CAMEL-21719: Neo4j Embedding Data transfomer for RAG results

Author: zbendhiba

catalog/camel-catalog/src/generated/resources/org/apache/camel/catalog/transformers.properties

@@ -29,6 +29,7 @@ google-storage-application-cloudevents
 http-application-cloudevents
 milvus-embeddings
 neo4j-embeddings
+neo4j-rag
 pinecone-embeddings
 protobuf-binary
 protobuf-x-java-object

catalog/camel-catalog/src/generated/resources/org/apache/camel/catalog/transformers/neo4j-rag.json

@@ -0,0 +1,14 @@
+{
+  "transformer": {
+    "kind": "transformer",
+    "name": "neo4j:rag",
+    "title": "Neo4j (Rag)",
+    "description": "Prepares the similarity search LangChain4j embeddings to become a List of String for LangChain4j RAG",
+    "deprecated": false,
+    "javaType": "org.apache.camel.component.neo4j.transformer.Neo4jReverseEmbeddingsDataTypeTransformer",
+    "groupId": "org.apache.camel",
+    "artifactId": "camel-neo4j",
+    "version": "4.10.0-SNAPSHOT"
+  }
+}
+

components/camel-ai/camel-langchain4j-embeddings/src/test/java/org/apache/camel/component/langchain4j/embeddings/LangChain4jEmbeddingsComponentNeo4jTargetIT.java

@@ -16,6 +16,7 @@
  */
 package org.apache.camel.component.langchain4j.embeddings;
 
+import java.util.Collection;
 import java.util.List;
 import java.util.Map;
 
@@ -28,6 +29,7 @@
 import org.apache.camel.component.neo4j.Neo4Operation;
 import org.apache.camel.component.neo4j.Neo4jComponent;
 import org.apache.camel.component.neo4j.Neo4jConstants;
+import org.apache.camel.spi.DataType;
 import org.apache.camel.test.infra.neo4j.services.Neo4jService;
 import org.apache.camel.test.infra.neo4j.services.Neo4jServiceFactory;
 import org.apache.camel.test.junit5.CamelTestSupport;
@@ -47,7 +49,7 @@
 @TestMethodOrder(MethodOrderer.OrderAnnotation.class)
 public class LangChain4jEmbeddingsComponentNeo4jTargetIT extends CamelTestSupport {
 
-    public static final String NEO4J_URI = "neo4j:neo4j";
+    public static final String NEO4J_URI = "neo4j:neo4j?vectorIndexName=myIndex&label=Test";
     @RegisterExtension
     static Neo4jService NEO4J = Neo4jServiceFactory.createSingletonService();
 
@@ -138,6 +140,20 @@ void testSearchEmbedding() {
 
     }
 
+    @Test
+    @Order(3)
+    public void rag_similarity_search() {
+        Exchange result = fluentTemplate.to("direct:search")
+                .withBody("hi")
+                .request(Exchange.class);
+
+        assertThat(result).isNotNull();
+        assertThat(result.getException()).isNull();
+
+        assertThat(result.getIn().getBody()).isInstanceOfSatisfying(Collection.class, c -> assertThat(c).hasSize(1));
+        assertTrue(result.getIn().getBody(List.class).contains("hi"));
+    }
+
     @Override
     protected RoutesBuilder createRouteBuilder() {
         return new RouteBuilder() {
@@ -149,6 +165,17 @@ public void configure() {
                         .setHeader(Neo4jConstants.Headers.LABEL).constant("Test")
                         .transform(new org.apache.camel.spi.DataType("neo4j:embeddings"))
                         .to(NEO4J_URI);
+
+                from("direct:search")
+                        .to("langchain4j-embeddings:test")
+                        // transform prompt into embeddings for search
+                        .transform(
+                                new DataType("neo4j:embeddings"))
+                        .setHeader(Neo4jConstants.Headers.OPERATION, constant(Neo4Operation.VECTOR_SIMILARITY_SEARCH))
+                        .to(NEO4J_URI)
+                        // decode retrieved embeddings for RAG
+                        .transform(
+                                new DataType("neo4j:rag"));
             }
         };
     }

components/camel-ai/camel-neo4j/src/generated/resources/META-INF/services/org/apache/camel/transformer.properties

