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 <title data-rh="true">Pulsar WebSocket API | Apache Pulsar</title><meta data-rh="true" name="viewport" content="width=device-width,initial-scale=1"><meta data-rh="true" name="twitter:card" content="summary_large_image"><meta data-rh="true" property="og:image" content="https://pulsar.apache.org/img/pulsar-social-media-card.png"><meta data-rh="true" name="twitter:image" content="https://pulsar.apache.org/img/pulsar-social-media-card.png"><meta data-rh="true" property="og:url" content="https://pulsar.apache.org/docs/3.1.x/client-libraries-websocket/"><meta data-rh="true" name="docusaurus_locale" content="en"><meta data-rh="true" name="docsearch:language" content="en"><meta data-rh="true" name="docusaurus_version" content="3.1.x"><meta data-rh="true" name="docusaurus_tag" content="docs-default-3.1.x"><meta data-rh="true" name="docsearch:version" content="3.1.x"><meta data-rh="true" name="docsearch:docusaurus_tag" content="docs-default-3.1.x"><meta data-rh="true" property="og:title" content="Pulsar WebSocket API | Apache Pulsar"><meta data-rh="true" name="description" content="Pulsar WebSocket API provides a simple way to interact with Pulsar using languages that do not have an official client library. You can use Pulsar WebSocket API with any WebSocket client library. See Python and Node.js examples for more details."><meta data-rh="true" property="og:description" content="Pulsar WebSocket API provides a simple way to interact with Pulsar using languages that do not have an official client library. You can use Pulsar WebSocket API with any WebSocket client library. See Python and Node.js examples for more details."><link data-rh="true" rel="icon" href="/img/favicon.ico"><link data-rh="true" rel="alternate" href="https://pulsar.apache.org/docs/3.1.x/client-libraries-websocket/" hreflang="en"><link data-rh="true" rel="alternate" href="https://pulsar.apache.org/docs/3.1.x/client-libraries-websocket/" hreflang="x-default"><link data-rh="true" rel="canonical" href="https://pulsar.apache.org/docs/client-libraries-websocket/"><link data-rh="true" rel="preconnect" href="https://WK2YL0SALL-dsn.algolia.net" crossorigin="anonymous"><link rel="alternate" type="application/rss+xml" href="/blog/rss.xml" title="Apache Pulsar RSS Feed">
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class="breadcrumbHomeIcon_YNFT"><path d="M10 19v-5h4v5c0 .55.45 1 1 1h3c.55 0 1-.45 1-1v-7h1.7c.46 0 .68-.57.33-.87L12.67 3.6c-.38-.34-.96-.34-1.34 0l-8.36 7.53c-.34.3-.13.87.33.87H5v7c0 .55.45 1 1 1h3c.55 0 1-.45 1-1z" fill="currentColor"></path></svg></a></li><li class="breadcrumbs__item"><span class="breadcrumbs__link">Client Libraries</span><meta itemprop="position" content="1"></li><li class="breadcrumbs__item"><span class="breadcrumbs__link">Get started</span><meta itemprop="position" content="2"></li><li itemscope="" itemprop="itemListElement" itemtype="https://schema.org/ListItem" class="breadcrumbs__item breadcrumbs__item--active"><span class="breadcrumbs__link" itemprop="name">WebSocket</span><meta itemprop="position" content="3"></li></ul></nav><div class="tocCollapsible_ETCw theme-doc-toc-mobile tocMobile_ITEo"><button type="button" class="clean-btn tocCollapsibleButton_TO0P">On this page</button></div><div class="theme-doc-markdown markdown"><header><h1>Pulsar WebSocket API</h1></header><p>Pulsar <a href="https://developer.mozilla.org/en-US/docs/Web/API/WebSockets_API" target="_blank" rel="noopener noreferrer">WebSocket</a> API provides a simple way to interact with Pulsar using languages that do not have an official <a href="/docs/3.1.x/client-libraries/">client library</a>. You can use Pulsar WebSocket API with any WebSocket client library. See <a href="#client-examples">Python and Node.js examples</a> for more details.</p><p>Through WebSocket, you can publish and consume messages and use features available on the <a href="/client-feature-matrix/">Client Feature Matrix</a> page.</p><h2 class="anchor anchorWithStickyNavbar_LWe7" id="run-the-websocket-service">Run the WebSocket service<a href="#run-the-websocket-service" class="hash-link" aria-label="Direct link to Run the WebSocket service" title="Direct link to Run the WebSocket service"></a></h2><p>The standalone variant of Pulsar that we recommend using for <a href="/docs/3.1.x/getting-started-standalone/">local development</a> already has the WebSocket service enabled.</p><p>In non-standalone mode, there are two ways to deploy the WebSocket service:</p><ul><li><a href="#embedded-with-a-pulsar-broker">embedded</a> with a Pulsar broker</li><li>as a <a href="#as-a-separate-component">separate component</a></li></ul><h3 class="anchor anchorWithStickyNavbar_LWe7" id="embedded-with-a-pulsar-broker">Embedded with a Pulsar broker<a href="#embedded-with-a-pulsar-broker" class="hash-link" aria-label="Direct link to Embedded with a Pulsar broker" title="Direct link to Embedded with a Pulsar broker"></a></h3><p>In this mode, the WebSocket service will run within the same HTTP service that&#x27;s already running in the broker. To enable this mode, set the <a href="/docs/3.1.x/reference-configuration/#broker-webSocketServiceEnabled"><code>webSocketServiceEnabled</code></a> parameter in the <a href="/docs/3.1.x/reference-configuration/#broker"><code>conf/broker.conf</code></a> configuration file in your installation.</p><div class="language-properties codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#F8F8F2;--prism-background-color:#282A36"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-properties codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#F8F8F2"><span class="token key attr-name" style="color:rgb(241, 250, 140)">webSocketServiceEnabled</span><span class="token punctuation" style="color:rgb(248, 248, 242)">=</span><span class="token value attr-value">true</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg class="copyButtonIcon_y97N" viewBox="0 0 24 24"><path d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg class="copyButtonSuccessIcon_LjdS" viewBox="0 0 24 24"><path d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><h3 class="anchor anchorWithStickyNavbar_LWe7" id="as-a-separate-component">As a separate component<a href="#as-a-separate-component" class="hash-link" aria-label="Direct link to As a separate component" title="Direct link to As a separate component"></a></h3><p>In this mode, the WebSocket service will be run from a Pulsar <a href="/docs/3.1.x/reference-terminology/#broker">broker</a> as a separate service. Configuration for this mode is handled in the <a href="/docs/3.1.x/reference-configuration/#websocket"><code>conf/websocket.conf</code></a> configuration file. You&#x27;ll need to set <em>at least</em> the following parameters:</p><ul><li><a href="/docs/3.1.x/reference-configuration/#websocket"><code>configurationMetadataStoreUrl</code></a></li><li><a href="/docs/3.1.x/reference-configuration/#websocket-webServicePort"><code>webServicePort</code></a></li><li><a href="/docs/3.1.x/reference-configuration/#websocket-clusterName"><code>clusterName</code></a></li></ul><p>Here&#x27;s an example:</p><div class="language-properties codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#F8F8F2;--prism-background-color:#282A36"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-properties codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#F8F8F2"><span class="token key attr-name" style="color:rgb(241, 250, 140)">configurationMetadataStoreUrl</span><span class="token punctuation" style="color:rgb(248, 248, 242)">=</span><span class="token value attr-value">zk1:2181,zk2:2181,zk3:2181</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token key attr-name" style="color:rgb(241, 250, 140)">webServicePort</span><span class="token punctuation" style="color:rgb(248, 248, 242)">=</span><span class="token value attr-value">8080</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token key attr-name" style="color:rgb(241, 250, 140)">clusterName</span><span class="token punctuation" style="color:rgb(248, 248, 242)">=</span><span class="token value attr-value">my-cluster</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg class="copyButtonIcon_y97N" viewBox="0 0 24 24"><path d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg class="copyButtonSuccessIcon_LjdS" viewBox="0 0 24 24"><path d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><h3 class="anchor anchorWithStickyNavbar_LWe7" id="security-settings">Security settings<a href="#security-settings" class="hash-link" aria-label="Direct link to Security settings" title="Direct link to Security settings"></a></h3><p>To enable TLS encryption on WebSocket service, configure the following parameters in the <code>conf/broker.conf</code> file.</p><div class="language-properties codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#F8F8F2;--prism-background-color:#282A36"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-properties codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#F8F8F2"><span class="token key attr-name" style="color:rgb(241, 250, 140)">tlsEnabled</span><span class="token punctuation" style="color:rgb(248, 248, 242)">=</span><span class="token value attr-value">true</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token key attr-name" style="color:rgb(241, 250, 140)">tlsAllowInsecureConnection</span><span class="token punctuation" style="color:rgb(248, 248, 242)">=</span><span class="token value attr-value">false</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token key attr-name" style="color:rgb(241, 250, 140)">tlsCertificateFilePath</span><span class="token punctuation" style="color:rgb(248, 248, 242)">=</span><span class="token value attr-value">/path/to/client-websocket.cert.pem</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token key attr-name" style="color:rgb(241, 250, 140)">tlsKeyFilePath</span><span class="token punctuation" style="color:rgb(248, 248, 242)">=</span><span class="token value attr-value">/path/to/client-websocket.key-pk8.pem</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token key attr-name" style="color:rgb(241, 250, 140)">tlsTrustCertsFilePath</span><span class="token punctuation" style="color:rgb(248, 248, 242)">=</span><span class="token value attr-value">/path/to/ca.cert.pem</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg class="copyButtonIcon_y97N" viewBox="0 0 24 24"><path d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg class="copyButtonSuccessIcon_LjdS" viewBox="0 0 24 24"><path d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><p>To enable encryption at rest on WebSocket service, add CryptoKeyReaderFactory factory class in classpath which will create CryptoKeyReader for WebSocket and that helps to load encryption keys for producer/consumer.