CocoIndex makes it easy to build and maintain knowledge graphs with continuous source updates. In this blog, we will process a list of documents (using CocoIndex documentation as an example). We will use LLM to extract relationships between the concepts in each document. We will generate two kinds of relationships: Relationships between subjects and objects. E.g., "CocoIndex supports Incremental Processing" Mentions of entities in a document. E.g., "core/basics.mdx" mentions CocoIndex and Incremental Processing. Relationships between subjects and objects. E.g., "CocoIndex supports Incremental Processing" Mentions of entities in a document. E.g., "core/basics.mdx" mentions CocoIndex and Incremental Processing. CocoIndex Incremental Processing We are constantly improving, and more features and examples are coming soon. Stay tuned and follow our progress by starring Stay tuned and follow our progress by starring ⭐ our GitHub repo. our GitHub repo. GitHub repo Prerequisites Install PostgreSQL. CocoIndex uses PostgreSQL internally for incremental processing. Install Neo4j, a graph database. Configure your OpenAI API key. Alternatively, you can switch to Ollama, which runs LLM models locally - guide. Install PostgreSQL. CocoIndex uses PostgreSQL internally for incremental processing. Install PostgreSQL Install Neo4j, a graph database. Install Neo4j Configure your OpenAI API key. Alternatively, you can switch to Ollama, which runs LLM models locally - guide. Configure your OpenAI API key guide Documentation You can read the official CocoIndex Documentation for Property Graph Targets here. here Data flow to build knowledge graph Add documents as source We will process CocoIndex documentation markdown files (.md, .mdx) from the docs/core directory (markdown files, deployed docs). .md .mdx docs/core markdown files deployed docs @cocoindex.flow_def(name="DocsToKG") def docs_to_kg_flow(flow_builder: cocoindex.FlowBuilder, data_scope: cocoindex.DataScope): data_scope["documents"] = flow_builder.add_source( cocoindex.sources.LocalFile(path="../../docs/docs/core", included_patterns=["*.md", "*.mdx"])) @cocoindex.flow_def(name="DocsToKG") def docs_to_kg_flow(flow_builder: cocoindex.FlowBuilder, data_scope: cocoindex.DataScope): data_scope["documents"] = flow_builder.add_source( cocoindex.sources.LocalFile(path="../../docs/docs/core", included_patterns=["*.md", "*.mdx"])) Here flow_builder.add_source creates a KTable. filename is the key of the KTable. flow_builder.add_source KTable filename Add data collectors Add collectors at the root scope: document_node = data_scope.add_collector() entity_relationship = data_scope.add_collector() entity_mention = data_scope.add_collector() document_node = data_scope.add_collector() entity_relationship = data_scope.add_collector() entity_mention = data_scope.add_collector() document_node collects documents. E.g., core/basics.mdx is a document. entity_relationship collects relationships. E.g., "CocoIndex supports Incremental Processing" indicates a relationship between CocoIndex and Incremental Processing. entity_mention collects mentions of entities in a document. E.g., core/basics.mdx mentions CocoIndex and Incremental Processing. document_node collects documents. E.g., core/basics.mdx is a document. document_node core/basics.mdx entity_relationship collects relationships. E.g., "CocoIndex supports Incremental Processing" indicates a relationship between CocoIndex and Incremental Processing. entity_relationship CocoIndex Incremental Processing entity_mention collects mentions of entities in a document. E.g., core/basics.mdx mentions CocoIndex and Incremental Processing. entity_mention core/basics.mdx CocoIndex Incremental Processing Process each document and extract summary Define a DocumentSummary data class to extract the summary of a document. DocumentSummary @dataclasses.dataclass class DocumentSummary: title: str summary: str @dataclasses.dataclass class DocumentSummary: title: str summary: str Within the flow, use cocoindex.functions.ExtractByLlm for structured output. cocoindex.functions.ExtractByLlm with data_scope["documents"].row() as doc: doc["summary"] = doc["content"].transform( cocoindex.functions.ExtractByLlm( llm_spec=cocoindex.LlmSpec( api_type=cocoindex.LlmApiType.OPENAI, model="gpt-4o"), output_type=DocumentSummary, instruction="Please summarize the content of the document.")) document_node.collect( filename=doc["filename"], title=doc["summary"]["title"], summary=doc["summary"]["summary"]) with data_scope["documents"].row() as doc: doc["summary"] = doc["content"].transform( cocoindex.functions.ExtractByLlm( llm_spec=cocoindex.LlmSpec( api_type=cocoindex.LlmApiType.OPENAI, model="gpt-4o"), output_type=DocumentSummary, instruction="Please summarize the content of the document.")) document_node.collect( filename=doc["filename"], title=doc["summary"]["title"], summary=doc["summary"]["summary"]) doc["summary"] adds