diff --git a/.github/workflows/maven.yml b/.github/workflows/maven.yml
index 2e169522..b5134da5 100644
--- a/.github/workflows/maven.yml
+++ b/.github/workflows/maven.yml
@@ -35,6 +35,11 @@ jobs:
 
       - name: Build with Maven
         if: '!matrix.isMainBuildEnv'
+        env:
+          # Necessary for IMS IT
+          ACTOOL_IMS_IT_ORGANIZATIONID: ${{ vars.ACTOOL_IMS_IT_ORGANIZATIONID }}
+          ACTOOL_IMS_IT_CLIENTID: ${{ vars.ACTOOL_IMS_IT_CLIENTID }}
+          ACTOOL_IMS_IT_CLIENTSECRET: ${{ secrets.ACTOOL_IMS_IT_CLIENTSECRET }}
         run: mvn -e -B -V -Pintegration-tests clean verify
       - name: Build and Analyse with Maven
         if: github.ref != 'refs/heads/develop' && matrix.isMainBuildEnv
@@ -45,6 +50,10 @@ jobs:
           SONAR_TOKEN: ${{ secrets.SONAR_TOKEN }}
           # Needed to get some information about the pull request, if any
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          # Necessary for IMS IT
+          ACTOOL_IMS_IT_ORGANIZATIONID: ${{ vars.ACTOOL_IMS_IT_ORGANIZATIONID }}
+          ACTOOL_IMS_IT_CLIENTID: ${{ vars.ACTOOL_IMS_IT_CLIENTID }}
+          ACTOOL_IMS_IT_CLIENTSECRET: ${{ secrets.ACTOOL_IMS_IT_CLIENTSECRET }}
         run: mvn -e -B -V clean verify org.sonarsource.scanner.maven:sonar-maven-plugin:sonar -Dsonar.projectKey=Netcentric_accesscontroltool -Dsonar.organization=netcentric -Dsonar.host.url=https://sonarcloud.io -DnvdApiKeyEnvironmentVariable=NVD_API_KEY -Pdependency-check,coverage-report,integration-tests
 
       - name: Build, Analyse and Deploy with Maven
@@ -58,4 +67,8 @@ jobs:
           SONAR_TOKEN: ${{ secrets.SONAR_TOKEN }}
           # Needed to get some information about the pull request, if any
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          # Necessary for IMS IT
+          ACTOOL_IMS_IT_ORGANIZATIONID: ${{ vars.ACTOOL_IMS_IT_ORGANIZATIONID }}
+          ACTOOL_IMS_IT_CLIENTID: ${{ vars.ACTOOL_IMS_IT_CLIENTID }}
+          ACTOOL_IMS_IT_CLIENTSECRET: ${{ secrets.ACTOOL_IMS_IT_CLIENTSECRET }}
         run: mvn -e -B -V clean deploy org.sonarsource.scanner.maven:sonar-maven-plugin:sonar -Dsonar.projectKey=Netcentric_accesscontroltool -Dsonar.organization=netcentric -Dsonar.host.url=https://sonarcloud.io -DnvdApiKeyEnvironmentVariable=NVD_API_KEY -Pdependency-check,coverage-report,integration-tests
diff --git a/accesscontroltool-bundle/bnd.bnd b/accesscontroltool-bundle/bnd.bnd
index c601423c..f536c90e 100644
--- a/accesscontroltool-bundle/bnd.bnd
+++ b/accesscontroltool-bundle/bnd.bnd
@@ -11,6 +11,8 @@ Import-Package: \
 com.adobe.granite.crypto;resolution:=optional,\
 com.adobe.granite.keystore;resolution:=optional,\
 com.adobe.granite.jmx.annotation;resolution:=optional,\
+com.fasterxml.jackson.databind;resolution:=optional,\
+org.apache.http.*;resolution:=optional,\
 org.bouncycastle.*;resolution:=optional,\
 org.apache.sling.commons.scheduler.*;resolution:=optional,\
 org.apache.jackrabbit.oak.spi.security.principal;version="[1.5.0,3)",\
diff --git a/accesscontroltool-bundle/pom.xml b/accesscontroltool-bundle/pom.xml
index e3bb6566..f87be44b 100644
--- a/accesscontroltool-bundle/pom.xml
+++ b/accesscontroltool-bundle/pom.xml
@@ -150,6 +150,12 @@
             <artifactId>slf4j-simple</artifactId>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.osgi</groupId>
+            <artifactId>org.osgi.util.converter</artifactId>
+            <version>1.0.9</version>
+            <scope>test</scope>
+        </dependency>
         <!-- IT dependencies -->
         <dependency>
             <groupId>org.apache.jackrabbit</groupId>
@@ -183,7 +189,17 @@
             <version>3.6.8</version>
             <scope>test</scope>
         </dependency>
-        
+        <dependency>
+            <groupId>org.apache.httpcomponents</groupId>
+            <artifactId>httpclient-osgi</artifactId>
+            <version>4.5.13</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-databind</artifactId>
+            <scope>test</scope>
+        </dependency>
         <!-- END: Test Dependencies -->
 
         <!-- use the uber-jar always as last dependency because a lot of classes are provided also by other artifacts
diff --git a/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/authorizableinstaller/impl/AuthorizableInstallerServiceImpl.java b/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/authorizableinstaller/impl/AuthorizableInstallerServiceImpl.java
index 8e3f64c3..b9a9254b 100644
--- a/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/authorizableinstaller/impl/AuthorizableInstallerServiceImpl.java
+++ b/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/authorizableinstaller/impl/AuthorizableInstallerServiceImpl.java
@@ -18,6 +18,7 @@
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Iterator;
+import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
@@ -65,6 +66,7 @@
 import biz.netcentric.cq.tools.actool.configmodel.pkcs.Key;
 import biz.netcentric.cq.tools.actool.configmodel.pkcs.RandomPassword;
 import biz.netcentric.cq.tools.actool.crypto.DecryptionService;
+import biz.netcentric.cq.tools.actool.externalusermanagement.ExternalGroupManagement;
 import biz.netcentric.cq.tools.actool.helper.AcHelper;
 import biz.netcentric.cq.tools.actool.helper.AccessControlUtils;
 import biz.netcentric.cq.tools.actool.helper.Constants;
@@ -102,7 +104,10 @@ public class AuthorizableInstallerServiceImpl implements
 
