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<div class="bd-toc-item navbar-nav"><p aria-level="2" class="caption" role="heading"><span class="caption-text">Getting Started</span></p>
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<li class="toctree-l1"><a class="reference internal" href="../overview.html">Overview</a></li>
<li class="toctree-l1"><a class="reference internal" href="../quick-start-guide.html">Quick Start Guide</a></li>
<li class="toctree-l1 has-children"><a class="reference internal" href="../installation/index.html">Installation</a><details><summary><span class="toctree-toggle" role="presentation"><i class="fa-solid fa-chevron-down"></i></span></summary><ul>
<li class="toctree-l2"><a class="reference internal" href="../installation/containers.html">Pre-built release container images on NGC</a></li>
<li class="toctree-l2"><a class="reference internal" href="../installation/linux.html">Installing on Linux via <code class="docutils literal notranslate"><span class="pre">pip</span></code></a></li>
<li class="toctree-l2"><a class="reference internal" href="../installation/build-from-source-linux.html">Building from Source Code on Linux</a></li>
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<p aria-level="2" class="caption" role="heading"><span class="caption-text">Deployment Guide</span></p>
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<li class="toctree-l1 has-children"><a class="reference internal" href="../examples/llm_api_examples.html">LLM Examples</a><details><summary><span class="toctree-toggle" role="presentation"><i class="fa-solid fa-chevron-down"></i></span></summary><ul>
<li class="toctree-l2"><a class="reference internal" href="../examples/llm_inference.html">Generate text</a></li>
<li class="toctree-l2"><a class="reference internal" href="../examples/llm_inference_async.html">Generate text asynchronously</a></li>
<li class="toctree-l2"><a class="reference internal" href="../examples/llm_inference_async_streaming.html">Generate text in streaming</a></li>
<li class="toctree-l2"><a class="reference internal" href="../examples/llm_inference_distributed.html">Distributed LLM Generation</a></li>
<li class="toctree-l2"><a class="reference internal" href="../examples/llm_guided_decoding.html">Generate text with guided decoding</a></li>
<li class="toctree-l2"><a class="reference internal" href="../examples/llm_logits_processor.html">Control generated text using logits processor</a></li>
<li class="toctree-l2"><a class="reference internal" href="../examples/llm_multilora.html">Generate text with multiple LoRA adapters</a></li>
<li class="toctree-l2"><a class="reference internal" href="../examples/llm_sparse_attention.html">Sparse Attention</a></li>
<li class="toctree-l2"><a class="reference internal" href="../examples/llm_speculative_decoding.html">Speculative Decoding</a></li>
<li class="toctree-l2"><a class="reference internal" href="../examples/llm_kv_cache_connector.html">KV Cache Connector</a></li>
<li class="toctree-l2"><a class="reference internal" href="../examples/llm_kv_cache_offloading.html">KV Cache Offloading</a></li>
<li class="toctree-l2"><a class="reference internal" href="../examples/llm_runtime.html">Runtime Configuration Examples</a></li>
<li class="toctree-l2"><a class="reference internal" href="../examples/llm_sampling.html">Sampling Techniques Showcase</a></li>
<li class="toctree-l2"><a class="reference internal" href="../examples/llm_mgmn_llm_distributed.html">Run LLM-API with pytorch backend on Slurm</a></li>
<li class="toctree-l2"><a class="reference internal" href="../examples/llm_mgmn_trtllm_bench.html">Run trtllm-bench with pytorch backend on Slurm</a></li>
<li class="toctree-l2"><a class="reference internal" href="../examples/llm_mgmn_trtllm_serve.html">Run trtllm-serve with pytorch backend on Slurm</a></li>
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<li class="toctree-l1 has-children"><a class="reference internal" href="../examples/trtllm_serve_examples.html">Online Serving Examples</a><details><summary><span class="toctree-toggle" role="presentation"><i class="fa-solid fa-chevron-down"></i></span></summary><ul>
<li class="toctree-l2"><a class="reference internal" href="../examples/curl_chat_client.html">Curl Chat Client</a></li>
<li class="toctree-l2"><a class="reference internal" href="../examples/curl_chat_client_for_multimodal.html">Curl Chat Client For Multimodal</a></li>
<li class="toctree-l2"><a class="reference internal" href="../examples/curl_completion_client.html">Curl Completion Client</a></li>
<li class="toctree-l2"><a class="reference internal" href="../examples/curl_responses_client.html">Curl Responses Client</a></li>
<li class="toctree-l2"><a class="reference internal" href="../examples/deepseek_r1_reasoning_parser.html">Deepseek R1 Reasoning Parser</a></li>
<li class="toctree-l2"><a class="reference internal" href="../examples/genai_perf_client.html">Genai Perf Client</a></li>
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<li class="toctree-l1 has-children"><a class="reference internal" href="../deployment-guide/index.html">Model Recipes</a><details><summary><span class="toctree-toggle" role="presentation"><i class="fa-solid fa-chevron-down"></i></span></summary><ul>
<li class="toctree-l2"><a class="reference internal" href="../deployment-guide/deployment-guide-for-deepseek-r1-on-trtllm.html">Deployment Guide for DeepSeek R1 on TensorRT LLM - Blackwell &amp; Hopper Hardware</a></li>
<li class="toctree-l2"><a class="reference internal" href="../deployment-guide/deployment-guide-for-llama3.3-70b-on-trtllm.html">Deployment Guide for Llama3.3 70B on TensorRT LLM - Blackwell &amp; Hopper Hardware</a></li>
<li class="toctree-l2"><a class="reference internal" href="../deployment-guide/deployment-guide-for-llama4-scout-on-trtllm.html">Deployment Guide for Llama4 Scout 17B on TensorRT LLM - Blackwell &amp; Hopper Hardware</a></li>
<li class="toctree-l2"><a class="reference internal" href="../deployment-guide/deployment-guide-for-gpt-oss-on-trtllm.html">Deployment Guide for GPT-OSS on TensorRT-LLM - Blackwell Hardware</a></li>
<li class="toctree-l2"><a class="reference internal" href="../deployment-guide/deployment-guide-for-qwen3-on-trtllm.html">Deployment Guide for Qwen3 on TensorRT LLM - Blackwell &amp; Hopper Hardware</a></li>
<li class="toctree-l2"><a class="reference internal" href="../deployment-guide/deployment-guide-for-qwen3-next-on-trtllm.html">Deployment Guide for Qwen3 Next on TensorRT LLM - Blackwell &amp; Hopper Hardware</a></li>
<li class="toctree-l2"><a class="reference internal" href="../deployment-guide/deployment-guide-for-kimi-k2-thinking-on-trtllm.html">Deployment Guide for Kimi K2 Thinking on TensorRT LLM - Blackwell</a></li>
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<p aria-level="2" class="caption" role="heading"><span class="caption-text">Models</span></p>
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<li class="toctree-l2"><a class="reference internal" href="../commands/trtllm-serve/run-benchmark-with-trtllm-serve.html">Run benchmarking with <code class="docutils literal notranslate"><span class="pre">trtllm-serve</span></code></a></li>
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<p aria-level="2" class="caption" role="heading"><span class="caption-text">API Reference</span></p>
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<li class="toctree-l1"><a class="reference internal" href="../llm-api/index.html">LLM API Introduction</a></li>
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<p aria-level="2" class="caption" role="heading"><span class="caption-text">Features</span></p>
<ul class="current nav bd-sidenav">
<li class="toctree-l1"><a class="reference internal" href="feature-combination-matrix.html">Feature Combination Matrix</a></li>
<li class="toctree-l1"><a class="reference internal" href="attention.html">Multi-Head, Multi-Query, and Group-Query Attention</a></li>
<li class="toctree-l1"><a class="reference internal" href="disagg-serving.html">Disaggregated Serving</a></li>
<li class="toctree-l1"><a class="reference internal" href="kvcache.html">KV Cache System</a></li>
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<li class="toctree-l1"><a class="reference internal" href="multi-modality.html">Multimodal Support in TensorRT LLM</a></li>
<li class="toctree-l1"><a class="reference internal" href="overlap-scheduler.html">Overlap Scheduler</a></li>
<li class="toctree-l1"><a class="reference internal" href="paged-attention-ifb-scheduler.html">Paged Attention, IFB, and Request Scheduling</a></li>
<li class="toctree-l1"><a class="reference internal" href="parallel-strategy.html">Parallelism in TensorRT LLM</a></li>
