#protocol #fastcgi #web #tokio #async


FastCGI handler (responder, authorizer, filter) library for Tokio

2 stable releases

Uses new Rust 2021

1.1.0 Aug 7, 2022
1.0.0 Jun 5, 2022

#587 in Web programming


660 lines

Rust Current Version Docs.rs License Apache 2.0

Async FastCGI handler library

This crate implements a FastCGI handler for Tokio. It's a complete re-implementation of the FastCGI protocol in safe rust and supports all three FastCGI roles: Responder, Authorizer and Filter. The Role enum documents the different roles and their input and output parameters.

If you just want to use this library, look at the examples, open the documentation and start using it by adding the following to the [dependencies] section of your Cargo.toml:

tokio-fastcgi = "1.0"

Principle of operation

The tokio-fastcgi library handles FastCGI requests that are sent by a server. Accepting the connection and spawning a new task to handle the requests is done via Tokio. Within the handler task, Requests::from_split_socket is called to create an asynchronous requests stream. Calling Requests::next().await on this stream will return a new Request instance as soon as it was completely received from the web-server.

The returned Request instance has a process method that accepts an asynchronous callback function or closure that will process the request. The current request will be passed to the callback as a parameter and can be used to retrieve the input streams sent by the web-server and to write to the output streams. The callback returns a result or an error, if processing the request failed.

This is repeated while the Requests instance for the connection returns more requests. If no more requests are returned, the stream will be dropped and the connection to the web-server will be closed.

This library handles connection reuse and aborting requests for the user. See Requests::next for more details.


The library contains two examples: A bare bones one and a litte REST API. Just have a look :)


  • Version 1.0.0
    Initial release

  • Version 1.1.0
    Add methods to enumerate the parameters of a request (params_iter and str_params_iter).


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