GraphRAG for .NET

GraphRAG for .NET is a ground-up port of Microsoft’s GraphRAG reference implementation to the modern .NET 9 stack. The port keeps parity with the original Python pipelines while embracing native .NET idioms—dependency injection, logging abstractions, async I/O, and strongly-typed configuration.

ℹ️ The upstream Python code remains available under submodules/graphrag-python for side-by-side reference. Treat it as read-only unless a task explicitly targets the submodule.

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Feature Highlights

• End-to-end indexing workflows. All standard GraphRAG stages—document loading, chunking, graph extraction, community building, and summarisation—ship as discrete workflows that can be registered with a single AddGraphRag(...) call.
• Heuristic ingestion & maintenance. Built-in overlapping chunk windows, semantic deduplication, orphan-node linking, relationship enhancement/validation, and token-budget trimming keep your graph clean without bespoke services.
• Fast label propagation communities. A configurable fast label propagation detector (with connected-component fallback) mirrors the behaviour of the GraphRag.Net demo directly inside the pipeline.
• Pluggable graph stores. Ready-made adapters for Azure Cosmos DB, Neo4j, and Apache AGE/PostgreSQL conform to IGraphStore so you can swap back-ends without touching workflows.
• Prompt orchestration. Prompt templates cascade through manual, auto-tuned, and default sources using Microsoft.Extensions.AI keyed clients for chat and embedding models.
• Deterministic integration tests. Testcontainers spin up the real databases, while stub embeddings provide stable heuristics coverage so CI can validate the full pipeline.

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Repository Structure

graphrag/
├── GraphRag.slnx                          # Solution spanning runtime + test projects
├── Directory.Build.props / Directory.Packages.props
├── src/
│   ├── ManagedCode.GraphRag               # Core pipeline orchestration & abstractions
│   ├── ManagedCode.GraphRag.CosmosDb      # Azure Cosmos DB graph adapter
│   ├── ManagedCode.GraphRag.Neo4j         # Neo4j adapter & Bolt integration
│   └── ManagedCode.GraphRag.Postgres      # Apache AGE/PostgreSQL graph adapter
├── tests/
│   └── ManagedCode.GraphRag.Tests
│       ├── Integration/                   # Live container-backed scenarios
│       └── … unit-level suites
└── submodules/
    └── graphrag-python                    # Original Python implementation (read-only)

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Prerequisites

Requirement	Notes
.NET SDK 9.0	The solution targets net9.0. Use the in-repo dotnet-install.sh helper on CI.
Docker Desktop / compatible runtime	Required for Testcontainers-backed integration tests (Neo4j & Apache AGE/PostgreSQL).
(Optional) Azure Cosmos DB Emulator	Set COSMOS_EMULATOR_CONNECTION_STRING to enable Cosmos-specific tests.

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Quick Start

1. Clone & initialise submodules

   git clone https://github.com/<your-org>/graphrag.git
   cd graphrag
   git submodule update --init --recursive

2. Install .NET 9 if needed

   ./dotnet-install.sh --version 9.0.100
   export PATH="$HOME/.dotnet:$PATH"

3. Restore & build (always build before testing)

   dotnet build GraphRag.slnx

4. Run the full test suite

   dotnet test GraphRag.slnx --logger "console;verbosity=minimal"

   This command restores packages, launches Neo4j and Apache AGE/PostgreSQL containers via Testcontainers, runs unit + integration tests, and tears everything down automatically.

5. Target a specific scenario (optional)

   dotnet test tests/ManagedCode.GraphRag.Tests/ManagedCode.GraphRag.Tests.csproj \
       --filter "FullyQualifiedName~HeuristicMaintenanceIntegrationTests" \
       --logger "console;verbosity=normal"

6. Format before committing

   dotnet format GraphRag.slnx

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Using GraphRAG in Your Application

Register GraphRAG services and provide keyed Microsoft.Extensions.AI clients for every model reference:

using Azure;
using Azure.AI.OpenAI;
using GraphRag;
using GraphRag.Config;
using Microsoft.Extensions.AI;

var openAi = new OpenAIClient(new Uri(endpoint), new AzureKeyCredential(key));

builder.Services.AddKeyedSingleton<IChatClient>(
    "chat_model",
    _ => openAi.GetChatClient(chatDeployment));

builder.Services.AddKeyedSingleton<IEmbeddingGenerator<string, Embedding>>(
    "embedding_model",
    _ => openAi.GetEmbeddingClient(embeddingDeployment));

builder.Services.AddGraphRag();

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Pipeline Cache & Extensibility

Every workflow in a pipeline shares the same IPipelineCache instance via PipelineRunContext. The default DI registration wires up MemoryPipelineCache, letting workflows reuse expensive intermediate artefacts (LLM responses, chunk expansions, graph lookups) without recomputation. Swap in your own implementation by registering IPipelineCache before invoking AddGraphRag()—for example to persist cache entries or aggregate diagnostics.