a new column to the KTable data_scope["documents"]. doc["summary"] data_scope["documents"] Extract relationships from the document using LLM Define a data class to represent relationship for the LLM extraction. @dataclasses.dataclass class Relationship: """ Describe a relationship between two entities. Subject and object should be Core CocoIndex concepts only, should be nouns. For example, `CocoIndex`, `Incremental Processing`, `ETL`, `Data` etc. """ subject: str predicate: str object: str @dataclasses.dataclass class Relationship: """ Describe a relationship between two entities. Subject and object should be Core CocoIndex concepts only, should be nouns. For example, `CocoIndex`, `Incremental Processing`, `ETL`, `Data` etc. """ subject: str predicate: str object: str The Data class defines a knowledge graph relationship. We recommend putting detailed instructions in the class-level docstring to help the LLM extract relationships correctly. subject: Represents the entity the statement is about (e.g., 'CocoIndex'). predicate: Describes the type of relationship or property connecting the subject and object (e.g., 'supports'). object: Represents the entity or value that the subject is related to via the predicate (e.g., 'Incremental Processing'). subject: Represents the entity the statement is about (e.g., 'CocoIndex'). subject predicate: Describes the type of relationship or property connecting the subject and object (e.g., 'supports'). predicate object: Represents the entity or value that the subject is related to via the predicate (e.g., 'Incremental Processing'). object This structure represents facts like "CocoIndex supports Incremental Processing". Its graph representation is: Next, we will use cocoindex.functions.ExtractByLlm to extract the relationships from the document. cocoindex.functions.ExtractByLlm doc["relationships"] = doc["content"].transform( cocoindex.functions.ExtractByLlm( llm_spec=cocoindex.LlmSpec( api_type=cocoindex.LlmApiType.OPENAI, model="gpt-4o" ), output_type=list[Relationship], instruction=( "Please extract relationships from CocoIndex documents. " "Focus on concepts and ignore examples and code. " ) ) ) doc["relationships"] = doc["content"].transform( cocoindex.functions.ExtractByLlm( llm_spec=cocoindex.LlmSpec( api_type=cocoindex.LlmApiType.OPENAI, model="gpt-4o" ), output_type=list[Relationship], instruction=( "Please extract relationships from CocoIndex documents. " "Focus on concepts and ignore examples and code. " ) ) ) doc["relationships"] adds a new field relationships to each document. output_type=list[Relationship] specifies that the output of the transformation is a LTable. doc["relationships"] relationships output_type=list[Relationship] LTable Collect relationships with doc["relationships"].row() as relationship: # relationship between two entities entity_relationship.collect( id=cocoindex.GeneratedField.UUID, subject=relationship["subject"], object=relationship["object"], predicate=relationship["predicate"], ) # mention of an entity in a document, for subject entity_mention.collect( id=cocoindex.GeneratedField.UUID, entity=relationship["subject"], filename=doc["filename"], ) # mention of an entity in a document, for object entity_mention.collect( id=cocoindex.GeneratedField.UUID, entity=relationship["object"], filename=doc["filename"], ) with doc["relationships"].row() as relationship: # relationship between two entities entity_relationship.collect( id=cocoindex.GeneratedField.UUID, subject=relationship["subject"], object=relationship["object"], predicate=relationship["predicate"], ) # mention of an entity in a document, for subject entity_mention.collect( id=cocoindex.GeneratedField.UUID, entity=relationship["subject"], filename=doc["filename"], ) # mention of an entity in a document, for object entity_mention.collect( id=cocoindex.GeneratedField.UUID, entity=relationship["object"], filename=doc["filename"], ) entity_relationship collects relationships between subjects and objects. entity_mention collects mentions of entities (as subjects or objects) in the document separately. For example, core/basics.mdx has a sentence CocoIndex supports Incremental Processing. We want to collect: core/basics.mdx mentions CocoIndex. core/basics.mdx mentions Incremental Processing. entity_relationship collects relationships between subjects and objects. entity_relationship entity_mention collects mentions of entities (as subjects or objects) in the document separately. For example, core/basics.mdx has a sentence CocoIndex supports Incremental Processing. We want to collect: core/basics.mdx mentions CocoIndex. core/basics.mdx mentions Incremental Processing. entity_mention core/basics.mdx CocoIndex supports Incremental Processing core/basics.mdx mentions CocoIndex. core/basics.mdx mentions Incremental