AI rule node: add API for sending arbitrary chat requests to LLM model

application/src/main/java/org/thingsboard/server/actors/ActorSystemContext.java

@@ -30,7 +30,6 @@ import org.springframework.context.annotation.Lazy;
 import org.springframework.data.redis.core.RedisTemplate;
 import org.springframework.stereotype.Component;
 import org.thingsboard.common.util.JacksonUtil;
-import org.thingsboard.rule.engine.api.AiRequestsExecutor;
 import org.thingsboard.rule.engine.api.DeviceStateManager;
 import org.thingsboard.rule.engine.api.JobManager;
 import org.thingsboard.rule.engine.api.MailService;
@@ -322,10 +321,6 @@ public class ActorSystemContext {
     @Getter
     private AiModelSettingsService aiModelSettingsService;
 
-    @Autowired
-    @Getter
-    private AiRequestsExecutor aiRequestsExecutor;
-
     @Autowired
     @Getter
     private EntityViewService entityViewService;

application/src/main/java/org/thingsboard/server/actors/ruleChain/DefaultTbContext.java

@@ -23,7 +23,6 @@ import org.bouncycastle.util.Arrays;
 import org.thingsboard.common.util.DebugModeUtil;
 import org.thingsboard.common.util.JacksonUtil;
 import org.thingsboard.common.util.ListeningExecutor;
-import org.thingsboard.rule.engine.api.AiRequestsExecutor;
 import org.thingsboard.rule.engine.api.DeviceStateManager;
 import org.thingsboard.rule.engine.api.JobManager;
 import org.thingsboard.rule.engine.api.MailService;
@@ -1037,11 +1036,6 @@ public class DefaultTbContext implements TbContext {
         return mainCtx.getAiModelSettingsService();
     }
 
-    @Override
-    public AiRequestsExecutor getAiRequestsExecutor() {
-        return mainCtx.getAiRequestsExecutor();
-    }
-
     @Override
     public MqttClientSettings getMqttClientSettings() {
         return mainCtx.getMqttClientSettings();

application/src/main/java/org/thingsboard/server/controller/AiModelController.java

@@ -0,0 +1,63 @@
+/**
+ * Copyright © 2016-2025 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.controller;
+
+import com.google.common.util.concurrent.ListenableFuture;
+import dev.langchain4j.model.chat.request.ChatRequest;
+import jakarta.validation.Valid;
+import lombok.RequiredArgsConstructor;
+import org.springframework.security.access.prepost.PreAuthorize;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.context.request.async.DeferredResult;
+import org.thingsboard.server.common.data.ai.dto.TbChatRequest;
+import org.thingsboard.server.common.data.ai.dto.TbChatResponse;
+import org.thingsboard.server.common.data.ai.model.chat.AiChatModel;
+import org.thingsboard.server.config.annotations.ApiOperation;
+import org.thingsboard.server.service.ai.AiModelService;
+
+import static com.google.common.util.concurrent.MoreExecutors.directExecutor;
+import static org.thingsboard.server.controller.ControllerConstants.TENANT_AUTHORITY_PARAGRAPH;
+
+@RestController
+@RequiredArgsConstructor
+@RequestMapping("/api/ai/model")
+class AiModelController extends BaseController {
+
+    private final AiModelService aiModelService;
+
+    @ApiOperation(
+            value = "Send request to AI chat model (sendChatRequest)",
+            notes = "Submits a single prompt - made up of an optional system message and a required user message - to the specified AI chat model " +
+                    "and returns either the generated answer or an error envelope." +
+                    TENANT_AUTHORITY_PARAGRAPH
+    )
+    @PreAuthorize("hasAuthority('TENANT_ADMIN')")
+    @PostMapping("/chat")
+    public DeferredResult<TbChatResponse> sendChatRequest(@Valid @RequestBody TbChatRequest tbChatRequest) {
+        ChatRequest langChainChatRequest = tbChatRequest.toLangChainChatRequest();
+        AiChatModel<?> chatModel = tbChatRequest.chatModel();
+
+        ListenableFuture<TbChatResponse> future = aiModelService.sendChatRequestAsync(chatModel, langChainChatRequest)
+                .transform(chatResponse -> (TbChatResponse) new TbChatResponse.Success(chatResponse.aiMessage().text()), directExecutor())
+                .catching(Throwable.class, ex -> new TbChatResponse.Failure(ex.getMessage()), directExecutor());
+
+        return wrapFuture(future);
+    }
+
+}

application/src/main/java/org/thingsboard/server/service/ai/AiModelService.java

@@ -0,0 +1,20 @@
+/**
+ * Copyright © 2016-2025 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.service.ai;
+
+import org.thingsboard.rule.engine.api.RuleEngineAiModelService;
+
+public interface AiModelService extends RuleEngineAiModelService {}

application/src/main/java/org/thingsboard/server/service/ai/AiModelServiceImpl.java

