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Rust Libraries

Rust libraries for implementing ActivityPub.

activitypub-federation​

Battle-tested library from Lemmy.

PropertyValue
Repositorygithub.com/LemmyNet/activitypub-federation-rust
crates.ioactivitypub-federation
LicenseAGPL-3.0
StatusActive, Production Ready

Features​

  • Complete S2S federation
  • HTTP Signatures
  • WebFinger
  • Activity queue
  • Async/await

Example​

use activitypub_federation::{
    config::FederationConfig,
    traits::Actor,
};

#[derive(Clone)]
struct MyActor {
    id: Url,
    inbox: Url,
    public_key: String,
}

impl Actor for MyActor {
    fn id(&self) -> Url {
        self.id.clone()
    }

    fn public_key_pem(&self) -> &str {
        &self.public_key
    }

    fn inbox(&self) -> Url {
        self.inbox.clone()
    }
}

Sending Activities​

use activitypub_federation::activity_sending::SendActivityTask;

let activity = Create {
    actor: actor.id(),
    object: note,
};

SendActivityTask::prepare(&activity, &actor, vec![inbox_url])
    .await?
    .send(&data)
    .await?;

activitystreams​

Type-safe ActivityStreams vocabulary.

PropertyValue
Repositorycrates.io/crates/activitystreams
LicenseGPL-3.0
StatusActive

Example​

use activitystreams::{
    activity::Create,
    object::Note,
    prelude::*,
};

let note = Note::new()
    .set_content("Hello from Rust!")
    .set_attributed_to("https://example.com/users/alice".parse()?);

let create = Create::new(
    "https://example.com/users/alice".parse()?,
    note.into_any_base()?,
);

http-signature-normalization​

HTTP Signature handling.

PropertyValue
Repositorycrates.io/crates/http-signature-normalization
LicenseAGPL-3.0
StatusActive

Signing​

use http_signature_normalization_actix::prelude::*;

let config = Config::default()
    .set_expiration(Duration::seconds(30));

let signed = config
    .begin_sign("POST", "/inbox", headers)?
    .sign(key_id, |signing_string| {
        // Sign with private key
        sign_with_rsa(signing_string, private_key)
    })?;

Verification​

let unverified = config.begin_verify(
    request.method(),
    request.uri().path_and_query(),
    request.headers(),
)?;

let key_id = unverified.key_id();
// Fetch public key
let verified = unverified.verify(|signing_string, signature| {
    verify_rsa(signing_string, signature, public_key)
})?;

webfinger​

WebFinger client.

PropertyValue
Repositorycrates.io/crates/webfinger
LicenseMIT
StatusStable

Example​

use webfinger::WebFinger;

let wf = WebFinger::fetch("alice@example.com").await?;

for link in wf.links {
    if link.rel == "self" {
        println!("Actor URL: {}", link.href);
    }
}

Comparison​

LibraryScopeComplexityUse Case
activitypub-federationFull federationHighProduction servers
activitystreamsTypes onlyMediumType safety
http-signature-normalizationSigningLowHTTP Signatures

Production Examples​

Lemmy​

lemmy/crates/apub/
├── src/
│   ├── activities/     # Activity handlers
│   ├── objects/        # AP objects
│   └── protocol/       # Type definitions

Quick Start​

For new projects: Use activitypub-federation.

For custom implementations: Combine activitystreams + http-signature-normalization.

See Also​