@@ -1,5 +1,5 @@
 # Generated by camel build tools - do NOT edit this file!
-transformers=neo4j:embeddings
+transformers=neo4j:embeddings neo4j:rag
 groupId=org.apache.camel
 artifactId=camel-neo4j
 version=4.10.0-SNAPSHOT

components/camel-ai/camel-neo4j/src/generated/resources/META-INF/services/org/apache/camel/transformer/neo4j-rag

@@ -0,0 +1,2 @@
+# Generated by camel build tools - do NOT edit this file!
+class=org.apache.camel.component.neo4j.transformer.Neo4jReverseEmbeddingsDataTypeTransformer

components/camel-ai/camel-neo4j/src/generated/resources/META-INF/services/org/apache/camel/transformer/neo4j-rag.json

@@ -0,0 +1,14 @@
+{
+  "transformer": {
+    "kind": "transformer",
+    "name": "neo4j:rag",
+    "title": "Neo4j (Rag)",
+    "description": "Prepares the similarity search LangChain4j embeddings to become a List of String for LangChain4j RAG",
+    "deprecated": false,
+    "javaType": "org.apache.camel.component.neo4j.transformer.Neo4jReverseEmbeddingsDataTypeTransformer",
+    "groupId": "org.apache.camel",
+    "artifactId": "camel-neo4j",
+    "version": "4.10.0-SNAPSHOT"
+  }
+}
+

components/camel-ai/camel-neo4j/src/main/docs/neo4j-component.adoc

@@ -223,16 +223,20 @@ The URI endpoint should contain also specify the vector index name.
 === Create a vector
 To create a vector in a database named `test`, use the operation `CREATE_VECTOR`.
 The URI endpoint should also specify the label, the alias and the vector index name.
+Put the vector array in the `CamelLangChain4jEmbeddingsVector` header, and the corresponding text in the body.
+The `id` can be generated by Camel Neo4j.
+
+Camel Neo4j will create the node and store the vector as an `embedding` property, the text as `text` property and the `id`as `id` property.
 
-Camel Neo4j will create the node and store the vector as an `embedding` property.
 
 .Example:
 [source,java]
 ----
-         Exchange result = fluentTemplate.to("neo4j:test?vectorIndexName=movieIdx&label=Movie&alias=m")
-                .withHeader(Neo4j.Headers.OPERATION, Neo4Operation.CREATE_VECTOR)
-                .withHeader(Neo4j.Headers.VECTOR_ID, testData.getId())
-                .withBody(List.of(0.8f, 0.6f))
+            Exchange result = fluentTemplate.to("neo4j:test?vectorIndexName=myIndex&label=Test&alias=t")
+                .withHeader(Neo4jConstants.Headers.OPERATION, Neo4Operation.CREATE_VECTOR)
+                .withHeader(Neo4jConstants.Headers.VECTOR_ID, "1")
+                .withHeader("CamelLangChain4jEmbeddingsVector", new float[] { 10.8f, 10.6f })
+                .withBody("Hello World!")
                 .request(Exchange.class);
 ----
 
@@ -244,23 +248,48 @@ The URI endpoint should also specify the label, the alias and the vector index n
 .Example:
 [source,java]
 ----
-         Exchange result = fluentTemplate.to("neo4j:test?vectorIndexName=movieIdx&label=Movie&alias=m")
-                .withHeader(Neo4j.Headers.OPERATION, Neo4Operation.CREATE_VECTOR)
-                .withHeader(Neo4j.Headers.VECTOR_ID, testData.getId())
+         Exchange result = fluentTemplate.to("neo4j:test?vectorIndexName=myIndex&label=Test&alias=t")
+                .withHeader(Neo4jConstants.Headers.OPERATION, Neo4Operation.VECTOR_SIMILARITY_SEARCH)
                 .withBody(List.of(0.75f, 0.65f))
                 .request(Exchange.class);
 ----
 
 == Generate Embeddings with Langchain4j-embeddings
 You can generate embeddings with an Embedding Models using the camel Lancghain4j Embeddings components. Camel Neo4j introduces a DataType `neo4j:embeddings` that automates the transformations of the Lancghain4j embeddings to Neo4j vectors.
 
