A high-level, batteries-included [Matrix](https://matrix.org/) client library
written in Rust.

This crate seeks to be a general-purpose library for writing software using the
Matrix [Client-Server API](https://spec.matrix.org/latest/client-server-api/)
to communicate with a Matrix homeserver. If you're writing a typical Matrix
client or bot, this is likely the crate you need.

However, the crate is designed in a modular way and depends on several
other lower-level crates. If you're attempting something more custom, you might be interested in these:

- [`matrix_sdk_base`]: A no-network-IO client state machine which can be used
  to embed a Matrix client into an existing network stack or to build a new
  Matrix client library on top.
- [`matrix_sdk_crypto`]: A no-network-IO encryption state machine which can be used to add Matrix E2EE
  support into an existing client or library.

# Getting started

The central component you'll be interacting with is the [`Client`]. A basic use
case will include instantiating the client, logging in as a user, registering
some event handlers and then syncing.

This is demonstrated in the example below.

```rust,no_run
use matrix_sdk::{
    Client, config::SyncSettings,
    ruma::{user_id, events::room::message::SyncRoomMessageEvent},
};

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    let alice = user_id!("@alice:example.org");
    let client = Client::builder().server_name(alice.server_name()).build().await?;

    // First we need to log in.
    client.matrix_auth().login_username(alice, "password").send().await?;

    client.add_event_handler(|ev: SyncRoomMessageEvent| async move {
        println!("Received a message {:?}", ev);
    });

    // Syncing is important to synchronize the client state with the server.
    // This method will never return unless there is an error.
    client.sync(SyncSettings::default()).await?;

    Ok(())
}
```

More examples can be found in the [examples] directory.

# Crate Feature Flags

The following crate feature flags are available:

| Feature             | Default | Description                                                                                                                |
| ------------------- | :-----: | -------------------------------------------------------------------------------------------------------------------------- |
| `anyhow`            |   No    | Better logging for event handlers that return `anyhow::Result`                                                             |
| `e2e-encryption`    |   Yes   | End-to-end encryption (E2EE) support                                                                                       |
| `eyre`              |   No    | Better logging for event handlers that return `eyre::Result`                                                               |
| `js`                |   No    | Enables JavaScript API usage on WASM (does nothing on other targets)                                                       |
| `markdown`          |   No    | Support for sending Markdown-formatted messages                                                                            |
| `qrcode`            |   Yes   | QR code verification support                                                                                               |
| `sqlite`            |   Yes   | Persistent storage of state and E2EE data (optionally, if feature `e2e-encryption` is enabled), via SQLite available on system  |
| `bundled-sqlite`    |   No  | Persistent storage of state and E2EE data (optionally, if feature `e2e-encryption` is enabled), via SQLite compiled and bundled with the binary  |
| `indexeddb`         |   No    | Persistent storage of state and E2EE data (optionally, if feature `e2e-encryption` is enabled) for browsers, via IndexedDB |
| `socks`             |   No    | SOCKS support in the default HTTP client, [`reqwest`]                                                                      |
| `sso-login`         |   No    | Support for SSO login with a local HTTP server                                                                             |

[`reqwest`]: https://docs.rs/reqwest/0.11.5/reqwest/index.html

# Enabling logging

Users of the matrix-sdk crate can enable log output by depending on the
`tracing-subscriber` crate and including the following line in their
application (e.g. at the start of `main`):

```rust
tracing_subscriber::fmt::init();
```

The log output is controlled via the `RUST_LOG` environment variable by
setting it to one of the `error`, `warn`, `info`, `debug` or `trace` levels.
The output is printed to stdout.

The `RUST_LOG` variable also supports a more advanced syntax for filtering
log output more precisely, for instance with crate-level granularity. For
more information on this, check out the [tracing_subscriber documentation].

[examples]: https://github.com/matrix-org/matrix-rust-sdk/tree/main/examples/
[tracing_subscriber documentation]: https://tracing.rs/tracing_subscriber/filter/struct.envfilter
[`matrix_sdk_crypto`]: https://docs.rs/matrix-sdk-crypto/
[`matrix_sdk_base`]: https://docs.rs/matrix-sdk-base/