<li class="toctree-l1"><a class="reference internal" href="quantization.html">Quantization</a></li>
<li class="toctree-l1"><a class="reference internal" href="sampling.html">Sampling</a></li>
<li class="toctree-l1"><a class="reference internal" href="additional-outputs.html">Additional Outputs</a></li>
<li class="toctree-l1 current active"><a class="current reference internal" href="#">Guided Decoding</a></li>
<li class="toctree-l1"><a class="reference internal" href="speculative-decoding.html">Speculative Decoding</a></li>
<li class="toctree-l1"><a class="reference internal" href="checkpoint-loading.html">Checkpoint Loading</a></li>
<li class="toctree-l1"><a class="reference internal" href="auto_deploy/auto-deploy.html">AutoDeploy (Prototype)</a></li>
<li class="toctree-l1"><a class="reference internal" href="ray-orchestrator.html">Ray Orchestrator (Prototype)</a></li>
<li class="toctree-l1"><a class="reference internal" href="torch_compile_and_piecewise_cuda_graph.html">Torch Compile &amp; Piecewise CUDA Graph</a></li>
<li class="toctree-l1"><a class="reference internal" href="helix.html">Helix Parallelism</a></li>
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<li class="toctree-l1"><a class="reference internal" href="../developer-guide/perf-benchmarking.html">TensorRT LLM Benchmarking</a></li>
<li class="toctree-l1"><a class="reference internal" href="../developer-guide/ci-overview.html">Continuous Integration Overview</a></li>
<li class="toctree-l1"><a class="reference internal" href="../developer-guide/dev-containers.html">Using Dev Containers</a></li>
<li class="toctree-l1"><a class="reference internal" href="../developer-guide/api-change.html">LLM API Change Guide</a></li>
<li class="toctree-l1"><a class="reference internal" href="../developer-guide/kv-transfer.html">Introduction to KV Cache Transmission</a></li>
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<section class="tex2jax_ignore mathjax_ignore" id="guided-decoding">
<h1>Guided Decoding<a class="headerlink" href="#guided-decoding" title="Link to this heading">#</a></h1>
<p>Guided decoding (or interchangeably constrained decoding, structured generation) guarantees that the LLM outputs are amenable to a user-specified grammar (e.g., JSON schema, <a class="reference external" href="https://en.wikipedia.org/wiki/Regular_expression">regular expression</a> or <a class="reference external" href="https://en.wikipedia.org/wiki/Extended_Backus%E2%80%93Naur_form">EBNF</a> grammar).</p>
<p>TensorRT LLM supports two grammar backends:</p>
<ul class="simple">
<li><p><a class="reference external" href="https://github.com/mlc-ai/xgrammar/blob/v0.1.21/python/xgrammar/matcher.py#L341-L350">XGrammar</a>: Supports JSON schema, regular expression, EBNF and <a class="reference external" href="https://xgrammar.mlc.ai/docs/tutorials/structural_tag.html">structural tag</a>.</p></li>
<li><p><a class="reference external" href="https://github.com/guidance-ai/llguidance/blob/v1.1.1/python/llguidance/_lib.pyi#L363-L366">LLGuidance</a>: Supports JSON schema, regular expression, EBNF.</p></li>
</ul>
<section id="online-api-trtllm-serve">
<h2>Online API: <code class="docutils literal notranslate"><span class="pre">trtllm-serve</span></code><a class="headerlink" href="#online-api-trtllm-serve" title="Link to this heading">#</a></h2>
<p>If you are using <code class="docutils literal notranslate"><span class="pre">trtllm-serve</span></code>, enable guided decoding by specifying <code class="docutils literal notranslate"><span class="pre">guided_decoding_backend</span></code> with <code class="docutils literal notranslate"><span class="pre">xgrammar</span></code> or <code class="docutils literal notranslate"><span class="pre">llguidance</span></code> in the YAML configuration file, and pass it to <code class="docutils literal notranslate"><span class="pre">--extra_llm_api_options</span></code>. For example,</p>
<div class="highlight-bash notranslate"><div class="highlight"><pre><span></span>cat<span class="w"> </span>&gt;<span class="w"> </span>extra_llm_api_options.yaml<span class="w"> </span><span class="s">&lt;&lt;EOF</span>
<span class="s">guided_decoding_backend: xgrammar</span>
<span class="s">EOF</span>
trtllm-serve<span class="w"> </span>nvidia/Llama-3.1-8B-Instruct-FP8<span class="w"> </span>--extra_llm_api_options<span class="w"> </span>extra_llm_api_options.yaml
</pre></div>
</div>
<p>You should see a log like the following, which indicates the grammar backend is successfully enabled.</p>
<div class="highlight-txt notranslate"><div class="highlight"><pre><span></span>......
[TRT-LLM] [I] Guided decoder initialized with backend: GuidedDecodingBackend.XGRAMMAR
......
</pre></div>
</div>
<section id="json-schema">
<h3>JSON Schema<a class="headerlink" href="#json-schema" title="Link to this heading">#</a></h3>
<p>Define a JSON schema and pass it to <code class="docutils literal notranslate"><span class="pre">response_format</span></code> when creating the OpenAI chat completion request. Alternatively, the JSON schema can be created using <a class="reference external" href="https://docs.pydantic.dev/latest/">pydantic</a>.</p>
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="kn">from</span><span class="w"> </span><span class="nn">openai</span><span class="w"> </span><span class="kn">import</span> <span class="n">OpenAI</span>
<span class="n">client</span> <span class="o">=</span> <span class="n">OpenAI</span><span class="p">(</span>
<span class="n">base_url</span><span class="o">=</span><span class="s2">&quot;http://localhost:8000/v1&quot;</span><span class="p">,</span>
<span class="n">api_key</span><span class="o">=</span><span class="s2">&quot;tensorrt_llm&quot;</span><span class="p">,</span>
<span class="p">)</span>
<span class="n">json_schema</span> <span class="o">=</span> <span class="p">{</span>
<span class="s2">&quot;type&quot;</span><span class="p">:</span> <span class="s2">&quot;object&quot;</span><span class="p">,</span>
<span class="s2">&quot;properties&quot;</span><span class="p">:</span> <span class="p">{</span>
<span class="s2">&quot;name&quot;</span><span class="p">:</span> <span class="p">{</span>
<span class="s2">&quot;type&quot;</span><span class="p">:</span> <span class="s2">&quot;string&quot;</span><span class="p">,</span>
<span class="s2">&quot;pattern&quot;</span><span class="p">:</span> <span class="s2">&quot;^[</span><span class="se">\\</span><span class="s2">w]+$&quot;</span>
<span class="p">},</span>
<span class="s2">&quot;population&quot;</span><span class="p">:</span> <span class="p">{</span>
<span class="s2">&quot;type&quot;</span><span class="p">:</span> <span class="s2">&quot;integer&quot;</span>
<span class="p">},</span>
<span class="p">},</span>
<span class="s2">&quot;required&quot;</span><span class="p">:</span> <span class="p">[</span><span class="s2">&quot;name&quot;</span><span class="p">,</span> <span class="s2">&quot;population&quot;</span><span class="p">],</span>
<span class="p">}</span>
<span class="n">messages</span> <span class="o">=</span> <span class="p">[</span>
<span class="p">{</span>
<span class="s2">&quot;role&quot;</span><span class="p">:</span> <span class="s2">&quot;system&quot;</span><span class="p">,</span>
<span class="s2">&quot;content&quot;</span><span class="p">:</span> <span class="s2">&quot;You are a helpful assistant.&quot;</span><span class="p">,</span>
<span class="p">},</span>
<span class="p">{</span>
<span class="s2">&quot;role&quot;</span><span class="p">:</span> <span class="s2">&quot;user&quot;</span><span class="p">,</span>
<span class="s2">&quot;content&quot;</span><span class="p">:</span> <span class="s2">&quot;Give me the information of the capital of France in the JSON format.&quot;</span><span class="p">,</span>
<span class="p">},</span>
<span class="p">]</span>
<span class="n">chat_completion</span> <span class="o">=</span> <span class="n">client</span><span class="o">.</span><span class="n">chat</span><span class="o">.</span><span class="n">completions</span><span class="o">.</span><span class="n">create</span><span class="p">(</span>
<span class="n">model</span><span class="o">=</span><span class="s2">&quot;nvidia/Llama-3.1-8B-Instruct-FP8&quot;</span><span class="p">,</span>
<span class="n">messages</span><span class="o">=</span><span class="n">messages</span><span class="p">,</span>
<span class="n">max_completion_tokens</span><span class="o">=</span><span class="mi">256</span><span class="p">,</span>
<span class="n">response_format</span><span class="o">=</span><span class="p">{</span>
<span class="s2">&quot;type&quot;</span><span class="p">:</span> <span class="s2">&quot;json&quot;</span><span class="p">,</span>
