openai_api_completions.ipynb

{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# OpenAI APIs - Completions\n",
    "\n",
    "SGLang provides OpenAI-compatible APIs to enable a smooth transition from OpenAI services to self-hosted local models.\n",
    "A complete reference for the API is available in the [OpenAI API Reference](https://platform.openai.com/docs/api-reference).\n",
    "\n",
    "This tutorial covers the following popular APIs:\n",
    "\n",
    "- `chat/completions`\n",
    "- `completions`\n",
    "- `batches`\n",
    "\n",
    "Check out other tutorials to learn about [vision APIs](https://docs.sglang.ai/backend/openai_api_vision.html) for vision-language models and [embedding APIs](https://docs.sglang.ai/backend/openai_api_embeddings.html) for embedding models."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Launch A Server\n",
    "\n",
    "Launch the server in your terminal and wait for it to initialize."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "from sglang.test.test_utils import is_in_ci\n",
    "\n",
    "if is_in_ci():\n",
    "    from patch import launch_server_cmd\n",
    "else:\n",
    "    from sglang.utils import launch_server_cmd\n",
    "\n",
    "from sglang.utils import wait_for_server, print_highlight, terminate_process\n",
    "\n",
    "\n",
    "server_process, port = launch_server_cmd(\n",
    "    \"python3 -m sglang.launch_server --model-path qwen/qwen2.5-0.5b-instruct --host 0.0.0.0 --mem-fraction-static 0.8\"\n",
    ")\n",
    "\n",
    "wait_for_server(f\"http://localhost:{port}\")\n",
    "print(f\"Server started on http://localhost:{port}\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Chat Completions\n",
    "\n",
    "### Usage\n",
    "\n",
    "The server fully implements the OpenAI API.\n",
    "It will automatically apply the chat template specified in the Hugging Face tokenizer, if one is available.\n",
    "You can also specify a custom chat template with `--chat-template` when launching the server."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "import openai\n",
    "\n",
    "client = openai.Client(base_url=f\"http://127.0.0.1:{port}/v1\", api_key=\"None\")\n",
    "\n",
    "response = client.chat.completions.create(\n",
    "    model=\"qwen/qwen2.5-0.5b-instruct\",\n",
    "    messages=[\n",
    "        {\"role\": \"user\", \"content\": \"List 3 countries and their capitals.\"},\n",
    "    ],\n",
    "    temperature=0,\n",
    "    max_tokens=64,\n",
    ")\n",
    "\n",
    "print_highlight(f\"Response: {response}\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Parameters\n",
    "\n",
    "The chat completions API accepts OpenAI Chat Completions API's parameters. Refer to [OpenAI Chat Completions API](https://platform.openai.com/docs/api-reference/chat/create) for more details.\n",
    "\n",
    "Here is an example of a detailed chat completion request:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "response = client.chat.completions.create(\n",
    "    model=\"qwen/qwen2.5-0.5b-instruct\",\n",
    "    messages=[\n",
    "        {\n",
    "            \"role\": \"system\",\n",
    "            \"content\": \"You are a knowledgeable historian who provides concise responses.\",\n",
    "        },\n",
    "        {\"role\": \"user\", \"content\": \"Tell me about ancient Rome\"},\n",
    "        {\n",
    "            \"role\": \"assistant\",\n",
    "            \"content\": \"Ancient Rome was a civilization centered in Italy.\",\n",
    "        },\n",
    "        {\"role\": \"user\", \"content\": \"What were their major achievements?\"},\n",
    "    ],\n",
    "    temperature=0.3,  # Lower temperature for more focused responses\n",
    "    max_tokens=128,  # Reasonable length for a concise response\n",
    "    top_p=0.95,  # Slightly higher for better fluency\n",
    "    presence_penalty=0.2,  # Mild penalty to avoid repetition\n",
    "    frequency_penalty=0.2,  # Mild penalty for more natural language\n",
    "    n=1,  # Single response is usually more stable\n",
    "    seed=42,  # Keep for reproducibility\n",
    ")\n",
    "\n",
    "print_highlight(response.choices[0].message.content)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Streaming mode is also supported."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "stream = client.chat.completions.create(\n",
