Implements support notes in RuleChain entity

application/src/main/data/upgrade/basic/schema_update.sql

@@ -14,3 +14,9 @@
 -- limitations under the License.
 --
 
+
+-- RULE CHAIN NOTES START
+
+ALTER TABLE rule_chain ADD COLUMN IF NOT EXISTS notes text;
+
+-- RULE CHAIN NOTES END

common/data/src/main/java/org/thingsboard/server/common/data/rule/RuleChain.java

@@ -61,6 +61,9 @@ public class RuleChain extends BaseDataWithAdditionalInfo<RuleChainId> implement
     private RuleChainId externalId;
     private Long version;
 
+    @JsonIgnore
+    private String notes;
+
     @JsonIgnore
     private byte[] configurationBytes;
 
@@ -82,6 +85,7 @@ public class RuleChain extends BaseDataWithAdditionalInfo<RuleChainId> implement
         this.setConfiguration(ruleChain.getConfiguration());
         this.setExternalId(ruleChain.getExternalId());
         this.version = ruleChain.getVersion();
+        this.notes = ruleChain.getNotes();
     }
 
     @Override

common/data/src/main/java/org/thingsboard/server/common/data/rule/RuleChainMetaData.java

@@ -15,6 +15,7 @@
  */
 package org.thingsboard.server.common.data.rule;
 
+import com.fasterxml.jackson.annotation.JsonInclude;
 import io.swagger.v3.oas.annotations.media.Schema;
 import lombok.Data;
 import org.thingsboard.server.common.data.HasVersion;
@@ -48,6 +49,10 @@ public class RuleChainMetaData implements HasVersion {
     @Schema(requiredMode = Schema.RequiredMode.REQUIRED, description = "List of JSON objects that represent connections between rule nodes and other rule chains.")
     private List<RuleChainConnectionInfo> ruleChainConnections;
 
+    @JsonInclude(JsonInclude.Include.NON_EMPTY)
+    @Schema(requiredMode = Schema.RequiredMode.NOT_REQUIRED, description = "List of sticky notes placed on the rule chain canvas")
+    private List<RuleChainNote> notes;
+
     public void addConnectionInfo(int fromIndex, int toIndex, String type) {
         NodeConnectionInfo connectionInfo = new NodeConnectionInfo();
         connectionInfo.setFromIndex(fromIndex);

common/data/src/main/java/org/thingsboard/server/common/data/rule/RuleChainNote.java

@@ -0,0 +1,58 @@
+/**
+ * Copyright © 2016-2026 The Thingsboard Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.thingsboard.server.common.data.rule;
+
+import com.fasterxml.jackson.annotation.JsonInclude;
+import io.swagger.v3.oas.annotations.media.Schema;
+import lombok.Data;
+
+/**
+ * Represents a sticky note on the rule chain canvas.
+ * Notes are purely visual metadata and are stored as part of the rule chain.
+ */
+@Schema
+@Data
+@JsonInclude(JsonInclude.Include.NON_NULL)
+public class RuleChainNote {
+
+    @Schema(description = "Unique identifier of the note on the canvas")
+    private String id;
+
+    @Schema(description = "Horizontal position of the note on the canvas, in pixels")
+    private int x;
+
+    @Schema(description = "Vertical position of the note on the canvas, in pixels")
+    private int y;
+
+    @Schema(description = "Width of the note, in pixels")
+    private int width;
+
+    @Schema(description = "Height of the note, in pixels")
+    private int height;
+
+    @Schema(description = "Markdown or HTML content of the note")
+    private String content;
+
+    @Schema(description = "Background color of the note in CSS hex format, e.g. '#FFF9C4'")
+    private String backgroundColor;
+
+    @Schema(description = "Whether to apply the default markdown stylesheet to the note content")
+    private Boolean applyDefaultMarkdownStyle;
+
+    @Schema(description = "Custom CSS styles applied to the note content")
+    private String markdownCss;
+
+}

dao/src/main/java/org/thingsboard/server/dao/model/ModelConstants.java

@@ -420,6 +420,7 @@ public class ModelConstants {
     public static final String RULE_CHAIN_FIRST_RULE_NODE_ID_PROPERTY = "first_rule_node_id";
     public static final String RULE_CHAIN_ROOT_PROPERTY = "root";
     public static final String RULE_CHAIN_CONFIGURATION_PROPERTY = "configuration";
+    public static final String RULE_CHAIN_NOTES_PROPERTY = "notes";
 