<span class="s2">&quot;schema&quot;</span><span class="p">:</span> <span class="n">json_schema</span>
<span class="p">},</span>
<span class="p">)</span>
<span class="n">message</span> <span class="o">=</span> <span class="n">chat_completion</span><span class="o">.</span><span class="n">choices</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span><span class="o">.</span><span class="n">message</span>
<span class="nb">print</span><span class="p">(</span><span class="n">message</span><span class="o">.</span><span class="n">content</span><span class="p">)</span>
</pre></div>
</div>
<p>The output would look like:</p>
<div class="highlight-txt notranslate"><div class="highlight"><pre><span></span>{
&quot;name&quot;: &quot;Paris&quot;,
&quot;population&quot;: 2145200
}
</pre></div>
</div>
</section>
<section id="regular-expression">
<h3>Regular expression<a class="headerlink" href="#regular-expression" title="Link to this heading">#</a></h3>
<p>Define a regular expression and pass it to <code class="docutils literal notranslate"><span class="pre">response_format</span></code> when creating the OpenAI chat completion request.</p>
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="kn">from</span><span class="w"> </span><span class="nn">openai</span><span class="w"> </span><span class="kn">import</span> <span class="n">OpenAI</span>
<span class="n">client</span> <span class="o">=</span> <span class="n">OpenAI</span><span class="p">(</span>
<span class="n">base_url</span><span class="o">=</span><span class="s2">&quot;http://localhost:8000/v1&quot;</span><span class="p">,</span>
<span class="n">api_key</span><span class="o">=</span><span class="s2">&quot;tensorrt_llm&quot;</span><span class="p">,</span>
<span class="p">)</span>
<span class="n">messages</span> <span class="o">=</span> <span class="p">[</span>
<span class="p">{</span>
<span class="s2">&quot;role&quot;</span><span class="p">:</span> <span class="s2">&quot;system&quot;</span><span class="p">,</span>
<span class="s2">&quot;content&quot;</span><span class="p">:</span> <span class="s2">&quot;You are a helpful assistant.&quot;</span><span class="p">,</span>
<span class="p">},</span>
<span class="p">{</span>
<span class="s2">&quot;role&quot;</span><span class="p">:</span> <span class="s2">&quot;user&quot;</span><span class="p">,</span>
<span class="s2">&quot;content&quot;</span><span class="p">:</span> <span class="s2">&quot;What is the capital of France?&quot;</span><span class="p">,</span>
<span class="p">},</span>
<span class="p">]</span>
<span class="n">chat_completion</span> <span class="o">=</span> <span class="n">client</span><span class="o">.</span><span class="n">chat</span><span class="o">.</span><span class="n">completions</span><span class="o">.</span><span class="n">create</span><span class="p">(</span>
<span class="n">model</span><span class="o">=</span><span class="s2">&quot;nvidia/Llama-3.1-8B-Instruct-FP8&quot;</span><span class="p">,</span>
<span class="n">messages</span><span class="o">=</span><span class="n">messages</span><span class="p">,</span>
<span class="n">max_completion_tokens</span><span class="o">=</span><span class="mi">256</span><span class="p">,</span>
<span class="n">response_format</span><span class="o">=</span><span class="p">{</span>
<span class="s2">&quot;type&quot;</span><span class="p">:</span> <span class="s2">&quot;regex&quot;</span><span class="p">,</span>
<span class="s2">&quot;regex&quot;</span><span class="p">:</span> <span class="s2">&quot;(Paris|London)&quot;</span>
<span class="p">},</span>
<span class="p">)</span>
<span class="n">message</span> <span class="o">=</span> <span class="n">chat_completion</span><span class="o">.</span><span class="n">choices</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span><span class="o">.</span><span class="n">message</span>
<span class="nb">print</span><span class="p">(</span><span class="n">message</span><span class="o">.</span><span class="n">content</span><span class="p">)</span>
</pre></div>
</div>
<p>The output would look like:</p>
<div class="highlight-txt notranslate"><div class="highlight"><pre><span></span>Paris
</pre></div>
</div>
</section>
<section id="ebnf-grammar">
<h3>EBNF grammar<a class="headerlink" href="#ebnf-grammar" title="Link to this heading">#</a></h3>
<p>Define an EBNF grammar and pass it to <code class="docutils literal notranslate"><span class="pre">response_format</span></code> when creating the OpenAI chat completion request.</p>
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="kn">from</span><span class="w"> </span><span class="nn">openai</span><span class="w"> </span><span class="kn">import</span> <span class="n">OpenAI</span>
<span class="n">client</span> <span class="o">=</span> <span class="n">OpenAI</span><span class="p">(</span>
<span class="n">base_url</span><span class="o">=</span><span class="s2">&quot;http://localhost:8000/v1&quot;</span><span class="p">,</span>
<span class="n">api_key</span><span class="o">=</span><span class="s2">&quot;tensorrt_llm&quot;</span><span class="p">,</span>
<span class="p">)</span>
<span class="n">ebnf_grammar</span> <span class="o">=</span> <span class="s2">&quot;&quot;&quot;root ::= description</span>
<span class="s2">city ::= &quot;London&quot; | &quot;Paris&quot; | &quot;Berlin&quot; | &quot;Rome&quot;</span>
<span class="s2">description ::= city &quot; is &quot; status</span>
<span class="s2">status ::= &quot;the capital of &quot; country</span>
<span class="s2">country ::= &quot;England&quot; | &quot;France&quot; | &quot;Germany&quot; | &quot;Italy&quot;</span>
<span class="s2">&quot;&quot;&quot;</span>
<span class="n">messages</span> <span class="o">=</span> <span class="p">[</span>
<span class="p">{</span>
<span class="s2">&quot;role&quot;</span><span class="p">:</span> <span class="s2">&quot;system&quot;</span><span class="p">,</span>
<span class="s2">&quot;content&quot;</span><span class="p">:</span> <span class="s2">&quot;You are a helpful geography bot.&quot;</span>
<span class="p">},</span>
<span class="p">{</span>
<span class="s2">&quot;role&quot;</span><span class="p">:</span> <span class="s2">&quot;user&quot;</span><span class="p">,</span>
<span class="s2">&quot;content&quot;</span><span class="p">:</span> <span class="s2">&quot;Give me the information of the capital of France.&quot;</span><span class="p">,</span>
<span class="p">},</span>
<span class="p">]</span>
<span class="n">chat_completion</span> <span class="o">=</span> <span class="n">client</span><span class="o">.</span><span class="n">chat</span><span class="o">.</span><span class="n">completions</span><span class="o">.</span><span class="n">create</span><span class="p">(</span>
<span class="n">model</span><span class="o">=</span><span class="s2">&quot;nvidia/Llama-3.1-8B-Instruct-FP8&quot;</span><span class="p">,</span>
<span class="n">messages</span><span class="o">=</span><span class="n">messages</span><span class="p">,</span>
<span class="n">max_completion_tokens</span><span class="o">=</span><span class="mi">256</span><span class="p">,</span>
<span class="n">response_format</span><span class="o">=</span><span class="p">{</span>
<span class="s2">&quot;type&quot;</span><span class="p">:</span> <span class="s2">&quot;ebnf&quot;</span><span class="p">,</span>
<span class="s2">&quot;ebnf&quot;</span><span class="p">:</span> <span class="n">ebnf_grammar</span>
<span class="p">},</span>
<span class="p">)</span>
<span class="n">message</span> <span class="o">=</span> <span class="n">chat_completion</span><span class="o">.</span><span class="n">choices</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span><span class="o">.</span><span class="n">message</span>
<span class="nb">print</span><span class="p">(</span><span class="n">message</span><span class="o">.</span><span class="n">content</span><span class="p">)</span>
</pre></div>
</div>
<p>The output would look like:</p>
<div class="highlight-txt notranslate"><div class="highlight"><pre><span></span>Paris is the capital of France
</pre></div>
</div>
</section>
<section id="structural-tag">
<h3>Structural tag<a class="headerlink" href="#structural-tag" title="Link to this heading">#</a></h3>
<p>Define a structural tag and pass it to <code class="docutils literal notranslate"><span class="pre">response_format</span></code> when creating the OpenAI chat completion request.</p>
<p>Structural tag is supported by <code class="docutils literal notranslate"><span class="pre">xgrammar</span></code> backend only. It is a powerful and flexible tool to represent the LLM output constraints. Please see <a class="reference external" href="https://xgrammar.mlc.ai/docs/tutorials/structural_tag.html">structural tag usage</a> for a comprehensive tutorial. Below is an example of function calling with customized function call format for <code class="docutils literal notranslate"><span class="pre">Llama-3.1-8B-Instruct</span></code>.</p>