     @Reference(policyOption = ReferencePolicyOption.GREEDY)
     SlingRepository repository;
-    
+
+    @Reference(policyOption = ReferencePolicyOption.GREEDY, cardinality = ReferenceCardinality.MULTIPLE)
+    List<ExternalGroupManagement> externalGroupManagementServices;
+
     @Override
     public void installAuthorizables(
             AcConfiguration acConfiguration,
@@ -113,16 +118,32 @@ public void installAuthorizables(
         AuthInstallerUserManager userManager = new AuthInstallerUserManagerPrefetchingImpl(AccessControlUtils.getUserManagerAutoSaveDisabled(session), session.getValueFactory(), installLog);
 
         Set<String> authorizablesFromConfigurations = authorizablesConfigBeans.getAuthorizableIds();
+        Collection<AuthorizableConfigBean> groupsToSyncWithExternalUserMgmt = new LinkedList<>();
         for (AuthorizableConfigBean authorizableConfigBean : authorizablesConfigBeans) {
 
             installAuthorizableConfigurationBean(session, userManager, acConfiguration,
                     authorizableConfigBean, installLog, authorizablesFromConfigurations);
+            
+            if (authorizableConfigBean.isSyncWithExternalUserManagement() && authorizableConfigBean.isGroup() && !externalGroupManagementServices.isEmpty()) {
+                groupsToSyncWithExternalUserMgmt.add(authorizableConfigBean);
+            }
         }
 
         installLog.addMessage(LOG, "Created "+installLog.getCountAuthorizablesCreated() + " authorizables (moved "+installLog.getCountAuthorizablesMoved() + " authorizables)");
+        syncWithExternalGroupManagement(groupsToSyncWithExternalUserMgmt, installLog);
 
     }
 
+    private void syncWithExternalGroupManagement(Collection<AuthorizableConfigBean> groupConfigBeans, InstallationLogger installLog) throws IOException {
+        if (groupConfigBeans.isEmpty()) {
+            return;
+        }
+        for (ExternalGroupManagement externalGroupManagement : externalGroupManagementServices) {
+            externalGroupManagement.updateGroups(groupConfigBeans);
+            installLog.addMessage(LOG, "Synchronized " + groupConfigBeans.size() + " groups with external user management " + externalGroupManagement.getLabel());
+        }
+    }
+    
     private void installAuthorizableConfigurationBean(final Session session,
             AuthInstallerUserManager userManager,
             AcConfiguration acConfiguration,
diff --git a/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/authorizableinstaller/impl/ExternalGroupInstallerServiceImpl.java b/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/authorizableinstaller/impl/ExternalGroupInstallerServiceImpl.java
index 35c934a5..11d9a04d 100644
--- a/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/authorizableinstaller/impl/ExternalGroupInstallerServiceImpl.java
+++ b/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/authorizableinstaller/impl/ExternalGroupInstallerServiceImpl.java
@@ -34,7 +34,7 @@
 import biz.netcentric.cq.tools.actool.helper.Constants;
 import biz.netcentric.cq.tools.actool.history.InstallationLogger;
 
-/** SCR component to create external groups (as configured using "externalId"). Only available if package
+/** SCR component to create groups in AEM which are linked to external directory entries (as configured using {@code externalId}). Only available if package
  * o.a.j.oak.spi.security.authentication.external.basic (optional OSGi import) is available (this is the case starting from AEM 6.1+SP1, the
  * functionality is crucial since the change in AEM 6.2 + oak 1.4.7 (see #140).
  * 
diff --git a/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/configmodel/AuthorizableConfigBean.java b/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/configmodel/AuthorizableConfigBean.java
index 7fc65eff..358ad9ff 100644
--- a/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/configmodel/AuthorizableConfigBean.java
+++ b/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/configmodel/AuthorizableConfigBean.java
@@ -19,6 +19,7 @@
 import biz.netcentric.cq.tools.actool.configmodel.pkcs.Key;
 import biz.netcentric.cq.tools.actool.dumpservice.AcDumpElement;
 import biz.netcentric.cq.tools.actool.dumpservice.AcDumpElementVisitor;
+import biz.netcentric.cq.tools.actool.externalusermanagement.ExternalGroupManagement;
 
 public class AuthorizableConfigBean implements AcDumpElement {
 
@@ -59,6 +60,11 @@ public class AuthorizableConfigBean implements AcDumpElement {
     private Map<String, Key> keys;
     private List<String> impersonationAllowedFor;
 
+    /**
+     * if {@true} synchronized with external user managed. Synchronization happens via all active services of type {@link ExternalGroupManagement}
+     */
+    private boolean syncWithExternalUserManagement;
+    
     public String getAuthorizableId() {
         return authorizableId;
     }
@@ -320,8 +326,9 @@ public String toString() {
         sb.append("isMemberOf: " + getIsMemberOfString() + "\n");
         sb.append("members: " + getMembersString() + "\n");
         sb.append("appendToKeyStore: " + isAppendToKeyStore() + "\n");
-        sb.append("keys:" + getKeys());
-        sb.append("impersonationAllowedFor:" + getImpersonationAllowedFor());
+        sb.append("keys:" + getKeys() + "\n");
+        sb.append("impersonationAllowedFor:" + getImpersonationAllowedFor() + "\n");
+        sb.append("syncWithExternalUserManagement: " + isSyncWithExternalUserManagement());
         return sb.toString();
     }
 
@@ -341,4 +348,12 @@ public void accept(final AcDumpElementVisitor acDumpElementVisitor) {
         acDumpElementVisitor.visit(this);
     }
 
