Mem0Sharp

Long-term memory for AI applications in .NET 10. Mem0Sharp is an independent, standalone C#/.NET implementation of the open-source Mem0 project, with one service API for saving, searching, updating, and deleting semantic memories while keeping embedding and storage providers replaceable. It does not call the hosted Mem0 Platform API or depend on mem0.ai at runtime.

Mem0Sharp is not affiliated with, sponsored by, or endorsed by Mem0 or mem0ai.

Mem0Sharp goes beyond porting Mem0 to .NET. It adds native capabilities such as memory behaviors, letting agents remember normally, consolidate experiences like dreams, surface spontaneous associations, or shape first-person memories through their own identity and personality.

Install

dotnet add package Mem0Sharp

Mem0Sharp targets .NET 10. The package has one direct runtime dependency,
Npgsql; the default in-memory configuration does not require PostgreSQL or
any external service.

Documentation

• Start: Documentation home, getting started, and runnable samples.
• Deploy: Providers and persistence for Ollama, OpenAI-compatible APIs, PostgreSQL, and Qdrant.
• Reference: API reference and Mem0 Python feature parity.
• Contribute: Architecture and the contribution guide.

Dependency stack

Mem0Sharp keeps its runtime dependency stack deliberately small: it has one
direct NuGet dependency, Npgsql, for
the PostgreSQL and pgvector stores. The default in-memory service and the
provider interfaces use only .NET 10 and the base class libraries; no AI SDK,
HTTP client package, ORM, or vector database package is required.

Model access is provider-based. Implement IChatCompletionClient and
IEmbeddingGenerator for the model service used by your application, or use
the built-in local components for offline development. PostgreSQL itself and
its vector extension are infrastructure prerequisites, not NuGet dependencies.

Features

• Semantic memory search with configurable result limits.
• Hybrid semantic and BM25 retrieval with explanations and LLM, Cohere, ZeroEntropy, or local cross-encoder reranking.
• OpenAI-compatible, Anthropic, and Ollama model protocols with local, PostgreSQL/pgvector, and Qdrant vector storage.
• CRUD operations plus filtered bulk deletion.
• Persistent ADD, UPDATE, and DELETE history with audit timestamps, deletion state, actor, and role for built-in stores.
• Scope-aware deduplication and conflict-aware Add/Update/Delete/None decisions.
• Memory behaviors beyond traditional fact storage: normal, dreaming, random thoughts, and personality-shaped first-person memory.
• Expiration, paging, nested metadata filters, entities, and optional graph memory.
• Batch embedding and transactional PostgreSQL batch persistence.
• Native synchronous facade, opt-in telemetry, and nine local MCP tools.
• User, session, and agent scopes with user, agent, and run filters.
• Metadata attached to each memory.
• Zero-dependency in-memory storage for tests and local development.
• One direct runtime package dependency: Npgsql; all other provider boundaries are native .NET abstractions.
• Deterministic local embeddings for offline development.
• PostgreSQL persistence with pgvector and optional HNSW indexing.

Quick start

The default service uses in-memory storage, deterministic lexical hashing embeddings, and basic message extraction. It is a good starting point for development and tests; use model-backed embeddings and persistent storage for production workloads.

using Mem0Sharp;

var memory = new MemoryService();
await memory.AddAsync("I prefer dark mode and vim keybindings", userId: "alice");

var results = await memory.SearchAsync(
	"What editor settings does Alice prefer?",
	new MemoryFilter(UserId: "alice"),
	topK: 3);

foreach (var result in results)
{
    Console.WriteLine($"{result.Score:F3}: {result.Memory.Text}");
}

var allAliceMemories = await memory.GetAllAsync(new MemoryFilter(UserId: "alice"));
var memoryId = allAliceMemories[0].Id;
await memory.UpdateAsync(memoryId, "I prefer dark mode and Vim keybindings");
await memory.DeleteAsync(memoryId);

var history = await memory.GetHistoryAsync(memoryId);

Run this complete workflow from the repository with:

dotnet run --project .\samples\GettingStarted\GettingStarted.csproj

To add memories extracted from a conversation, pass Message values. The default extractor stores non-empty message content; the LLM-backed extractor is shown in the provider guide.

await memory.AddAsync(
[
    new Message("user", "I live in Berlin."),
    new Message("assistant", "Thanks, I will remember that.")
],
userId: "alice",
scope: MemoryScope.User);

PostgreSQL with pgvector

Install PostgreSQL with the vector extension and set MEM0_POSTGRES to a valid connection string. Then initialize a store using the same embedding dimension as your configured IEmbeddingGenerator:

using Mem0Sharp;

var embeddings = new LocalEmbeddingGenerator(384);
await using var store = new PostgresMemoryStore(new PostgresMemoryStoreOptions
{
	ConnectionString = Environment.GetEnvironmentVariable("MEM0_POSTGRES")!,
	EmbeddingDimensions = 384,
	TableName = "mem0_memories"
});
await store.InitializeAsync();

var memory = new MemoryService(store, embeddings);

The store persists memory metadata and embeddings, applies user/agent/run/scope filters in SQL, uses cosine distance for vector search, and creates an HNSW index when the embedding dimension is supported by pgvector. CreateExtension = false can be used when the database user cannot create extensions.

MemoryService also provides SearchManyAsync for batch queries, using batch-capable embedding and vector-store providers when available, and DeleteAllAsync for filtered bulk deletion.

Mem0Sharp never sends memories to a Mem0 or mem0.ai backend. Supply your own
implementations of IChatCompletionClient and IEmbeddingGenerator when you
need model-backed extraction or embeddings. Use the built-in local components
for a fully offline deployment. See Providers and persistence
for provider contracts, embedding dimensions, and initialization details.

Samples

• Getting started - zero-setup CRUD, search, and history.
• Memory behaviors - compare conventional fact extraction with dreaming, random thoughts, and agent-personal memory.
• Ollama - local model-backed extraction and embeddings.
• PostgreSQL and OpenAI - persistent pgvector storage with OpenAI-compatible models.

Attribution and trademarks

Mem0Sharp is an independent .NET implementation inspired by the open-source
Mem0 project. The original Mem0 project is
copyright 2023 Taranjeet Singh and is licensed under the Apache License 2.0.
Copyright for the Mem0Sharp implementation and its modifications is held by
Jihad Khawaja and contributors. See NOTICE and LICENSE
for the complete attribution and license terms.

Mem0 and related names, logos, and marks belong to their respective owners.
This project does not grant or claim any trademark rights and is not affiliated
with, sponsored by, or endorsed by the Mem0 project or mem0ai.

Build and test

dotnet build .\Mem0Sharp.slnx
dotnet test .\tests\Mem0Sharp.Tests\Mem0Sharp.Tests.csproj