     /**
      * Rule node constants.

dao/src/main/java/org/thingsboard/server/dao/model/sql/RuleChainEntity.java

@@ -69,6 +69,9 @@ public class RuleChainEntity extends BaseVersionedEntity<RuleChain> {
     @Column(name = ModelConstants.ADDITIONAL_INFO_PROPERTY)
     private JsonNode additionalInfo;
 
+    @Column(name = ModelConstants.RULE_CHAIN_NOTES_PROPERTY, columnDefinition = "TEXT")
+    private String notes;
+
     @Column(name = ModelConstants.EXTERNAL_ID_PROPERTY)
     private UUID externalId;
 
@@ -87,6 +90,7 @@ public class RuleChainEntity extends BaseVersionedEntity<RuleChain> {
         this.debugMode = ruleChain.isDebugMode();
         this.configuration = ruleChain.getConfiguration();
         this.additionalInfo = ruleChain.getAdditionalInfo();
+        this.notes = ruleChain.getNotes();
         if (ruleChain.getExternalId() != null) {
             this.externalId = ruleChain.getExternalId().getId();
         }
@@ -107,6 +111,7 @@ public class RuleChainEntity extends BaseVersionedEntity<RuleChain> {
         ruleChain.setDebugMode(debugMode);
         ruleChain.setConfiguration(configuration);
         ruleChain.setAdditionalInfo(additionalInfo);
+        ruleChain.setNotes(notes);
         if (externalId != null) {
             ruleChain.setExternalId(new RuleChainId(externalId));
         }

dao/src/main/java/org/thingsboard/server/dao/rule/BaseRuleChainService.java

@@ -16,6 +16,7 @@
 package org.thingsboard.server.dao.rule;
 
 import com.datastax.oss.driver.api.core.uuid.Uuids;
+import com.fasterxml.jackson.core.type.TypeReference;
 import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.node.ObjectNode;
 import com.google.common.util.concurrent.FluentFuture;
@@ -53,6 +54,7 @@ import org.thingsboard.server.common.data.rule.RuleChainConnectionInfo;
 import org.thingsboard.server.common.data.rule.RuleChainData;
 import org.thingsboard.server.common.data.rule.RuleChainImportResult;
 import org.thingsboard.server.common.data.rule.RuleChainMetaData;
+import org.thingsboard.server.common.data.rule.RuleChainNote;
 import org.thingsboard.server.common.data.rule.RuleChainType;
 import org.thingsboard.server.common.data.rule.RuleChainUpdateResult;
 import org.thingsboard.server.common.data.rule.RuleNode;
@@ -316,6 +318,8 @@ public class BaseRuleChainService extends AbstractEntityService implements RuleC
         if (!relations.isEmpty()) {
             relationService.saveRelations(tenantId, relations);
         }
+        ruleChain.setNotes(ruleChainMetaData.getNotes() != null && !ruleChainMetaData.getNotes().isEmpty()
+                ? JacksonUtil.toString(ruleChainMetaData.getNotes()) : null);
         ruleChain = ruleChainDao.save(tenantId, ruleChain);
         eventPublisher.publishEvent(SaveEntityEvent.builder().tenantId(tenantId).entity(ruleChain)
                 .entityId(ruleChain.getId()).broadcastEvent(publishSaveEvent).build());
@@ -376,6 +380,9 @@ public class BaseRuleChainService extends AbstractEntityService implements RuleC
             Collections.sort(ruleChainMetaData.getConnections(), Comparator.comparingInt(NodeConnectionInfo::getFromIndex)
                     .thenComparing(NodeConnectionInfo::getToIndex).thenComparing(NodeConnectionInfo::getType));
         }
+        if (ruleChain.getNotes() != null) {
+            ruleChainMetaData.setNotes(JacksonUtil.fromString(ruleChain.getNotes(), new TypeReference<List<RuleChainNote>>() {}));
+        }
         return ruleChainMetaData;
     }
 

dao/src/main/resources/sql/schema-entities.sql

@@ -169,6 +169,7 @@ CREATE TABLE IF NOT EXISTS rule_chain (
     debug_mode boolean,
     tenant_id uuid,
     external_id uuid,
+    notes text,
     version BIGINT DEFAULT 1,
     CONSTRAINT rule_chain_external_id_unq_key UNIQUE (tenant_id, external_id)
 );