---
title: MongoDB Store
description: Document-oriented MetadataStore using Grove ORM with mongodriver for MongoDB.
---

The `store/mongo` package provides a MongoDB-backed MetadataStore using the [Grove ORM](https://github.com/xraph/grove) with `mongodriver`. It stores collections, documents, and chunks in MongoDB collections with compound indexes for efficient tenant-scoped queries.

## Installation

```bash
go get github.com/xraph/weave/store/mongo
```

## Setup

```go
import (
    "github.com/xraph/grove"
    "github.com/xraph/grove/drivers/mongodriver"
    mongostore "github.com/xraph/weave/store/mongo"
)

// Open a MongoDB connection via Grove's mongodriver.
db := grove.Open(mongodriver.New(
    mongodriver.WithURI("mongodb://localhost:27017"),
    mongodriver.WithDatabase("weave"),
))

store := mongostore.New(db)
```

## Migrations

```go
if err := store.Migrate(ctx); err != nil {
    log.Fatal("migrate:", err)
}
```

Creates collections with JSON Schema validation (auto-generated from Grove model structs) and applies compound and unique indexes on all three collections (`weave_collections`, `weave_documents`, `weave_chunks`) for efficient queries scoped by tenant and app.

## Pairing with a vector store

Pair the MongoDB metadata store with a vector store for similarity search:

```go
import (
    mongostore "github.com/xraph/weave/store/mongo"
    pgvec "github.com/xraph/weave/vectorstore/pgvector"
)

eng, err := engine.New(
    engine.WithStore(mongostore.New(db)),
    engine.WithVectorStore(pgvec.New(pool)),
    engine.WithEmbedder(emb),
)
```

## Internals

| Aspect | Detail |
|--------|--------|
| Driver | Grove ORM with `mongodriver` (MongoDB) |
| Migrations | Grove migrations with JSON Schema validation + indexes |
| Transactions | Individual operations are atomic; multi-document transactions require explicit sessions |

## Collections

| Collection | Entity |
|------------|--------|
| `weave_collections` | Collection metadata -- name, model, chunk config, counters |
| `weave_documents` | Document records -- state, hashes, source info |
| `weave_chunks` | Chunk text and byte offsets |

All collections include `tenant_id` and `app_id` fields, and queries filter on them automatically.

## Lifecycle

| Method | Behaviour |
|--------|-----------|
| `Migrate(ctx)` | Creates collections with JSON Schema validation and indexes |
| `Ping(ctx)` | Verifies database connectivity |
| `Close()` | Disconnects from MongoDB |

## Grove Migrations

The store exports a `Migrations` group for use with Grove's migration orchestrator. This enables tracked, versioned migrations across all stores in your application:

```go
import mongostore "github.com/xraph/weave/store/mongo"

// mongostore.Migrations is a migrate.Group for the weave mongo store.
// Register it with the grove migration orchestrator for coordinated migrations.
```

## When to use

- **Document-oriented workloads** -- flexible schemas that evolve with your application.
- **Horizontal scaling** -- MongoDB sharding for large-scale deployments.
- **Cloud-native** -- MongoDB Atlas for fully managed deployments.
- **Teams familiar with MongoDB** -- leverage existing document database expertise.