[Feature] Function Calling (#2544)

Co-authored-by: Haoyu Wang <120358163+HaoyuWang4188@users.noreply.github.com>

docs/backend/function_calling.ipynb

@@ -0,0 +1,146 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Function Calling\n",
+    "\n",
+    "This notebook provides a quick-start guide to use function tooling using  SGLang chat completions API\n",
+    "\n",
+    "## Supported Models\n",
+    "\n",
+    "Currently, we added the support for tools calling in the following models:\n",
+    "  - Llama 3.2 models\n",
+    "  - Llama 3.1 models\n",
+    "  - Qwen 2.5 models\n",
+    "  - InternLM Models"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Usage\n",
+    "\n",
+    "### Launch a server\n",
+    "\n",
+    "This code block is equivalent to executing\n",
+    "\n",
+    "`python -m sglang.launch_server --model-path meta-llama/Meta-Llama-3.1-8B-Instruct \\\n",
+    "--port 30000 --host 0.0.0.0`\n",
+    "in your terminal and wait for the server to be ready. Once the server is running, you can send test requests using curl or requests. The server implements the OpenAI-compatible APIs."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "from sglang.utils import (\n",
+    "    execute_shell_command,\n",
+    "    wait_for_server,\n",
+    "    terminate_process,\n",
+    "    print_highlight,\n",
+    ")\n",
+    "\n",
+    "\n",
+    "server_process = execute_shell_command(\n",
+    "    \"\"\"\n",
+    " python -m sglang.launch_server --model-path meta-llama/Meta-Llama-3.1-8B-Instruct --port 30000 --host 0.0.0.0\n",
+    "\"\"\"\n",
+    ")\n",
+    "\n",
+    "wait_for_server(\"http://localhost:30000\")"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "### Single Round Invocation"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "from openai import OpenAI\n",
+    "\n",
+    "tools = [\n",
+    "    {\n",
+    "        \"type\": \"function\",\n",
+    "        \"function\": {\n",
+    "            \"name\": \"get_current_weather\",\n",
+    "            \"description\": \"Get the current weather in a given location\",\n",
+    "            \"parameters\": {\n",
+    "                \"type\": \"object\",\n",
+    "                \"properties\": {\n",
+    "                    \"location\": {\n",
+    "                        \"type\": \"string\",\n",
+    "                        \"description\": \"The city and state, e.g. San Francisco, CA\",\n",
+    "                    },\n",
+    "                    \"unit\": {\"type\": \"string\", \"enum\": [\"celsius\", \"fahrenheit\"]},\n",
+    "                },\n",
+    "                \"required\": [\"location\"],\n",
+    "            },\n",
+    "        },\n",
+    "    }\n",
+    "]\n",
+    "messages = [{\"role\": \"user\", \"content\": \"What's the weather like in Boston today?\"}]\n",
+    "\n",
+    "client = OpenAI(api_key=\"YOUR_API_KEY\", base_url=\"http://0.0.0.0:30000/v1\")\n",
+    "model_name = client.models.list().data[0].id\n",
+    "response = client.chat.completions.create(\n",
+    "    model=model_name,\n",
+    "    messages=messages,\n",
+    "    temperature=0.8,\n",
+    "    top_p=0.8,\n",
+    "    stream=False,\n",
+    "    tools=tools,\n",
+    ")\n",
+    "\n",
+    "print(response)\n",
+    "\n",
+    "\"\"\"\n",
+    "\n",
+    "ChatCompletion(id='d6f620e1767e490d85b5ce45c15151cf', choices=[Choice(finish_reason='stop', index=0, logprobs=None, message=ChatCompletionMessage(content=None, refusal=None, \n",
+    "role='assistant', audio=None, function_call=None, tool_calls=[ChatCompletionMessageToolCall(id='0', function=Function(arguments='{\"a\": \"3\", \"b\": \"5\"}', name='add'), type='function')]), \n",
+    "matched_stop=128008)], created=1735411703, model='meta-llama/Llama-3.2-1B-Instruct', object='chat.completion', service_tier=None, system_fingerprint=None, \n",
+    "usage=CompletionUsage(completion_tokens=23, prompt_tokens=198, total_tokens=221, completion_tokens_details=None, prompt_tokens_details=None))\n",
+    "\n",
+    "\"\"\""
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "terminate_process(server_process)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## How to support a new model?\n",
+    "\n",
+    "For adding support of more different models:\n",
+    " 1. Update the `TOOLS_TAG_LIST` in `sglang/srt/utils.py` with the tool tag used by the model.\n",
+    " 2. Add support in `parse_tool_response` function for converting into tool calls `sglang/srt/utils.py`\n"
+   ]
+  }
+ ],
+ "metadata": {
+  "language_info": {
+   "name": "python"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 2
+}