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="kn">from</span><span class="w"> </span><span class="nn">openai</span><span class="w"> </span><span class="kn">import</span> <span class="n">OpenAI</span>
<span class="n">client</span> <span class="o">=</span> <span class="n">OpenAI</span><span class="p">(</span>
<span class="n">base_url</span><span class="o">=</span><span class="s2">&quot;http://localhost:8000/v1&quot;</span><span class="p">,</span>
<span class="n">api_key</span><span class="o">=</span><span class="s2">&quot;tensorrt_llm&quot;</span><span class="p">,</span>
<span class="p">)</span>
<span class="n">tool_get_current_weather</span> <span class="o">=</span> <span class="p">{</span>
<span class="s2">&quot;type&quot;</span><span class="p">:</span> <span class="s2">&quot;function&quot;</span><span class="p">,</span>
<span class="s2">&quot;function&quot;</span><span class="p">:</span> <span class="p">{</span>
<span class="s2">&quot;name&quot;</span><span class="p">:</span> <span class="s2">&quot;get_current_weather&quot;</span><span class="p">,</span>
<span class="s2">&quot;description&quot;</span><span class="p">:</span> <span class="s2">&quot;Get the current weather in a given location&quot;</span><span class="p">,</span>
<span class="s2">&quot;parameters&quot;</span><span class="p">:</span> <span class="p">{</span>
<span class="s2">&quot;type&quot;</span><span class="p">:</span> <span class="s2">&quot;object&quot;</span><span class="p">,</span>
<span class="s2">&quot;properties&quot;</span><span class="p">:</span> <span class="p">{</span>
<span class="s2">&quot;city&quot;</span><span class="p">:</span> <span class="p">{</span>
<span class="s2">&quot;type&quot;</span><span class="p">:</span> <span class="s2">&quot;string&quot;</span><span class="p">,</span>
<span class="s2">&quot;description&quot;</span><span class="p">:</span> <span class="s2">&quot;The city to find the weather for, e.g. &#39;San Francisco&#39;&quot;</span><span class="p">,</span>
<span class="p">},</span>
<span class="s2">&quot;state&quot;</span><span class="p">:</span> <span class="p">{</span>
<span class="s2">&quot;type&quot;</span><span class="p">:</span> <span class="s2">&quot;string&quot;</span><span class="p">,</span>
<span class="s2">&quot;description&quot;</span><span class="p">:</span> <span class="s2">&quot;the two-letter abbreviation for the state that the city is in, e.g. &#39;CA&#39; which would mean &#39;California&#39;&quot;</span><span class="p">,</span>
<span class="p">},</span>
<span class="s2">&quot;unit&quot;</span><span class="p">:</span> <span class="p">{</span>
<span class="s2">&quot;type&quot;</span><span class="p">:</span> <span class="s2">&quot;string&quot;</span><span class="p">,</span>
<span class="s2">&quot;description&quot;</span><span class="p">:</span> <span class="s2">&quot;The unit to fetch the temperature in&quot;</span><span class="p">,</span>
<span class="s2">&quot;enum&quot;</span><span class="p">:</span> <span class="p">[</span><span class="s2">&quot;celsius&quot;</span><span class="p">,</span> <span class="s2">&quot;fahrenheit&quot;</span><span class="p">],</span>
<span class="p">},</span>
<span class="p">},</span>
<span class="s2">&quot;required&quot;</span><span class="p">:</span> <span class="p">[</span><span class="s2">&quot;city&quot;</span><span class="p">,</span> <span class="s2">&quot;state&quot;</span><span class="p">,</span> <span class="s2">&quot;unit&quot;</span><span class="p">],</span>
<span class="p">},</span>
<span class="p">},</span>
<span class="p">}</span>
<span class="n">tool_get_current_date</span> <span class="o">=</span> <span class="p">{</span>
<span class="s2">&quot;type&quot;</span><span class="p">:</span> <span class="s2">&quot;function&quot;</span><span class="p">,</span>
<span class="s2">&quot;function&quot;</span><span class="p">:</span> <span class="p">{</span>
<span class="s2">&quot;name&quot;</span><span class="p">:</span> <span class="s2">&quot;get_current_date&quot;</span><span class="p">,</span>
<span class="s2">&quot;description&quot;</span><span class="p">:</span> <span class="s2">&quot;Get the current date and time for a given timezone&quot;</span><span class="p">,</span>
<span class="s2">&quot;parameters&quot;</span><span class="p">:</span> <span class="p">{</span>
<span class="s2">&quot;type&quot;</span><span class="p">:</span> <span class="s2">&quot;object&quot;</span><span class="p">,</span>
<span class="s2">&quot;properties&quot;</span><span class="p">:</span> <span class="p">{</span>
<span class="s2">&quot;timezone&quot;</span><span class="p">:</span> <span class="p">{</span>
<span class="s2">&quot;type&quot;</span><span class="p">:</span> <span class="s2">&quot;string&quot;</span><span class="p">,</span>
<span class="s2">&quot;description&quot;</span><span class="p">:</span> <span class="s2">&quot;The timezone to fetch the current date and time for, e.g. &#39;America/New_York&#39;&quot;</span><span class="p">,</span>
<span class="p">}</span>
<span class="p">},</span>
<span class="s2">&quot;required&quot;</span><span class="p">:</span> <span class="p">[</span><span class="s2">&quot;timezone&quot;</span><span class="p">],</span>
<span class="p">},</span>
<span class="p">},</span>
<span class="p">}</span>
<span class="n">system_prompt</span> <span class="o">=</span> <span class="sa">f</span><span class="s2">&quot;&quot;&quot;# Tool Instructions</span>
<span class="s2">- Always execute python code in messages that you share.</span>
<span class="s2">- When looking for real time information use relevant functions if available else fallback to brave_search</span>
<span class="s2">You have access to the following functions:</span>
<span class="s2">Use the function &#39;get_current_weather&#39; to: Get the current weather in a given location</span>
<span class="si">{</span><span class="n">tool_get_current_weather</span><span class="p">[</span><span class="s2">&quot;function&quot;</span><span class="p">]</span><span class="si">}</span>
<span class="s2">Use the function &#39;get_current_date&#39; to: Get the current date and time for a given timezone</span>
<span class="si">{</span><span class="n">tool_get_current_date</span><span class="p">[</span><span class="s2">&quot;function&quot;</span><span class="p">]</span><span class="si">}</span>
<span class="s2">If a you choose to call a function ONLY reply in the following format:</span>
<span class="s2">&lt;</span><span class="se">{{</span><span class="s2">start_tag</span><span class="se">}}</span><span class="s2">=</span><span class="se">{{</span><span class="s2">function_name</span><span class="se">}}</span><span class="s2">&gt;</span><span class="se">{{</span><span class="s2">parameters</span><span class="se">}}{{</span><span class="s2">end_tag</span><span class="se">}}</span>
<span class="s2">where</span>
<span class="s2">start_tag =&gt; `&lt;function`</span>
<span class="s2">parameters =&gt; a JSON dict with the function argument name as key and function argument value as value.</span>
<span class="s2">end_tag =&gt; `&lt;/function&gt;`</span>
<span class="s2">Here is an example,</span>
<span class="s2">&lt;function=example_function_name&gt;</span><span class="se">{{</span><span class="s2">&quot;example_name&quot;: &quot;example_value&quot;</span><span class="se">}}</span><span class="s2">&lt;/function&gt;</span>
<span class="s2">Reminder:</span>
<span class="s2">- Function calls MUST follow the specified format</span>
<span class="s2">- Required parameters MUST be specified</span>
<span class="s2">- Only call one function at a time</span>
<span class="s2">- Put the entire function call reply on one line</span>
<span class="s2">- Always add your sources when using search results to answer the user query</span>
<span class="s2">You are a helpful assistant.&quot;&quot;&quot;</span>
<span class="n">user_prompt</span> <span class="o">=</span> <span class="s2">&quot;You are in New York. Please get the current date and time, and the weather.&quot;</span>
<span class="n">messages</span> <span class="o">=</span> <span class="p">[</span>
<span class="p">{</span>
<span class="s2">&quot;role&quot;</span><span class="p">:</span> <span class="s2">&quot;system&quot;</span><span class="p">,</span>
<span class="s2">&quot;content&quot;</span><span class="p">:</span> <span class="n">system_prompt</span><span class="p">,</span>
<span class="p">},</span>
<span class="p">{</span>