+    public boolean isSyncWithExternalUserManagement() {
+        return syncWithExternalUserManagement;
+    }
+
+    public void setSyncWithExternalUserManagement(boolean syncWithExternalUserManagement) {
+        this.syncWithExternalUserManagement = syncWithExternalUserManagement;
+    }
+
 }
diff --git a/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/configreader/YamlConfigReader.java b/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/configreader/YamlConfigReader.java
index c61024c5..022db16a 100644
--- a/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/configreader/YamlConfigReader.java
+++ b/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/configreader/YamlConfigReader.java
@@ -80,6 +80,7 @@ public class YamlConfigReader implements ConfigReader {
     private static final String GROUP_CONFIG_PROPERTY_UNMANAGED_EXTERNAL_MEMBERS_REGEX = "unmanagedExternalMembersRegex";
 
     private static final String GROUP_CONFIG_IS_VIRTUAL = "virtual";
+    private static final String GROUP_CONFIG_SYNC_WITH_EXTERNAL_USERMANAGEMENT = "syncWithExternalUserManagement";
 
     private static final String USER_CONFIG_PROPERTY_IS_SYSTEM_USER = "isSystemUser";
 
@@ -427,6 +428,9 @@ protected void setupAuthorizableBean(
         authorizableConfigBean.setVirtual(Boolean.valueOf(getMapValueAsString(currentPrincipalDataMap,
                 GROUP_CONFIG_IS_VIRTUAL)));
 
