graphmemory 1.1.2

Graph-based memory system using DuckDB

GraphMemory

An embedded graph database for RAG and knowledge graph applications, powered by DuckDB. Vector similarity search, full-text search, hybrid search, merge/upsert, graph traversal, and a full GraphRAG retrieval pipeline — all in a single Python package.

Features

• Vector Search — HNSW-indexed nearest neighbors (L2, cosine, inner product)
• Full-Text Search — BM25-scored search across node properties
• Hybrid Search — Combined vector + text with configurable weights
• GraphRAG — Retrieval pipeline: hybrid search → graph expansion → context assembly → LLM Q&A
• Merge / Upsert — Deduplicate nodes by property keys and edges by (source, target, relation)
• Query Builder — Fluent, parameterized API with multi-hop traversal
• DSPy Extraction — Entity/relationship extraction from text via DSPy (optional)
• Graph Algorithms — PageRank, centrality, components via NetworkX (optional)
• Import / Export — JSON, CSV, GraphML
• Thread-Safe — Connection pooling, transactions, automatic retry with exponential backoff

Installation

pip install graphmemory

# Optional
pip install graphmemory[extraction]   # DSPy extraction
pip install graphmemory[algorithms]   # NetworkX algorithms

Quick Start

from graphmemory import GraphMemory, Node, Edge

graph = GraphMemory(database="graph.db", vector_length=3, distance_metric="cosine")

# Insert nodes
alice = Node(type="Person", properties={"name": "Alice", "role": "engineer"}, vector=[0.1, 0.8, 0.3])
bob = Node(type="Person", properties={"name": "Bob", "role": "manager"}, vector=[0.2, 0.7, 0.4])
graph.insert_node(alice)
graph.insert_node(bob)

# Insert edge
graph.insert_edge(Edge(source_id=alice.id, target_id=bob.id, relation="reports_to", weight=1.0))

# Vector search
nearest = graph.nearest_nodes(vector=[0.1, 0.8, 0.3], limit=5)

# Full-text search
results = graph.search_nodes("engineer", limit=10)

# Hybrid search
results = graph.hybrid_search("engineer", query_vector=[0.1, 0.8, 0.3], text_weight=0.5, vector_weight=0.5)

# Context manager
with GraphMemory(database="graph.db", vector_length=3) as graph:
    graph.insert_node(alice)

Usage

Query Builder

# Filter by type and properties
results = graph.query().match(type="Person").where(role="engineer").execute()

# Multi-hop traversal
results = graph.query().traverse(source_id=alice.id, depth=2).execute()

# Paginate and order
results = graph.query().match(type="Person").order_by("name").limit(10).offset(0).execute()

# Query edges
edges = graph.query().match(type="Person").edges().execute()

Merge / Upsert

Insert-or-update nodes matched by property keys. Edges deduplicate on (source_id, target_id, relation).

from graphmemory import MergeStrategy

# Insert if no match, update if "name" matches an existing Person node
result = graph.merge_node(alice, match_keys=["name"])
print(result.created)  # True = inserted, False = updated

# Bulk merge with strategy
results = graph.bulk_merge_nodes(nodes, match_keys=["name"], strategy=MergeStrategy.UPDATE)

# Edge merge
result = graph.merge_edge(edge)
results = graph.bulk_merge_edges(edges)

Strategy	Behavior
UPDATE	Shallow merge — existing keys preserved, incoming keys added/overwritten (default)
REPLACE	Incoming properties fully replace existing
KEEP	Existing properties unchanged; only new nodes inserted

GraphRAG Retrieval

Full pipeline: hybrid search → multi-hop graph expansion → token-aware context assembly → LLM generation.

# Retrieve context
result = graph.retrieve(query="Who leads ML?", query_vector=embedding, max_hops=2, max_tokens=4000)
print(result.context_text)      # Prompt-ready string
print(result.token_estimate)    # Token count estimate

# End-to-end Q&A
answer = graph.ask(query="Who leads ML?", query_vector=embedding, llm_callable=my_llm)
print(answer["answer"])

DSPy Extraction

Requires pip install graphmemory[extraction]. Uses DSPy typed predictors to extract entities and relationships from text.

from graphmemory.extraction import extract_and_store, extract_and_merge
import dspy

dspy.configure(lm=dspy.LM("openai/gpt-4o-mini"))

text = """George Washington was the first President. Thomas Jefferson
served as Secretary of State under Washington."""

