ably-chat-rs

An unofficial, ergonomic Rust client for the Ably Chat REST API (v4). Not affiliated with or endorsed by Ably.

The crate publishes as ably-chat-rs and imports as ably_chat.

Install

cargo add ably-chat-rs

By default the pure-Rust rustls TLS backend is used (no OpenSSL). To use the system native-tls backend instead:

cargo add ably-chat-rs --no-default-features --features native-tls

Usage

Build a Client with an Auth credential, scope it to a room with client.room(name), then chain into messages, reactions, or occupancy. Every operation is a builder that terminates in a bare .await; every fallible call returns ably_chat::Result<T>. Handles are cheap to Clone (Arc-backed) and Send + Sync.

use ably_chat::prelude::*;
use futures::StreamExt;

async fn run() -> ably_chat::Result<()> {
    // Rooms are implicit — scoping to one creates nothing server-side.
    let client = Client::builder(Auth::api_key("appId.keyId:keySecret")).build();
    let room = client.room("my-room");

    // Send a message.
    let sent = room.messages().send("hello, world").await?;
    println!("sent message {}", sent.serial);

    // Stream history (newest first by default), following pagination. The
    // stream is `!Unpin`, so pin it before polling with `.next()`.
    let mut history = std::pin::pin!(room.messages().history().into_stream());
    while let Some(message) = history.next().await {
        let message = message?;
        println!("{}: {}", message.client_id, message.text);
    }
    Ok(())
}

What this crate covers

The ten REST operations of the Ably Chat REST API:

Messages: send, get, update (full-replace), soft-delete, history, versions.
Reactions: send, delete, and a client's reactions on a message.
Occupancy: room occupancy metrics.

Not covered

No realtime. Live message/presence/typing subscriptions, room reactions, and live reaction summaries are realtime-transport features with no REST endpoint; they are out of scope. Use Ably's realtime SDKs for those.
No room/channel CRUD. Chat rooms are channel-backed and implicit — a room exists the first time a client uses it. There is no create-room / delete-room operation and this crate does not expose one.

Cargo features

All features are additive.

Feature	Default	Effect
`rustls`	yes	TLS via `rustls` (Rust; aws-lc-rs + platform verifier).
`native-tls`	no	TLS via the system's native library (OpenSSL/SChannel).
`chrono`	no	`Timestamp::to_chrono()` conversion to `chrono::DateTime`.

Low-level escape hatch: `ably_chat::raw`

The generated OpenAPI bindings (ably-chat-openapi) are re-exported as ably_chat::raw. Drop down to them when the ergonomic layer has a gap. This module is not covered by the pre-1.0 stability guarantee and may change on regeneration.

Caveat: singleton response bodies

Single-resource responses (getMessage, sendMessage, updateMessage, deleteMessage, getOccupancy, getClientReactions) are modelled as bare JSON objects, following Ably's documented REST convention. This is corroborated but not yet wire-captured; it should be confirmed against a live endpoint before 1.0:

curl -sS "https://rest.ably.io/chat/v4/rooms/my-room/occupancy" \
  -H "X-Ably-Version: 4" -u "{keyName}:{keySecret}" | head -c1
# '{'  → bare object (matches this crate's model)
# '['  → 1-element array (the model would need adjusting)

Minimum supported Rust version

MSRV is 1.85 (edition 2024).

License

Dual-licensed under either Apache-2.0 or MIT at your option.

ably-chat-rs 0.1.0