• Child scopes. MemoryPipelineCache.CreateChild("stage") prefixes keys with the stage name so multi-step workflows remain isolated.
• Debug payloads. Entries can include optional debug data; clearing the cache removes both the value and associated trace metadata.
• Custom lifetimes. Register a scoped cache if you want to align the cache with a single HTTP request rather than the default singleton lifetime.

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Heuristic Ingestion & Maintenance

The .NET port incorporates the ingestion behaviours showcased in GraphRag.Net directly inside the indexing pipeline:

• Overlapping chunk windows produce coherent context spans that survive community trimming.
• Semantic deduplication drops duplicate text units by comparing embedding cosine similarity against a configurable threshold.
• Token-budget trimming automatically enforces global and per-community token ceilings during summarisation.
• Orphan-node linking reconnects isolated entities through high-confidence relationships before finalisation.
• Relationship enhancement & validation reconciles LLM output with existing edges to avoid duplicates while strengthening weights.

Configure the heuristics via GraphRagConfig.Heuristics (for example in appsettings.json):

{
  "GraphRag": {
    "Models": [ "chat_model", "embedding_model" ],
    "EmbedText": {
      "ModelId": "embedding_model"
    },
    "Heuristics": {
      "MinimumChunkOverlap": 128,
      "EnableSemanticDeduplication": true,
      "SemanticDeduplicationThreshold": 0.92,
      "MaxTokensPerTextUnit": 1200,
      "MaxDocumentTokenBudget": 6000,
      "MaxTextUnitsPerRelationship": 6,
      "LinkOrphanEntities": true,
      "OrphanLinkMinimumOverlap": 0.25,
      "OrphanLinkWeight": 0.35,
      "EnhanceRelationships": true,
      "RelationshipConfidenceFloor": 0.35
    }
  }
}

See docs/indexing-and-query.md for the full list of knobs and how they map to the original research flow.

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Community Detection & Graph Analytics

Community creation defaults to the fast label propagation algorithm. Tweak clustering directly through configuration:

{
  "GraphRag": {
    "Models": [ "chat_model", "embedding_model" ],
    "ClusterGraph": {
      "Algorithm": "FastLabelPropagation",
      "MaxIterations": 40,
      "MaxClusterSize": 25,
      "UseLargestConnectedComponent": true,
      "Seed": 3735928559
    }
  }
}

If the graph is sparse, the pipeline falls back to connected components to ensure every node participates in a community. The heuristics integration tests (Integration/HeuristicMaintenanceIntegrationTests.cs) cover both the label propagation path and the connected-component fallback.

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Integration Testing Strategy

• Real services only. All graph operations run against containerised Neo4j and Apache AGE/PostgreSQL instances provisioned by Testcontainers.
• Deterministic heuristics. StubEmbeddingGenerator guarantees stable embeddings so semantic-dedup and token-budget assertions remain reliable.
• Cross-store validation. Shared integration fixtures verify that workflows succeed against each adapter (Cosmos tests activate when the emulator connection string is present).
• Prompt precedence. Tests validate that manual prompt overrides win over auto-tuned variants while still cascading correctly to the default templates.
• Telemetry coverage. Runtime tests assert pipeline callbacks and execution statistics so custom instrumentation keeps working.

To run just the container-backed suite:

dotnet test tests/ManagedCode.GraphRag.Tests/ManagedCode.GraphRag.Tests.csproj \
    --filter "Category=Integration" \
    --logger "console;verbosity=normal"

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Apache AGE / PostgreSQL Setup

GraphRAG ships with a first-class Apache AGE adapter (ManagedCode.GraphRag.Postgres). AGE is enabled on top of PostgreSQL, so you only need a standard Postgres instance with the AGE extension installed.

