spacedrive/docs/core/data-model.mdx

---
title: Data Model
sidebarTitle: Data Model
---

Spacedrive's data model powers a Virtual Distributed File System (VDFS) that unifies files across all your devices. It enables instant organization, content deduplication, and powerful semantic search while maintaining performance at scale.

## Core Design

The system separates concerns into distinct entities:

- **SdPath** - Address any file; local, peer device, cloud, or by content ID
- **Entry** - File and directory representation
- **ContentIdentity** - Unique file content for deduplication
- **UserMetadata** - Organization data (tags, notes, favorites)
- **Location** - Monitored directories
- **Device** - Individual machines in your network
- **Volume** - Real storage volumes, local, external and cloud
- **Sidecar** - Dirivitive and associated data

## Domain vs. Database Entity Models

It is critical to understand the distinction between two data modeling layers in Spacedrive:

- **Domain Models**: These are the rich objects used throughout the application's business logic. They contain computed fields and methods that provide a powerful, high-level interface to the underlying data. For example, the `domain::File` structure represents several database models such as `entities::entry`, `entities::content_identity`, and `entities::user_metadata`.
- **Database Entity Models**: These are simpler structs that map directly to the database tables (e.g., `entities::entry`). They represent the raw, persisted state of the data and are optimized for storage and query performance.

The code examples in this document generally refer to the database entity models to accurately represent what is stored on disk. The domain models provide a convenient abstraction over this raw data.

## SdPath

The `SdPath` enum is the universal addressing system for files across all storage backends:

```rust
pub enum SdPath {
    /// A direct pointer to a file on a specific local device
    Physical {
        device_slug: String,  // The device slug (e.g., "jamies-macbook")
        path: PathBuf,        // The local filesystem path
    },

    /// A cloud storage path within a cloud volume
    Cloud {
        service: CloudServiceType,  // The cloud service type (S3, GoogleDrive, etc.)
        identifier: String,         // The cloud identifier (bucket name, drive name, etc.)
        path: String,              // The cloud-native path (e.g., "photos/vacation.jpg")
    },

    /// An abstract, location-independent handle via content ID
    Content {
        content_id: Uuid,   // The unique content identifier
    },

    /// A derivative data file (thumbnail, OCR text, embedding, etc.)
    Sidecar {
        content_id: Uuid,         // The content this sidecar is derived from
        kind: SidecarKind,        // The type of sidecar (thumb, ocr, embeddings, etc.)
        variant: SidecarVariant,  // The specific variant (e.g., "grid@2x", "1080p")
        format: SidecarFormat,    // The storage format (webp, json, msgpack, etc.)
    },
}
```

This enum enables transparent operations across local filesystems, cloud storage, content-addressed files, and derivative data. The `Physical` variant handles traditional filesystem paths, `Cloud` manages cloud storage locations, `Content` enables deduplication-aware operations by referencing files by their content, and `Sidecar` addresses generated derivative data like thumbnails and embeddings.

### Unified Addressing

Spacedrive displays paths using a unified addressing scheme that matches industry standards:

```rust
// Display user-friendly URIs
let uri = sd_path.display_with_context(&context).await;

// Examples:
// Physical: "local://jamies-macbook/Users/james/Documents/report.pdf"
// Cloud:    "s3://my-bucket/photos/vacation.jpg"
// Content:  "content://550e8400-e29b-41d4-a716-446655440000"
```

The addressing system uses:

- **Device slugs** for local paths (e.g., `local://jamies-macbook/path`)
- **Service-native URIs** for cloud storage (e.g., `s3://`, `gdrive://`, `onedrive://`)
- **Content UUIDs** for location-independent references

See [Unified Addressing](/docs/core/addressing) for complete details on URI formats and resolution.

