Axum Web Integration

xstate-axum

axum integration for xstate-core machines: the Rust counterpart of the Python library’s Starlette registry and FastAPI router.

• StatechartRegistry: named machines over one StateStore; every request is one create, act, persist, discard cycle through persisted, with an authorizer, a principal-scoped idempotency inbox, post-save fan-out to stream subscribers, probes, the durable-timer scanner and a graceful drain.
• router: GET /{name}/{id}, POST /{name}/{id}/send, POST /{name}/{id}/events/{E}, GET /{name}/{id}/events, GET .../diagram.mmd, GET .../stream (SSE), GET .../ws. The WebSocket enforces the same per-event gates (RouterOptions::per_event_gates) as the HTTP routes, and the POST routes check the Origin header like the streams do.
• problem() / ApiError: RFC 9457 problem details with the Python titles, never exception text.
• inspector_router: the Stately Inspector over WebSocket, debug-only and token-gated.

Status: 0.1.0.

#![allow(unused)]
fn main() {
use std::sync::Arc;
use xstate_axum::{RegisterOptions, RouterOptions, StatechartRegistry, allow_all, router};
use xstate_core::{Machine, MachineLogic};
use xstate_persistence::MemoryStore;

async fn run() -> Result<(), Box<dyn std::error::Error>> {
let machine = Machine::from_json(
    r#"{"id":"order","initial":"pending","states":{"pending":{"on":{"PAY":"paid"}},"paid":{}}}"#,
)?;
// RegisterOptions has no `Default`: the authorizer is a required argument, so a registry
// cannot be exposed unauthenticated by accident. `allow_all` is for development only; pass your
// own Authorizer in production.
let options = RegisterOptions::new(allow_all());
let registry = StatechartRegistry::builder(Arc::new(MemoryStore::new()))
    .register("order", machine, MachineLogic::dynamic(), options)?
    .build()?;
registry.start()?;
let app = router(&registry, "order", RouterOptions::default())?.merge(registry.probes_router());
axum::serve(tokio::net::TcpListener::bind("127.0.0.1:8000").await?, app).await?;
Ok(()) }
}

Features

None.

Python counterpart

contrib.starlette and contrib.fastapi.