+        authorizableConfigBean.setSyncWithExternalUserManagement(Boolean.valueOf(getMapValueAsString(currentPrincipalDataMap,
+                GROUP_CONFIG_SYNC_WITH_EXTERNAL_USERMANAGEMENT)));
+
         authorizableConfigBean.setIsGroup(isGroupSection);
         authorizableConfigBean.setIsSystemUser(Boolean.valueOf(getMapValueAsString(currentPrincipalDataMap,
                 USER_CONFIG_PROPERTY_IS_SYSTEM_USER)));
diff --git a/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/externalusermanagement/ExternalGroupManagement.java b/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/externalusermanagement/ExternalGroupManagement.java
new file mode 100644
index 00000000..373b3d1b
--- /dev/null
+++ b/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/externalusermanagement/ExternalGroupManagement.java
@@ -0,0 +1,19 @@
+package biz.netcentric.cq.tools.actool.externalusermanagement;
+
+import java.io.IOException;
+import java.util.Collection;
+
+import biz.netcentric.cq.tools.actool.configmodel.AuthorizableConfigBean;
+
+/**
+ * Implementations of this service synchronize (i.e. create/update/delete) groups in an external directory (outside AEM).
+ */
+public interface ExternalGroupManagement {
+    void updateGroups(Collection<AuthorizableConfigBean> groupConfigs) throws IOException;
+
+    /**
+     * 
+     * @return a label for the external group management tool (e.g. IMS)
+     */
+    String getLabel();
+}
diff --git a/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/externalusermanagement/ims/IMSUserManagement.java b/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/externalusermanagement/ims/IMSUserManagement.java
new file mode 100644
index 00000000..945b170b
--- /dev/null
+++ b/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/externalusermanagement/ims/IMSUserManagement.java
@@ -0,0 +1,268 @@
+package biz.netcentric.cq.tools.actool.externalusermanagement.ims;
+
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.Reader;
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.nio.charset.Charset;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.stream.Collectors;
+
+import org.apache.http.Consts;
+import org.apache.http.Header;
+import org.apache.http.HttpEntity;
+import org.apache.http.HttpResponse;
+import org.apache.http.NameValuePair;
+import org.apache.http.StatusLine;
+import org.apache.http.client.ClientProtocolException;
+import org.apache.http.client.HttpResponseException;
+import org.apache.http.client.ResponseHandler;
+import org.apache.http.client.ServiceUnavailableRetryStrategy;
+import org.apache.http.client.config.RequestConfig;
+import org.apache.http.client.entity.UrlEncodedFormEntity;
+import org.apache.http.client.methods.HttpPost;
+import org.apache.http.entity.ContentType;
+import org.apache.http.entity.StringEntity;
+import org.apache.http.impl.client.CloseableHttpClient;
+import org.apache.http.message.BasicNameValuePair;
+import org.apache.http.osgi.services.HttpClientBuilderFactory;
+import org.apache.http.protocol.HttpContext;
+import org.apache.http.util.EntityUtils;
+import org.osgi.service.component.annotations.Activate;
+import org.osgi.service.component.annotations.Component;
+import org.osgi.service.component.annotations.ConfigurationPolicy;
+import org.osgi.service.component.annotations.Deactivate;
+import org.osgi.service.component.annotations.Reference;
+import org.osgi.service.metatype.annotations.AttributeDefinition;
+import org.osgi.service.metatype.annotations.AttributeType;
+import org.osgi.service.metatype.annotations.Designate;
+import org.osgi.service.metatype.annotations.ObjectClassDefinition;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+import biz.netcentric.cq.tools.actool.configmodel.AuthorizableConfigBean;
+import biz.netcentric.cq.tools.actool.externalusermanagement.ExternalGroupManagement;
+import biz.netcentric.cq.tools.actool.externalusermanagement.ims.IMSUserManagement.Configuration;
+import biz.netcentric.cq.tools.actool.externalusermanagement.ims.request.ActionCommand;
+import biz.netcentric.cq.tools.actool.externalusermanagement.ims.request.CreateGroupStep;
+import biz.netcentric.cq.tools.actool.externalusermanagement.ims.request.UserGroupActionCommand;
+import biz.netcentric.cq.tools.actool.externalusermanagement.ims.response.AccessToken;
+import biz.netcentric.cq.tools.actool.externalusermanagement.ims.response.ActionCommandResponse;
+
+/**
+ * Managing Adobe IMS groups via the UMAPI.
+ * 
+ * @see <a href="https://adobe-apiplatform.github.io/umapi-documentation/en/">UMAPI Documentation</a>
+ */
+@Component(configurationPolicy = ConfigurationPolicy.REQUIRE)
+@Designate(ocd=Configuration.class)
+public class IMSUserManagement implements ExternalGroupManagement {
+
+    @ObjectClassDefinition(name = "AC Tool Adobe IMS User Management", description = "Settings of the API for user management tasks (UMAPI) in the Adobe IMS")
+    protected static @interface Configuration {
+        @AttributeDefinition(name = "UMAPI Base URL", description = "UMAPI Endpoint Base URL (the part prior the organization id)")
+        String umapiBaseUrl() default "https://usermanagement.adobe.io/v2/usermanagement/action/";
+        @AttributeDefinition(name = "Organization ID", description = "The unique identifier for an organization. This is a string of the form A495E53@AdobeOrg where the prefix before the @ is a hexadecimal number. You can find this value as part of the URL path for the organization in the Adobe Admin Console or in the Adobe Developer Console for your User Management integration.")
+        String organizationId();
+        @AttributeDefinition(name = "Test Only", description = "If true, parameter syntactic and (limited) semantic checking is done, but the specified operations are not performed, so no user/group accounts or group memberships are created, changed, or deleted.")
+        boolean isTestOnly();
+        @AttributeDefinition(name = "IMS Token Endpoint URL", description = "The URL from which to retrieve the access token.")
+        String imsTokenEndpointUrl() default "https://ims-na1.adobelogin.com/ims/token/v3";
+        @AttributeDefinition(name = "Client ID", description = "The client ID exposed in the Adobe IO Console for the UMAPI integration used to authorize the session. Also used as \"X-Api-Key\" header value.")
+        String clientId();
+        @AttributeDefinition(name = "Client Secret", description = "The client secret exposed in the Adobe IO Console for the UMAPI integration used to authorize the session.", type = AttributeType.PASSWORD)
+        String clientSecret();
+        @AttributeDefinition(name = "OAuth Scopes", description = "Scopes for which the access token is requested.")
+        String[] scopes() default { "openid","AdobeID","user_management_sdk" };
+        @AttributeDefinition(name = "Connect Timeout", description = "The maximum time to establish the connection with the remote host in milliseconds.")
+        int connectTimeout() default 2000;
+        @AttributeDefinition(name = "Socket Timeout", description = "The time waiting for data – after establishing the connection; maximum time of inactivity between two data packets. Given in milliseconds.")
