feat: add FalkorDB integration page (#477)

Adds integration page and logo for the FalkorDB document store integration
(falkordb-haystack), including FalkorDBDocumentStore, FalkorDBEmbeddingRetriever,
and FalkorDBCypherRetriever components.

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: julian-risch

integrations/falkordb.md

@@ -0,0 +1,194 @@
+---
+layout: integration
+name: FalkorDB
+description: Use FalkorDB as a document store with native vector search for GraphRAG workloads in Haystack
+authors:
+  - name: deepset
+    socials:
+      github: deepset-ai
+      twitter: deepset_ai
+      linkedin: https://www.linkedin.com/company/deepset-ai/
+pypi: https://pypi.org/project/falkordb-haystack/
+repo: https://github.com/deepset-ai/haystack-core-integrations/tree/main/integrations/falkordb
+type: Document Store
+report_issue: https://github.com/deepset-ai/haystack-core-integrations/issues
+logo: /logos/falkordb.png
+version: Haystack 2.0
+toc: true
+---
+
+### Table of Contents
+
+- [Overview](#overview)
+- [Installation](#installation)
+- [Usage](#usage)
+  - [Writing documents](#writing-documents)
+  - [Retrieving documents](#retrieving-documents)
+  - [Graph queries with Cypher](#graph-queries-with-cypher)
+- [License](#license)
+
+## Overview
+
+An integration of [FalkorDB](https://www.falkordb.com/) with [Haystack](https://docs.haystack.deepset.ai/docs/intro) by [deepset](https://www.deepset.ai).
+
+FalkorDB is a high-performance graph database optimized for GraphRAG workloads. It stores documents as graph nodes and supports native vector search — no APOC is required. All bulk writes use `UNWIND` + `MERGE` for safe, idiomatic OpenCypher upserts.
+
+The library provides a `FalkorDBDocumentStore` that implements the Haystack [DocumentStore protocol](https://docs.haystack.deepset.ai/docs/document-store#documentstore-protocol), plus two pipeline-ready retriever components:
+
+- **FalkorDBDocumentStore** — stores Documents as labeled graph nodes in a named FalkorDB graph, with `meta` fields stored flat alongside `id` and `content`. Embeddings are indexed using FalkorDB's native vector index.
+- **FalkorDBEmbeddingRetriever** — a [retriever component](https://docs.haystack.deepset.ai/docs/retrievers) that queries the native vector index to find Documents by dense similarity, with support for metadata filtering.
+- **FalkorDBCypherRetriever** — a power-user retriever for executing arbitrary [OpenCypher](https://opencypher.org/) queries, enabling graph traversal and multi-hop queries in GraphRAG pipelines.
+
+```text
+                                   +-----------------------------+
+                                   |      FalkorDB Database      |
+                                   +-----------------------------+
+                                   |                             |
+                                   |      +----------------+     |
+                                   |      |    Document    |     |
+                write_documents    |      +----------------+     |
+          +------------------------+----->|   properties   |     |
+          |                        |      |                |     |
++---------+----------+             |      |   embedding    |     |
+|                    |             |      +--------+-------+     |
+| FalkorDBDocument   |             |               |             |
+|       Store        |             |               |index/query  |
++---------+----------+             |               |             |
+          |                        |     +---------+---------+   |
+          |                        |     | Native Vector Idx |   |
+          +----------------------->|     |                   |   |
+              _embedding_retrieval |     |  (vecf32 index)   |   |
+                                   |     +-------------------+   |
+                                   |                             |
+                                   +-----------------------------+
+```
+
+In the above diagram:
+
+- `Document` is a FalkorDB node with a configurable label (default: `"Document"`)
+- `properties` are Document [attributes](https://docs.haystack.deepset.ai/docs/data-classes#document) and `meta` fields stored flat on the node
+- `embedding` is stored as a `vecf32` vector property indexed by FalkorDB's native vector index
+- The native vector index enables approximate nearest neighbor search via `db.idx.vector.queryNodes`
+
+## Installation
+
+`falkordb-haystack` can be installed using pip:
+
+```bash
+pip install falkordb-haystack
+```
+
+You will need a running FalkorDB instance. The simplest way is with Docker:
+
+```bash
+docker run -d -p 6379:6379 falkordb/falkordb:latest
+```
+
+## Usage
+
+```python
+from haystack_integrations.document_stores.falkordb import FalkorDBDocumentStore
+
+document_store = FalkorDBDocumentStore(
+    host="localhost",
+    port=6379,
+    embedding_dim=384,
+    similarity="cosine",
+)
+```
+
+### Writing documents
+
+```python
+from haystack import Document
+from haystack.document_stores.types import DuplicatePolicy
+
+documents = [
+    Document(
+        content="FalkorDB is a high-performance graph database for GraphRAG.",
+        meta={"source": "docs", "category": "database"},
+    )
+]
+document_store.write_documents(documents, policy=DuplicatePolicy.OVERWRITE)
+```
+
+### Retrieving documents
+
+`FalkorDBEmbeddingRetriever` can be used in a pipeline to retrieve documents by querying the native vector index with an embedded query, with optional metadata filtering:
+
+```python
+from haystack import Document, Pipeline
+from haystack.components.embedders import (
+    SentenceTransformersDocumentEmbedder,
+    SentenceTransformersTextEmbedder,
+)
+from haystack_integrations.document_stores.falkordb import FalkorDBDocumentStore
+from haystack_integrations.components.retrievers.falkordb import FalkorDBEmbeddingRetriever
+
+document_store = FalkorDBDocumentStore(
+    host="localhost",
+    port=6379,
+    embedding_dim=384,
+    recreate_graph=True,
+)
+
+documents = [
+    Document(
+        content="My name is Morgan and I live in Paris.",
+        meta={"release_date": "2018-12-09"},
+    )
+]
+
+document_embedder = SentenceTransformersDocumentEmbedder(
+    model="sentence-transformers/all-MiniLM-L6-v2"
+)
+document_embedder.warm_up()
+documents_with_embeddings = document_embedder.run(documents)
+document_store.write_documents(documents_with_embeddings["documents"])
+
+pipeline = Pipeline()
+pipeline.add_component(
+    "text_embedder",
+    SentenceTransformersTextEmbedder(model="sentence-transformers/all-MiniLM-L6-v2"),
+)
+pipeline.add_component(
+    "retriever",
+    FalkorDBEmbeddingRetriever(document_store=document_store),
+)
+pipeline.connect("text_embedder.embedding", "retriever.query_embedding")
+
+result = pipeline.run(
+    data={
+        "text_embedder": {"text": "What cities do people live in?"},
+        "retriever": {
+            "top_k": 5,
+            "filters": {"field": "release_date", "operator": "==", "value": "2018-12-09"},
+        },
+    }
+)
+
+documents = result["retriever"]["documents"]
+```
+
+### Graph queries with Cypher
+
+`FalkorDBCypherRetriever` allows you to run arbitrary OpenCypher queries against the graph, which is useful for multi-hop traversals and custom GraphRAG patterns. Use parameterized queries to avoid injection vulnerabilities:
+
+```python
+from haystack_integrations.document_stores.falkordb import FalkorDBDocumentStore
+from haystack_integrations.components.retrievers.falkordb import FalkorDBCypherRetriever
+
+document_store = FalkorDBDocumentStore(host="localhost", port=6379)
+
+retriever = FalkorDBCypherRetriever(
+    document_store=document_store,
+    custom_cypher_query="MATCH (d:Document {topic: $topic}) RETURN d",
+)
+
+result = retriever.run(parameters={"topic": "GraphRAG"})
+documents = result["documents"]
+```
+
+## License
+
+`falkordb-haystack` is distributed under the terms of the [Apache 2.0](https://spdx.org/licenses/Apache-2.0.html) license.