# Extract and insert (may create duplicates on repeated calls)
nodes, edges = extract_and_store(graph, text)

# Extract and merge (deduplicates against existing graph)
node_results, edge_results = extract_and_merge(graph, text, match_keys=["name"])

Function	Description
extract_nodes(text)	Extract entity nodes from text
extract_edges(text, nodes)	Extract relationships between known nodes
extract(text)	Extract both nodes and edges
extract_and_store(graph, text)	Extract and insert into graph
extract_and_merge(graph, text, match_keys)	Extract and merge (deduplicated)

Graph Algorithms

Requires pip install graphmemory[algorithms]. Powered by NetworkX.

from graphmemory.algorithms import pagerank, betweenness_centrality, connected_components, to_networkx

scores = pagerank(graph)
centrality = betweenness_centrality(graph)
components = connected_components(graph)
G = to_networkx(graph)  # Export to NetworkX DiGraph

Function	Description
pagerank(graph, alpha=0.85)	PageRank scores for all nodes
betweenness_centrality(graph)	Betweenness centrality scores
degree_distribution(graph)	In/out/total degree per node
connected_components(graph)	Weakly connected components (largest first)
to_networkx(graph)	Export to networkx.DiGraph

Import / Export

# Export
data = graph.export_graph(format="json")       # also: "csv", "graphml", "json_string"

# Import
graph.import_graph(data, format="json")

Data Models

Model	Fields
Node	id: UUID, type: str, properties: dict, vector: list[float]
Edge	id: UUID, source_id: UUID, target_id: UUID, relation: str, weight: float
NearestNode	node: Node, distance: float
SearchResult	node: Node, score: float
TraversalResult	node: Node, depth: int, path: list[UUID]
MergeResult	node: Node, created: bool
EdgeMergeResult	edge: Edge, created: bool
RetrievalResult	query: str, contexts: list, context_text: str, token_estimate: int

All IDs are auto-generated UUIDs. All models are Pydantic BaseModel instances.

API Reference

Connection

Method	Description
GraphMemory(database=None, vector_length=3, distance_metric='l2')	Initialize. None = in-memory.
close()	Close connection (thread-safe, idempotent).
transaction()	Context manager for atomic operations.

Nodes

Method	Description
insert_node(node) -> UUID	Insert a node.
bulk_insert_nodes(nodes) -> list[Node]	Bulk insert.
merge_node(node, match_keys, strategy=UPDATE) -> MergeResult	Insert or update by property match.
bulk_merge_nodes(nodes, match_keys, ...) -> list[MergeResult]	Bulk merge.
get_node(node_id) -> Node	Get by ID.
update_node(node_id, **kwargs) -> bool	Update fields.
delete_node(node_id)	Delete node and its edges.
bulk_delete_nodes(node_ids)	Bulk delete.
nodes_by_attribute(attr, value) -> list[Node]	Query by property.

Edges

Method	Description
insert_edge(edge)	Insert an edge.
bulk_insert_edges(edges)	Bulk insert.
merge_edge(edge) -> EdgeMergeResult	Insert or update by (source, target, relation).
bulk_merge_edges(edges) -> list[EdgeMergeResult]	Bulk merge.
get_edge(edge_id) -> Edge	Get by ID.
update_edge(edge_id, **kwargs) -> bool	Update fields.
delete_edge(source_id, target_id)	Delete by endpoints.
bulk_delete_edges(edge_ids)	Bulk delete.

Search

Method	Description
nearest_nodes(vector, limit) -> list[NearestNode]	Vector similarity search.
search_nodes(query_text, limit=10) -> list[SearchResult]	Full-text BM25 search.
hybrid_search(query_text, query_vector, ...) -> list[SearchResult]	Combined text + vector search.
create_index()	Create HNSW index for faster vector search.

Retrieval

Method	Description
retrieve(query, query_vector, ...) -> RetrievalResult	Full GraphRAG retrieval pipeline.
ask(query, query_vector, llm_callable, ...) -> dict	Retrieval + LLM generation.

Traversal

Method	Description
connected_nodes(node_id) -> list[Node]	All nodes connected to a node.
query() -> QueryBuilder	Fluent query builder.

Import / Export

Method	Description
export_graph(format='json')	Export as JSON, CSV, GraphML, or JSON string.
import_graph(data, format='json')	Import from any supported format.

Examples

See examples/ for complete usage:

• openai_example.py — OpenAI embeddings, similarity search, attribute queries
• lexical_graph.py — Wikipedia text with SentenceTransformer embeddings
• dspy_example_typed_pred.py — Knowledge graph extraction with DSPy

Testing

265 tests covering all functionality.

python3 -m pytest tests/tests.py -v

License

MIT License. See LICENSE.

Contributing

Contributions welcome — open an issue or submit a PR.