+        int socketTimeout() default 10000;
+    }
+
+    public static final Logger LOG = LoggerFactory.getLogger(IMSUserManagement.class);
+    private static final int MAX_NUM_COMMANDS_PER_REQUEST = 10;
+
+    private final Configuration config;
+    private final CloseableHttpClient client;
+
+    /**
+     * Strategy evaluating the {@code retry-after} response header with status code 429.
+     * This class is not thread safe (due to mutable state in {@code retryDelayInSeconds}).
+     * Necessary due to <a href="https://adobe-apiplatform.github.io/umapi-documentation/en/api/ActionsRef.html#actionThrottle">throttling of UMAPI requests</a>.
+     * @see <a href="https://datatracker.ietf.org/doc/html/rfc6585#section-4">RFC6585</a>
+     * 
+     */
+    static final class TooManyRequestsRetryStrategy implements ServiceUnavailableRetryStrategy {
+        private final int maxRetryCount;
+        private final int defaultRetryDelayInSeconds;
+        private int retryDelayInSeconds;
+ 
+        public TooManyRequestsRetryStrategy(int maxRetryCount, int defaultRetryDelayInSeconds) {
+            super();
+            this.maxRetryCount = maxRetryCount;
+            this.defaultRetryDelayInSeconds = defaultRetryDelayInSeconds;
+            retryDelayInSeconds = defaultRetryDelayInSeconds;
+        }
+
+        @Override
+        public boolean retryRequest(HttpResponse response, int executionCount, HttpContext context) {
+            retryDelayInSeconds = defaultRetryDelayInSeconds;
+            boolean shouldRetry = (executionCount <= maxRetryCount && response.getStatusLine().getStatusCode() == 429);
+            if (shouldRetry) {
+                Header retryAfterHeader = response.getFirstHeader("Retry-After");
+                if (retryAfterHeader != null) {
+                    retryDelayInSeconds = Integer.parseInt(retryAfterHeader.getValue());
+                }
+            }
+            return shouldRetry;
+        }
+
+        @Override
+        public long getRetryInterval() {
+            return retryDelayInSeconds * 1000l;
+        } 
+    }
+
+    @Activate
+    public IMSUserManagement(Configuration config, @Reference HttpClientBuilderFactory httpClientBuilderFactory) {
+        this.config = config;
+        RequestConfig requestConfig = RequestConfig.custom()
+                .setConnectTimeout(config.connectTimeout())
+                .setConnectionRequestTimeout(config.socketTimeout())
+                .setSocketTimeout(config.socketTimeout()).build();
+        client = httpClientBuilderFactory.newBuilder()
+                .setDefaultRequestConfig(requestConfig)
+                .setServiceUnavailableRetryStrategy(new TooManyRequestsRetryStrategy(3, 5))
+                .build();
+    }
+    
+    @Deactivate
+    public void deactivate() throws IOException {
+        client.close();
+    }
+
+    private URI getUserManagementActionUrl() throws URISyntaxException {
+        URI uri = new URI(config.umapiBaseUrl() + config.organizationId());
+        if (config.isTestOnly()) {
+            uri = new URI(uri.getScheme(), uri.getAuthority(),
+                    uri.getPath(), "testOnly=true", uri.getFragment());
+        }
+        return uri;
+    }
+
+    @Override
+    public String getLabel() {
+        return "Adobe IMS";
+    }
+
+    @Override
+    public void updateGroups(Collection<AuthorizableConfigBean> groupConfigs) throws IOException {
+        List<ActionCommand> actionCommands = new LinkedList<>();
+        for (AuthorizableConfigBean groupConfig : groupConfigs) {
+            UserGroupActionCommand actionCommand = new UserGroupActionCommand(groupConfig.getAuthorizableId());
+            CreateGroupStep createGroupStep = new CreateGroupStep();
+            createGroupStep.description = groupConfig.getDescription();
+            actionCommand.addStep(createGroupStep);
+            actionCommands.add(actionCommand);
+        }
+        // update in batches of 10 commands
+        AtomicInteger counter = new AtomicInteger();
+        final Collection<List<ActionCommand>> actionCommandsBatches = actionCommands.stream().collect(Collectors.groupingBy
+                (it->counter.getAndIncrement() / MAX_NUM_COMMANDS_PER_REQUEST))
+                .values();
+        String token = getOAuthServer2ServerToken();
+        for (List<ActionCommand> actionCommandBatch : actionCommandsBatches) {
+            ActionCommandResponse response = sendActionCommand(token, actionCommandBatch);
+            if (!response.errors.isEmpty()) {
+                throw new IOException("Errors updating groups: " + response.errors);
+            }
+            if (!response.warnings.isEmpty()) {
+                response.warnings.stream().forEach(w -> LOG.warn("Warning updating a group: {}", w));
+            }
+        }
+    }
+
+    private ActionCommandResponse sendActionCommand(String token, Collection<ActionCommand> actions) throws IOException {
+        ObjectMapper objectMapper = new ObjectMapper();
+        HttpPost httpPost;
+        try {
+            httpPost = new HttpPost(getUserManagementActionUrl());
+        } catch (URISyntaxException e) {
+            throw new IllegalArgumentException("Could not create valid URI from configuration", e);
+        }
+        String jsonPayload = objectMapper.writeValueAsString(actions);
+        httpPost.setEntity(new StringEntity(jsonPayload, ContentType.create("application/json"))); // must be without charset
+        httpPost.setHeader("Authorization", "Bearer " + token);
+        httpPost.setHeader("X-Api-Key", config.clientId());
+        ResponseHandler<ActionCommandResponse> rh = new ResponseHandler<ActionCommandResponse>() {
+            @Override
+            public ActionCommandResponse handleResponse(
+                    final HttpResponse response) throws IOException {
+                StatusLine statusLine = response.getStatusLine();
+                HttpEntity entity = response.getEntity();
+                if (statusLine.getStatusCode() >= 300) {
+                    throw new HttpResponseException(
+                            statusLine.getStatusCode(),
+                            statusLine.getReasonPhrase() + ", body:" + EntityUtils.toString(entity));
+                }
+                if (entity == null) {
+                    throw new ClientProtocolException("Response contains no content");
+                }
+                return objectMapper.readValue(entity.getContent(), ActionCommandResponse.class);
+            }
+        };
+        LOG.debug("Calling UMAPI via {}", httpPost);
+        return client.execute(httpPost, rh);
+    }
+
+    /**
+     * Requests an access token using the OAuth Server to Server authentication flow (OAuth 2.0 client credential grant).
+     * It is valid for 24 hours.
+     * @return the access token
+     * @throws IOException 
+     * @see <a href="https://adobe-apiplatform.github.io/umapi-documentation/en/UM_Authentication.html">OAuth Server to Server Authentication</a>
+     */
+    private String getOAuthServer2ServerToken() throws IOException {
+        HttpPost httpPost = new HttpPost(config.imsTokenEndpointUrl());
+        List<NameValuePair> params = new ArrayList<>();