    "    model=\"qwen/qwen2.5-0.5b-instruct\",\n",
    "    messages=[{\"role\": \"user\", \"content\": \"Say this is a test\"}],\n",
    "    stream=True,\n",
    ")\n",
    "for chunk in stream:\n",
    "    if chunk.choices[0].delta.content is not None:\n",
    "        print(chunk.choices[0].delta.content, end=\"\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Completions\n",
    "\n",
    "### Usage\n",
    "Completions API is similar to Chat Completions API, but without the `messages` parameter or chat templates."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "response = client.completions.create(\n",
    "    model=\"qwen/qwen2.5-0.5b-instruct\",\n",
    "    prompt=\"List 3 countries and their capitals.\",\n",
    "    temperature=0,\n",
    "    max_tokens=64,\n",
    "    n=1,\n",
    "    stop=None,\n",
    ")\n",
    "\n",
    "print_highlight(f\"Response: {response}\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Parameters\n",
    "\n",
    "The completions API accepts OpenAI Completions API's parameters.  Refer to [OpenAI Completions API](https://platform.openai.com/docs/api-reference/completions/create) for more details.\n",
    "\n",
    "Here is an example of a detailed completions request:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "response = client.completions.create(\n",
    "    model=\"qwen/qwen2.5-0.5b-instruct\",\n",
    "    prompt=\"Write a short story about a space explorer.\",\n",
    "    temperature=0.7,  # Moderate temperature for creative writing\n",
    "    max_tokens=150,  # Longer response for a story\n",
    "    top_p=0.9,  # Balanced diversity in word choice\n",
    "    stop=[\"\\n\\n\", \"THE END\"],  # Multiple stop sequences\n",
    "    presence_penalty=0.3,  # Encourage novel elements\n",
    "    frequency_penalty=0.3,  # Reduce repetitive phrases\n",
    "    n=1,  # Generate one completion\n",
    "    seed=123,  # For reproducible results\n",
    ")\n",
    "\n",
    "print_highlight(f\"Response: {response}\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Structured Outputs (JSON, Regex, EBNF)\n",
    "\n",
    "For OpenAI compatible structed outputs API, refer to [Structured Outputs](https://docs.sglang.ai/backend/structured_outputs.html#OpenAI-Compatible-API) for more details.\n"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Batches\n",
    "\n",
    "Batches API for chat completions and completions are also supported. You can upload your requests in `jsonl` files, create a batch job, and retrieve the results when the batch job is completed (which takes longer but costs less).\n",
    "\n",
    "The batches APIs are:\n",
    "\n",
    "- `batches`\n",
    "- `batches/{batch_id}/cancel`\n",
    "- `batches/{batch_id}`\n",
    "\n",
    "Here is an example of a batch job for chat completions, completions are similar.\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "import json\n",
    "import time\n",
    "from openai import OpenAI\n",
    "\n",
    "client = OpenAI(base_url=f\"http://127.0.0.1:{port}/v1\", api_key=\"None\")\n",
    "\n",
    "requests = [\n",
    "    {\n",
    "        \"custom_id\": \"request-1\",\n",
    "        \"method\": \"POST\",\n",
    "        \"url\": \"/chat/completions\",\n",
    "        \"body\": {\n",
    "            \"model\": \"qwen/qwen2.5-0.5b-instruct\",\n",
    "            \"messages\": [\n",
    "                {\"role\": \"user\", \"content\": \"Tell me a joke about programming\"}\n",
    "            ],\n",
    "            \"max_tokens\": 50,\n",
    "        },\n",
    "    },\n",
    "    {\n",
    "        \"custom_id\": \"request-2\",\n",
    "        \"method\": \"POST\",\n",
    "        \"url\": \"/chat/completions\",\n",
    "        \"body\": {\n",
    "            \"model\": \"qwen/qwen2.5-0.5b-instruct\",\n",
    "            \"messages\": [{\"role\": \"user\", \"content\": \"What is Python?\"}],\n",
    "            \"max_tokens\": 50,\n",
    "        },\n",
    "    },\n",
    "]\n",
    "\n",
    "input_file_path = \"batch_requests.jsonl\"\n",
    "\n",
    "with open(input_file_path, \"w\") as f:\n",
    "    for req in requests:\n",
