# ATCR AppView

The **AppView** is the OCI-compliant registry server for ATCR (ATProto Container Registry). It provides the Docker Registry HTTP API V2 and a web interface for browsing container images.

## What is AppView?

AppView serves as the central registry server that:

- **Serves OCI Distribution API** - Compatible with Docker, containerd, podman, and other OCI clients
- **Resolves ATProto identities** - Converts handles and DIDs to PDS endpoints
- **Routes manifests** - Stores container manifests as ATProto records in users' Personal Data Servers
- **Routes blobs** - Proxies blob operations to hold services (S3-compatible storage)
- **Provides web UI** - Browse, search, and star repositories

## Image Format

Container images use ATProto identities:

```
atcr.io/alice.bsky.social/myapp:latest
atcr.io/did:plc:xyz123/myapp:latest
```

## Using ATCR

### Push Images

```bash
# Install credential helper
curl -fsSL https://atcr.io/install.sh | bash

# Configure Docker (add to ~/.docker/config.json)
{
  "credHelpers": {
    "atcr.io": "atcr"
  }
}

# Push images (authenticates automatically)
docker tag myapp:latest atcr.io/yourhandle/myapp:latest
docker push atcr.io/yourhandle/myapp:latest
```

### Pull Images

```bash
# Public images (no auth required)
docker pull atcr.io/alice.bsky.social/myapp:latest

# Private images (automatic OAuth authentication)
docker pull atcr.io/yourhandle/private-app:latest
```

## Running Your Own AppView

Deploy your own registry instance with Docker Compose:

```bash
# Create configuration
cp .env.appview.example .env.appview
# Edit .env.appview with your settings

# Start services
docker-compose up -d
```

### Configuration

Key environment variables:

- `ATCR_HTTP_ADDR` - HTTP listen address (default: `:5000`)
- `ATCR_BASE_URL` - Public URL for OAuth/JWT realm
- `ATCR_DEFAULT_HOLD_DID` - Default hold service DID for blob storage (required)
- `ATCR_UI_ENABLED` - Enable web interface (default: `true`)
- `JETSTREAM_URL` - ATProto event stream URL for real-time updates

See [deployment documentation](https://tangled.org/@evan.jarrett.net/at-container-registry/blob/main/deploy/README.md) for production setup.

## Features

- ✅ **OCI-compliant** - Full Docker Registry API V2 support
- ✅ **ATProto OAuth** - Secure authentication with DPoP
- ✅ **Decentralized storage** - Manifests stored in users' PDS
- ✅ **Web UI** - Browse repositories, view tags, search images
- ✅ **Real-time updates** - Jetstream integration for live indexing
- ✅ **Multi-arch support** - ARM64, AMD64, and other platforms
- ✅ **BYOS** - Bring Your Own Storage via hold services

## Storage Architecture

**Hybrid model:**
- **Manifests** → ATProto records in user's PDS (small JSON metadata)
- **Blobs** → Hold services with S3-compatible backends (large binary layers)

This design keeps metadata portable and federated while leveraging cheap blob storage for layers.

## License

MIT

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**Documentation:** https://tangled.org/@evan.jarrett.net/at-container-registry
**Source Code:** https://tangled.org/@evan.jarrett.net/at-container-registry