</p><div class="codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#F8F8F2;--prism-background-color:#282A36"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-text codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#F8F8F2"><span class="token plain">cryptoKeyReaderFactoryClassName=org.apache.pulsar.MyCryptoKeyReaderFactoryClassImpl</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg class="copyButtonIcon_y97N" viewBox="0 0 24 24"><path d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg class="copyButtonSuccessIcon_LjdS" viewBox="0 0 24 24"><path d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><h3 class="anchor anchorWithStickyNavbar_LWe7" id="start-the-broker">Start the broker<a href="#start-the-broker" class="hash-link" aria-label="Direct link to Start the broker" title="Direct link to Start the broker"></a></h3><p>When the configuration is set, you can start the service using the <a href="/docs/3.1.x/reference-cli-tools/"><code>pulsar-daemon</code></a> tool:</p><div class="language-shell codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#F8F8F2;--prism-background-color:#282A36"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-shell codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#F8F8F2"><span class="token plain">bin/pulsar-daemon start websocket</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg class="copyButtonIcon_y97N" viewBox="0 0 24 24"><path d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg class="copyButtonSuccessIcon_LjdS" viewBox="0 0 24 24"><path d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><h2 class="anchor anchorWithStickyNavbar_LWe7" id="release-notes">Release notes<a href="#release-notes" class="hash-link" aria-label="Direct link to Release notes" title="Direct link to Release notes"></a></h2><p>For the changelog of Pulsar WebSocket APIs, see <a href="/release-notes/client-ws/">release notes</a>.</p><h2 class="anchor anchorWithStickyNavbar_LWe7" id="api-reference">API Reference<a href="#api-reference" class="hash-link" aria-label="Direct link to API Reference" title="Direct link to API Reference"></a></h2><p>Pulsar&#x27;s WebSocket API offers three endpoints for <a href="#producer-endpoint">producing</a>, <a href="#consumer-endpoint">consuming</a>, and <a href="#reader-endpoint">reading</a> messages.</p><p>All exchanges via the WebSocket API use JSON.</p><h3 class="anchor anchorWithStickyNavbar_LWe7" id="authentication">Authentication<a href="#authentication" class="hash-link" aria-label="Direct link to Authentication" title="Direct link to Authentication"></a></h3><h4 class="anchor anchorWithStickyNavbar_LWe7" id="browser-javascript-websocket-client">Browser javascript WebSocket client<a href="#browser-javascript-websocket-client" class="hash-link" aria-label="Direct link to Browser javascript WebSocket client" title="Direct link to Browser javascript WebSocket client"></a></h4><p>Use the query param <code>token</code> to transport the authentication token.</p><div class="language-http codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#F8F8F2;--prism-background-color:#282A36"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-http codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#F8F8F2"><span class="token header header-name keyword" style="color:rgb(189, 147, 249);font-style:italic">ws</span><span class="token header punctuation" style="color:rgb(248, 248, 242)">:</span><span class="token header header-value">//broker-service-url:8080/path?token=token</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg class="copyButtonIcon_y97N" viewBox="0 0 24 24"><path d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg class="copyButtonSuccessIcon_LjdS" viewBox="0 0 24 24"><path d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><h3 class="anchor anchorWithStickyNavbar_LWe7" id="producer-endpoint">Producer endpoint<a href="#producer-endpoint" class="hash-link" aria-label="Direct link to Producer endpoint" title="Direct link to Producer endpoint"></a></h3><p>The producer endpoint requires you to specify a tenant, namespace, and topic in the URL:</p><div class="language-http codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#F8F8F2;--prism-background-color:#282A36"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-http codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#F8F8F2"><span class="token header header-name keyword" style="color:rgb(189, 147, 249);font-style:italic">ws</span><span class="token header punctuation" style="color:rgb(248, 248, 242)">:</span><span class="token header header-value">//broker-service-url:8080/ws/v2/producer/persistent/:tenant/:namespace/:topic</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg class="copyButtonIcon_y97N" viewBox="0 0 24 24"><path d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg class="copyButtonSuccessIcon_LjdS" viewBox="0 0 24 24"><path d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><h5 class="anchor anchorWithStickyNavbar_LWe7" id="query-param">Query param<a href="#query-param" class="hash-link" aria-label="Direct link to Query param" title="Direct link to Query param"></a></h5><table><thead><tr><th align="left">Key</th><th align="left">Type</th><th align="left">Required?</th><th align="left">Explanation</th></tr></thead><tbody><tr><td align="left"><code>sendTimeoutMillis</code></td><td align="left">long</td><td align="left">no</td><td align="left">Send timeout (default: 30 secs)</td></tr><tr><td align="left"><code>batchingEnabled</code></td><td align="left">boolean</td><td align="left">no</td><td align="left">Enable batching of messages (default: false)</td></tr><tr><td align="left"><code>batchingMaxMessages</code></td><td align="left">int</td><td align="left">no</td><td align="left">Maximum number of messages permitted in a batch (default: 1000)</td></tr><tr><td align="left"><code>maxPendingMessages</code></td><td align="left">int</td><td align="left">no</td><td align="left">Set the max size of the internal-queue holding the messages (default: 1000)</td></tr><tr><td align="left"><code>batchingMaxPublishDelay</code></td><td align="left">long</td><td align="left">no</td><td align="left">Time period within which the messages will be batched (default: 10ms)</td></tr><tr><td align="left"><code>messageRoutingMode</code></td><td align="left">string</td><td align="left">no</td><td align="left">Message <a href="https://pulsar.apache.org/api/client/3.1.x/index.html?org/apache/pulsar/client/api/ProducerConfiguration.MessageRoutingMode.html" target="_blank" rel="noopener noreferrer">routing mode</a> for the partitioned producer: <code>SinglePartition</code>, <code>RoundRobinPartition</code></td></tr><tr><td align="left"><code>compressionType</code></td><td align="left">string</td><td align="left">no</td><td align="left">Compression <a href="https://pulsar.apache.org/api/client/3.1.x/index.html?org/apache/pulsar/client/api/CompressionType.html" target="_blank" rel="noopener noreferrer">type</a>: <code>LZ4</code>, <code>ZLIB</code></td></tr><tr><td align="left"><code>producerName</code></td><td align="left">string</td><td align="left">no</td><td align="left">Specify the name for the producer. Pulsar will enforce only one producer with same name can be publishing on a topic</td></tr><tr><td align="left"><code>initialSequenceId</code></td><td align="left">long</td><td align="left">no</td><td align="left">Set the baseline for the sequence ids for messages published by the producer.</td></tr><tr><td align="left"><code>hashingScheme</code></td><td align="left">string</td><td align="left">no</td><td align="left"><a href="https://pulsar.apache.org/api/client/3.1.x/org/apache/pulsar/client/api/ProducerConfiguration.HashingScheme.html" target="_blank" rel="noopener noreferrer">Hashing function</a> to use when publishing on a partitioned topic: <code>JavaStringHash</code>, <code>Murmur3_32Hash</code></td></tr><tr><td align="left"><code>token</code></td><td align="left">string</td><td align="left">no</td><td align="left">Authentication token, this is used for the browser javascript client</td></tr><tr><td align="left"><code>encryptionKeys</code></td><td align="left">string</td><td align="left">no</td><td align="left">Encryption key to encrypt published message only if encryption reader is configured using cryptoKeyReaderFactoryClassName config in websocket-configuration.</td></tr></tbody></table><h4 class="anchor anchorWithStickyNavbar_LWe7" id="publish-a-message">Publish a message<a href="#publish-a-message" class="hash-link" aria-label="Direct link to Publish a message" title="Direct link to Publish a message"></a></h4><div class="language-json codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#F8F8F2;--prism-background-color:#282A36"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-json codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#F8F8F2"><span class="token punctuation" style="color:rgb(248, 248, 242)">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">  </span><span class="token property">&quot;payload&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&quot;SGVsbG8gV29ybGQ=&quot;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">  </span><span class="token property">&quot;properties&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token punctuation" style="color:rgb(248, 248, 242)">{</span><span class="token property">&quot;key1&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&quot;value1&quot;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"> </span><span class="token property">&quot;key2&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&quot;value2&quot;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">}</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">  </span><span class="token property">&quot;context&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&quot;1&quot;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token punctuation" style="color:rgb(248, 248, 242)">}</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg class="copyButtonIcon_y97N" viewBox="0 0 24 24"><path d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg class="copyButtonSuccessIcon_LjdS" viewBox="0 0 24 24"><path d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><table><thead><tr><th align="left">Key</th><th align="left">Type</th><th align="left">Required?