+        params.add(new BasicNameValuePair("client_id", config.clientId()));
+        params.add(new BasicNameValuePair("client_secret", config.clientSecret()));
+        params.add(new BasicNameValuePair("grant_type", "client_credentials"));
+        params.add(new BasicNameValuePair("scope", String.join(",", config.scopes())));
+        UrlEncodedFormEntity entity = new UrlEncodedFormEntity(params, Consts.UTF_8);
+        httpPost.setEntity(entity);
+
+        ResponseHandler<AccessToken> rh = new ResponseHandler<AccessToken>() {
+            @Override
+            public AccessToken handleResponse(
+                    final HttpResponse response) throws IOException {
+                StatusLine statusLine = response.getStatusLine();
+                HttpEntity entity = response.getEntity();
+                if (statusLine.getStatusCode() >= 300) {
+                    throw new HttpResponseException(
+                            statusLine.getStatusCode(),
+                            statusLine.getReasonPhrase() + ", body:" + EntityUtils.toString(entity));
+                }
+                if (entity == null) {
+                    throw new ClientProtocolException("Response contains no content");
+                }
+                ObjectMapper objectMapper = new ObjectMapper();
+                ContentType contentType = ContentType.getOrDefault(entity);
+                Charset charset = contentType.getCharset();
+                try (Reader reader = new InputStreamReader(entity.getContent(), charset)) {
+                    return objectMapper.readValue(reader, AccessToken.class);
+                }
+            }
+        };
+        AccessToken token = client.execute(httpPost, rh);
+        return token.token;
+    }
+}
diff --git a/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/externalusermanagement/ims/request/ActionCommand.java b/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/externalusermanagement/ims/request/ActionCommand.java
new file mode 100644
index 00000000..7b77397c
--- /dev/null
+++ b/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/externalusermanagement/ims/request/ActionCommand.java
@@ -0,0 +1,20 @@
+package biz.netcentric.cq.tools.actool.externalusermanagement.ims.request;
+
+import java.util.Collection;
+import java.util.LinkedList;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+public class ActionCommand {
+
+    @JsonProperty("do")
+    final Collection<Step> steps;
+
+    public ActionCommand() {
+        steps = new LinkedList<>();
+    }
+
+    public boolean addStep(Step step) {
+        return steps.add(step);
+    }
+}
diff --git a/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/externalusermanagement/ims/request/CreateGroupStep.java b/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/externalusermanagement/ims/request/CreateGroupStep.java
new file mode 100644
index 00000000..43c25c6b
--- /dev/null
+++ b/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/externalusermanagement/ims/request/CreateGroupStep.java
@@ -0,0 +1,18 @@
+package biz.netcentric.cq.tools.actool.externalusermanagement.ims.request;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+
+@JsonTypeName("createUserGroup")
+public class CreateGroupStep implements Step {
+
+    // this cannot be a constant, but still needs to be serialized as literal
+    @JsonProperty("option")
+    final String defaultOption = "ignoreIfAlreadyExists"; // the option "updateIfAlreadyExists" fails in case the group is new, tracked in https://adminconsole.adobe.com/FA907D44536A3C2B0A490D4D@AdobeOrg/support/support-cases/E-001223901
+    // unclear why name should be passed here as well: https://github.com/adobe-apiplatform/umapi-documentation/issues/87
+    //@JsonProperty
+    //String name; 
+    @JsonProperty
+    public
+    String description;
+}
diff --git a/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/externalusermanagement/ims/request/Step.java b/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/externalusermanagement/ims/request/Step.java
new file mode 100644
index 00000000..88ea3cc7
--- /dev/null
+++ b/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/externalusermanagement/ims/request/Step.java
@@ -0,0 +1,14 @@
+package biz.netcentric.cq.tools.actool.externalusermanagement.ims.request;
+
+import com.fasterxml.jackson.annotation.JsonSubTypes;
+import com.fasterxml.jackson.annotation.JsonSubTypes.Type;
+import com.fasterxml.jackson.annotation.JsonTypeInfo;
+import com.fasterxml.jackson.annotation.JsonTypeInfo.As;
+
+@JsonTypeInfo(
+        use = JsonTypeInfo.Id.NAME, 
+        include = As.WRAPPER_OBJECT, visible = true)
+@JsonSubTypes({@Type(CreateGroupStep.class)})
+public interface Step {
+
+}
diff --git a/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/externalusermanagement/ims/request/UserGroupActionCommand.java b/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/externalusermanagement/ims/request/UserGroupActionCommand.java
new file mode 100644
index 00000000..6381e4e9
--- /dev/null
+++ b/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/externalusermanagement/ims/request/UserGroupActionCommand.java
@@ -0,0 +1,13 @@
+package biz.netcentric.cq.tools.actool.externalusermanagement.ims.request;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+public class UserGroupActionCommand extends ActionCommand {
+
+    public UserGroupActionCommand(String userGroup) {
+        this.userGroup = userGroup;
+    }
+
+    @JsonProperty("usergroup")
+    String userGroup;
+}
diff --git a/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/externalusermanagement/ims/response/AccessToken.java b/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/externalusermanagement/ims/response/AccessToken.java
new file mode 100644
index 00000000..78556b8a
--- /dev/null
+++ b/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/externalusermanagement/ims/response/AccessToken.java
@@ -0,0 +1,15 @@
+package biz.netcentric.cq.tools.actool.externalusermanagement.ims.response;
+
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+/** OAuth 2.0 Access Token JSON Format as specified in <a href="https://datatracker.ietf.org/doc/html/rfc6749#section-5.1">RFC6749</a>. */
+@JsonIgnoreProperties(ignoreUnknown = true)
+public class AccessToken {
+    @JsonProperty("access_token")
+    public String token;
+    @JsonProperty("token_type")
+    public String type;
+    @JsonProperty("expires_in")
+    public long lifeTimeInSeconds;
+}
diff --git a/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/externalusermanagement/ims/response/ActionCommandError.java b/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/externalusermanagement/ims/response/ActionCommandError.java
new file mode 100644
index 00000000..d16a5253
--- /dev/null
+++ b/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/externalusermanagement/ims/response/ActionCommandError.java
@@ -0,0 +1,21 @@
+package biz.netcentric.cq.tools.actool.externalusermanagement.ims.response;
+
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+/**
+ * 
+ * @see <a href="https://adobe-apiplatform.github.io/umapi-documentation/en/api/ActionsRef.html#responses">Action Response Format</a>
+ */
+@JsonIgnoreProperties(ignoreUnknown = true)