<span class="s2">&quot;role&quot;</span><span class="p">:</span> <span class="s2">&quot;user&quot;</span><span class="p">,</span>
<span class="s2">&quot;content&quot;</span><span class="p">:</span> <span class="n">user_prompt</span><span class="p">,</span>
<span class="p">},</span>
<span class="p">]</span>
<span class="n">chat_completion</span> <span class="o">=</span> <span class="n">client</span><span class="o">.</span><span class="n">chat</span><span class="o">.</span><span class="n">completions</span><span class="o">.</span><span class="n">create</span><span class="p">(</span>
<span class="n">model</span><span class="o">=</span><span class="s2">&quot;nvidia/Llama-3.1-8B-Instruct-FP8&quot;</span><span class="p">,</span>
<span class="n">messages</span><span class="o">=</span><span class="n">messages</span><span class="p">,</span>
<span class="n">max_completion_tokens</span><span class="o">=</span><span class="mi">256</span><span class="p">,</span>
<span class="n">response_format</span><span class="o">=</span><span class="p">{</span>
<span class="s2">&quot;type&quot;</span><span class="p">:</span> <span class="s2">&quot;structural_tag&quot;</span><span class="p">,</span>
<span class="s2">&quot;format&quot;</span><span class="p">:</span> <span class="p">{</span>
<span class="s2">&quot;type&quot;</span><span class="p">:</span> <span class="s2">&quot;triggered_tags&quot;</span><span class="p">,</span>
<span class="s2">&quot;triggers&quot;</span><span class="p">:</span> <span class="p">[</span><span class="s2">&quot;&lt;function=&quot;</span><span class="p">],</span>
<span class="s2">&quot;tags&quot;</span><span class="p">:</span> <span class="p">[</span>
<span class="p">{</span>
<span class="s2">&quot;begin&quot;</span><span class="p">:</span> <span class="s2">&quot;&lt;function=get_current_weather&gt;&quot;</span><span class="p">,</span>
<span class="s2">&quot;content&quot;</span><span class="p">:</span> <span class="p">{</span>
<span class="s2">&quot;type&quot;</span><span class="p">:</span> <span class="s2">&quot;json_schema&quot;</span><span class="p">,</span>
<span class="s2">&quot;json_schema&quot;</span><span class="p">:</span> <span class="n">tool_get_current_weather</span><span class="p">[</span><span class="s2">&quot;function&quot;</span><span class="p">][</span><span class="s2">&quot;parameters&quot;</span><span class="p">]</span>
<span class="p">},</span>
<span class="s2">&quot;end&quot;</span><span class="p">:</span> <span class="s2">&quot;&lt;/function&gt;&quot;</span><span class="p">,</span>
<span class="p">},</span>
<span class="p">{</span>
<span class="s2">&quot;begin&quot;</span><span class="p">:</span> <span class="s2">&quot;&lt;function=get_current_date&gt;&quot;</span><span class="p">,</span>
<span class="s2">&quot;content&quot;</span><span class="p">:</span> <span class="p">{</span>
<span class="s2">&quot;type&quot;</span><span class="p">:</span> <span class="s2">&quot;json_schema&quot;</span><span class="p">,</span>
<span class="s2">&quot;json_schema&quot;</span><span class="p">:</span> <span class="n">tool_get_current_date</span><span class="p">[</span><span class="s2">&quot;function&quot;</span><span class="p">][</span><span class="s2">&quot;parameters&quot;</span><span class="p">]</span>
<span class="p">},</span>
<span class="s2">&quot;end&quot;</span><span class="p">:</span> <span class="s2">&quot;&lt;/function&gt;&quot;</span><span class="p">,</span>
<span class="p">},</span>
<span class="p">],</span>
<span class="p">},</span>
<span class="p">},</span>
<span class="p">)</span>
<span class="n">message</span> <span class="o">=</span> <span class="n">chat_completion</span><span class="o">.</span><span class="n">choices</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span><span class="o">.</span><span class="n">message</span>
<span class="nb">print</span><span class="p">(</span><span class="n">message</span><span class="o">.</span><span class="n">content</span><span class="p">)</span>
</pre></div>
</div>
<p>The output would look like:</p>
<div class="highlight-txt notranslate"><div class="highlight"><pre><span></span>&lt;function=get_current_date&gt;{&quot;timezone&quot;: &quot;America/New_York&quot;}&lt;/function&gt;
&lt;function=get_current_weather&gt;{&quot;city&quot;: &quot;New York&quot;, &quot;state&quot;: &quot;NY&quot;, &quot;unit&quot;: &quot;fahrenheit&quot;}&lt;/function&gt;
</pre></div>
</div>
</section>
</section>
<section id="offline-api-llm-api">
<h2>Offline API: LLM API<a class="headerlink" href="#offline-api-llm-api" title="Link to this heading">#</a></h2>
<p>If you are using LLM API, enable guided decoding by specifying <code class="docutils literal notranslate"><span class="pre">guided_decoding_backend</span></code> with <code class="docutils literal notranslate"><span class="pre">xgrammar</span></code> or <code class="docutils literal notranslate"><span class="pre">llguidance</span></code> when creating the LLM instance. For example,</p>
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="kn">from</span><span class="w"> </span><span class="nn">tensorrt_llm</span><span class="w"> </span><span class="kn">import</span> <span class="n">LLM</span>
<span class="n">llm</span> <span class="o">=</span> <span class="n">LLM</span><span class="p">(</span><span class="s2">&quot;nvidia/Llama-3.1-8B-Instruct-FP8&quot;</span><span class="p">,</span> <span class="n">guided_decoding_backend</span><span class="o">=</span><span class="s2">&quot;xgrammar&quot;</span><span class="p">)</span>
</pre></div>
</div>
<section id="id1">
<h3>JSON Schema<a class="headerlink" href="#id1" title="Link to this heading">#</a></h3>
<p>Create a <code class="docutils literal notranslate"><span class="pre">GuidedDecodingParams</span></code> with the <code class="docutils literal notranslate"><span class="pre">json</span></code> field specified with a JSON schema, use it to create <code class="docutils literal notranslate"><span class="pre">SamplingParams</span></code>, and then pass to <code class="docutils literal notranslate"><span class="pre">llm.generate</span></code> or <code class="docutils literal notranslate"><span class="pre">llm.generate_async</span></code>. Alternatively, the JSON schema can be created using <a class="reference external" href="https://docs.pydantic.dev/latest/">pydantic</a>.</p>
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="kn">from</span><span class="w"> </span><span class="nn">tensorrt_llm</span><span class="w"> </span><span class="kn">import</span> <span class="n">LLM</span>
<span class="kn">from</span><span class="w"> </span><span class="nn">tensorrt_llm.sampling_params</span><span class="w"> </span><span class="kn">import</span> <span class="n">SamplingParams</span><span class="p">,</span> <span class="n">GuidedDecodingParams</span>
<span class="k">if</span> <span class="vm">__name__</span> <span class="o">==</span> <span class="s2">&quot;__main__&quot;</span><span class="p">:</span>
<span class="n">llm</span> <span class="o">=</span> <span class="n">LLM</span><span class="p">(</span><span class="s2">&quot;nvidia/Llama-3.1-8B-Instruct-FP8&quot;</span><span class="p">,</span> <span class="n">guided_decoding_backend</span><span class="o">=</span><span class="s2">&quot;xgrammar&quot;</span><span class="p">)</span>
<span class="n">json_schema</span> <span class="o">=</span> <span class="p">{</span>
<span class="s2">&quot;type&quot;</span><span class="p">:</span> <span class="s2">&quot;object&quot;</span><span class="p">,</span>
<span class="s2">&quot;properties&quot;</span><span class="p">:</span> <span class="p">{</span>
<span class="s2">&quot;name&quot;</span><span class="p">:</span> <span class="p">{</span>
<span class="s2">&quot;type&quot;</span><span class="p">:</span> <span class="s2">&quot;string&quot;</span><span class="p">,</span>
<span class="s2">&quot;pattern&quot;</span><span class="p">:</span> <span class="s2">&quot;^[</span><span class="se">\\</span><span class="s2">w]+$&quot;</span>
<span class="p">},</span>
<span class="s2">&quot;population&quot;</span><span class="p">:</span> <span class="p">{</span>
<span class="s2">&quot;type&quot;</span><span class="p">:</span> <span class="s2">&quot;integer&quot;</span>
<span class="p">},</span>
<span class="p">},</span>
<span class="s2">&quot;required&quot;</span><span class="p">:</span> <span class="p">[</span><span class="s2">&quot;name&quot;</span><span class="p">,</span> <span class="s2">&quot;population&quot;</span><span class="p">],</span>
<span class="p">}</span>
<span class="n">messages</span> <span class="o">=</span> <span class="p">[</span>
<span class="p">{</span>
<span class="s2">&quot;role&quot;</span><span class="p">:</span> <span class="s2">&quot;system&quot;</span><span class="p">,</span>
