tool response: <error message here>",
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  "fallback_content": "Function execution failure - weather API down.",
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  "level": "warn"
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}
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// 4. EVI generates a response based on the failure
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{
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  "type": "assistant_message",
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  "message": {
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    "role": "assistant",
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    "content": "Sorry, our weather resource is unavailable. Can I help with anything else?"
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  },
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  // ...etc
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}

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import { Hume } from 'hume';
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async function handleToolCallMessage(
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  toolCallMessage: Hume.empathicVoice.ToolCallMessage,
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  socket: Hume.empathicVoice.chat.ChatSocket): Promise<void> {
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  if (toolCallMessage.name === "get_current_weather") {
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    try{
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      // parse the parameters from the Tool Call message
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      const args = JSON.parse(toolCallMessage.parameters) as {
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        location: string;
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        format: string;
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      };
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      // extract the individual arguments
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      const { location, format } = args;
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      // call fetch weather function with extracted arguments
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      const weather = await fetchWeather(location, format);
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      // send Tool Response message to the WebSocket
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      const toolResponseMessage = {
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        type: "tool_response",
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        toolCallId: toolCallMessage.toolCallId,
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        content: weather,
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      };
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      socket.sendToolResponseMessage(toolResponseMessage);
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    } catch (error) {
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      // send Tool Error message if weather fetching fails
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      const weatherToolErrorMessage = {
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        type: "tool_error",
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        toolCallId: toolCallMessage.toolCallId,
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        error: "Weather tool error",
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        content: "There was an error with the weather tool",
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      };
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      socket.sendToolErrorMessage(weatherToolErrorMessage);
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    }
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  } else {
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    // send Tool Error message if the requested tool was not found
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    const toolNotFoundErrorMessage = {
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      type: "tool_error",
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      toolCallId: toolCallMessage.toolCallId,
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      error: "Tool not found",
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      content: "The tool you requested was not found",
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    };
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    socket.sendToolErrorMessage(toolNotFoundErrorMessage);
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  }
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}