</th><th align="left">Explanation</th></tr></thead><tbody><tr><td align="left"><code>payload</code></td><td align="left">string</td><td align="left">yes</td><td align="left">Base-64 encoded payload</td></tr><tr><td align="left"><code>properties</code></td><td align="left">key-value pairs</td><td align="left">no</td><td align="left">Application-defined properties</td></tr><tr><td align="left"><code>context</code></td><td align="left">string</td><td align="left">no</td><td align="left">Application-defined request identifier</td></tr><tr><td align="left"><code>key</code></td><td align="left">string</td><td align="left">no</td><td align="left">For partitioned topics, decides which partition to use</td></tr><tr><td align="left"><code>replicationClusters</code></td><td align="left">array</td><td align="left">no</td><td align="left">Restrict replication to this list of <a href="/docs/3.1.x/reference-terminology/#cluster">clusters</a>, specified by name</td></tr></tbody></table><h5 class="anchor anchorWithStickyNavbar_LWe7" id="example-success-response">Example success response<a href="#example-success-response" class="hash-link" aria-label="Direct link to Example success response" title="Direct link to Example success response"></a></h5><div class="language-json codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#F8F8F2;--prism-background-color:#282A36"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-json codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#F8F8F2"><span class="token punctuation" style="color:rgb(248, 248, 242)">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">   </span><span class="token property">&quot;result&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&quot;ok&quot;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">   </span><span class="token property">&quot;messageId&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&quot;CAAQAw==&quot;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">   </span><span class="token property">&quot;context&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&quot;1&quot;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"> </span><span class="token punctuation" style="color:rgb(248, 248, 242)">}</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg class="copyButtonIcon_y97N" viewBox="0 0 24 24"><path d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg class="copyButtonSuccessIcon_LjdS" viewBox="0 0 24 24"><path d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><h5 class="anchor anchorWithStickyNavbar_LWe7" id="example-failure-response">Example failure response<a href="#example-failure-response" class="hash-link" aria-label="Direct link to Example failure response" title="Direct link to Example failure response"></a></h5><div class="language-json codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#F8F8F2;--prism-background-color:#282A36"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-json codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#F8F8F2"><span class="token plain"> </span><span class="token punctuation" style="color:rgb(248, 248, 242)">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">   </span><span class="token property">&quot;result&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&quot;send-error:3&quot;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">   </span><span class="token property">&quot;errorMsg&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&quot;Failed to de-serialize from JSON&quot;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">   </span><span class="token property">&quot;context&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&quot;1&quot;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"> </span><span class="token punctuation" style="color:rgb(248, 248, 242)">}</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg class="copyButtonIcon_y97N" viewBox="0 0 24 24"><path d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg class="copyButtonSuccessIcon_LjdS" viewBox="0 0 24 24"><path d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><table><thead><tr><th align="left">Key</th><th align="left">Type</th><th align="left">Required?</th><th align="left">Explanation</th></tr></thead><tbody><tr><td align="left"><code>result</code></td><td align="left">string</td><td align="left">yes</td><td align="left"><code>ok</code> if successful or an error message if unsuccessful</td></tr><tr><td align="left"><code>messageId</code></td><td align="left">string</td><td align="left">yes</td><td align="left">Message ID assigned to the published message</td></tr><tr><td align="left"><code>context</code></td><td align="left">string</td><td align="left">no</td><td align="left">Application-defined request identifier</td></tr></tbody></table><h3 class="anchor anchorWithStickyNavbar_LWe7" id="consumer-endpoint">Consumer endpoint<a href="#consumer-endpoint" class="hash-link" aria-label="Direct link to Consumer endpoint" title="Direct link to Consumer endpoint"></a></h3><p>The consumer endpoint requires you to specify a tenant, namespace, and topic, as well as a subscription, in the URL:</p><div class="language-http codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#F8F8F2;--prism-background-color:#282A36"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-http codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#F8F8F2"><span class="token header header-name keyword" style="color:rgb(189, 147, 249);font-style:italic">ws</span><span class="token header punctuation" style="color:rgb(248, 248, 242)">:</span><span class="token header header-value">//broker-service-url:8080/ws/v2/consumer/persistent/:tenant/:namespace/:topic/:subscription</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg class="copyButtonIcon_y97N" viewBox="0 0 24 24"><path d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg class="copyButtonSuccessIcon_LjdS" viewBox="0 0 24 24"><path d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><h5 class="anchor anchorWithStickyNavbar_LWe7" id="query-param-1">Query param<a href="#query-param-1" class="hash-link" aria-label="Direct link to Query param" title="Direct link to Query param"></a></h5><table><thead><tr><th align="left">Key</th><th align="left">Type</th><th align="left">Required?</th><th align="left">Explanation</th></tr></thead><tbody><tr><td align="left"><code>ackTimeoutMillis</code></td><td align="left">long</td><td align="left">no</td><td align="left">Set the timeout for unacked messages (default: 0)</td></tr><tr><td align="left"><code>subscriptionType</code></td><td align="left">string</td><td align="left">no</td><td align="left"><a href="https://pulsar.apache.org/api/client/3.1.x/index.html?org/apache/pulsar/client/api/SubscriptionType.html" target="_blank" rel="noopener noreferrer">Subscription type</a>: <code>Exclusive</code>, <code>Failover</code>, <code>Shared</code>, <code>Key_Shared</code></td></tr><tr><td align="left"><code>receiverQueueSize</code></td><td align="left">int</td><td align="left">no</td><td align="left">Size of the consumer receive queue (default: 1000)</td></tr><tr><td align="left"><code>consumerName</code></td><td align="left">string</td><td align="left">no</td><td align="left">Consumer name</td></tr><tr><td align="left"><code>priorityLevel</code></td><td align="left">int</td><td align="left">no</td><td align="left">Define a <a href="https://pulsar.apache.org/api/client/3.1.x/org/apache/pulsar/client/api/ConsumerConfiguration.html#setPriorityLevel-int-" target="_blank" rel="noopener noreferrer">priority</a> for the consumer</td></tr><tr><td align="left"><code>maxRedeliverCount</code></td><td align="left">int</td><td align="left">no</td><td align="left">Define a <a href="https://pulsar.apache.org/api/client/3.1.x/org/apache/pulsar/client/api/ConsumerBuilder.html#deadLetterPolicy-org.apache.pulsar.client.api.DeadLetterPolicy-" target="_blank" rel="noopener noreferrer">maxRedeliverCount</a> for the consumer (default: 0). Activates <a href="https://github.com/apache/pulsar/wiki/PIP-22%3A-Pulsar-Dead-Letter-Topic" target="_blank" rel="noopener noreferrer">Dead Letter Topic</a> feature.</td></tr><tr><td align="left"><code>deadLetterTopic</code></td><td align="left">string</td><td align="left">no</td><td align="left">Define a <a href="https://pulsar.apache.org/api/client/3.1.x/org/apache/pulsar/client/api/ConsumerBuilder.html#deadLetterPolicy-org.apache.pulsar.client.api.DeadLetterPolicy-" target="_blank" rel="noopener noreferrer">deadLetterTopic</a> for the consumer (default: {topic}-{subscription}-DLQ). Activates <a href="https://github.com/apache/pulsar/wiki/PIP-22%3A-Pulsar-Dead-Letter-Topic" target="_blank" rel="noopener noreferrer">Dead Letter Topic</a> feature.</td></tr><tr><td align="left"><code>pullMode</code></td><td align="left">boolean</td><td align="left">no</td><td align="left">Enable pull mode (default: false). See &quot;Flow Control&quot; below.</td></tr><tr><td align="left"><code>negativeAckRedeliveryDelay</code></td><td align="left">int</td><td align="left">no</td><td align="left">When a message is negatively acknowledged, the delay time before the message is redelivered (in milliseconds). The default value is 60000.</td></tr><tr><td align="left"><code>token</code></td><td align="left">string</td><td align="left">no</td><td align="left">Authentication token, this is used for the browser javascript client</td></tr></tbody></table><div class="theme-admonition theme-admonition-note alert alert--secondary admonition_LlT9"><div class="admonitionHeading_tbUL"><span class="admonitionIcon_kALy"><svg viewBox="0 0 14 16"><path fill-rule="evenodd" d="M6.3 5.69a.942.942 0 0 1-.28-.7c0-.28.09-.52.28-.7.19-.18.42-.28.7-.28.28 0 .52.09.7.28.18.19.28.42.28.7 0 .28-.09.52-.28.7a1 1 0 0 1-.7.3c-.28 0-.52-.11-.7-.3zM8 7.99c-.02-.25-.11-.48-.31-.69-.2-.19-.42-.3-.69-.31H6c-.27.02-.48.13-.69.31-.2.2-.3.44-.31.69h1v3c.02.27.11.5.31.69.2.2.42.31.69.31h1c.27 0 .48-.11.69-.31.2-.19.3-.42.31-.69H8V7.98v.01zM7 2.3c-3.14 0-5.7 2.54-5.7 5.68 0 3.14 2.56 5.7 5.7 5.7s5.7-2.55 5.7-5.7c0-3.15-2.56-5.69-5.7-5.69v.01zM7 .98c3.86 0 7 3.14 7 7s-3.14 7-7 7-7-3.12-7-7 3.14-7 7-7z"></path></svg></span>note</div><div class="admonitionContent_S0QG"><p>These parameters (except <code>pullMode</code>) apply to the internal consumers of the WebSocket service.