@@ -15,23 +15,27 @@
  */
 package org.thingsboard.server.service.ai;
 
+import com.google.common.util.concurrent.FluentFuture;
 import dev.langchain4j.model.chat.ChatModel;
+import dev.langchain4j.model.chat.request.ChatRequest;
+import dev.langchain4j.model.chat.response.ChatResponse;
 import lombok.RequiredArgsConstructor;
 import org.springframework.stereotype.Service;
-import org.thingsboard.rule.engine.api.RuleEngineAiModelService;
 import org.thingsboard.server.common.data.ai.model.chat.AiChatModel;
 import org.thingsboard.server.common.data.ai.model.chat.AiChatModelConfig;
 import org.thingsboard.server.common.data.ai.model.chat.Langchain4jChatModelConfigurer;
 
 @Service
 @RequiredArgsConstructor
-class AiModelServiceImpl implements RuleEngineAiModelService {
+class AiModelServiceImpl implements AiModelService {
 
     private final Langchain4jChatModelConfigurer chatModelConfigurer;
+    private final AiRequestsExecutor aiRequestsExecutor;
 
     @Override
-    public <C extends AiChatModelConfig<C>> ChatModel configureChatModel(AiChatModel<C> chatModel) {
-        return chatModel.configure(chatModelConfigurer);
+    public <C extends AiChatModelConfig<C>> FluentFuture<ChatResponse> sendChatRequestAsync(AiChatModel<C> chatModel, ChatRequest chatRequest) {
+        ChatModel lc4jChatModel = chatModel.configure(chatModelConfigurer);
+        return aiRequestsExecutor.sendChatRequestAsync(lc4jChatModel, chatRequest);
     }
 
 }

rule-engine/rule-engine-api/src/main/java/org/thingsboard/rule/engine/api/AiRequestsExecutor.java → application/src/main/java/org/thingsboard/server/service/ai/AiRequestsExecutor.java

@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.thingsboard.rule.engine.api;
+package org.thingsboard.server.service.ai;
 
 import com.google.common.util.concurrent.FluentFuture;
 import dev.langchain4j.model.chat.ChatModel;

application/src/main/java/org/thingsboard/server/service/ai/DefaultAiRequestsExecutor.java

@@ -33,7 +33,6 @@ import org.springframework.context.annotation.Lazy;
 import org.springframework.stereotype.Component;
 import org.springframework.validation.annotation.Validated;
 import org.thingsboard.common.util.ThingsBoardThreadFactory;
-import org.thingsboard.rule.engine.api.AiRequestsExecutor;
 
 import java.time.Duration;
 import java.util.concurrent.Executors;

common/data/src/main/java/org/thingsboard/server/common/data/ai/dto/TbChatRequest.java

@@ -0,0 +1,79 @@
+/**
+ * Copyright © 2016-2025 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.ai.dto;
+
+import dev.langchain4j.data.message.ChatMessage;
+import dev.langchain4j.data.message.Content;
+import dev.langchain4j.data.message.SystemMessage;
+import dev.langchain4j.data.message.UserMessage;
+import dev.langchain4j.model.chat.request.ChatRequest;
+import io.swagger.v3.oas.annotations.media.Schema;
+import jakarta.validation.Valid;
+import jakarta.validation.constraints.NotNull;
+import org.thingsboard.server.common.data.ai.model.chat.AiChatModel;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public record TbChatRequest(
+        @Schema(
+                requiredMode = Schema.RequiredMode.NOT_REQUIRED,
+                accessMode = Schema.AccessMode.READ_WRITE,
+                description = "A system-level instruction that frames the user's input, setting the persona, tone, and constraints for the generated response",
+                example = "You are a helpful assistant. Only output valid JSON."
+        )
+        String systemMessage,
+
+        @Schema(
+                requiredMode = Schema.RequiredMode.REQUIRED,
+                accessMode = Schema.AccessMode.READ_WRITE,
+                description = "The actual user prompt that will be answered by the AI model"
+        )
+        @NotNull @Valid
+        TbUserMessage userMessage,
+
+        @Schema(
+                requiredMode = Schema.RequiredMode.REQUIRED,
+                accessMode = Schema.AccessMode.READ_WRITE,
+                description = "Configuration of the AI chat model that should execute the request"
+        )
+        @NotNull @Valid
+        AiChatModel<?> chatModel
+) {
+
+    public ChatRequest toLangChainChatRequest() {
+        return ChatRequest.builder()
+                .messages(getLangChainMessages())
+                .build();
+    }
+
+    private List<ChatMessage> getLangChainMessages() {
+        List<ChatMessage> messages = new ArrayList<>(2);
+
+        if (systemMessage != null) {
+            messages.add(SystemMessage.from(systemMessage));
+        }
+
+        List<Content> langChainContents = userMessage.contents().stream()
+                .map(TbContent::toLangChainContent)
+                .toList();
+
+        messages.add(UserMessage.from(langChainContents));
+
+        return messages;
+    }
+
+}

common/data/src/main/java/org/thingsboard/server/common/data/ai/dto/TbChatResponse.java

