<label for="userAgent" class="col-sm-3 text-sm-right col-form-label"><la:message
                                            key="labels.userAgent"/></label>
                                    <div class="col-sm-9">
                                        <la:errors property="userAgent"/>
                                        <la:text styleId="userAgent" property="userAgent" styleClass="form-control"/>

                                    </tr>
                                    <tr>
                                        <th><la:message key="labels.userAgent"/></th>
                                        <td>${f:h(userAgent)}<la:hidden property="userAgent"/></td>
                                    </tr>
                                    </tbody>
                                </table>
                            </div>

        final SetOnce<Map<String, Object>> initParamMapSet = new SetOnce<>();
        WebConfig webConfig = new WebConfig();
        final String userAgent = "TestAgent";
        webConfig.setUserAgent(userAgent);
        webConfig.setConfigParameter("""
                client.robotsTxtEnabled=false
                """);

                                    </tr>
                                    <tr>
                                        <th><la:message key="labels.user_agent"/></th>
                                        <td>${f:h(userAgent)}<la:hidden property="userAgent"/></td>
                                    </tr>
                                    <tr>

                                    <label for="userAgent" class="col-sm-3 text-sm-right col-form-label"><la:message
                                            key="labels.user_agent"/></label>
                                    <div class="col-sm-9">
                                        <la:errors property="userAgent"/>
                                        <la:text styleId="userAgent" property="userAgent" styleClass="form-control"/>

            requestConfigBuilder.setResponseTimeout(Timeout.ofMilliseconds(soTimeoutParam));
        }

        // user agent
        userAgent = getInitParameter(USER_AGENT_PROPERTY, userAgent, String.class);
        if (StringUtil.isNotBlank(userAgent)) {
            httpClientBuilder.setUserAgent(userAgent);
        }

        final HttpRoutePlanner planner = buildRoutePlanner();
        if (planner != null) {

    ├── Hc4HttpClient
    └── Hc5HttpClient
```

Switch via system property: `-Dfess.crawler.http.client=hc4` or `hc5` (default)

**Key Properties**: `connectionTimeout`, `soTimeout`, `proxyHost`, `proxyPort`, `userAgent`, `robotsTxtEnabled`, `ignoreSslCertificate`, `maxTotalConnection`, `defaultMaxConnectionPerRoute`

### CrawlerClientFactory

Pattern-based client selection (from `crawler/client.xml`):

            final SearchLog searchLog = queue.poll();
            if (searchLog != null) {
                final String userAgent = searchLog.getUserAgent();
                final boolean isBot =
                        userAgent != null && stream(botNames).get(stream -> stream.anyMatch(botName -> userAgent.indexOf(botName) >= 0));
                if (!isBot) {
                    searchLog.getUserInfo().ifPresent(userInfo -> {

labels.regex=Regex
labels.regularName=Regular Name
labels.replacement=Replacement
labels.sessionId=Session ID
labels.sortOrder=Sort Order
labels.updatedBy=Updated By
labels.updatedTime=Updated Time
labels.urls=URLs
labels.userAgent=User Agent
labels.username=Username
labels.value=Value
labels.versionNo=Version No
labels.cronExpression=Schedule
labels.dayForCleanup=Delete documents older than specified days

labels.regularName=Regulärer Name
labels.replacement=Ersetzung
labels.sessionId=Sitzungs-ID
labels.sortOrder=Sortierreihenfolge
labels.updatedBy=Aktualisiert von
labels.updatedTime=Aktualisierungszeit
labels.urls=URLs
labels.userAgent=User-Agent
labels.username=Benutzername
labels.value=Wert
labels.versionNo=Versionsnummer
labels.cronExpression=Zeitplan
labels.dayForCleanup=Dokumente löschen, die älter als die angegebenen Tage sind