    "        f.write(json.dumps(req) + \"\\n\")\n",
    "\n",
    "with open(input_file_path, \"rb\") as f:\n",
    "    file_response = client.files.create(file=f, purpose=\"batch\")\n",
    "\n",
    "batch_response = client.batches.create(\n",
    "    input_file_id=file_response.id,\n",
    "    endpoint=\"/v1/chat/completions\",\n",
    "    completion_window=\"24h\",\n",
    ")\n",
    "\n",
    "print_highlight(f\"Batch job created with ID: {batch_response.id}\")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "while batch_response.status not in [\"completed\", \"failed\", \"cancelled\"]:\n",
    "    time.sleep(3)\n",
    "    print(f\"Batch job status: {batch_response.status}...trying again in 3 seconds...\")\n",
    "    batch_response = client.batches.retrieve(batch_response.id)\n",
    "\n",
    "if batch_response.status == \"completed\":\n",
    "    print(\"Batch job completed successfully!\")\n",
    "    print(f\"Request counts: {batch_response.request_counts}\")\n",
    "\n",
    "    result_file_id = batch_response.output_file_id\n",
    "    file_response = client.files.content(result_file_id)\n",
    "    result_content = file_response.read().decode(\"utf-8\")\n",
    "\n",
    "    results = [\n",
    "        json.loads(line) for line in result_content.split(\"\\n\") if line.strip() != \"\"\n",
    "    ]\n",
    "\n",
    "    for result in results:\n",
    "        print_highlight(f\"Request {result['custom_id']}:\")\n",
    "        print_highlight(f\"Response: {result['response']}\")\n",
    "\n",
    "    print_highlight(\"Cleaning up files...\")\n",
    "    # Only delete the result file ID since file_response is just content\n",
    "    client.files.delete(result_file_id)\n",
    "else:\n",
    "    print_highlight(f\"Batch job failed with status: {batch_response.status}\")\n",
    "    if hasattr(batch_response, \"errors\"):\n",
    "        print_highlight(f\"Errors: {batch_response.errors}\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "It takes a while to complete the batch job. You can use these two APIs to retrieve the batch job status or cancel the batch job.\n",
    "\n",
    "1. `batches/{batch_id}`: Retrieve the batch job status.\n",
    "2. `batches/{batch_id}/cancel`: Cancel the batch job.\n",
    "\n",
    "Here is an example to check the batch job status."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "import json\n",
    "import time\n",
    "from openai import OpenAI\n",
    "\n",
    "client = OpenAI(base_url=f\"http://127.0.0.1:{port}/v1\", api_key=\"None\")\n",
    "\n",
    "requests = []\n",
    "for i in range(20):\n",
    "    requests.append(\n",
    "        {\n",
    "            \"custom_id\": f\"request-{i}\",\n",
    "            \"method\": \"POST\",\n",
    "            \"url\": \"/chat/completions\",\n",
    "            \"body\": {\n",
    "                \"model\": \"qwen/qwen2.5-0.5b-instruct\",\n",
    "                \"messages\": [\n",
    "                    {\n",
    "                        \"role\": \"system\",\n",
    "                        \"content\": f\"{i}: You are a helpful AI assistant\",\n",
    "                    },\n",
    "                    {\n",
    "                        \"role\": \"user\",\n",
    "                        \"content\": \"Write a detailed story about topic. Make it very long.\",\n",
    "                    },\n",
    "                ],\n",
    "                \"max_tokens\": 64,\n",
    "            },\n",
    "        }\n",
    "    )\n",
    "\n",
    "input_file_path = \"batch_requests.jsonl\"\n",
    "with open(input_file_path, \"w\") as f:\n",
    "    for req in requests:\n",
    "        f.write(json.dumps(req) + \"\\n\")\n",
    "\n",
    "with open(input_file_path, \"rb\") as f:\n",
    "    uploaded_file = client.files.create(file=f, purpose=\"batch\")\n",
    "\n",
    "batch_job = client.batches.create(\n",
    "    input_file_id=uploaded_file.id,\n",
    "    endpoint=\"/v1/chat/completions\",\n",
    "    completion_window=\"24h\",\n",
    ")\n",
    "\n",
    "print_highlight(f\"Created batch job with ID: {batch_job.id}\")\n",
    "print_highlight(f\"Initial status: {batch_job.status}\")\n",
    "\n",
    "time.sleep(10)\n",
    "\n",
    "max_checks = 5\n",