<span class="s2">&quot;content&quot;</span><span class="p">:</span> <span class="s2">&quot;You are a helpful assistant.&quot;</span><span class="p">,</span>
<span class="p">},</span>
<span class="p">{</span>
<span class="s2">&quot;role&quot;</span><span class="p">:</span> <span class="s2">&quot;user&quot;</span><span class="p">,</span>
<span class="s2">&quot;content&quot;</span><span class="p">:</span> <span class="s2">&quot;Give me the information of the capital of France in the JSON format.&quot;</span><span class="p">,</span>
<span class="p">},</span>
<span class="p">]</span>
<span class="n">prompt</span> <span class="o">=</span> <span class="n">llm</span><span class="o">.</span><span class="n">tokenizer</span><span class="o">.</span><span class="n">apply_chat_template</span><span class="p">(</span><span class="n">messages</span><span class="p">,</span> <span class="n">tokenize</span><span class="o">=</span><span class="kc">False</span><span class="p">,</span> <span class="n">add_generation_prompt</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span>
<span class="n">output</span> <span class="o">=</span> <span class="n">llm</span><span class="o">.</span><span class="n">generate</span><span class="p">(</span>
<span class="n">prompt</span><span class="p">,</span>
<span class="n">sampling_params</span><span class="o">=</span><span class="n">SamplingParams</span><span class="p">(</span><span class="n">max_tokens</span><span class="o">=</span><span class="mi">256</span><span class="p">,</span> <span class="n">guided_decoding</span><span class="o">=</span><span class="n">GuidedDecodingParams</span><span class="p">(</span><span class="n">json</span><span class="o">=</span><span class="n">json_schema</span><span class="p">)),</span>
<span class="p">)</span>
<span class="nb">print</span><span class="p">(</span><span class="n">output</span><span class="o">.</span><span class="n">outputs</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span><span class="o">.</span><span class="n">text</span><span class="p">)</span>
</pre></div>
</div>
<p>The output would look like:</p>
<div class="highlight-txt notranslate"><div class="highlight"><pre><span></span>{
&quot;name&quot;: &quot;Paris&quot;,
&quot;population&quot;: 2145206
}
</pre></div>
</div>
</section>
<section id="id2">
<h3>Regular expression<a class="headerlink" href="#id2" title="Link to this heading">#</a></h3>
<p>Create a <code class="docutils literal notranslate"><span class="pre">GuidedDecodingParams</span></code> with the <code class="docutils literal notranslate"><span class="pre">regex</span></code> field specified with a regular expression, use it to create <code class="docutils literal notranslate"><span class="pre">SamplingParams</span></code>, and then pass to <code class="docutils literal notranslate"><span class="pre">llm.generate</span></code> or <code class="docutils literal notranslate"><span class="pre">llm.generate_async</span></code>.</p>
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="kn">from</span><span class="w"> </span><span class="nn">tensorrt_llm</span><span class="w"> </span><span class="kn">import</span> <span class="n">LLM</span>
<span class="kn">from</span><span class="w"> </span><span class="nn">tensorrt_llm.sampling_params</span><span class="w"> </span><span class="kn">import</span> <span class="n">SamplingParams</span><span class="p">,</span> <span class="n">GuidedDecodingParams</span>
<span class="k">if</span> <span class="vm">__name__</span> <span class="o">==</span> <span class="s2">&quot;__main__&quot;</span><span class="p">:</span>
<span class="n">llm</span> <span class="o">=</span> <span class="n">LLM</span><span class="p">(</span><span class="s2">&quot;nvidia/Llama-3.1-8B-Instruct-FP8&quot;</span><span class="p">,</span> <span class="n">guided_decoding_backend</span><span class="o">=</span><span class="s2">&quot;xgrammar&quot;</span><span class="p">)</span>
<span class="n">messages</span> <span class="o">=</span> <span class="p">[</span>
<span class="p">{</span>
<span class="s2">&quot;role&quot;</span><span class="p">:</span> <span class="s2">&quot;system&quot;</span><span class="p">,</span>
<span class="s2">&quot;content&quot;</span><span class="p">:</span> <span class="s2">&quot;You are a helpful assistant.&quot;</span><span class="p">,</span>
<span class="p">},</span>
<span class="p">{</span>
<span class="s2">&quot;role&quot;</span><span class="p">:</span> <span class="s2">&quot;user&quot;</span><span class="p">,</span>
<span class="s2">&quot;content&quot;</span><span class="p">:</span> <span class="s2">&quot;What is the capital of France?&quot;</span><span class="p">,</span>
<span class="p">},</span>
<span class="p">]</span>
<span class="n">prompt</span> <span class="o">=</span> <span class="n">llm</span><span class="o">.</span><span class="n">tokenizer</span><span class="o">.</span><span class="n">apply_chat_template</span><span class="p">(</span><span class="n">messages</span><span class="p">,</span> <span class="n">tokenize</span><span class="o">=</span><span class="kc">False</span><span class="p">,</span> <span class="n">add_generation_prompt</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span>
<span class="n">output</span> <span class="o">=</span> <span class="n">llm</span><span class="o">.</span><span class="n">generate</span><span class="p">(</span>
<span class="n">prompt</span><span class="p">,</span>
<span class="n">sampling_params</span><span class="o">=</span><span class="n">SamplingParams</span><span class="p">(</span><span class="n">max_tokens</span><span class="o">=</span><span class="mi">256</span><span class="p">,</span> <span class="n">guided_decoding</span><span class="o">=</span><span class="n">GuidedDecodingParams</span><span class="p">(</span><span class="n">regex</span><span class="o">=</span><span class="s2">&quot;(Paris|London)&quot;</span><span class="p">)),</span>
<span class="p">)</span>
<span class="nb">print</span><span class="p">(</span><span class="n">output</span><span class="o">.</span><span class="n">outputs</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span><span class="o">.</span><span class="n">text</span><span class="p">)</span>
</pre></div>
</div>
<p>The output would look like:</p>
<div class="highlight-txt notranslate"><div class="highlight"><pre><span></span>Paris
</pre></div>
</div>
</section>
<section id="id3">
<h3>EBNF grammar<a class="headerlink" href="#id3" title="Link to this heading">#</a></h3>
<p>Create a <code class="docutils literal notranslate"><span class="pre">GuidedDecodingParams</span></code> with the <code class="docutils literal notranslate"><span class="pre">grammar</span></code> field specified with an EBNF grammar, use it to create <code class="docutils literal notranslate"><span class="pre">SamplingParams</span></code>, and then pass to <code class="docutils literal notranslate"><span class="pre">llm.generate</span></code> or <code class="docutils literal notranslate"><span class="pre">llm.generate_async</span></code>.</p>
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="kn">from</span><span class="w"> </span><span class="nn">tensorrt_llm</span><span class="w"> </span><span class="kn">import</span> <span class="n">LLM</span>
<span class="kn">from</span><span class="w"> </span><span class="nn">tensorrt_llm.sampling_params</span><span class="w"> </span><span class="kn">import</span> <span class="n">SamplingParams</span><span class="p">,</span> <span class="n">GuidedDecodingParams</span>
<span class="k">if</span> <span class="vm">__name__</span> <span class="o">==</span> <span class="s2">&quot;__main__&quot;</span><span class="p">:</span>
<span class="n">llm</span> <span class="o">=</span> <span class="n">LLM</span><span class="p">(</span><span class="s2">&quot;nvidia/Llama-3.1-8B-Instruct-FP8&quot;</span><span class="p">,</span> <span class="n">guided_decoding_backend</span><span class="o">=</span><span class="s2">&quot;xgrammar&quot;</span><span class="p">)</span>
<span class="n">ebnf_grammar</span> <span class="o">=</span> <span class="s2">&quot;&quot;&quot;root ::= description</span>
<span class="s2">city ::= &quot;London&quot; | &quot;Paris&quot; | &quot;Berlin&quot; | &quot;Rome&quot;</span>
<span class="s2">description ::= city &quot; is &quot; status</span>
<span class="s2">status ::= &quot;the capital of &quot; country</span>
<span class="s2">country ::= &quot;England&quot; | &quot;France&quot; | &quot;Germany&quot; | &quot;Italy&quot;</span>
<span class="s2">&quot;&quot;&quot;</span>
<span class="n">messages</span> <span class="o">=</span> <span class="p">[</span>
<span class="p">{</span>
