# slap_yjs v0.4.0 - Table of Contents

> Yjs documents stored in Durable Streams (y_ex).

## Pages

- [slap_yjs](readme.md)
- [Changelog](changelog.md)
- [LICENSE](license.md)

## Modules

- Documents
  - [Slap.Yjs.DocServer](Slap.Yjs.DocServer.md): A `Yex.DocServer` whose document is stored with `Slap.Yjs.Store`, and shared
with the servers of the same document on other nodes through it.
  - [Slap.Yjs.Docs](Slap.Yjs.Docs.md): The document servers of this node, one per `{module, doc_id}`, started on
the first `join/3` and stopped after `:idle_timeout` without subscribers.
Each node that has clients for a document runs its own server; the
servers share the document through its `.updates` stream and presence
through a `:pg` group (see `Slap.Yjs.DocServer`).
  - [Slap.Yjs.Presence](Slap.Yjs.Presence.md): Publishes an awareness state for a server-side participant, such as an
agent or tool. The process subscribes to a document and keeps one client id
for its lifetime.
  - [Slap.Yjs.Store](Slap.Yjs.Store.md): Yjs documents as `Slap.SnapshotLog`s, in the reference `y-durable-streams`
server's layout, so its HTTP clients can later read the same documents

- Wire format
  - [Slap.Yjs.Awareness](Slap.Yjs.Awareness.md): Encodes and decodes awareness (presence) updates in the y-protocols format.
An update starts with its entry count as a varuint. Each entry contains a
client id and clock as varuints, then a length-prefixed JSON state;
`"null"` removes the client's state.
  - [Slap.Yjs.Frame](Slap.Yjs.Frame.md): The framing of Yjs updates in a `.updates` stream, as lib0's
`writeVarUint8Array` writes it and the reference `y-durable-streams`
provider reads it: each update is its byte size as a varuint, then the
update. Frames are concatenated, so a batch of frames is itself valid
framing.