fx

building something similar to workerd for fun and learning purposes.

features

• deploy functions written in Rust (see fx for sdk and fx-services for examples) compiled to wasm (wasm32-unknown-unknown).
• functions can be triggered by http requests, messages from Kafka topics or by cron schedule.
• functions are async and can handle requests concurrently.
• function input and output can be a stream.
• KV storage.
• sql databases powered by sqlite.
• functions can call other functions via RPC (callee is run in the same thread, so no networking is involved resulting in very low latency).
• log, fetch, random, time apis.
• livereload functions.

still, note that this is a toy project with a lot of apis missing. it is also missing handling for various edge cases/errors. do not expect it to handle any significant rps as well at this moment.

example function

use { fx::{FxCtx, HttpRequest, HttpResponse, rpc}, tracing::info };

#[rpc]
pub async fn http(ctx: &FxCtx, req: HttpRequest) -> HttpResponse {
    ctx.init_logger();
    info!("this function is compiled to wasm and is running within fx: {}", req.url);
    HttpResponse::new().body("hello fx!\n")
}

see fx-services for more examples.

usage

invoke functions using cli interface

build hello world example (alternatively, compile your own function to .wasm):

just app-hello-world

then run function using fx:

cargo run -p fx-server -- run target/wasm32-unknown-unknown/release/fx_app_hello_world example

expected output:

target/wasm32-unknown-unknown/release/fx_app_hello_world | {"message": Text("hello from fx!")}