@@ -0,0 +1,68 @@
+/**
+ * Copyright © 2016-2025 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.ai.dto;
+
+import com.fasterxml.jackson.annotation.JsonSubTypes;
+import com.fasterxml.jackson.annotation.JsonTypeInfo;
+import io.swagger.v3.oas.annotations.media.Schema;
+
+@JsonTypeInfo(
+        use = JsonTypeInfo.Id.NAME,
+        property = "status",
+        include = JsonTypeInfo.As.PROPERTY,
+        visible = true
+)
+@JsonSubTypes({
+        @JsonSubTypes.Type(value = TbChatResponse.Success.class, name = "SUCCESS"),
+        @JsonSubTypes.Type(value = TbChatResponse.Failure.class, name = "FAILURE")
+})
+public sealed interface TbChatResponse permits TbChatResponse.Success, TbChatResponse.Failure {
+
+    @Schema(
+            description = "Indicates whether the request was successful or not",
+            example = "SUCCESS"
+    )
+    String getStatus();
+
+    record Success(
+            @Schema(description = "The text content generated by the model")
+            String generatedContent
+    ) implements TbChatResponse {
+
+        @Override
+        @Schema(example = "SUCCESS")
+        public String getStatus() {
+            return "SUCCESS";
+        }
+
+    }
+
+    record Failure(
+            @Schema(
+                    description = "A string containing details about the failure"
+            )
+            String errorDetails
+    ) implements TbChatResponse {
+
+        @Override
+        @Schema(example = "FAILURE")
+        public String getStatus() {
+            return "FAILURE";
+        }
+
+    }
+
+}

common/data/src/main/java/org/thingsboard/server/common/data/ai/dto/TbContent.java

@@ -0,0 +1,73 @@
+/**
+ * Copyright © 2016-2025 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.ai.dto;
+
+import com.fasterxml.jackson.annotation.JsonSubTypes;
+import com.fasterxml.jackson.annotation.JsonTypeInfo;
+import dev.langchain4j.data.message.Content;
+import dev.langchain4j.data.message.TextContent;
+import io.swagger.v3.oas.annotations.media.Schema;
+import jakarta.validation.constraints.NotBlank;
+
+import static org.thingsboard.server.common.data.ai.dto.TbContent.TbTextContent;
+
+@JsonTypeInfo(
+        use = JsonTypeInfo.Id.NAME,
+        include = JsonTypeInfo.As.PROPERTY,
+        property = "contentType",
+        visible = true
+)
+@JsonSubTypes({
+        @JsonSubTypes.Type(value = TbTextContent.class, name = "TEXT")
+})
+public sealed interface TbContent permits TbTextContent {
+
+    TbContentType contentType();
+
+    Content toLangChainContent();
+
+    enum TbContentType {
+
+        TEXT
+
+    }
+
+    @Schema(
+            description = "Text-based content part of a user's prompt"
+    )
+    record TbTextContent(
+            @NotBlank
+            @Schema(
+                    requiredMode = Schema.RequiredMode.REQUIRED,
+                    description = "The text content",
+                    example = "What is the weather like in Kyiv today?"
+            )
+            String text
+    ) implements TbContent {
+
+        @Override
+        public TbContentType contentType() {
+            return TbContentType.TEXT;
+        }
+
+        @Override
+        public Content toLangChainContent() {
+            return TextContent.from(text);
+        }
+
+    }
+
+}

common/data/src/main/java/org/thingsboard/server/common/data/ai/dto/TbUserMessage.java

@@ -0,0 +1,32 @@
+/**
+ * Copyright © 2016-2025 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.ai.dto;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+import jakarta.validation.Valid;
+import jakarta.validation.constraints.NotEmpty;
+
+import java.util.List;
+
+public record TbUserMessage(
+        @NotEmpty
+        @Valid
+        @Schema(
+                requiredMode = Schema.RequiredMode.REQUIRED,
+                description = "A list of content parts that make up the complete user prompt"
+        )
+        List<TbContent> contents
+) {}

rule-engine/rule-engine-api/src/main/java/org/thingsboard/rule/engine/api/RuleEngineAiModelService.java

@@ -15,12 +15,14 @@
  */
 package org.thingsboard.rule.engine.api;
 
