AppViewLite

AppViewLite is an ATProto (Bluesky) appview focused on low resource consumption, able to run independently of the main appview APIs.

It includes:

• A firehose listener and indexer (AppViewLite)
• A simple web UI for viewing the indexed data (AppViewLite.Web)
• An XRPC interface that allows you to reuse the official TypeScript client implementation

Indexing the firehose (posts, likes, reposts, follows, blocks) takes about 2.2 GB of disk space per day. By contrast, the raw data from the firehose (without inverse indexes) is reported to be around 200 GB per day.

Tip: You can browse to http://localhost:PORT/profile/... to easily convert a bsky.app URL into an AppViewLite one, or you can paste a profile URL into the search bar.

Platform independence

One of the goals is to be as independent as possible from the official Bluesky PBC infrastructure.

This AppView runs independently of the main bsky.app APIs.

• Relays: you can choose a relay (bsky.network or JetStream), and optionally specify individual extra PDSes to listen to, making them uncensorable.
• PDSes: AppViewLite connects directly to PDSes to fetch any missing records.
• PLC directory: fetched incrementally, can be bootstrapped from a Parquet bundle. You can override individual PLC entries using a configuration file.
• Image serving: you can choose whether to proxy/cache images yourself, or to reuse cdn.bsky.app

Implementation status

Feature	AppViewLite (read)	AppViewLite (edit)	bsky.app
Posts	✅	⚠️ Text only	✅
Likes, bookmarks, reposts	✅	✅	⚠️ No bookmarks
Profile pages	✅		⚠️ No likes list
Follows	✅	✅	⚠️ No private follows
Search	✅	✅	⚠️ No media search
Media grid view	✅		⛔
Video download	✅		⛔
Notifications	✅		✅
Feeds	⚠️No pinning		✅
Built-in feed: Recent	✅		✅
Built-in feed: Balanced	✅		⛔
Live post stat updates	✅		⛔
Keyboard navigation (JK)	✅		⛔
Recently viewed post history	✅		⛔
Post interaction settings	✅ Blurred posts	⛔	✅ Nuclear blocks
Blocks	✅ Blurred posts	⛔	✅ Nuclear blocks
Labels	⚠️ Not configurable		✅
Lists	✅	⛔	✅
Mutes	✅	⚠️ No expiration	⚠️ No user-specific mute words ⚠️ No mute by post type
Protocol: ATProto	✅	✅	✅
Protocol: Fediverse/Mastodon	✅	⛔	⛔
Protocol: RSS	✅	⛔	⛔
Protocol: Nostr	✅	⛔	⛔
Protocol: Imageboards	✅	⛔	⛔
Protocol: Tumblr	✅	⛔	⛔
Appearance settings	⛔		✅
Chat	⛔	⛔	✅
Data export	✅		⚠️ No images, no private data
Self-hosting	✅ Single-process ✅ Low-resource focused		⚠️ Complex, resource intensive

Building and running

• Install .NET 9
• cd src/AppViewLite.Web
• dotnet run -c Release

Optionally, you can set various configuration settings, including APPVIEWLITE_DIRECTORY to specify where the data should be stored.

Storage mechanism

Each "table" is a set of memory-mapped columnar storage files that associates one key, to one or many values. Both the keys and the values within a key are ordered to enable fast binary search lookups. All the slices of a table are periodically compacted into larger slices.

A primary / readonly replica mechanism is used (within the same process) with read/write lock semantics to allow for effectively lock-less reads for most HTTP requests.

Identifiers

Accounts are rekeyed using 32-bit integers. RKeys are converted back into their underlying 64-bit values in order to save space.

Post text

Post data is compressed by turning it into GPT/Tiktoken tokens, then encoding the 18-bit tokens using a variable-length bit representation, and then serializing everything into a Protobuf message (along with other metadata).