## Entry

The `Entry` is the core entity representing a file or directory. The database entity (`entities::entry::Model`) stores the fundamental hierarchy and metadata.

```rust Expandable theme={null}
pub struct Entry {
    pub id: i32,                      // Database primary key
    pub uuid: Option<Uuid>,           // Global identifier (assigned immediately during indexing)
    pub name: String,                 // File or directory name
    pub kind: i32,                    // 0=File, 1=Directory, 2=Symlink
    pub extension: Option<String>,    // File extension (without dot)

    // Relationships
    pub parent_id: Option<i32>,       // Parent directory (self-referential)
    pub metadata_id: Option<i32>,     // User metadata (when present)
    pub content_id: Option<i32>,      // Content identity (for deduplication)

    // Size and hierarchy
    pub size: i64,                    // File size in bytes
    pub aggregate_size: i64,          // Total size including children
    pub child_count: i32,             // Direct children count
    pub file_count: i32,              // Total files in subtree

    // Filesystem metadata
    pub permissions: Option<String>,  // Unix-style permissions
    pub inode: Option<i64>,           // Platform-specific identifier

    // Timestamps
    pub created_at: DateTime<Utc>,
    pub modified_at: DateTime<Utc>,
    pub accessed_at: Option<DateTime<Utc>>,
    pub indexed_at: Option<DateTime<Utc>>,  // When this entry was indexed, used for sync

}
```

### UUID Assignment

All entries receive UUIDs immediately during indexing for UI caching compatibility. However, sync readiness is determined separately:

- **Directories** - Sync ready immediately (no content to identify)
- **Empty files** - Sync ready immediately (size = 0)
- **Regular files** - Sync ready only after content identification (content_id present)

This ensures files sync only after proper content identification, while allowing the UI to cache and track all entries from the moment they're discovered.

### Hierarchical Queries

A closure table enables efficient ancestor/descendant queries:

```rust
pub struct EntryClosure {
    pub ancestor_id: i32,
    pub descendant_id: i32,
    pub depth: i32,  // 0=self, 1=child, 2=grandchild
}
```

This structure allows instant queries like "find all files under this directory" without recursion.

## ContentIdentity

ContentIdentity represents unique file content, enabling deduplication across your entire library:

```rust Expandable theme={null}
pub struct ContentIdentity {
    pub id: i32,
    pub uuid: Option<Uuid>,           // Globally deterministic from content_hash only

    // Hashing
    pub content_hash: String,         // Fast sampled hash (for deduplication)
    pub integrity_hash: Option<String>, // Full hash (for validation)

    // Classification
    pub mime_type_id: Option<i32>,    // FK to MimeType
    pub kind_id: i32,                 // FK to ContentKind (enum)

    // Content metadata
    pub text_content: Option<String>, // Extracted text
    pub image_media_data_id: Option<i32>,  // FK to image-specific metadata
    pub video_media_data_id: Option<i32>,  // FK to video-specific metadata
    pub audio_media_data_id: Option<i32>,  // FK to audio-specific metadata

    // Statistics
    pub total_size: i64,              // Size of one instance
    pub entry_count: i32,             // Entries sharing this content (in library)

    pub first_seen_at: DateTime<Utc>,
    pub last_verified_at: DateTime<Utc>,

}

```

### Two-Stage Hashing

**Content Hash** - Fast sampling for deduplication
**Integrity Hash** - Full file hash for verification

### Deduplication

Multiple entries can point to the same ContentIdentity. When you have duplicate files, they all reference a single ContentIdentity record.

## UserMetadata

UserMetadata stores how you organize your files:

```rust Expandable theme={null}
pub struct UserMetadata {
    pub id: i32,
    pub uuid: Uuid,

    // Scope - exactly one must be set
    pub entry_uuid: Option<Uuid>,           // File-specific metadata
    pub content_identity_uuid: Option<Uuid>, // Content-universal metadata

    // Organization
    pub notes: Option<String>,
    pub favorite: bool,
    pub hidden: bool,
    pub custom_data: Json,            // Extensible JSON fields

    pub created_at: DateTime<Utc>,
    pub updated_at: DateTime<Utc>,

}

```

### Metadata Scoping

UserMetadata can be scoped two ways:

**Entry-Scoped** - Applies to a specific file instance
**Content-Scoped** - Applies to all instances of the same content

## Semantic Tags

Spacedrive uses a graph-based tagging system that understands context and relationships:

```rust Expandable theme={null}
pub struct Tag {
    pub id: i32,
    pub uuid: Uuid,

    // Core identity
    pub canonical_name: String,       // Primary name
    pub display_name: Option<String>, // Display variant

    // Semantic variants
    pub formal_name: Option<String>,  // Formal variant
    pub abbreviation: Option<String>, // Short form
    pub aliases: Option<Json>,        // Vec<String> as JSON

    // Context
    pub namespace: Option<String>,    // Disambiguation namespace
    pub tag_type: String,             // "standard" | "organizational" | "privacy" | "system"

    // Visual properties
    pub color: Option<String>,        // Hex color
    pub icon: Option<String>,         // Icon identifier
    pub description: Option<String>,

    // Behavior
    pub is_organizational_anchor: bool,
    pub privacy_level: String,        // "normal" | "archive" | "hidden"
    pub search_weight: i32,           // Search ranking

    // Extensibility
    pub attributes: Option<Json>,        // HashMap<String, Value> as JSON
    pub composition_rules: Option<Json>, // Vec<CompositionRule> as JSON

    pub created_at: DateTime<Utc>,
    pub updated_at: DateTime<Utc>,
    pub created_by_device: Option<Uuid>,

}

```

### Polymorphic Naming

The same name can mean different things in different contexts:

```rust
// Different tags with same name
Tag { canonical_name: "vacation", namespace: "travel", uuid: uuid_1 }
Tag { canonical_name: "vacation", namespace: "work",   uuid: uuid_2 }
```

### Tag Relationships

Tags form hierarchies and semantic networks:

```rust
pub struct TagRelationship {
    pub parent_tag_id: i32,
    pub child_tag_id: i32,
    pub relationship_type: String,  // "parent_child" | "synonym" | "related"
    pub strength: f32,              // 0.0-1.0
}
```

Examples:

- Parent/Child: "Animals" → "Dogs" → "Puppies"
- Synonyms: "Car" "Automobile"
- Related: "Photography" "Camera"

Tag hierarchies use closure tables for efficient ancestor/descendant queries, similar to entries.

## Location

Locations are directories that Spacedrive monitors:

```rust Expandable theme={null}
pub struct Location {
    pub id: i32,
    pub uuid: Uuid,
    pub device_id: i32,               // Device that owns this location
    pub entry_id: Option<i32>,        // Root entry for this location (nullable during sync)
    pub name: Option<String>,         // User-friendly name

    // Indexing configuration
    pub index_mode: String,           // "shallow" | "content" | "deep"
    pub scan_state: String,           // "pending" | "scanning" | "completed" | "error"

    // Statistics
    pub last_scan_at: Option<DateTime<Utc>>,
    pub error_message: Option<String>,
    pub total_file_count: i64,
    pub total_byte_size: i64,
    pub job_policies: Option<String>, // JSON-serialized JobPolicies (local config)

    pub created_at: DateTime<Utc>,
    pub updated_at: DateTime<Utc>,

}
```

### Index Modes

- **Shallow** - Metadata only (fast, no content hashing)
- **Content** - Metadata + deduplication
- **Deep** - Full analysis including media extraction

## Device

Devices represent machines in your Spacedrive network:

```rust Expandable theme={null}
pub struct Device {
    pub id: i32,
    pub uuid: Uuid,
    pub name: String,
    pub slug: String,                 // URL-safe unique identifier

    // System information
    pub os: String,
    pub os_version: Option<String>,
    pub hardware_model: Option<String>,

    // Network
    pub network_addresses: Json,      // Array of IP addresses
    pub is_online: bool,
    pub last_seen_at: DateTime<Utc>,

    // Capabilities
    pub capabilities: Json,           // Feature flags

    // Sync
    pub sync_enabled: bool,
    pub last_sync_at: Option<DateTime<Utc>>,

    pub created_at: DateTime<Utc>,
    pub updated_at: DateTime<Utc>,

}

```

## Volume

Volumes track physical drives and partitions:

```rust Expandable theme={null}
pub struct Volume {
    pub id: i32,
    pub uuid: Uuid,
    pub device_id: Uuid,              // FK to Device
    pub fingerprint: String,          // Stable identifier across mounts

    pub display_name: Option<String>,
    pub mount_point: Option<String>,
    pub file_system: Option<String>,

    // Capacity
    pub total_capacity: Option<i64>,
    pub available_capacity: Option<i64>,
    pub unique_bytes: Option<i64>,    // Deduplicated storage usage

    // Performance
    pub read_speed_mbps: Option<i32>,
    pub write_speed_mbps: Option<i32>,
    pub last_speed_test_at: Option<DateTime<Utc>>,

    // Classification
    pub is_removable: Option<bool>,
    pub is_network_drive: Option<bool>,
    pub device_model: Option<String>,
    pub volume_type: Option<String>,
    pub is_user_visible: Option<bool>,     // Visible in UI
    pub auto_track_eligible: Option<bool>, // Eligible for auto-tracking
    pub cloud_identifier: Option<String>,  // Cloud volume identifier

    // Tracking
    pub tracked_at: DateTime<Utc>,
    pub last_seen_at: DateTime<Utc>,
    pub is_online: bool,

}