1. Run an AGE-enabled Postgres instance. The integration tests use the official container and you can do the same locally:

   docker run --rm \
     -e POSTGRES_USER=postgres \
     -e POSTGRES_PASSWORD=postgres \
     -e POSTGRES_DB=graphrag \
     -p 5432:5432 \
     apache/age:latest

2. Provide a connection string. AgeConnectionManager accepts a standard Npgsql-style string (for example Host=localhost;Port=5432;Username=postgres;Password=postgres;Database=graphrag). The manager automatically runs CREATE EXTENSION IF NOT EXISTS age;, LOAD 'age';, and SET search_path = ag_catalog, "$user", public; before any query executes.
3. Configure the store. Either bind PostgresGraphStoreOptions in code or use configuration. The snippet below shows the JSON shape (environment variables can follow the same hierarchy, e.g. GraphRag__GraphStores__postgres__ConnectionString):

   {
     "GraphRag": {
       "GraphStores": {
         "postgres": {
           "ConnectionString": "Host=localhost;Port=5432;Username=postgres;Password=postgres;Database=graphrag",
           "GraphName": "graphrag",
           "MaxConnections": 40,
           "MakeDefault": true
         }
       }
     }
   }

4. Register through DI. services.AddPostgresGraphStore("postgres", configure: ...) wires up IAgeConnectionManager, IAgeClientFactory, and IGraphStore automatically. MaxConnections caps the number of concurrent AGE sessions (the default is 40 so you stay under the container’s max_connections).

Tip: IGraphStore now exposes GetNodesAsync and GetRelationshipsAsync in addition to the targeted APIs (InitializeAsync, Upsert*, GetOutgoingRelationshipsAsync). These use the new AGE-powered enumerations so you can inspect or export the full graph without dropping down to concrete implementations.

Pagination: GetNodesAsync and GetRelationshipsAsync accept an optional GraphTraversalOptions object (new GraphTraversalOptions { Skip = 100, Take = 50 }) if you want to page through very large graphs. The defaults stream everything, one record at a time, without materialising the entire graph in memory.

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Credits

• pg-age (Allison-E/pg-age) — we vendor this Apache AGE client library (see src/ManagedCode.GraphRag.Postgres/ApacheAge) so GraphRAG for .NET can rely on a battle-tested connector. Many thanks to Allison and contributors for making AGE on PostgreSQL accessible.

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Additional Documentation & Diagrams

• docs/indexing-and-query.md explains how each workflow maps to the GraphRAG research diagrams (default data flow, query orchestrations, prompt tuning strategies) published at microsoft.github.io/graphrag.
• docs/dotnet-port-plan.md outlines the migration strategy from Python to .NET and references the canonical architecture diagrams used during the port.
• The upstream documentation contains the latest diagrams for indexing, query, and data schema. Use those diagrams when presenting the system—it matches the pipeline implemented here.

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Local Cosmos Testing

1. Install and start the Azure Cosmos DB Emulator.
2. Export the connection string:

   export COSMOS_EMULATOR_CONNECTION_STRING="AccountEndpoint=https://localhost:8081/;AccountKey=..."

3. Run dotnet test; Cosmos-specific scenarios will seed the emulator and validate storage behaviour.

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Development Tips

• Solution layout. Open GraphRag.slnx in your IDE for a full workspace view.
• Formatting & analyzers. Run dotnet format GraphRag.slnx before committing.
• Coding conventions. Nullable reference types and implicit usings are enabled; keep annotations accurate and suffix async methods with Async.
• Extending graph adapters. Implement IGraphStore and register your service through DI when adding new storage back-ends.

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Contributing

1. Fork the repository and create a feature branch from main.
2. Make your changes, ensuring dotnet build GraphRag.slnx succeeds before you run tests.
3. Execute dotnet test GraphRag.slnx (with Docker running) and dotnet format GraphRag.slnx before opening a pull request.
4. Include the test output in your PR description and link any related issues.

See CONTRIBUTING.md for detailed guidance.

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License & Credits

• Licensed under the MIT License.
• GraphRAG is © Microsoft. This repository reimplements the pipelines for the .NET ecosystem while staying aligned with the official documentation and diagrams.

Have questions or feedback? Open an issue or start a discussion—we’re actively evolving the .NET port and welcome contributions! 🚀