Processing. core/basics.mdx mentions CocoIndex. core/basics.mdx CocoIndex core/basics.mdx mentions Incremental Processing. core/basics.mdx Incremental Processing Build knowledge graph Basic concepts All nodes for Neo4j need two things: Label: The type of the node. E.g., Document, Entity. Primary key field: The field that uniquely identifies the node. E.g., filename for Document nodes. Label: The type of the node. E.g., Document, Entity. Document Entity Primary key field: The field that uniquely identifies the node. E.g., filename for Document nodes. filename Document CocoIndex uses the primary key field to match the nodes and deduplicate them. If you have multiple nodes with the same primary key, CocoIndex keeps only one of them. There are two ways to map nodes: When you have a collector just for the node, you can directly export it to Neo4j. When you have a collector for relationships connecting to the node, you can map nodes from selected fields in the relationship collector. You must declare a node label and primary key field. When you have a collector just for the node, you can directly export it to Neo4j. When you have a collector for relationships connecting to the node, you can map nodes from selected fields in the relationship collector. You must declare a node label and primary key field. Configure Neo4j connection: conn_spec = cocoindex.add_auth_entry( "Neo4jConnection", cocoindex.storages.Neo4jConnection( uri="bolt://localhost:7687", user="neo4j", password="cocoindex", )) conn_spec = cocoindex.add_auth_entry( "Neo4jConnection", cocoindex.storages.Neo4jConnection( uri="bolt://localhost:7687", user="neo4j", password="cocoindex", )) Export Document nodes to Neo4j Document document_node.export( "document_node", cocoindex.storages.Neo4j( connection=conn_spec, mapping=cocoindex.storages.Nodes(label="Document")), primary_key_fields=["filename"], ) document_node.export( "document_node", cocoindex.storages.Neo4j( connection=conn_spec, mapping=cocoindex.storages.Nodes(label="Document")), primary_key_fields=["filename"], ) This exports Neo4j nodes with label Document from the document_node collector. Document document_node It declares Neo4j node label Document. It specifies filename as the primary key field. It carries all the fields from document_node collector to Neo4j nodes with label Document. It declares Neo4j node label Document. It specifies filename as the primary key field. Document filename It carries all the fields from document_node collector to Neo4j nodes with label Document. document_node Document Export RELATIONSHIP and Entity nodes to Neo4j RELATIONSHIP Entity We don't have explicit collector for Entity nodes. They are part of the entity_relationship collector and fields are collected during the relationship extraction. Entity entity_relationship To export them as Neo4j nodes, we need to first declare Entity nodes. Entity flow_builder.declare( cocoindex.storages.Neo4jDeclaration( connection=conn_spec, nodes_label="Entity", primary_key_fields=["value"], ) ) flow_builder.declare( cocoindex.storages.Neo4jDeclaration( connection=conn_spec, nodes_label="Entity", primary_key_fields=["value"], ) ) Next, export the entity_relationship to Neo4j. entity_relationship entity_relationship.export( "entity_relationship", cocoindex.storages.Neo4j( connection=conn_spec, mapping=cocoindex.storages.Relationships( rel_type="RELATIONSHIP", source=cocoindex.storages.NodeFromFields( label="Entity", fields=[ cocoindex.storages.TargetFieldMapping( source="subject", target="value"), ] ), target=cocoindex.storages.NodeFromFields( label="Entity", fields=[ cocoindex.storages.TargetFieldMapping( source="object", target="value"), ] ), ), ), primary_key_fields=["id"], ) ) entity_relationship.export( "entity_relationship", cocoindex.storages.Neo4j( connection=conn_spec, mapping=cocoindex.storages.Relationships( rel_type="RELATIONSHIP", source=cocoindex.storages.NodeFromFields( label="Entity", fields=[ cocoindex.storages.TargetFieldMapping( source="subject", target="value"), ] ), target=cocoindex.storages.NodeFromFields( label="Entity", fields=[ cocoindex.storages.TargetFieldMapping( source="object", target="value"), ] ), ), ), primary_key_fields=["id"], ) ) The cocoindex.storages.Relationships declares how to map relationships in Neo4j. cocoindex.storages.Relationships In a relationship, there's: A source node and a target node. A relationship connecting the source and target. Note that different relationships may share the same source and target nodes. A source node and a target node. A relationship connecting the source and target. Note that different relationships may share the same source and target nodes. NodeFromFields takes the fields from the entity_relationship collector and creates Entity nodes. NodeFromFields entity_relationship Entity Export the entity_mention to Neo4j. entity_mention