+public class ActionCommandError extends ActionCommandIssue {
+
+    @JsonProperty
+    String errorCode;
+
+    @Override
+    public String toString() {
+        return "ActionCommandError [errorCode=" + errorCode + ", requestID=" + requestID + ", index=" + index + ", step=" + step
+                + ", message=" + message + ", user=" + user + "]";
+    }
+}
diff --git a/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/externalusermanagement/ims/response/ActionCommandIssue.java b/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/externalusermanagement/ims/response/ActionCommandIssue.java
new file mode 100644
index 00000000..4a814bc1
--- /dev/null
+++ b/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/externalusermanagement/ims/response/ActionCommandIssue.java
@@ -0,0 +1,25 @@
+package biz.netcentric.cq.tools.actool.externalusermanagement.ims.response;
+
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+@JsonIgnoreProperties(ignoreUnknown = true)
+public class ActionCommandIssue {
+
+    @JsonProperty(required = false)
+    String requestID;
+    @JsonProperty
+    int index;
+    @JsonProperty
+    int step;
+    @JsonProperty
+    String message;
+    @JsonProperty
+    String user;
+
+    @Override
+    public String toString() {
+        return "ActionCommandIssue [requestID=" + requestID + ", index=" + index + ", step=" + step + ", message=" + message + ", user="
+                + user + "]";
+    }
+}
diff --git a/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/externalusermanagement/ims/response/ActionCommandResponse.java b/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/externalusermanagement/ims/response/ActionCommandResponse.java
new file mode 100644
index 00000000..2b493757
--- /dev/null
+++ b/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/externalusermanagement/ims/response/ActionCommandResponse.java
@@ -0,0 +1,32 @@
+package biz.netcentric.cq.tools.actool.externalusermanagement.ims.response;
+
+import java.util.Collections;
+import java.util.List;
+
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+/** General response format for UMAPI requests */
+@JsonIgnoreProperties(ignoreUnknown = true)
+public class ActionCommandResponse {
+
+    public ActionCommandResponse() {
+        errors = Collections.emptyList();
+        warnings = Collections.emptyList();
+    }
+
+    @JsonProperty("completed")
+    public int numCompletedActions;
+    
+    @JsonProperty("notCompleted")
+    public int numNotCompletedActions;
+    
+    @JsonProperty("completedInTestMode")
+    public int numCompletedActionsInTestMode;
+    
+    @JsonProperty("errors")
+    public List<ActionCommandError> errors;
+    
+    @JsonProperty("warnings")
+    public List<ActionCommandWarning> warnings;
+}
diff --git a/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/externalusermanagement/ims/response/ActionCommandWarning.java b/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/externalusermanagement/ims/response/ActionCommandWarning.java
new file mode 100644
index 00000000..90dcef1e
--- /dev/null
+++ b/accesscontroltool-bundle/src/main/java/biz/netcentric/cq/tools/actool/externalusermanagement/ims/response/ActionCommandWarning.java
@@ -0,0 +1,21 @@
+package biz.netcentric.cq.tools.actool.externalusermanagement.ims.response;
+
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+/**
+ * 
+ * @see <a href="https://adobe-apiplatform.github.io/umapi-documentation/en/api/ActionsRef.html#responses">Action Response Format</a>
+ */
+@JsonIgnoreProperties(ignoreUnknown = true)
+public class ActionCommandWarning extends ActionCommandIssue {
+
+    @JsonProperty
+    String warningCode;
+
+    @Override
+    public String toString() {
+        return "ActionCommandWarning [warningCode=" + warningCode + ", requestID=" + requestID + ", index=" + index + ", step=" + step
+                + ", message=" + message + ", user=" + user + "]";
+    }
+}
\ No newline at end of file
diff --git a/accesscontroltool-bundle/src/test/java/biz/netcentric/cq/tools/actool/externalusermanagement/ims/IMSUserManagementIT.java b/accesscontroltool-bundle/src/test/java/biz/netcentric/cq/tools/actool/externalusermanagement/ims/IMSUserManagementIT.java
new file mode 100644
index 00000000..223009c7
--- /dev/null
+++ b/accesscontroltool-bundle/src/test/java/biz/netcentric/cq/tools/actool/externalusermanagement/ims/IMSUserManagementIT.java
@@ -0,0 +1,58 @@
+package biz.netcentric.cq.tools.actool.externalusermanagement.ims;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.io.IOException;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+
+import org.apache.http.impl.client.HttpClientBuilder;
+import org.apache.http.osgi.services.HttpClientBuilderFactory;
+import org.junit.jupiter.api.Test;
+import org.osgi.util.converter.Converters;
+
+import biz.netcentric.cq.tools.actool.configmodel.AuthorizableConfigBean;
+import biz.netcentric.cq.tools.actool.externalusermanagement.ims.IMSUserManagement.Configuration;
+
+/**
+ * Example Adobe Developer Console Project: https://developer.adobe.com/console/projects/25605/4566206088345177434/overview (Organization: Netcentric).
+ * This IT requires the following environment variables to be set:
+ * <ul>
+ * <li>actool_ims_it_organizationid</li>
+ * <li>actool_ims_it_clientid</li>
+ * <li>actool_ims_it_clientsecret</li>
+ * </ul>
+ */
+class IMSUserManagementIT {
+
+    @Test
+    void test() throws IOException {
+        Map<String, Object> properties = new HashMap<>();
+        properties.put("organizationId", getMandatoryEnvironmentVariable("ACTOOL_IMS_IT_ORGANIZATIONID"));
+        properties.put("clientId", getMandatoryEnvironmentVariable("ACTOOL_IMS_IT_CLIENTID"));
+        properties.put("clientSecret", getMandatoryEnvironmentVariable("ACTOOL_IMS_IT_CLIENTSECRET"));
+        properties.put("isTestOnly", Boolean.TRUE);
+        Configuration config = Converters.standardConverter().convert(properties).to(Configuration.class);
+        
+        IMSUserManagement imsUserManagement = new IMSUserManagement(config, new HttpClientBuilderFactory() {
+            @Override
+            public HttpClientBuilder newBuilder() {
+                return HttpClientBuilder.create();
+            }
+        });
+        assertEquals("Adobe IMS", imsUserManagement.getLabel());
+        AuthorizableConfigBean group = new AuthorizableConfigBean();
+        group.setAuthorizableId("testGroup");
+        group.setDescription("my description");
+        imsUserManagement.updateGroups(Collections.singleton(group));
+    }
+
+    private static String getMandatoryEnvironmentVariable(String name) {
+        String value = System.getenv(name);
+        if (value == null) {
+            throw new IllegalStateException("Missing environment variable \"" + name + "\" which is necessary for the IT in " + IMSUserManagementIT.class);
+        }
+        return value;
+    }
+}
diff --git a/docs/AdvancedFeatures.md b/docs/AdvancedFeatures.md
index 9d141d27..a898b818 100644
--- a/docs/AdvancedFeatures.md
+++ b/docs/AdvancedFeatures.md
@@ -303,9 +303,8 @@ Example:
      name: "TU %{group.name}"
      path: /home/users/myproj-test-users
      skipForRunmodes: prod, preprod
-``` 
+```
 