 So messages will be subject to the redelivery settings as soon as they get into the receive queue,
 even if the client doesn&#x27;t consume on the WebSocket.</p></div></div><h5 class="anchor anchorWithStickyNavbar_LWe7" id="receive-messages">Receive messages<a href="#receive-messages" class="hash-link" aria-label="Direct link to Receive messages" title="Direct link to Receive messages"></a></h5><p>Server will push messages on the WebSocket session:</p><div class="language-json codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#F8F8F2;--prism-background-color:#282A36"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-json codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#F8F8F2"><span class="token punctuation" style="color:rgb(248, 248, 242)">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">  </span><span class="token property">&quot;messageId&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&quot;CAMQADAA&quot;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">  </span><span class="token property">&quot;payload&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&quot;hvXcJvHW7kOSrUn17P2q71RA5SdiXwZBqw==&quot;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">  </span><span class="token property">&quot;properties&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token punctuation" style="color:rgb(248, 248, 242)">{</span><span class="token punctuation" style="color:rgb(248, 248, 242)">}</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">  </span><span class="token property">&quot;publishTime&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&quot;2021-10-29T16:01:38.967-07:00&quot;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">  </span><span class="token property">&quot;redeliveryCount&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token number">0</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">  </span><span class="token property">&quot;encryptionContext&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token punctuation" style="color:rgb(248, 248, 242)">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    </span><span class="token property">&quot;keys&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token punctuation" style="color:rgb(248, 248, 242)">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">      </span><span class="token property">&quot;client-rsa.pem&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token punctuation" style="color:rgb(248, 248, 242)">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">        </span><span class="token property">&quot;keyValue&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&quot;jEuwS+PeUzmCo7IfLNxqoj4h7txbLjCQjkwpaw5AWJfZ2xoIdMkOuWDkOsqgFmWwxiecakS6GOZHs94x3sxzKHQx9Oe1jpwBg2e7L4fd26pp+WmAiLm/ArZJo6JotTeFSvKO3u/yQtGTZojDDQxiqFOQ1ZbMdtMZA8DpSMuq+Zx7PqLo43UdW1+krjQfE5WD+y+qE3LJQfwyVDnXxoRtqWLpVsAROlN2LxaMbaftv5HckoejJoB4xpf/dPOUqhnRstwQHf6klKT5iNhjsY4usACt78uILT0pEPd14h8wEBidBz/vAlC/zVMEqiDVzgNS7dqEYS4iHbf7cnWVCn3Hxw==&quot;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">        </span><span class="token property">&quot;metadata&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token punctuation" style="color:rgb(248, 248, 242)">{</span><span class="token punctuation" style="color:rgb(248, 248, 242)">}</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">      </span><span class="token punctuation" style="color:rgb(248, 248, 242)">}</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    </span><span class="token punctuation" style="color:rgb(248, 248, 242)">}</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    </span><span class="token property">&quot;param&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&quot;Tfu1PxVm6S9D3+Hk&quot;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    </span><span class="token property">&quot;compressionType&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&quot;NONE&quot;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    </span><span class="token property">&quot;uncompressedMessageSize&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token number">0</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    </span><span class="token property">&quot;batchSize&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token punctuation" style="color:rgb(248, 248, 242)">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">      </span><span class="token property">&quot;empty&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token boolean">false</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">      </span><span class="token property">&quot;present&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token boolean">true</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    </span><span class="token punctuation" style="color:rgb(248, 248, 242)">}</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">  </span><span class="token punctuation" style="color:rgb(248, 248, 242)">}</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token punctuation" style="color:rgb(248, 248, 242)">}</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg class="copyButtonIcon_y97N" viewBox="0 0 24 24"><path d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg class="copyButtonSuccessIcon_LjdS" viewBox="0 0 24 24"><path d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><p>Below are the parameters in the WebSocket consumer response.</p><ul><li><p>General parameters</p><table><thead><tr><th align="left">Key</th><th align="left">Type</th><th align="left">Required?</th><th align="left">Explanation</th></tr></thead><tbody><tr><td align="left"><code>messageId</code></td><td align="left">string</td><td align="left">yes</td><td align="left">Message ID</td></tr><tr><td align="left"><code>payload</code></td><td align="left">string</td><td align="left">yes</td><td align="left">Base-64 encoded payload</td></tr><tr><td align="left"><code>publishTime</code></td><td align="left">string</td><td align="left">yes</td><td align="left">Publish timestamp</td></tr><tr><td align="left"><code>redeliveryCount</code></td><td align="left">number</td><td align="left">yes</td><td align="left">Number of times this message was already delivered</td></tr><tr><td align="left"><code>properties</code></td><td align="left">key-value pairs</td><td align="left">no</td><td align="left">Application-defined properties</td></tr><tr><td align="left"><code>key</code></td><td align="left">string</td><td align="left">no</td><td align="left">Original routing key set by producer</td></tr><tr><td align="left"><code>encryptionContext</code></td><td align="left">EncryptionContext</td><td align="left">no</td><td align="left">Encryption context that consumers can use to decrypt received messages</td></tr><tr><td align="left"><code>param</code></td><td align="left">string</td><td align="left">no</td><td align="left">Initialization vector for cipher (Base64 encoding)</td></tr><tr><td align="left"><code>batchSize</code></td><td align="left">string</td><td align="left">no</td><td align="left">Number of entries in a message (if it is a batch message)</td></tr><tr><td align="left"><code>uncompressedMessageSize</code></td><td align="left">string</td><td align="left">no</td><td align="left">Message size before compression</td></tr><tr><td align="left"><code>compressionType</code></td><td align="left">string</td><td align="left">no</td><td align="left">Algorithm used to compress the message payload</td></tr></tbody></table></li><li><p><code>encryptionContext</code> related parameter</p><table><thead><tr><th align="left">Key</th><th align="left">Type</th><th align="left">Required?</th><th align="left">Explanation</th></tr></thead><tbody><tr><td align="left"><code>keys</code></td><td align="left">key-EncryptionKey pairs</td><td align="left">yes</td><td align="left">Key in <code>key-EncryptionKey</code> pairs is an encryption key name. Value in <code>key-EncryptionKey</code> pairs is an encryption key object.</td></tr></tbody></table></li><li><p><code>encryptionKey</code> related parameters</p><table><thead><tr><th align="left">Key</th><th align="left">Type</th><th align="left">Required?</th><th align="left">Explanation</th></tr></thead><tbody><tr><td align="left"><code>keyValue</code></td><td align="left">string</td><td align="left">yes</td><td align="left">Encryption key (Base64 encoding)</td></tr><tr><td align="left"><code>metadata</code></td><td align="left">key-value pairs</td><td align="left">no</td><td align="left">Application-defined metadata</td></tr></tbody></table></li></ul><h4 class="anchor anchorWithStickyNavbar_LWe7" id="acknowledge-the-message">Acknowledge the message<a href="#acknowledge-the-message" class="hash-link" aria-label="Direct link to Acknowledge the message" title="Direct link to Acknowledge the message"></a></h4><p>Consumer needs to acknowledge the successful processing of the message to
 have the Pulsar broker delete it.</p><div class="language-json codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#F8F8F2;--prism-background-color:#282A36"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-json codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#F8F8F2"><span class="token punctuation" style="color:rgb(248, 248, 242)">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">  </span><span class="token property">&quot;messageId&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&quot;CAAQAw==&quot;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token punctuation" style="color:rgb(248, 248, 242)">}</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg class="copyButtonIcon_y97N" viewBox="0 0 24 24"><path d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg class="copyButtonSuccessIcon_LjdS" viewBox="0 0 24 24"><path d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><table><thead><tr><th align="left">Key</th><th align="left">Type</th><th align="left">Required?</th><th align="left">Explanation</th></tr></thead><tbody><tr><td align="left"><code>messageId</code></td><td align="left">string</td><td align="left">yes</td><td align="left">Message ID of the processed message</td></tr></tbody></table><h4 class="anchor anchorWithStickyNavbar_LWe7" id="negatively-acknowledge-messages">Negatively acknowledge messages<a href="#negatively-acknowledge-messages" class="hash-link" aria-label="Direct link to Negatively acknowledge messages" title="Direct link to Negatively acknowledge messages"></a></h4><div class="language-json codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#F8F8F2;--prism-background-color:#282A36"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-json codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#F8F8F2"><span class="token punctuation" style="color:rgb(248, 248, 242)">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">  </span><span class="token property">&quot;type&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&quot;negativeAcknowledge&quot;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">  </span><span class="token property">&quot;messageId&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&quot;CAAQAw==&quot;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token punctuation" style="color:rgb(248, 248, 242)">}</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg class="copyButtonIcon_y97N" viewBox="0 0 24 24"><path d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg class="copyButtonSuccessIcon_LjdS" viewBox="0 0 24 24"><path d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><table><thead><tr><th align="left">Key</th><th align="left">Type</th><th align="left">Required?</th><th align="left">Explanation</th></tr></thead><tbody><tr><td align="left"><code>messageId</code></td><td align="left">string</td><td align="left">yes</td><td align="left">Message ID of the processed message</td></tr></tbody></table><h4 class="anchor anchorWithStickyNavbar_LWe7" id="flow-control">Flow control<a href="#flow-control" class="hash-link" aria-label="Direct link to Flow control" title="Direct link to Flow control"></a></h4><h5 class="anchor anchorWithStickyNavbar_LWe7" id="push-mode">Push Mode<a href="#push-mode" class="hash-link" aria-label="Direct link to Push Mode" title="Direct link to Push Mode"></a></h5><p>By default (<code>pullMode=false</code>), the consumer endpoint will use the <code>receiverQueueSize</code> parameter both to size its internal receive queue and to limit the number of unacknowledged messages that are passed to the WebSocket client.