```

## Sidecar

Sidecars store generated content like thumbnails:

```rust Expandable theme={null}
pub struct Sidecar {
    pub id: i32,
    pub uuid: Uuid,
    pub content_uuid: Uuid,           // FK to ContentIdentity

    // Classification
    pub kind: String,                 // "thumbnail" | "preview" | "metadata"
    pub variant: String,              // Size/quality variant
    pub format: String,               // File format

    // Storage
    pub rel_path: String,             // Relative path to sidecar
    pub source_entry_id: Option<i32>, // Reference to existing file

    // Metadata
    pub size: i64,
    pub checksum: Option<String>,
    pub status: String,               // "pending" | "processing" | "ready" | "error"
    pub source: Option<String>,       // Source of the sidecar
    pub version: i32,

    pub created_at: DateTime<Utc>,
    pub updated_at: DateTime<Utc>,
}
```

<Note>
  Sidecars link to ContentIdentity, not Entry. This means one thumbnail serves
  all duplicate files.
</Note>

## Extension Models

Extensions create custom tables at runtime to store domain-specific data. These integrate seamlessly with core tagging and organization.

<Note type="warning">
  The extension system is currently a work in progress. The API and
  implementation details described here are subject to change.
</Note>

### Table Naming

Extension tables use prefixed naming:

```sql
-- Photos extension creates:
CREATE TABLE ext_photos_person (
    id BLOB PRIMARY KEY,
    name TEXT NOT NULL,
    birth_date TEXT,
    metadata_id INTEGER NOT NULL,
    FOREIGN KEY (metadata_id) REFERENCES user_metadata(id)
);

CREATE TABLE ext_photos_album (
    id BLOB PRIMARY KEY,
    title TEXT NOT NULL,
    description TEXT,
    created_date TEXT,
    metadata_id INTEGER NOT NULL,
    FOREIGN KEY (metadata_id) REFERENCES user_metadata(id)
);
```

### Model Definition

Extensions define models using SDK macros:

```rust
#[model(
    table_name = "person",
    version = "1.0.0",
    scope = "content",
    sync_strategy = "shared"
)]
struct Person {
    #[primary_key]
    id: Uuid,
    name: String,
    birth_date: Option<String>,
    #[metadata]
    metadata_id: i32,  // Links to UserMetadata
}
```

### Integration Benefits

1. **SQL Queries** - Direct database queries with JOINs and indexes
2. **Foreign Keys** - Referential integrity enforced by database
3. **Unified Organization** - Extension data can be tagged and searched
4. **Type Safety** - Compile-time schema validation

## Sync Architecture

### Device-Owned Resources

**Entities**: Entry, Location
**Behavior**: Only owning device can modify, last state wins

### Shared Resources

**Entities**: Tag, UserMetadata, TagRelationship
**Behavior**: Any device can modify, HLC ordering for consistency

### Foreign Key Mapping

During sync, integer IDs map to UUIDs for wire format, then back to local IDs on receiving devices.

## Query Patterns

Find files with a specific tag:

```rust
Entry::find()
    .inner_join(UserMetadata)
    .inner_join(UserMetadataTag)
    .inner_join(Tag)
    .filter(tag::Column::CanonicalName.eq("vacation"))
    .all(db).await?
```

Find duplicate files:

```rust
ContentIdentity::find()
    .find_with_related(Entry)
    .filter(content_identity::Column::EntryCount.gt(1))
    .all(db).await?
```

## Performance Optimizations

1. **Closure Tables** - O(1) hierarchical queries
2. **Directory Path Table** - The full path for every directory is stored in a dedicated `directory_paths` table. This is the source of truth for directory paths and avoids storing redundant path information on every file entry, making path-based updates significantly more efficient.
3. **Aggregate Columns** - Pre-computed size/count fields
4. **Deterministic UUIDs** - Consistent references across devices
5. **Integer PKs** - Fast local joins, UUIDs only for sync

The data model provides a foundation for powerful file management that scales from single devices to complex multi-device networks.