-.Example of a camel Route that create embeddings with Camel Langchain4j Embeddings
+.Example of a camel Route that create embeddings with Camel Langchain4j Embeddings, and ingest them into Neo4j database.
 [source,java]
 ----
          from("direct:in")
             .to("langchain4j-embeddings:test")
             .setHeader(Neo4j.Headers.OPERATION).constant(Neo4Operation.CREATE_VECTOR)
             .setHeader(Neo4j.Headers.LABEL).constant("Test")
             .transform(new DataType("neo4j:embeddings"))
-            .to("neo4j:test");
+            .to("neo4j:neo4j?vectorIndexName=myIndex&label=Test");
 ----
+
+== Similarity Search for LangChain4j RAG
+You can enhance the Camel LangChain4j chat RAG experience by integrating Neo4j similarity search with Camel Neo4j DataTypes.
+
+To achieve this, use the `neo4j:embeddings` DataType to generate embeddings from the prompt. These embeddings will then be utilized for the similarity search operation.
+
+Next, use the `neo4j:rag` DataType to convert the retrieved embeddings into a List<String> for RAG. This list can be directly used with the `LangChain4jRagAggregatorStrategy` from the LangChain4j chat component.
+
+NOTE: The retrieved embeddings must be ingested in Neo4j as LangChain4j embeddings.
+
+.Example of a camel Route that performs a similarity search in the Vector index, using a string and returning a list of strings
+[source,java]
+----
+         from("direct:search")
+                        .to("langchain4j-embeddings:test")
+                        // transform prompt into embeddings for search
+                        .transform(
+                                new DataType("neo4j:embeddings"))
+                        .setHeader(Neo4jConstants.Headers.OPERATION, constant(Neo4Operation.VECTOR_SIMILARITY_SEARCH))
+                        .to("neo4j:neo4j?vectorIndexName=myIndex&label=Test")
+                        // decode retrieved embeddings for RAG
+                        .transform(
+                                new DataType("neo4j:rag"));
+----
+
+

components/camel-ai/camel-neo4j/src/main/java/org/apache/camel/component/neo4j/Neo4jEmbedding.java

@@ -0,0 +1,47 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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.apache.camel.component.neo4j;
+
+/**
+ * Class that represents the embedding to persist when using LangChain4j - The names of the properties correspond to the
+ * ones in LangChain4j project for compatibility.
+ */
+public class Neo4jEmbedding {
+    private String id;
+
+    private String text;
+
+    private float[] vectors;
+
+    public Neo4jEmbedding(String id, String text, float[] vectors) {
+        this.id = id;
+        this.text = text;
+        this.vectors = vectors;
+    }
+
+    public String getId() {
+        return id;
+    }
+
+    public String getText() {
+        return text;
+    }
+
+    public float[] getVectors() {
+        return vectors;
+    }
+}

components/camel-ai/camel-neo4j/src/main/java/org/apache/camel/component/neo4j/Neo4jProducer.java

@@ -25,6 +25,7 @@
 import org.apache.camel.InvalidPayloadException;
 import org.apache.camel.Message;
 import org.apache.camel.NoSuchHeaderException;
+import org.apache.camel.ai.CamelLangchain4jAttributes;
 import org.apache.camel.support.DefaultProducer;
 import org.apache.camel.util.ObjectHelper;
 import org.neo4j.driver.Driver;
@@ -242,37 +243,60 @@ private void dropVectorIndex(Exchange exchange) {
 
     private void createVector(Exchange exchange) {
         final String alias
-                = getEndpoint().getConfiguration().getAlias() != null ? getEndpoint().getConfiguration().getAlias() : "x";
+                = getEndpoint().getConfiguration().getAlias() != null ? getEndpoint().getConfiguration().getAlias() : "e";
 
-        final String label = exchange.getMessage().getHeader(Neo4jConstants.Headers.LABEL,
-                () -> getEndpoint().getConfiguration().getLabel(), String.class);
-        ObjectHelper.notNull(label, "label");
-
-        final String id
-                = exchange.getMessage().getHeader(Neo4jConstants.Headers.VECTOR_ID, () -> UUID.randomUUID(), String.class);
+        final String label
+                = getEndpoint().getConfiguration().getLabel() != null
+                        ? getEndpoint().getConfiguration().getLabel() : "Embedding";
 
-        final float[] body = exchange.getMessage().getBody(float[].class);
+        String id;
+        String text;
+        float[] vectors;
 
         final String databaseName = getEndpoint().getName();
 