 In this mode, if you don&#x27;t send acknowledgments, the Pulsar WebSocket service will stop sending messages after reaching
 <code>receiverQueueSize</code> unacked messages sent to the WebSocket client.</p><h5 class="anchor anchorWithStickyNavbar_LWe7" id="pull-mode">Pull Mode<a href="#pull-mode" class="hash-link" aria-label="Direct link to Pull Mode" title="Direct link to Pull Mode"></a></h5><p>If you set <code>pullMode</code> to <code>true</code>, the WebSocket client will need to send <code>permit</code> commands to permit the
 Pulsar WebSocket service to send more messages.</p><div class="language-json codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#F8F8F2;--prism-background-color:#282A36"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-json codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#F8F8F2"><span class="token punctuation" style="color:rgb(248, 248, 242)">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">  </span><span class="token property">&quot;type&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&quot;permit&quot;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">  </span><span class="token property">&quot;permitMessages&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token number">100</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token punctuation" style="color:rgb(248, 248, 242)">}</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg class="copyButtonIcon_y97N" viewBox="0 0 24 24"><path d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg class="copyButtonSuccessIcon_LjdS" viewBox="0 0 24 24"><path d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><table><thead><tr><th align="left">Key</th><th align="left">Type</th><th align="left">Required?</th><th align="left">Explanation</th></tr></thead><tbody><tr><td align="left"><code>type</code></td><td align="left">string</td><td align="left">yes</td><td align="left">Type of command. Must be <code>permit</code></td></tr><tr><td align="left"><code>permitMessages</code></td><td align="left">int</td><td align="left">yes</td><td align="left">Number of messages to permit</td></tr></tbody></table><blockquote><p>In this mode it&#x27;s possible to acknowledge messages in a different connection.</p></blockquote><h4 class="anchor anchorWithStickyNavbar_LWe7" id="check-if-reach-the-end-of-topic">Check if reach the end of topic<a href="#check-if-reach-the-end-of-topic" class="hash-link" aria-label="Direct link to Check if reach the end of topic" title="Direct link to Check if reach the end of topic"></a></h4><p>Consumers can check if it has reached the end of a topic by sending the <code>isEndOfTopic</code> request.</p><p><strong>Request</strong></p><div class="language-json codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#F8F8F2;--prism-background-color:#282A36"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-json codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#F8F8F2"><span class="token punctuation" style="color:rgb(248, 248, 242)">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">  </span><span class="token property">&quot;type&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&quot;isEndOfTopic&quot;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token punctuation" style="color:rgb(248, 248, 242)">}</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg class="copyButtonIcon_y97N" viewBox="0 0 24 24"><path d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg class="copyButtonSuccessIcon_LjdS" viewBox="0 0 24 24"><path d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><table><thead><tr><th align="left">Key</th><th align="left">Type</th><th align="left">Required?</th><th align="left">Explanation</th></tr></thead><tbody><tr><td align="left"><code>type</code></td><td align="left">string</td><td align="left">yes</td><td align="left">Type of command. Must be <code>isEndOfTopic</code></td></tr></tbody></table><p><strong>Response</strong></p><div class="language-json codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#F8F8F2;--prism-background-color:#282A36"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-json codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#F8F8F2"><span class="token punctuation" style="color:rgb(248, 248, 242)">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">   </span><span class="token property">&quot;endOfTopic&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&quot;true/false&quot;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"> </span><span class="token punctuation" style="color:rgb(248, 248, 242)">}</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg class="copyButtonIcon_y97N" viewBox="0 0 24 24"><path d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg class="copyButtonSuccessIcon_LjdS" viewBox="0 0 24 24"><path d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><h3 class="anchor anchorWithStickyNavbar_LWe7" id="reader-endpoint">Reader endpoint<a href="#reader-endpoint" class="hash-link" aria-label="Direct link to Reader endpoint" title="Direct link to Reader endpoint"></a></h3><p>The reader endpoint requires you to specify a tenant, namespace, and topic in the URL:</p><div class="language-http codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#F8F8F2;--prism-background-color:#282A36"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-http codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#F8F8F2"><span class="token header header-name keyword" style="color:rgb(189, 147, 249);font-style:italic">ws</span><span class="token header punctuation" style="color:rgb(248, 248, 242)">:</span><span class="token header header-value">//broker-service-url:8080/ws/v2/reader/persistent/:tenant/:namespace/:topic</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg class="copyButtonIcon_y97N" viewBox="0 0 24 24"><path d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg class="copyButtonSuccessIcon_LjdS" viewBox="0 0 24 24"><path d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><h5 class="anchor anchorWithStickyNavbar_LWe7" id="query-param-2">Query param<a href="#query-param-2" class="hash-link" aria-label="Direct link to Query param" title="Direct link to Query param"></a></h5><table><thead><tr><th align="left">Key</th><th align="left">Type</th><th align="left">Required?</th><th align="left">Explanation</th></tr></thead><tbody><tr><td align="left"><code>readerName</code></td><td align="left">string</td><td align="left">no</td><td align="left">Reader name</td></tr><tr><td align="left"><code>receiverQueueSize</code></td><td align="left">int</td><td align="left">no</td><td align="left">Size of the consumer receive queue (default: 1000)</td></tr><tr><td align="left"><code>messageId</code></td><td align="left">int or enum</td><td align="left">no</td><td align="left">Message ID to start from, <code>earliest</code> or <code>latest</code> (default: <code>latest</code>)</td></tr><tr><td align="left"><code>token</code></td><td align="left">string</td><td align="left">no</td><td align="left">Authentication token, this is used for the browser javascript client</td></tr></tbody></table><h5 class="anchor anchorWithStickyNavbar_LWe7" id="receiving-messages">Receiving messages<a href="#receiving-messages" class="hash-link" aria-label="Direct link to Receiving messages" title="Direct link to Receiving messages"></a></h5><p>Server will push messages on the WebSocket session:</p><div class="language-json codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#F8F8F2;--prism-background-color:#282A36"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-json codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#F8F8F2"><span class="token punctuation" style="color:rgb(248, 248, 242)">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">  </span><span class="token property">&quot;messageId&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&quot;CAAQAw==&quot;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">  </span><span class="token property">&quot;payload&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&quot;SGVsbG8gV29ybGQ=&quot;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">  </span><span class="token property">&quot;properties&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token punctuation" style="color:rgb(248, 248, 242)">{</span><span class="token property">&quot;key1&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&quot;value1&quot;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"> </span><span class="token property">&quot;key2&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&quot;value2&quot;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">}</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">  </span><span class="token property">&quot;publishTime&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&quot;2016-08-30 16:45:57.785&quot;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">  </span><span class="token property">&quot;redeliveryCount&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token number">4</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token punctuation" style="color:rgb(248, 248, 242)">}</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg class="copyButtonIcon_y97N" viewBox="0 0 24 24"><path d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg class="copyButtonSuccessIcon_LjdS" viewBox="0 0 24 24"><path d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><table><thead><tr><th align="left">Key</th><th align="left">Type</th><th align="left">Required?</th><th align="left">Explanation</th></tr></thead><tbody><tr><td align="left"><code>messageId</code></td><td align="left">string</td><td align="left">yes</td><td align="left">Message ID</td></tr><tr><td align="left"><code>payload</code></td><td align="left">string</td><td align="left">yes</td><td align="left">Base-64 encoded payload</td></tr><tr><td align="left"><code>publishTime</code></td><td align="left">string</td><td align="left">yes</td><td align="left">Publish timestamp</td></tr><tr><td align="left"><code>redeliveryCount</code></td><td align="left">number</td><td align="left">yes</td><td align="left">Number of times this message was already delivered</td></tr><tr><td align="left"><code>properties</code></td><td align="left">key-value pairs</td><td align="left">no</td><td align="left">Application-defined properties</td></tr><tr><td align="left"><code>key</code></td><td align="left">string</td><td align="left">no</td><td align="left">Original routing key set by producer</td></tr></tbody></table><h4 class="anchor anchorWithStickyNavbar_LWe7" id="acknowledging-the-message">Acknowledging the message<a href="#acknowledging-the-message" class="hash-link" aria-label="Direct link to Acknowledging the message" title="Direct link to Acknowledging the message"></a></h4><p><strong>In WebSocket</strong>, Reader needs to acknowledge the successful processing of the message to have the Pulsar WebSocket service update the number of pending messages.