    "for i in range(max_checks):\n",
    "    batch_details = client.batches.retrieve(batch_id=batch_job.id)\n",
    "\n",
    "    print_highlight(\n",
    "        f\"Batch job details (check {i+1} / {max_checks}) // ID: {batch_details.id} // Status: {batch_details.status} // Created at: {batch_details.created_at} // Input file ID: {batch_details.input_file_id} // Output file ID: {batch_details.output_file_id}\"\n",
    "    )\n",
    "    print_highlight(\n",
    "        f\"<strong>Request counts: Total: {batch_details.request_counts.total} // Completed: {batch_details.request_counts.completed} // Failed: {batch_details.request_counts.failed}</strong>\"\n",
    "    )\n",
    "\n",
    "    time.sleep(3)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Here is an example to cancel a batch job."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "import json\n",
    "import time\n",
    "from openai import OpenAI\n",
    "import os\n",
    "\n",
    "client = OpenAI(base_url=f\"http://127.0.0.1:{port}/v1\", api_key=\"None\")\n",
    "\n",
    "requests = []\n",
    "for i in range(5000):\n",
    "    requests.append(\n",
    "        {\n",
    "            \"custom_id\": f\"request-{i}\",\n",
    "            \"method\": \"POST\",\n",
    "            \"url\": \"/chat/completions\",\n",
    "            \"body\": {\n",
    "                \"model\": \"qwen/qwen2.5-0.5b-instruct\",\n",
    "                \"messages\": [\n",
    "                    {\n",
    "                        \"role\": \"system\",\n",
    "                        \"content\": f\"{i}: You are a helpful AI assistant\",\n",
    "                    },\n",
    "                    {\n",
    "                        \"role\": \"user\",\n",
    "                        \"content\": \"Write a detailed story about topic. Make it very long.\",\n",
    "                    },\n",
    "                ],\n",
    "                \"max_tokens\": 128,\n",
    "            },\n",
    "        }\n",
    "    )\n",
    "\n",
    "input_file_path = \"batch_requests.jsonl\"\n",
    "with open(input_file_path, \"w\") as f:\n",
    "    for req in requests:\n",
    "        f.write(json.dumps(req) + \"\\n\")\n",
    "\n",
    "with open(input_file_path, \"rb\") as f:\n",
    "    uploaded_file = client.files.create(file=f, purpose=\"batch\")\n",
    "\n",
    "batch_job = client.batches.create(\n",
    "    input_file_id=uploaded_file.id,\n",
    "    endpoint=\"/v1/chat/completions\",\n",
    "    completion_window=\"24h\",\n",
    ")\n",
    "\n",
    "print_highlight(f\"Created batch job with ID: {batch_job.id}\")\n",
    "print_highlight(f\"Initial status: {batch_job.status}\")\n",
    "\n",
    "time.sleep(10)\n",
    "\n",
    "try:\n",
    "    cancelled_job = client.batches.cancel(batch_id=batch_job.id)\n",
    "    print_highlight(f\"Cancellation initiated. Status: {cancelled_job.status}\")\n",
    "    assert cancelled_job.status == \"cancelling\"\n",
    "\n",
    "    # Monitor the cancellation process\n",
    "    while cancelled_job.status not in [\"failed\", \"cancelled\"]:\n",
    "        time.sleep(3)\n",
    "        cancelled_job = client.batches.retrieve(batch_job.id)\n",
    "        print_highlight(f\"Current status: {cancelled_job.status}\")\n",
    "\n",
    "    # Verify final status\n",
    "    assert cancelled_job.status == \"cancelled\"\n",
    "    print_highlight(\"Batch job successfully cancelled\")\n",
    "\n",
    "except Exception as e:\n",
    "    print_highlight(f\"Error during cancellation: {e}\")\n",
    "    raise e\n",
    "\n",
    "finally:\n",
    "    try:\n",
    "        del_response = client.files.delete(uploaded_file.id)\n",
    "        if del_response.deleted:\n",
    "            print_highlight(\"Successfully cleaned up input file\")\n",
    "        if os.path.exists(input_file_path):\n",
    "            os.remove(input_file_path)\n",
    "            print_highlight(\"Successfully deleted local batch_requests.jsonl file\")\n",
    "    except Exception as e:\n",
    "        print_highlight(f\"Error cleaning up: {e}\")\n",
    "        raise e"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "terminate_process(server_process)"
   ]
  }
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