+        Object body = exchange.getMessage().getBody();
+
+        if (body instanceof Neo4jEmbedding) {
+            id = ((Neo4jEmbedding) body).getId();
+            text = ((Neo4jEmbedding) body).getText();
+            vectors = ((Neo4jEmbedding) body).getVectors();
+        } else {
+            id = exchange.getMessage().getHeader(Neo4jConstants.Headers.VECTOR_ID, () -> UUID.randomUUID(), String.class);
+            vectors = exchange.getMessage().getHeader(CamelLangchain4jAttributes.CAMEL_LANGCHAIN4J_EMBEDDING_VECTOR,
+                    float[].class);
+            text = exchange.getMessage().getBody(String.class);
+        }
+
+        ObjectHelper.notNull(text, "text");
+        ObjectHelper.notNull(vectors, "vectors");
+
         String query = String.format("""
-                MERGE (%s:%s {id: $id})
+                MERGE (%s:%s {id: $id, text: $text})
                 WITH %s
                 CALL db.create.setNodeVectorProperty(%s, 'embedding', $embedding);
                 """, alias, label, alias, alias);
 
         Map<String, Object> params = Map.of(
-                "embedding", Values.value(body),
-                "id", id);
+                "embedding", Values.value(vectors),
+                "id", id,
+                "text", text);
 
         executeWriteQuery(exchange, query, params, databaseName, Neo4Operation.CREATE_VECTOR);
     }
 
-    public void similaritySearch(Exchange exchange) {
+    public void similaritySearch(Exchange exchange) throws InvalidPayloadException {
         final String vectorIndexName = getEndpoint().getConfiguration().getVectorIndexName();
         ObjectHelper.notNull(vectorIndexName, "vectorIndexName");
 
-        final float[] body = exchange.getMessage().getBody(float[].class);
+        float[] vectors;
+
+        Object body = exchange.getMessage().getMandatoryBody();
+        if (body instanceof Neo4jEmbedding) {
+            vectors = ((Neo4jEmbedding) body).getVectors();
+        } else {
+            vectors = exchange.getMessage().getBody(float[].class);
+        }
 
         final double minScore = getEndpoint().getConfiguration().getMinScore();
 
@@ -288,7 +312,7 @@ public void similaritySearch(Exchange exchange) {
                 """;
 
         Map<String, Object> params = Map.of("indexName", vectorIndexName,
-                "embeddingValue", body,
+                "embeddingValue", vectors,
                 "minScore", minScore,
                 "maxResults", maxResults);
 

components/camel-ai/camel-neo4j/src/main/java/org/apache/camel/component/neo4j/transformer/Neo4jEmbeddingDataTypeTransformer.java

@@ -16,9 +16,14 @@
  */
 package org.apache.camel.component.neo4j.transformer;
 
+import java.util.UUID;
+
 import dev.langchain4j.data.embedding.Embedding;
+import dev.langchain4j.data.segment.TextSegment;
 import org.apache.camel.Message;
 import org.apache.camel.ai.CamelLangchain4jAttributes;
+import org.apache.camel.component.neo4j.Neo4jConstants;
+import org.apache.camel.component.neo4j.Neo4jEmbedding;
 import org.apache.camel.spi.DataType;
 import org.apache.camel.spi.DataTypeTransformer;
 import org.apache.camel.spi.Transformer;
@@ -28,7 +33,15 @@
 public class Neo4jEmbeddingDataTypeTransformer extends Transformer {
     @Override
     public void transform(Message message, DataType fromType, DataType toType) {
-        Embedding embedding = message.getHeader(CamelLangchain4jAttributes.CAMEL_LANGCHAIN4J_EMBEDDING_VECTOR, Embedding.class);
-        message.setBody(embedding.vector());
+        final Embedding embedding
+                = message.getHeader(CamelLangchain4jAttributes.CAMEL_LANGCHAIN4J_EMBEDDING_VECTOR, Embedding.class);
+
+        final TextSegment text = message.getBody(TextSegment.class);
+
+        final String id = message.getHeader(Neo4jConstants.Headers.VECTOR_ID, () -> UUID.randomUUID(), String.class);
+
+        Neo4jEmbedding neo4jEmbedding = new Neo4jEmbedding(id, text.text(), embedding.vector());
+
+        message.setBody(neo4jEmbedding);
     }
 }