 If you don&#x27;t send acknowledgments, Pulsar WebSocket service will stop sending messages after reaching the <code>pendingMessages</code> limit.</p><div class="language-json codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#F8F8F2;--prism-background-color:#282A36"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-json codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#F8F8F2"><span class="token punctuation" style="color:rgb(248, 248, 242)">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">  </span><span class="token property">&quot;messageId&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&quot;CAAQAw==&quot;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token punctuation" style="color:rgb(248, 248, 242)">}</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg class="copyButtonIcon_y97N" viewBox="0 0 24 24"><path d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg class="copyButtonSuccessIcon_LjdS" viewBox="0 0 24 24"><path d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><table><thead><tr><th align="left">Key</th><th align="left">Type</th><th align="left">Required?</th><th align="left">Explanation</th></tr></thead><tbody><tr><td align="left"><code>messageId</code></td><td align="left">string</td><td align="left">yes</td><td align="left">Message ID of the processed message</td></tr></tbody></table><h4 class="anchor anchorWithStickyNavbar_LWe7" id="check-if-reach-the-end-of-topic-1">Check if reach the end of topic<a href="#check-if-reach-the-end-of-topic-1" class="hash-link" aria-label="Direct link to Check if reach the end of topic" title="Direct link to Check if reach the end of topic"></a></h4><p>Consumers can check if it has reached the end of a topic by sending the <code>isEndOfTopic</code> request.</p><p><strong>Request</strong></p><div class="language-json codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#F8F8F2;--prism-background-color:#282A36"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-json codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#F8F8F2"><span class="token punctuation" style="color:rgb(248, 248, 242)">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">  </span><span class="token property">&quot;type&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&quot;isEndOfTopic&quot;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token punctuation" style="color:rgb(248, 248, 242)">}</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg class="copyButtonIcon_y97N" viewBox="0 0 24 24"><path d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg class="copyButtonSuccessIcon_LjdS" viewBox="0 0 24 24"><path d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><table><thead><tr><th align="left">Key</th><th align="left">Type</th><th align="left">Required?</th><th align="left">Explanation</th></tr></thead><tbody><tr><td align="left"><code>type</code></td><td align="left">string</td><td align="left">yes</td><td align="left">Type of command. Must be <code>isEndOfTopic</code></td></tr></tbody></table><p><strong>Response</strong></p><div class="language-json codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#F8F8F2;--prism-background-color:#282A36"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-json codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#F8F8F2"><span class="token punctuation" style="color:rgb(248, 248, 242)">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">   </span><span class="token property">&quot;endOfTopic&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&quot;true/false&quot;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"> </span><span class="token punctuation" style="color:rgb(248, 248, 242)">}</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg class="copyButtonIcon_y97N" viewBox="0 0 24 24"><path d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg class="copyButtonSuccessIcon_LjdS" viewBox="0 0 24 24"><path d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><h3 class="anchor anchorWithStickyNavbar_LWe7" id="error-codes">Error codes<a href="#error-codes" class="hash-link" aria-label="Direct link to Error codes" title="Direct link to Error codes"></a></h3><p>In case of error the server will close the WebSocket session using the
 following error codes:</p><table><thead><tr><th align="left">Error Code</th><th align="left">Error Message</th></tr></thead><tbody><tr><td align="left">1</td><td align="left">Failed to create producer</td></tr><tr><td align="left">2</td><td align="left">Failed to subscribe</td></tr><tr><td align="left">3</td><td align="left">Failed to deserialize from JSON</td></tr><tr><td align="left">4</td><td align="left">Failed to serialize to JSON</td></tr><tr><td align="left">5</td><td align="left">Failed to authenticate client</td></tr><tr><td align="left">6</td><td align="left">Client is not authorized</td></tr><tr><td align="left">7</td><td align="left">Invalid payload encoding</td></tr><tr><td align="left">8</td><td align="left">Unknown error</td></tr></tbody></table><blockquote><p>The application is responsible for re-establishing a new WebSocket session after a backoff period.</p></blockquote><h2 class="anchor anchorWithStickyNavbar_LWe7" id="client-examples">Client examples<a href="#client-examples" class="hash-link" aria-label="Direct link to Client examples" title="Direct link to Client examples"></a></h2><p>Below you&#x27;ll find code examples for the Pulsar WebSocket API in <a href="#python">Python</a> and <a href="#nodejs">Node.js</a>.</p><h3 class="anchor anchorWithStickyNavbar_LWe7" id="python">Python<a href="#python" class="hash-link" aria-label="Direct link to Python" title="Direct link to Python"></a></h3><p>This example uses the <a href="https://pypi.python.org/pypi/websocket-client" target="_blank" rel="noopener noreferrer"><code>websocket-client</code></a> package. You can install it using <a href="https://pypi.python.org/pypi/pip" target="_blank" rel="noopener noreferrer">pip</a>:</p><div class="language-shell codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#F8F8F2;--prism-background-color:#282A36"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-shell codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#F8F8F2"><span class="token plain">pip </span><span class="token function" style="color:rgb(80, 250, 123)">install</span><span class="token plain"> websocket-client</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg class="copyButtonIcon_y97N" viewBox="0 0 24 24"><path d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg class="copyButtonSuccessIcon_LjdS" viewBox="0 0 24 24"><path d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><p>You can also download it from <a href="https://pypi.python.org/pypi/websocket-client" target="_blank" rel="noopener noreferrer">PyPI</a>.</p><h4 class="anchor anchorWithStickyNavbar_LWe7" id="python-producer">Python producer<a href="#python-producer" class="hash-link" aria-label="Direct link to Python producer" title="Direct link to Python producer"></a></h4><p>Here&#x27;s an example Python producer that sends a simple message to a Pulsar <a href="/docs/3.1.x/reference-terminology/#topic">topic</a>:</p><div class="language-python codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#F8F8F2;--prism-background-color:#282A36"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-python codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#F8F8F2"><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">import</span><span class="token plain"> websocket</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"> base64</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"> json</span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token comment" style="color:rgb(98, 114, 164)"># If set enableTLS to true, your have to set tlsEnabled to true in conf/websocket.conf.</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">enable_TLS </span><span class="token operator">=</span><span class="token plain"> </span><span class="token boolean">False</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">scheme </span><span class="token operator">=</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&#x27;ws&#x27;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">if</span><span class="token plain"> enable_TLS</span><span class="token punctuation" style="color:rgb(248, 248, 242)">:</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    scheme </span><span class="token operator">=</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&#x27;wss&#x27;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">TOPIC </span><span class="token operator">=</span><span class="token plain"> scheme </span><span class="token operator">+</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&#x27;://localhost:8080/ws/v2/producer/persistent/public/default/my-topic&#x27;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">ws </span><span class="token operator">=</span><span class="token plain"> websocket</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token plain">create_connection</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token plain">TOPIC</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token comment" style="color:rgb(98, 114, 164)"># encode message</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">s </span><span class="token operator">=</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&quot;Hello World&quot;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">firstEncoded </span><span class="token operator">=</span><span class="token plain"> s</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token plain">encode</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token string" style="color:rgb(255, 121, 198)">&quot;UTF-8&quot;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">binaryEncoded </span><span class="token operator">=</span><span class="token plain"> base64</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token plain">b64encode</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token plain">firstEncoded</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">payloadString </span><span class="token operator">=</span><span class="token plain"> binaryEncoded</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token plain">decode</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token string" style="color:rgb(255, 121, 198)">&#x27;UTF-8&#x27;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token comment" style="color:rgb(98, 114, 164)"># Send one message as JSON</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">ws</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token plain">send</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token plain">json</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token plain">dumps</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token punctuation" style="color:rgb(248, 248, 242)">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    </span><span class="token string" style="color:rgb(255, 121, 198)">&#x27;payload&#x27;</span><span class="token plain"> </span><span class="token punctuation" style="color:rgb(248, 248, 242)">:</span><span class="token plain"> payloadString</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    </span><span class="token string" style="color:rgb(255, 121, 198)">&#x27;properties&#x27;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">:</span><span class="token plain"> </span><span class="token punctuation" style="color:rgb(248, 248, 242)">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">        </span><span class="token string" style="color:rgb(255, 121, 198)">&#x27;key1&#x27;</span><span class="token plain"> </span><span class="token punctuation" style="color:rgb(248, 248, 242)">:</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&#x27;value1&#x27;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">        </span><span class="token string" style="color:rgb(255, 121, 198)">&#x27;key2&#x27;</span><span class="token plain"> </span><span class="token punctuation" style="color:rgb(248, 248, 242)">:</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&#x27;value2&#x27;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    </span><span class="token punctuation" style="color:rgb(248, 248, 242)">}</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    </span><span class="token string" style="color:rgb(255, 121, 198)">&#x27;context&#x27;</span><span class="token plain"> </span><span class="token punctuation" style="color:rgb(248, 248, 242)">:</span><span class="token plain"> </span><span class="token number">5</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token punctuation" style="color:rgb(248, 248, 242)">}</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">response </span><span class="token operator">=</span><span class="token plain">  json</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token plain">loads</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token plain">ws</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token plain">recv</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">if</span><span class="token plain"> response</span><span class="token punctuation" style="color:rgb(248, 248, 242)">[</span><span class="token string" style="color:rgb(255, 121, 198)">&#x27;result&#x27;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">]</span><span class="token plain"> </span><span class="token operator">==</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&#x27;ok&#x27;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">:</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    </span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">print</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&#x27;Message published successfully&#x27;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">else</span><span class="token punctuation" style="color:rgb(248, 248, 242)">:</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    </span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">print</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token string" style="color:rgb(255, 121, 198)">&#x27;Failed to publish message:&#x27;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"> response</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">ws</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token plain">close</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg class="copyButtonIcon_y97N" viewBox="0 0 24 24"><path d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg class="copyButtonSuccessIcon_LjdS" viewBox="0 0 24 24"><path d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><h4 class="anchor anchorWithStickyNavbar_LWe7" id="python-consumer">Python consumer<a href="#python-consumer" class="hash-link" aria-label="Direct link to Python consumer" title="Direct link to Python consumer"></a></h4><p>Here&#x27;s an example Python consumer that listens on a Pulsar topic and prints the message ID whenever a message arrives:</p><div class="language-python codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#F8F8F2;--prism-background-color:#282A36"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-python codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#F8F8F2"><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">import</span><span class="token plain"> websocket</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"> base64</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"> json</span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token comment" style="color:rgb(98, 114, 164)"># If set enableTLS to true, your have to set tlsEnabled to true in conf/websocket.conf.