Session Persistence

A session stores your auth key, DC address, and peer access hash cache. Without it, you’d need to log in on every run.

Binary file (default)

#![allow(unused)]
fn main() {
Config {
    session_path: "my.session".into(),
    ..Default::default()
}
}

After login:

#![allow(unused)]
fn main() {
client.save_session().await?;
}

The file is created at the given path and loaded automatically on the next Client::connect. Keep it in .gitignore — it’s equivalent to your account password.

In-memory (ephemeral)

Nothing written to disk. Useful for tests or short-lived scripts:

#![allow(unused)]
fn main() {
use layer_client::session_backend::InMemoryBackend;

// Using InMemoryBackend directly via Config
Config {
    // session_path is ignored when using a custom backend
    ..Default::default()
}
}

With an in-memory session, login is required on every run.

SQLite (robust, long-running servers)

Enable the feature flag:

layer-client = { version = "0.2.2", features = ["sqlite-session"] }

#![allow(unused)]
fn main() {
// SQLite session is automatically used when the feature is enabled
// and the session file has a .db extension
Config {
    session_path: "session.db".into(),
    ..Default::default()
}
}

SQLite is more robust against crash-corruption than the binary file format, making it ideal for production bots.

What’s stored in a session

Field	Description
Auth key	2048-bit DH-derived key for encryption
Auth key ID	Hash of the key, used as identifier
DC ID	Which Telegram data center to connect to
DC address	The IP:port of the DC
Server salt	Updated regularly by Telegram
Sequence numbers	For message ordering
Peer cache	User/channel access hashes (speeds up API calls)

Security

SECURITY: A stolen session file gives full API access to your account. Protect it like a password.

Add to .gitignore: *.session, *.session.db
Set restrictive permissions: chmod 600 my.session
Never log or print session file contents
If compromised: revoke from Telegram → Settings → Devices → Terminate session

Multi-session / multi-account

Each Client::connect call loads one session. For multiple accounts, use multiple files:

#![allow(unused)]
fn main() {
let client_a = Client::connect(Config {
    session_path: "account_a.session".into(),
    api_id, api_hash: api_hash.clone(), ..Default::default()
}).await?;

let client_b = Client::connect(Config {
    session_path: "account_b.session".into(),
    api_id, api_hash: api_hash.clone(), ..Default::default()
}).await?;
}

Keyboard shortcuts