-  
 ## Configure unmanaged aspects
 
 The following table gives an overview of what is managed (in terms of authorizables themselves, group memberships and ACLs) by AC Tool and what is not:
@@ -434,6 +433,15 @@ Sometimes it is also useful to create intermediate paths that do not even contai
                             </jcr:root>                    
 ```
 
+## Update Groups in External User Management Systems
+
+Since ACTool 3.1.0 there is support for creating/updating groups in [Adobe IMS](https://www.adobe.com/content/dam/cc/en/trust-center/ungated/whitepapers/corporate/adobe-identity-management-services-security-overview.pdf). Those are the groups which are exposed in the Adobe Admin Console and automatically used for [AEMaaCS](https://experienceleague.adobe.com/en/docs/experience-manager-cloud-service/content/security/ims-support) and also [AEM 6.5 hosted by AMS](https://experienceleague.adobe.com/en/docs/experience-manager-learn/foundation/authentication/adobe-ims-authentication-technical-video-understand).
+
+To enable that feature, just set the property `syncWithExternalUserManagement` on the groups in the YAML file to `true`.
+In addition an OSGi configuration for the leveraged [UMAPI](https://adobe-apiplatform.github.io/umapi-documentation/en/) needs to be provided in the configuration PID `biz.netcentric.cq.tools.actool.externalusermanagement.ims.IMSUserManagement`. This configuration should only be provided for run mode `author` to prevent the same groups from being created/updated multiple times.
+
+Only the group id (called name in IMS context) and the description are set for synchronized groups in IMS. Memberships are not modified.
+
 ## Health Check
 
 The AC Tool comes with a Sling Health Check to returns WARN if the last run of the AC Tool was not successful. The health check can be triggered via `/system/console/healthcheck?tags=actool`. Additional tags can be configured using PID `biz.netcentric.cq.tools.actool.healthcheck.LastRunSuccessHealthCheck` and property `hc.tags`. Also see [Sling Health Check Tools Documentation](https://sling.apache.org/documentation/bundles/sling-health-check-tool.html).
diff --git a/docs/Configuration.md b/docs/Configuration.md
index 387ab6b7..e38f9024 100644
--- a/docs/Configuration.md
+++ b/docs/Configuration.md
@@ -55,11 +55,12 @@ description | Description of the group | optional
 externalId | Required for groups which are synchronized from [external sources](https://jackrabbit.apache.org/oak/docs/security/authentication/externalloginmodule.html) like [LDAP](https://jackrabbit.apache.org/oak/docs/security/authentication/ldap.html) or [Adobe IMS](https://experienceleague.adobe.com/en/docs/experience-manager-cloud-service/content/security/ims-support#aem-configuration). This establishes a connection between an (internal) JCR group and an externally managed group (and is persisted in the group's node in the property `rep:externalId`). The value has to be in format `<external-id>;<provider-name>`.  How the external ID and provider name look like is *External Identity Provider dependent*: For **Adobe IMS** it usually is `<groupId>;ims` while for **Oak LDAP** it usually is `<LDAP-DN>;<IDP-NAME>` where LDAP-DN is the full distinguished name and IDP-NAME is configured in OSGI config PID `org.apache.jackrabbit.oak.security.authentication.ldap.impl.LdapIdentityProvider` property `provider-name`. LDAP Example: `externalId: "cn=group-name,ou=mydepart,ou=Groups,dc=comp,dc=com;IDPNAME"`. Make sure to also set the group id according to how it is extracted by the external identify provider (configurable via OSGi configuration of the external identity provider). Since v1.9.3 | optional
 path | Path of the intermediate node either relative or absolute. If relative, `/home/groups` is automatically prefixed. By default some implementation specific path is choosen. Usually the full group path is the (intermediate) path concatenated with a [randomized authorizable id](https://jackrabbit.apache.org/oak/docs/apidocs/org/apache/jackrabbit/oak/security/user/RandomAuthorizableNodeName.html).  | optional
 isMemberOf | List of groups this groups is a member of. May be provided as yaml list or as comma-separated yaml string (*the use of comma-separated yaml strings is deprecated*, available to remain backwards compatible). | optional
-memberOf | same meaning as `isMemberOf`. This property is *deprecated*, please use `isMemberOf` instead. | optional
+memberOf | Same meaning as `isMemberOf`. This property is *deprecated*, please use `isMemberOf` instead. | optional
 members | List of groups that are member of this group. May be provided as yaml list or as comma-separated yaml string (*the use of comma-separated yaml strings is deprecated*, available to remain backwards compatible). Allows to specify the relationship from the other side compared to `isMemberOf`. **NOTE**: The `isMemberOf` configuration should be preferred over `members` if possible for better readability. Since `isMemberOf` shows what a group inherits, `members` would only show on the other side where permissions get pushed to. Also choosing one approach makes the config files consistent. `members` should therefore only be used in special cases where it is not possible to use `isMemberOf`, e.g. to push rights to a group that is not in the configuration and hence that group can not be annotated with `isMemberOf` | optional
-migrateFrom | a group name assigned member users are taken over from | optional
+migrateFrom | A group name assigned member users are taken over from. This is not supported for external user management. | optional
 virtual | If true, the group is *not* created in repository but only its permissions and isMemberOf relationships are made effective to other groups using the virtual group in isMemberOf. Flattens the effective group tree of users at runtime, but enlarges ACLs as set on path (instead of the virtual group, all referencing groups are listed in a particular path's ACL used by the virtual group). Useful for functionality fragments. False by default. Since v2.1.0 | optional
 unmanaged* Properties | Only use sparsely and with care, see [Advanced Features](AdvancedFeatures.md)   | optional
+syncWithExternalUserManagement | Boolean flag determining whether the group should also be created or updated in a configured external user management system. For further details refer to [Update Groups in External User Management Systems](AdvancedFeatures.md#Update Groups in External User Management Systems). Since v3.1.0. | optional
 
 Example:
 
diff --git a/target-osgi-environment/maximum-environment/maximum-aem.bndrun b/target-osgi-environment/maximum-environment/maximum-aem.bndrun
index 75822b28..ef9c8872 100644
--- a/target-osgi-environment/maximum-environment/maximum-aem.bndrun
+++ b/target-osgi-environment/maximum-environment/maximum-aem.bndrun
@@ -24,5 +24,6 @@
 # workaround for https://issues.apache.org/jira/browse/SLING-7608 and https://issues.apache.org/jira/browse/SLING-7604
 -runsystemcapabilities: osgi.service;objectClass=org.apache.sling.commons.classloader.DynamicClassLoaderManager,\
 osgi.service;objectClass=com.adobe.granite.crypto.CryptoSupport,\
+osgi.service;objectClass=org.apache.http.osgi.services.HttpClientBuilderFactory,\
 osgi.service;objectClass=org.apache.sling.api.resource.ResourceResolverFactory,\
 osgi.service;objectClass:List<String>="javax.jcr.Repository,org.apache.sling.jcr.api.SlingRepository"
diff --git a/target-osgi-environment/minimum-environment/minimum-aem.bndrun b/target-osgi-environment/minimum-environment/minimum-aem.bndrun
index 5525edda..c95b4906 100644
--- a/target-osgi-environment/minimum-environment/minimum-aem.bndrun
+++ b/target-osgi-environment/minimum-environment/minimum-aem.bndrun
@@ -24,5 +24,6 @@
 # workaround for https://issues.apache.org/jira/browse/SLING-7608 and https://issues.apache.org/jira/browse/SLING-7604
 -runsystemcapabilities: osgi.service;objectClass=org.apache.sling.commons.classloader.DynamicClassLoaderManager,\
 osgi.service;objectClass=com.adobe.granite.crypto.CryptoSupport,\
+osgi.service;objectClass=org.apache.http.osgi.services.HttpClientBuilderFactory,\
 osgi.service;objectClass=org.apache.sling.api.resource.ResourceResolverFactory,\
 osgi.service;objectClass:List<String>="javax.jcr.Repository,org.apache.sling.jcr.api.SlingRepository"