</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">enable_TLS </span><span class="token operator">=</span><span class="token plain"> </span><span class="token boolean">False</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">scheme </span><span class="token operator">=</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&#x27;ws&#x27;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">if</span><span class="token plain"> enable_TLS</span><span class="token punctuation" style="color:rgb(248, 248, 242)">:</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    scheme </span><span class="token operator">=</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&#x27;wss&#x27;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">TOPIC </span><span class="token operator">=</span><span class="token plain"> scheme </span><span class="token operator">+</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&#x27;://localhost:8080/ws/v2/consumer/persistent/public/default/my-topic/my-sub&#x27;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">ws </span><span class="token operator">=</span><span class="token plain"> websocket</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token plain">create_connection</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token plain">TOPIC</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">while</span><span class="token plain"> </span><span class="token boolean">True</span><span class="token punctuation" style="color:rgb(248, 248, 242)">:</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    msg </span><span class="token operator">=</span><span class="token plain"> json</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token plain">loads</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token plain">ws</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token plain">recv</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    </span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">if</span><span class="token plain"> </span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">not</span><span class="token plain"> msg</span><span class="token punctuation" style="color:rgb(248, 248, 242)">:</span><span class="token plain"> </span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">break</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    </span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">print</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&quot;Received: {} - payload: {}&quot;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token builtin" style="color:rgb(189, 147, 249)">format</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token plain">msg</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"> base64</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token plain">b64decode</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token plain">msg</span><span class="token punctuation" style="color:rgb(248, 248, 242)">[</span><span class="token string" style="color:rgb(255, 121, 198)">&#x27;payload&#x27;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">]</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    </span><span class="token comment" style="color:rgb(98, 114, 164)"># Acknowledge successful processing</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    ws</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token plain">send</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token plain">json</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token plain">dumps</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token punctuation" style="color:rgb(248, 248, 242)">{</span><span class="token string" style="color:rgb(255, 121, 198)">&#x27;messageId&#x27;</span><span class="token plain"> </span><span class="token punctuation" style="color:rgb(248, 248, 242)">:</span><span class="token plain"> msg</span><span class="token punctuation" style="color:rgb(248, 248, 242)">[</span><span class="token string" style="color:rgb(255, 121, 198)">&#x27;messageId&#x27;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">]</span><span class="token punctuation" style="color:rgb(248, 248, 242)">}</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">ws</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token plain">close</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg class="copyButtonIcon_y97N" viewBox="0 0 24 24"><path d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg class="copyButtonSuccessIcon_LjdS" viewBox="0 0 24 24"><path d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><h4 class="anchor anchorWithStickyNavbar_LWe7" id="python-reader">Python reader<a href="#python-reader" class="hash-link" aria-label="Direct link to Python reader" title="Direct link to Python reader"></a></h4><p>Here&#x27;s an example Python reader that listens on a Pulsar topic and prints the message ID whenever a message arrives:</p><div class="language-python codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#F8F8F2;--prism-background-color:#282A36"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-python codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#F8F8F2"><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">import</span><span class="token plain"> websocket</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"> base64</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"> json</span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token comment" style="color:rgb(98, 114, 164)"># If set enableTLS to true, your have to set tlsEnabled to true in conf/websocket.conf.</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">enable_TLS </span><span class="token operator">=</span><span class="token plain"> </span><span class="token boolean">False</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">scheme </span><span class="token operator">=</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&#x27;ws&#x27;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">if</span><span class="token plain"> enable_TLS</span><span class="token punctuation" style="color:rgb(248, 248, 242)">:</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    scheme </span><span class="token operator">=</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&#x27;wss&#x27;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">TOPIC </span><span class="token operator">=</span><span class="token plain"> scheme </span><span class="token operator">+</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&#x27;://localhost:8080/ws/v2/reader/persistent/public/default/my-topic&#x27;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">ws </span><span class="token operator">=</span><span class="token plain"> websocket</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token plain">create_connection</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token plain">TOPIC</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">while</span><span class="token plain"> </span><span class="token boolean">True</span><span class="token punctuation" style="color:rgb(248, 248, 242)">:</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    msg </span><span class="token operator">=</span><span class="token plain"> json</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token plain">loads</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token plain">ws</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token plain">recv</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    </span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">if</span><span class="token plain"> </span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">not</span><span class="token plain"> msg</span><span class="token punctuation" style="color:rgb(248, 248, 242)">:</span><span class="token plain"> </span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">break</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    </span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">print</span><span class="token plain"> </span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&quot;Received: {} - payload: {}&quot;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token builtin" style="color:rgb(189, 147, 249)">format</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token plain">msg</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"> base64</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token plain">b64decode</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token plain">msg</span><span class="token punctuation" style="color:rgb(248, 248, 242)">[</span><span class="token string" style="color:rgb(255, 121, 198)">&#x27;payload&#x27;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">]</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    </span><span class="token comment" style="color:rgb(98, 114, 164)"># Acknowledge successful processing</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    ws</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token plain">send</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token plain">json</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token plain">dumps</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token punctuation" style="color:rgb(248, 248, 242)">{</span><span class="token string" style="color:rgb(255, 121, 198)">&#x27;messageId&#x27;</span><span class="token plain"> </span><span class="token punctuation" style="color:rgb(248, 248, 242)">:</span><span class="token plain"> msg</span><span class="token punctuation" style="color:rgb(248, 248, 242)">[</span><span class="token string" style="color:rgb(255, 121, 198)">&#x27;messageId&#x27;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">]</span><span class="token punctuation" style="color:rgb(248, 248, 242)">}</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">ws</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token plain">close</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg class="copyButtonIcon_y97N" viewBox="0 0 24 24"><path d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg class="copyButtonSuccessIcon_LjdS" viewBox="0 0 24 24"><path d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><h3 class="anchor anchorWithStickyNavbar_LWe7" id="nodejs">Node.js<a href="#nodejs" class="hash-link" aria-label="Direct link to Node.js" title="Direct link to Node.js"></a></h3><p>This example uses the <a href="https://websockets.github.io/ws/" target="_blank" rel="noopener noreferrer"><code>ws</code></a> package. You can install it using <a href="https://www.npmjs.com/" target="_blank" rel="noopener noreferrer">npm</a>:</p><div class="language-shell codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#F8F8F2;--prism-background-color:#282A36"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-shell codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#F8F8F2"><span class="token function" style="color:rgb(80, 250, 123)">npm</span><span class="token plain"> </span><span class="token function" style="color:rgb(80, 250, 123)">install</span><span class="token plain"> ws</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg class="copyButtonIcon_y97N" viewBox="0 0 24 24"><path d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg class="copyButtonSuccessIcon_LjdS" viewBox="0 0 24 24"><path d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><h4 class="anchor anchorWithStickyNavbar_LWe7" id="nodejs-producer">Node.js producer<a href="#nodejs-producer" class="hash-link" aria-label="Direct link to Node.js producer" title="Direct link to Node.js producer"></a></h4><p>Here&#x27;s an example Node.js producer that sends a simple message to a Pulsar topic:</p><div class="language-javascript codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#F8F8F2;--prism-background-color:#282A36"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-javascript codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#F8F8F2"><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">const</span><span class="token plain"> </span><span class="token maybe-class-name">WebSocket</span><span class="token plain"> </span><span class="token operator">=</span><span class="token plain"> </span><span class="token function" style="color:rgb(80, 250, 123)">require</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token string" style="color:rgb(255, 121, 198)">&#x27;ws&#x27;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token comment" style="color:rgb(98, 114, 164)">// If set enableTLS to true, your have to set tlsEnabled to true in conf/websocket.conf.</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">const</span><span class="token plain"> enableTLS </span><span class="token operator">=</span><span class="token plain"> </span><span class="token boolean">false</span><span class="token punctuation" style="color:rgb(248, 248, 242)">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">const</span><span class="token plain"> topic </span><span class="token operator">=</span><span class="token plain"> </span><span class="token template-string template-punctuation string" style="color:rgb(255, 121, 198)">`</span><span class="token template-string interpolation interpolation-punctuation punctuation" style="color:rgb(248, 248, 242)">${</span><span class="token template-string interpolation">enableTLS </span><span class="token template-string interpolation operator">?</span><span class="token template-string interpolation"> </span><span class="token template-string interpolation string" style="color:rgb(255, 121, 198)">&#x27;wss&#x27;</span><span class="token template-string interpolation"> </span><span class="token template-string interpolation operator">:</span><span class="token template-string interpolation"> </span><span class="token template-string interpolation string" style="color:rgb(255, 121, 198)">&#x27;ws&#x27;</span><span class="token template-string interpolation interpolation-punctuation punctuation" style="color:rgb(248, 248, 242)">}</span><span class="token template-string string" style="color:rgb(255, 121, 198)">://localhost:8080/ws/v2/producer/persistent/public/default/my-topic</span><span class="token template-string template-punctuation string" style="color:rgb(255, 121, 198)">`</span><span class="token punctuation" style="color:rgb(248, 248, 242)">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">const</span><span class="token plain"> ws </span><span class="token operator">=</span><span class="token plain"> </span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">new</span><span class="token plain"> </span><span class="token class-name">WebSocket</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token plain">topic</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">var</span><span class="token plain"> message </span><span class="token operator">=</span><span class="token plain"> </span><span class="token punctuation" style="color:rgb(248, 248, 242)">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">  </span><span class="token string-property property">&quot;payload&quot;</span><span class="token plain"> </span><span class="token operator">:</span><span class="token plain"> </span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">new</span><span class="token plain"> </span><span class="token class-name">Buffer</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token string" style="color:rgb(255, 121, 198)">&quot;Hello World&quot;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token method function property-access" style="color:rgb(80, 250, 123)">toString</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token string" style="color:rgb(255, 121, 198)">&#x27;base64&#x27;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">  </span><span class="token string-property property">&quot;properties&quot;</span><span class="token operator">:</span><span class="token plain"> </span><span class="token punctuation" style="color:rgb(248, 248, 242)">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    </span><span class="token string-property property">&quot;key1&quot;</span><span class="token plain"> </span><span class="token operator">:</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&quot;value1&quot;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    </span><span class="token string-property property">&quot;key2&quot;</span><span class="token plain"> </span><span class="token operator">:</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&quot;value2&quot;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">  </span><span class="token punctuation" style="color:rgb(248, 248, 242)">}</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">  </span><span class="token string-property property">&quot;context&quot;</span><span class="token plain"> </span><span class="token operator">:</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&quot;1&quot;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token punctuation" style="color:rgb(248, 248, 242)">}</span><span class="token punctuation" style="color:rgb(248, 248, 242)">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">ws</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token method function property-access" style="color:rgb(80, 250, 123)">on</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token string" style="color:rgb(255, 121, 198)">&#x27;open&#x27;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"> </span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">function</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token