<span class="s2">&quot;role&quot;</span><span class="p">:</span> <span class="s2">&quot;system&quot;</span><span class="p">,</span>
<span class="s2">&quot;content&quot;</span><span class="p">:</span> <span class="s2">&quot;You are a helpful geography bot.&quot;</span>
<span class="p">},</span>
<span class="p">{</span>
<span class="s2">&quot;role&quot;</span><span class="p">:</span> <span class="s2">&quot;user&quot;</span><span class="p">,</span>
<span class="s2">&quot;content&quot;</span><span class="p">:</span> <span class="s2">&quot;Give me the information of the capital of France.&quot;</span><span class="p">,</span>
<span class="p">},</span>
<span class="p">]</span>
<span class="n">prompt</span> <span class="o">=</span> <span class="n">llm</span><span class="o">.</span><span class="n">tokenizer</span><span class="o">.</span><span class="n">apply_chat_template</span><span class="p">(</span><span class="n">messages</span><span class="p">,</span> <span class="n">tokenize</span><span class="o">=</span><span class="kc">False</span><span class="p">,</span> <span class="n">add_generation_prompt</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span>
<span class="n">output</span> <span class="o">=</span> <span class="n">llm</span><span class="o">.</span><span class="n">generate</span><span class="p">(</span>
<span class="n">prompt</span><span class="p">,</span>
<span class="n">sampling_params</span><span class="o">=</span><span class="n">SamplingParams</span><span class="p">(</span><span class="n">max_tokens</span><span class="o">=</span><span class="mi">256</span><span class="p">,</span> <span class="n">guided_decoding</span><span class="o">=</span><span class="n">GuidedDecodingParams</span><span class="p">(</span><span class="n">grammar</span><span class="o">=</span><span class="n">ebnf_grammar</span><span class="p">)),</span>
<span class="p">)</span>
<span class="nb">print</span><span class="p">(</span><span class="n">output</span><span class="o">.</span><span class="n">outputs</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span><span class="o">.</span><span class="n">text</span><span class="p">)</span>
</pre></div>
</div>
<p>The output would look like:</p>
<div class="highlight-txt notranslate"><div class="highlight"><pre><span></span>Paris is the capital of France
</pre></div>
</div>
</section>
<section id="id4">
<h3>Structural tag<a class="headerlink" href="#id4" title="Link to this heading">#</a></h3>
<p>Create a <code class="docutils literal notranslate"><span class="pre">GuidedDecodingParams</span></code> with the <code class="docutils literal notranslate"><span class="pre">structural_tag</span></code> field specified with a structural tag string, use it to create <code class="docutils literal notranslate"><span class="pre">SamplingParams</span></code>, and then pass to <code class="docutils literal notranslate"><span class="pre">llm.generate</span></code> or <code class="docutils literal notranslate"><span class="pre">llm.generate_async</span></code>.</p>
<p>Structural tag is supported by <code class="docutils literal notranslate"><span class="pre">xgrammar</span></code> backend only. It is a powerful and flexible tool to represent the LLM output constraints. Please see <a class="reference external" href="https://xgrammar.mlc.ai/docs/tutorials/structural_tag.html">structural tag usage</a> for a comprehensive tutorial. Below is an example of function calling with customized function call format for <code class="docutils literal notranslate"><span class="pre">Llama-3.1-8B-Instruct</span></code>.</p>
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="kn">import</span><span class="w"> </span><span class="nn">json</span>
<span class="kn">from</span><span class="w"> </span><span class="nn">tensorrt_llm</span><span class="w"> </span><span class="kn">import</span> <span class="n">LLM</span>
<span class="kn">from</span><span class="w"> </span><span class="nn">tensorrt_llm.sampling_params</span><span class="w"> </span><span class="kn">import</span> <span class="n">SamplingParams</span><span class="p">,</span> <span class="n">GuidedDecodingParams</span>
<span class="k">if</span> <span class="vm">__name__</span> <span class="o">==</span> <span class="s2">&quot;__main__&quot;</span><span class="p">:</span>
<span class="n">llm</span> <span class="o">=</span> <span class="n">LLM</span><span class="p">(</span><span class="s2">&quot;nvidia/Llama-3.1-8B-Instruct-FP8&quot;</span><span class="p">,</span> <span class="n">guided_decoding_backend</span><span class="o">=</span><span class="s2">&quot;xgrammar&quot;</span><span class="p">)</span>
<span class="n">tool_get_current_weather</span> <span class="o">=</span> <span class="p">{</span>
<span class="s2">&quot;type&quot;</span><span class="p">:</span> <span class="s2">&quot;function&quot;</span><span class="p">,</span>
<span class="s2">&quot;function&quot;</span><span class="p">:</span> <span class="p">{</span>
<span class="s2">&quot;name&quot;</span><span class="p">:</span> <span class="s2">&quot;get_current_weather&quot;</span><span class="p">,</span>
<span class="s2">&quot;description&quot;</span><span class="p">:</span> <span class="s2">&quot;Get the current weather in a given location&quot;</span><span class="p">,</span>
<span class="s2">&quot;parameters&quot;</span><span class="p">:</span> <span class="p">{</span>
<span class="s2">&quot;type&quot;</span><span class="p">:</span> <span class="s2">&quot;object&quot;</span><span class="p">,</span>
<span class="s2">&quot;properties&quot;</span><span class="p">:</span> <span class="p">{</span>
<span class="s2">&quot;city&quot;</span><span class="p">:</span> <span class="p">{</span>
<span class="s2">&quot;type&quot;</span><span class="p">:</span> <span class="s2">&quot;string&quot;</span><span class="p">,</span>
<span class="s2">&quot;description&quot;</span><span class="p">:</span> <span class="s2">&quot;The city to find the weather for, e.g. &#39;San Francisco&#39;&quot;</span><span class="p">,</span>
<span class="p">},</span>
<span class="s2">&quot;state&quot;</span><span class="p">:</span> <span class="p">{</span>
<span class="s2">&quot;type&quot;</span><span class="p">:</span> <span class="s2">&quot;string&quot;</span><span class="p">,</span>
<span class="s2">&quot;description&quot;</span><span class="p">:</span> <span class="s2">&quot;the two-letter abbreviation for the state that the city is in, e.g. &#39;CA&#39; which would mean &#39;California&#39;&quot;</span><span class="p">,</span>
<span class="p">},</span>
<span class="s2">&quot;unit&quot;</span><span class="p">:</span> <span class="p">{</span>
<span class="s2">&quot;type&quot;</span><span class="p">:</span> <span class="s2">&quot;string&quot;</span><span class="p">,</span>
<span class="s2">&quot;description&quot;</span><span class="p">:</span> <span class="s2">&quot;The unit to fetch the temperature in&quot;</span><span class="p">,</span>
<span class="s2">&quot;enum&quot;</span><span class="p">:</span> <span class="p">[</span><span class="s2">&quot;celsius&quot;</span><span class="p">,</span> <span class="s2">&quot;fahrenheit&quot;</span><span class="p">],</span>
<span class="p">},</span>
<span class="p">},</span>
<span class="s2">&quot;required&quot;</span><span class="p">:</span> <span class="p">[</span><span class="s2">&quot;city&quot;</span><span class="p">,</span> <span class="s2">&quot;state&quot;</span><span class="p">,</span> <span class="s2">&quot;unit&quot;</span><span class="p">],</span>
<span class="p">},</span>
<span class="p">},</span>
<span class="p">}</span>
<span class="n">tool_get_current_date</span> <span class="o">=</span> <span class="p">{</span>
<span class="s2">&quot;type&quot;</span><span class="p">:</span> <span class="s2">&quot;function&quot;</span><span class="p">,</span>
<span class="s2">&quot;function&quot;</span><span class="p">:</span> <span class="p">{</span>
<span class="s2">&quot;name&quot;</span><span class="p">:</span> <span class="s2">&quot;get_current_date&quot;</span><span class="p">,</span>
<span class="s2">&quot;description&quot;</span><span class="p">:</span> <span class="s2">&quot;Get the current date and time for a given timezone&quot;</span><span class="p">,</span>
<span class="s2">&quot;parameters&quot;</span><span class="p">:</span> <span class="p">{</span>
<span class="s2">&quot;type&quot;</span><span class="p">:</span> <span class="s2">&quot;object&quot;</span><span class="p">,</span>
<span class="s2">&quot;properties&quot;</span><span class="p">:</span> <span class="p">{</span>
<span class="s2">&quot;timezone&quot;</span><span class="p">:</span> <span class="p">{</span>