-import dev.langchain4j.model.chat.ChatModel;
+import com.google.common.util.concurrent.FluentFuture;
+import dev.langchain4j.model.chat.request.ChatRequest;
+import dev.langchain4j.model.chat.response.ChatResponse;
 import org.thingsboard.server.common.data.ai.model.chat.AiChatModel;
 import org.thingsboard.server.common.data.ai.model.chat.AiChatModelConfig;
 
 public interface RuleEngineAiModelService {
 
-    <C extends AiChatModelConfig<C>> ChatModel configureChatModel(AiChatModel<C> chatModel);
+    <C extends AiChatModelConfig<C>> FluentFuture<ChatResponse> sendChatRequestAsync(AiChatModel<C> chatModel, ChatRequest chatRequest);
 
 }

rule-engine/rule-engine-api/src/main/java/org/thingsboard/rule/engine/api/TbContext.java

@@ -427,8 +427,6 @@ public interface TbContext {
 
     AiModelSettingsService getAiModelSettingsService();
 
-    AiRequestsExecutor getAiRequestsExecutor();
-
     // Configuration parameters for the MQTT client that is used in the MQTT node and Azure IoT hub node
 
     MqttClientSettings getMqttClientSettings();

rule-engine/rule-engine-components/src/main/java/org/thingsboard/rule/engine/ai/TbAiNode.java

@@ -21,7 +21,6 @@ import com.google.common.util.concurrent.FutureCallback;
 import dev.langchain4j.data.message.ChatMessage;
 import dev.langchain4j.data.message.SystemMessage;
 import dev.langchain4j.data.message.UserMessage;
-import dev.langchain4j.model.chat.ChatModel;
 import dev.langchain4j.model.chat.request.ChatRequest;
 import dev.langchain4j.model.chat.request.ResponseFormat;
 import dev.langchain4j.model.chat.request.ResponseFormatType;
@@ -119,29 +118,27 @@ public final class TbAiNode extends TbAbstractExternalNode implements TbNode {
                 .responseFormat(responseFormat)
                 .build();
 
-        configureChatModelAsync(ctx)
-                .transformAsync(chatModel -> ctx.getAiRequestsExecutor().sendChatRequestAsync(chatModel, chatRequest), directExecutor())
-                .addCallback(new FutureCallback<>() {
-                    @Override
-                    public void onSuccess(ChatResponse chatResponse) {
-                        String response = chatResponse.aiMessage().text();
-                        if (!isValidJsonObject(response)) {
-                            response = wrapInJsonObject(response);
-                        }
-                        tellSuccess(ctx, ackedMsg.transform()
-                                .data(response)
-                                .build());
-                    }
-
-                    @Override
-                    public void onFailure(@NonNull Throwable t) {
-                        tellFailure(ctx, ackedMsg, t);
-                    }
-                }, directExecutor());
+        sendChatRequestAsync(ctx, chatRequest).addCallback(new FutureCallback<>() {
+            @Override
+            public void onSuccess(ChatResponse chatResponse) {
+                String response = chatResponse.aiMessage().text();
+                if (!isValidJsonObject(response)) {
+                    response = wrapInJsonObject(response);
+                }
+                tellSuccess(ctx, ackedMsg.transform()
+                        .data(response)
+                        .build());
+            }
+
+            @Override
+            public void onFailure(@NonNull Throwable t) {
+                tellFailure(ctx, ackedMsg, t);
+            }
+        }, directExecutor());
     }
 
-    private <C extends AiChatModelConfig<C>> FluentFuture<ChatModel> configureChatModelAsync(TbContext ctx) {
-        return ctx.getAiModelSettingsService().findAiModelSettingsByTenantIdAndIdAsync(ctx.getTenantId(), modelSettingsId).transform(settingsOpt -> {
+    private <C extends AiChatModelConfig<C>> FluentFuture<ChatResponse> sendChatRequestAsync(TbContext ctx, ChatRequest chatRequest) {
+        return ctx.getAiModelSettingsService().findAiModelSettingsByTenantIdAndIdAsync(ctx.getTenantId(), modelSettingsId).transformAsync(settingsOpt -> {
             if (settingsOpt.isEmpty()) {
                 throw new NoSuchElementException("[" + ctx.getTenantId() + "] AI model settings with ID: [" + modelSettingsId + "] were not found");
             }
@@ -158,7 +155,7 @@ public final class TbAiNode extends TbAbstractExternalNode implements TbNode {
                     .withTimeoutSeconds(timeoutSeconds)
                     .withMaxRetries(0)); // disable retries to respect timeout set in rule node config
 
-            return ctx.getAiModelService().configureChatModel(chatModel);
+            return ctx.getAiModelService().sendChatRequestAsync(chatModel, chatRequest);
         }, ctx.getDbCallbackExecutor());
     }