plain"> </span><span class="token punctuation" style="color:rgb(248, 248, 242)">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">  </span><span class="token comment" style="color:rgb(98, 114, 164)">// Send one message</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">  ws</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token method function property-access" style="color:rgb(80, 250, 123)">send</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token known-class-name class-name">JSON</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token method function property-access" style="color:rgb(80, 250, 123)">stringify</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token plain">message</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token punctuation" style="color:rgb(248, 248, 242)">}</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">ws</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token method function property-access" style="color:rgb(80, 250, 123)">on</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token string" style="color:rgb(255, 121, 198)">&#x27;message&#x27;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"> </span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">function</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token parameter">message</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token plain"> </span><span class="token punctuation" style="color:rgb(248, 248, 242)">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">  </span><span class="token console class-name">console</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token method function property-access" style="color:rgb(80, 250, 123)">log</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token string" style="color:rgb(255, 121, 198)">&#x27;received ack: %s&#x27;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"> message</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token punctuation" style="color:rgb(248, 248, 242)">}</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">;</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg class="copyButtonIcon_y97N" viewBox="0 0 24 24"><path d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg class="copyButtonSuccessIcon_LjdS" viewBox="0 0 24 24"><path d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><h4 class="anchor anchorWithStickyNavbar_LWe7" id="nodejs-consumer">Node.js consumer<a href="#nodejs-consumer" class="hash-link" aria-label="Direct link to Node.js consumer" title="Direct link to Node.js consumer"></a></h4><p>Here&#x27;s an example Node.js consumer that listens on the same topic used by the producer above:</p><div class="language-javascript codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#F8F8F2;--prism-background-color:#282A36"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-javascript codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#F8F8F2"><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">const</span><span class="token plain"> </span><span class="token maybe-class-name">WebSocket</span><span class="token plain"> </span><span class="token operator">=</span><span class="token plain"> </span><span class="token function" style="color:rgb(80, 250, 123)">require</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token string" style="color:rgb(255, 121, 198)">&#x27;ws&#x27;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token comment" style="color:rgb(98, 114, 164)">// If set enableTLS to true, your have to set tlsEnabled to true in conf/websocket.conf.</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">const</span><span class="token plain"> enableTLS </span><span class="token operator">=</span><span class="token plain"> </span><span class="token boolean">false</span><span class="token punctuation" style="color:rgb(248, 248, 242)">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">const</span><span class="token plain"> topic </span><span class="token operator">=</span><span class="token plain"> </span><span class="token template-string template-punctuation string" style="color:rgb(255, 121, 198)">`</span><span class="token template-string interpolation interpolation-punctuation punctuation" style="color:rgb(248, 248, 242)">${</span><span class="token template-string interpolation">enableTLS </span><span class="token template-string interpolation operator">?</span><span class="token template-string interpolation"> </span><span class="token template-string interpolation string" style="color:rgb(255, 121, 198)">&#x27;wss&#x27;</span><span class="token template-string interpolation"> </span><span class="token template-string interpolation operator">:</span><span class="token template-string interpolation"> </span><span class="token template-string interpolation string" style="color:rgb(255, 121, 198)">&#x27;ws&#x27;</span><span class="token template-string interpolation interpolation-punctuation punctuation" style="color:rgb(248, 248, 242)">}</span><span class="token template-string string" style="color:rgb(255, 121, 198)">://localhost:8080/ws/v2/consumer/persistent/public/default/my-topic/my-sub</span><span class="token template-string template-punctuation string" style="color:rgb(255, 121, 198)">`</span><span class="token punctuation" style="color:rgb(248, 248, 242)">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">const</span><span class="token plain"> ws </span><span class="token operator">=</span><span class="token plain"> </span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">new</span><span class="token plain"> </span><span class="token class-name">WebSocket</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token plain">topic</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">ws</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token method function property-access" style="color:rgb(80, 250, 123)">on</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token string" style="color:rgb(255, 121, 198)">&#x27;message&#x27;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"> </span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">function</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token parameter">message</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token plain"> </span><span class="token punctuation" style="color:rgb(248, 248, 242)">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    </span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">var</span><span class="token plain"> receiveMsg </span><span class="token operator">=</span><span class="token plain"> </span><span class="token known-class-name class-name">JSON</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token method function property-access" style="color:rgb(80, 250, 123)">parse</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token plain">message</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    </span><span class="token console class-name">console</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token method function property-access" style="color:rgb(80, 250, 123)">log</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token string" style="color:rgb(255, 121, 198)">&#x27;Received: %s - payload: %s&#x27;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"> message</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"> </span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">new</span><span class="token plain"> </span><span class="token class-name">Buffer</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token plain">receiveMsg</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token property-access">payload</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&#x27;base64&#x27;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token method function property-access" style="color:rgb(80, 250, 123)">toString</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    </span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">var</span><span class="token plain"> ackMsg </span><span class="token operator">=</span><span class="token plain"> </span><span class="token punctuation" style="color:rgb(248, 248, 242)">{</span><span class="token string-property property">&quot;messageId&quot;</span><span class="token plain"> </span><span class="token operator">:</span><span class="token plain"> receiveMsg</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token property-access">messageId</span><span class="token punctuation" style="color:rgb(248, 248, 242)">}</span><span class="token punctuation" style="color:rgb(248, 248, 242)">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    ws</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token method function property-access" style="color:rgb(80, 250, 123)">send</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token known-class-name class-name">JSON</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token method function property-access" style="color:rgb(80, 250, 123)">stringify</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token plain">ackMsg</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token punctuation" style="color:rgb(248, 248, 242)">}</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">;</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg class="copyButtonIcon_y97N" viewBox="0 0 24 24"><path d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg class="copyButtonSuccessIcon_LjdS" viewBox="0 0 24 24"><path d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><h4 class="anchor anchorWithStickyNavbar_LWe7" id="nodejs-reader">NodeJS reader<a href="#nodejs-reader" class="hash-link" aria-label="Direct link to NodeJS reader" title="Direct link to NodeJS reader"></a></h4><div class="language-javascript codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#F8F8F2;--prism-background-color:#282A36"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-javascript codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#F8F8F2"><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">const</span><span class="token plain"> </span><span class="token maybe-class-name">WebSocket</span><span class="token plain"> </span><span class="token operator">=</span><span class="token plain"> </span><span class="token function" style="color:rgb(80, 250, 123)">require</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token string" style="color:rgb(255, 121, 198)">&#x27;ws&#x27;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token comment" style="color:rgb(98, 114, 164)">// If set enableTLS to true, your have to set tlsEnabled to true in conf/websocket.conf.</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">const</span><span class="token plain"> enableTLS </span><span class="token operator">=</span><span class="token plain"> </span><span class="token boolean">false</span><span class="token punctuation" style="color:rgb(248, 248, 242)">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">const</span><span class="token plain"> topic </span><span class="token operator">=</span><span class="token plain"> </span><span class="token template-string template-punctuation string" style="color:rgb(255, 121, 198)">`</span><span class="token template-string interpolation interpolation-punctuation punctuation" style="color:rgb(248, 248, 242)">${</span><span class="token template-string interpolation">enableTLS </span><span class="token template-string interpolation operator">?</span><span class="token template-string interpolation"> </span><span class="token template-string interpolation string" style="color:rgb(255, 121, 198)">&#x27;wss&#x27;</span><span class="token template-string interpolation"> </span><span class="token template-string interpolation operator">:</span><span class="token template-string interpolation"> </span><span class="token template-string interpolation string" style="color:rgb(255, 121, 198)">&#x27;ws&#x27;</span><span class="token template-string interpolation interpolation-punctuation punctuation" style="color:rgb(248, 248, 242)">}</span><span class="token template-string string" style="color:rgb(255, 121, 198)">://localhost:8080/ws/v2/reader/persistent/public/default/my-topic</span><span class="token template-string template-punctuation string" style="color:rgb(255, 121, 198)">`</span><span class="token punctuation" style="color:rgb(248, 248, 242)">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">const</span><span class="token plain"> ws </span><span class="token operator">=</span><span class="token plain"> </span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">new</span><span class="token plain"> </span><span class="token class-name">WebSocket</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token plain">topic</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">ws</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token method function property-access" style="color:rgb(80, 250, 123)">on</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token string" style="color:rgb(255, 121, 198)">&#x27;message&#x27;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"> </span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">function</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token parameter">message</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token plain"> </span><span class="token punctuation" style="color:rgb(248, 248, 242)">{</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    </span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">var</span><span class="token plain"> receiveMsg </span><span class="token operator">=</span><span class="token plain"> </span><span class="token known-class-name class-name">JSON</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token method function property-access" style="color:rgb(80, 250, 123)">parse</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token plain">message</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    </span><span class="token console class-name">console</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token method function property-access" style="color:rgb(80, 250, 123)">log</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token string" style="color:rgb(255, 121, 198)">&#x27;Received: %s - payload: %s&#x27;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"> message</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"> </span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">new</span><span class="token plain"> </span><span class="token class-name">Buffer</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token plain">receiveMsg</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token property-access">payload</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&#x27;base64&#x27;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token method function property-access" style="color:rgb(80, 250, 123)">toString</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    </span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">var</span><span class="token plain"> ackMsg </span><span class="token operator">=</span><span class="token plain"> </span><span class="token punctuation" style="color:rgb(248, 248, 242)">{</span><span class="token string-property property">&quot;messageId&quot;</span><span class="token plain"> </span><span class="token operator">:</span><span class="token plain"> receiveMsg</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token property-access">messageId</span><span class="token punctuation" style="color:rgb(248, 248, 242)">}</span><span class="token punctuation" style="color:rgb(248, 248, 242)">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    ws</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token method function property-access" style="color:rgb(80, 250, 123)">send</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token known-class-name class-name">JSON</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token method function property-access" style="color:rgb(80, 250, 123)">stringify</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token plain">ackMsg</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token punctuation" style="color:rgb(248, 248, 242)">}</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">;</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg class="copyButtonIcon_y97N" viewBox="0 0 24 24"><path d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg class="copyButtonSuccessIcon_LjdS" viewBox="0 0 24 24"><path 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