Jacquard#

A suite of Rust crates intended to make it much easier to get started with atproto development, without sacrificing flexibility or performance.

Jacquard is simpler because it is designed in a way which makes things simple that almost every other atproto library seems to make difficult.

It is also designed around zero-copy/borrowed deserialization: types like Post<'_> can borrow data (via the CowStr<'_> type and a host of other types built on top of it) directly from the response buffer instead of allocating owned copies. Owned versions are themselves mostly inlined or reference-counted pointers and are therefore still quite efficient. The IntoStatic trait (which is derivable) makes it easy to get an owned version and avoid worrying about lifetimes.

Goals and Features#

• Validated, spec-compliant, easy to work with, and performant baseline types
• Batteries-included, but easily replaceable batteries.
  • Easy to extend with custom lexicons using code generation or handwritten api types
  • Straightforward OAuth
  • Stateless options (or options where you handle the state) for rolling your own
  • All the building blocks of the convenient abstractions are available
  • Server-side convenience features
• Lexicon Data value type for working with unknown atproto data (dag-cbor or json)
• An order of magnitude less boilerplate than some existing crates
• Use as much or as little from the crates as you need

Example#

Dead simple API client. Logs in with OAuth and prints the latest 5 posts from your timeline.

// Note: this requires the `loopback` feature enabled (it is currently by default)
use clap::Parser;
use jacquard::CowStr;
use jacquard::api::app_bsky::feed::get_timeline::GetTimeline;
use jacquard::client::{Agent, FileAuthStore};
use jacquard::oauth::client::OAuthClient;
use jacquard::oauth::loopback::LoopbackConfig;
use jacquard::types::xrpc::XrpcClient;
use miette::IntoDiagnostic;

#[derive(Parser, Debug)]
#[command(author, version, about = "Jacquard - OAuth (DPoP) loopback demo")]
struct Args {
    /// Handle (e.g., alice.bsky.social), DID, or PDS URL
    input: CowStr<'static>,

    /// Path to auth store file (will be created if missing)
    #[arg(long, default_value = "/tmp/jacquard-oauth-session.json")]
    store: String,
}

#[tokio::main]
async fn main() -> miette::Result<()> {
    let args = Args::parse();

    // Build an OAuth client with file-backed auth store and default localhost config
    let oauth = OAuthClient::with_default_config(FileAuthStore::new(&args.store));
    // Authenticate with a PDS, using a loopback server to handle the callback flow
    let session = oauth
        .login_with_local_server(
            args.input.clone(),
            Default::default(),
            LoopbackConfig::default(),
        )
        .await?;
    // Wrap in Agent and fetch the timeline
    let agent: Agent<_> = Agent::from(session);
    let timeline = agent
        .send(&GetTimeline::new().limit(5).build())
        .await?
        .into_output()?;
    for (i, post) in timeline.feed.iter().enumerate() {
        println!("\n{}. by {}", i + 1, post.post.author.handle);
        println!(
            "   {}",
            serde_json::to_string_pretty(&post.post.record).into_diagnostic()?
        );
    }

    Ok(())
}

If you have just installed, you can run the examples using just example {example-name} {ARGS} or just examples to see what's available.

Component crates#

Jacquard is broken up into several crates for modularity. The correct one to use is generally jacquard itself, as it re-exports most of the others.

• jacquard: Main crate
• jacquard-common: Foundation crate
• jacquard-axum: Axum extractor and other helpers
• jacquard-api: Autogenerated API bindings
• jacquard-oauth: atproto OAuth implementation
• jacquard-identity: Identity resolution
• jacquard-lexicon: Lexicon parsing and code generation
• jacquard-derive: Macros for lexicon types

Changelog#

CHANGELOG.md

Highlights:

• better value type deserialization helpers
• service auth implementation
• XrpcRequest derive Macros
• more builders in generated api to make constructing things easier (lmk if compile time is awful)
• AgentSessionExt trait with a host of convenience methods for working with records and preferences
• Improvements to the Collection trait, code generation, and addition of the VecUpdate trait to enable that
• A bunch of examples, both in the docs and in the repository
• More lexicons in the generated API bindings.

Development#

This repo uses Flakes from the get-go.

# Dev shell
nix develop

# or run via cargo
nix develop -c cargo run

# build
nix build

There's also a justfile for Makefile-esque commands to be run inside of the devShell, and you can generally cargo ... or just ... whatever just fine if you don't want to use Nix and have the prerequisites installed.