entity_mention.export( "entity_mention", cocoindex.storages.Neo4j( connection=conn_spec, mapping=cocoindex.storages.Relationships( rel_type="MENTION", source=cocoindex.storages.NodesFromFields( label="Document", fields=[cocoindex.storages.TargetFieldMapping("filename")], ), target=cocoindex.storages.NodesFromFields( label="Entity", fields=[cocoindex.storages.TargetFieldMapping( source="entity", target="value")], ), ), ), primary_key_fields=["id"], ) entity_mention.export( "entity_mention", cocoindex.storages.Neo4j( connection=conn_spec, mapping=cocoindex.storages.Relationships( rel_type="MENTION", source=cocoindex.storages.NodesFromFields( label="Document", fields=[cocoindex.storages.TargetFieldMapping("filename")], ), target=cocoindex.storages.NodesFromFields( label="Entity", fields=[cocoindex.storages.TargetFieldMapping( source="entity", target="value")], ), ), ), primary_key_fields=["id"], ) Similarly here, we export entity_mention to Neo4j Relationships using cocoindex.storages.Relationships. It creates relationships by: entity_mention cocoindex.storages.Relationships Creating Document nodes and Entity nodes from the entity_mention collector. Connecting Document nodes and Entity nodes with relationship MENTION. Creating Document nodes and Entity nodes from the entity_mention collector. Document Entity entity_mention Connecting Document nodes and Entity nodes with relationship MENTION. Document Entity MENTION Main function Finally, the main function for the flow initializes the CocoIndex flow and runs it. @cocoindex.main_fn() def _run(): pass if __name__ == "__main__": load_dotenv(override=True) _run() @cocoindex.main_fn() def _run(): pass if __name__ == "__main__": load_dotenv(override=True) _run() Query and test your index 🎉 Now you are all set! Install the dependencies: pip install -e . Run following commands to setup and update the index. python main.py cocoindex setup python main.py cocoindex update You'll see the index updates state in the terminal. For example, you'll see the following output: documents: 7 added, 0 removed, 0 updated (Optional) I used CocoInsight to troubleshoot the index generation and understand the data lineage of the pipeline. It is in free beta now, you can give it a try. It just connects to your local CocoIndex server, with Zero pipeline data retention. Run following command to start CocoInsight: python3 main.py cocoindex server -c https://cocoindex.io And then open the url https://cocoindex.io/cocoinsight. Install the dependencies: pip install -e . Install the dependencies: pip install -e . pip install -e . Run following commands to setup and update the index. python main.py cocoindex setup python main.py cocoindex update You'll see the index updates state in the terminal. For example, you'll see the following output: documents: 7 added, 0 removed, 0 updated Run following commands to setup and update the index. python main.py cocoindex setup python main.py cocoindex update python main.py cocoindex setup python main.py cocoindex update You'll see the index updates state in the terminal. For example, you'll see the following output: documents: 7 added, 0 removed, 0 updated documents: 7 added, 0 removed, 0 updated (Optional) I used CocoInsight to troubleshoot the index generation and understand the data lineage of the pipeline. It is in free beta now, you can give it a try. It just connects to your local CocoIndex server, with Zero pipeline data retention. Run following command to start CocoInsight: python3 main.py cocoindex server -c https://cocoindex.io And then open the url https://cocoindex.io/cocoinsight. (Optional) I used CocoInsight to troubleshoot the index generation and understand the data lineage of the pipeline. It is in free beta now, you can give it a try. It just connects to your local CocoIndex server, with Zero pipeline data retention. Run following command to start CocoInsight: python3 main.py cocoindex server -c https://cocoindex.io python3 main.py cocoindex server -c https://cocoindex.io And then open the url https://cocoindex.io/cocoinsight. https://cocoindex.io/cocoinsight Browse the knowledge graph After the knowledge graph is built, you can explore the knowledge graph you built in Neo4j Browser. For the dev environment, you can connect to Neo4j browser using credentials: username: Neo4j password: cocoindex which is pre-configured in our docker compose config.yaml. username: Neo4j Neo4j password: cocoindex which is pre-configured in our docker compose config.yaml. cocoindex config.yaml You can open it at http://localhost:7474, and run the following Cypher query to get all relationships: http://localhost:7474 MATCH p=()-->() RETURN p MATCH p=()-->() RETURN p Support us We are constantly improving, and more features and examples are coming soon. If you love this article, please give us a star ⭐ at GitHub repo to help us grow. GitHub repo