<span class="s2">&quot;type&quot;</span><span class="p">:</span> <span class="s2">&quot;string&quot;</span><span class="p">,</span>
<span class="s2">&quot;description&quot;</span><span class="p">:</span> <span class="s2">&quot;The timezone to fetch the current date and time for, e.g. &#39;America/New_York&#39;&quot;</span><span class="p">,</span>
<span class="p">}</span>
<span class="p">},</span>
<span class="s2">&quot;required&quot;</span><span class="p">:</span> <span class="p">[</span><span class="s2">&quot;timezone&quot;</span><span class="p">],</span>
<span class="p">},</span>
<span class="p">},</span>
<span class="p">}</span>
<span class="n">system_prompt</span> <span class="o">=</span> <span class="sa">f</span><span class="s2">&quot;&quot;&quot;# Tool Instructions</span>
<span class="s2">- Always execute python code in messages that you share.</span>
<span class="s2">- When looking for real time information use relevant functions if available else fallback to brave_search</span>
<span class="s2">You have access to the following functions:</span>
<span class="s2">Use the function &#39;get_current_weather&#39; to: Get the current weather in a given location</span>
<span class="si">{</span><span class="n">tool_get_current_weather</span><span class="p">[</span><span class="s2">&quot;function&quot;</span><span class="p">]</span><span class="si">}</span>
<span class="s2">Use the function &#39;get_current_date&#39; to: Get the current date and time for a given timezone</span>
<span class="si">{</span><span class="n">tool_get_current_date</span><span class="p">[</span><span class="s2">&quot;function&quot;</span><span class="p">]</span><span class="si">}</span>
<span class="s2">If a you choose to call a function ONLY reply in the following format:</span>
<span class="s2">&lt;</span><span class="se">{{</span><span class="s2">start_tag</span><span class="se">}}</span><span class="s2">=</span><span class="se">{{</span><span class="s2">function_name</span><span class="se">}}</span><span class="s2">&gt;</span><span class="se">{{</span><span class="s2">parameters</span><span class="se">}}{{</span><span class="s2">end_tag</span><span class="se">}}</span>
<span class="s2">where</span>
<span class="s2">start_tag =&gt; `&lt;function`</span>
<span class="s2">parameters =&gt; a JSON dict with the function argument name as key and function argument value as value.</span>
<span class="s2">end_tag =&gt; `&lt;/function&gt;`</span>
<span class="s2">Here is an example,</span>
<span class="s2">&lt;function=example_function_name&gt;</span><span class="se">{{</span><span class="s2">&quot;example_name&quot;: &quot;example_value&quot;</span><span class="se">}}</span><span class="s2">&lt;/function&gt;</span>
<span class="s2">Reminder:</span>
<span class="s2">- Function calls MUST follow the specified format</span>
<span class="s2">- Required parameters MUST be specified</span>
<span class="s2">- Only call one function at a time</span>
<span class="s2">- Put the entire function call reply on one line</span>
<span class="s2">- Always add your sources when using search results to answer the user query</span>
<span class="s2">You are a helpful assistant.&quot;&quot;&quot;</span>
<span class="n">user_prompt</span> <span class="o">=</span> <span class="s2">&quot;You are in New York. Please get the current date and time, and the weather.&quot;</span>
<span class="n">structural_tag</span> <span class="o">=</span> <span class="p">{</span>
<span class="s2">&quot;type&quot;</span><span class="p">:</span> <span class="s2">&quot;structural_tag&quot;</span><span class="p">,</span>
<span class="s2">&quot;format&quot;</span><span class="p">:</span> <span class="p">{</span>
<span class="s2">&quot;type&quot;</span><span class="p">:</span> <span class="s2">&quot;triggered_tags&quot;</span><span class="p">,</span>
<span class="s2">&quot;triggers&quot;</span><span class="p">:</span> <span class="p">[</span><span class="s2">&quot;&lt;function=&quot;</span><span class="p">],</span>
<span class="s2">&quot;tags&quot;</span><span class="p">:</span> <span class="p">[</span>
<span class="p">{</span>
<span class="s2">&quot;begin&quot;</span><span class="p">:</span> <span class="s2">&quot;&lt;function=get_current_weather&gt;&quot;</span><span class="p">,</span>
<span class="s2">&quot;content&quot;</span><span class="p">:</span> <span class="p">{</span>
<span class="s2">&quot;type&quot;</span><span class="p">:</span> <span class="s2">&quot;json_schema&quot;</span><span class="p">,</span>
<span class="s2">&quot;json_schema&quot;</span><span class="p">:</span> <span class="n">tool_get_current_weather</span><span class="p">[</span><span class="s2">&quot;function&quot;</span><span class="p">][</span><span class="s2">&quot;parameters&quot;</span><span class="p">]</span>
<span class="p">},</span>
<span class="s2">&quot;end&quot;</span><span class="p">:</span> <span class="s2">&quot;&lt;/function&gt;&quot;</span><span class="p">,</span>
<span class="p">},</span>
<span class="p">{</span>
<span class="s2">&quot;begin&quot;</span><span class="p">:</span> <span class="s2">&quot;&lt;function=get_current_date&gt;&quot;</span><span class="p">,</span>
<span class="s2">&quot;content&quot;</span><span class="p">:</span> <span class="p">{</span>
<span class="s2">&quot;type&quot;</span><span class="p">:</span> <span class="s2">&quot;json_schema&quot;</span><span class="p">,</span>
<span class="s2">&quot;json_schema&quot;</span><span class="p">:</span> <span class="n">tool_get_current_date</span><span class="p">[</span><span class="s2">&quot;function&quot;</span><span class="p">][</span><span class="s2">&quot;parameters&quot;</span><span class="p">]</span>
<span class="p">},</span>
<span class="s2">&quot;end&quot;</span><span class="p">:</span> <span class="s2">&quot;&lt;/function&gt;&quot;</span><span class="p">,</span>
<span class="p">},</span>
<span class="p">],</span>
<span class="p">},</span>
<span class="p">}</span>
<span class="n">messages</span> <span class="o">=</span> <span class="p">[</span>
<span class="p">{</span>
<span class="s2">&quot;role&quot;</span><span class="p">:</span> <span class="s2">&quot;system&quot;</span><span class="p">,</span>
<span class="s2">&quot;content&quot;</span><span class="p">:</span> <span class="n">system_prompt</span><span class="p">,</span>
<span class="p">},</span>
<span class="p">{</span>
<span class="s2">&quot;role&quot;</span><span class="p">:</span> <span class="s2">&quot;user&quot;</span><span class="p">,</span>
<span class="s2">&quot;content&quot;</span><span class="p">:</span> <span class="n">user_prompt</span><span class="p">,</span>
<span class="p">},</span>
<span class="p">]</span>
<span class="n">prompt</span> <span class="o">=</span> <span class="n">llm</span><span class="o">.</span><span class="n">tokenizer</span><span class="o">.</span><span class="n">apply_chat_template</span><span class="p">(</span><span class="n">messages</span><span class="p">,</span> <span class="n">tokenize</span><span class="o">=</span><span class="kc">False</span><span class="p">,</span> <span class="n">add_generation_prompt</span><span class="o">=</span><span class="kc">True</span><span class="p">)</span>
<span class="n">output</span> <span class="o">=</span> <span class="n">llm</span><span class="o">.</span><span class="n">generate</span><span class="p">(</span>
<span class="n">prompt</span><span class="p">,</span>
<span class="n">sampling_params</span><span class="o">=</span><span class="n">SamplingParams</span><span class="p">(</span><span class="n">max_tokens</span><span class="o">=</span><span class="mi">256</span><span class="p">,</span> <span class="n">guided_decoding</span><span class="o">=</span><span class="n">GuidedDecodingParams</span><span class="p">(</span><span class="n">structural_tag</span><span class="o">=</span><span class="n">json</span><span class="o">.</span><span class="n">dumps</span><span class="p">(</span><span class="n">structural_tag</span><span class="p">))),</span>
<span class="p">)</span>
<span class="nb">print</span><span class="p">(</span><span class="n">output</span><span class="o">.</span><span class="n">outputs</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span><span class="o">.</span><span class="n">text</span><span class="p">)</span>
</pre></div>
</div>
<p>The output would look like:</p>
<div class="highlight-txt notranslate"><div class="highlight"><pre><span></span>&lt;function=get_current_date&gt;{&quot;timezone&quot;: &quot;America/New_York&quot;}&lt;/function&gt;
&lt;function=get_current_weather&gt;{&quot;city&quot;: &quot;New York&quot;, &quot;state&quot;: &quot;NY&quot;, &quot;unit&quot;: &quot;fahrenheit&quot;}&lt;/function&gt;
</pre></div>
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