curlite

A small blocking HTTP client on top of libcurl. For programs that call HTTP services and want to stay small: no async runtime, one libcurl handle per thread with connection reuse, request bodies held in memory once, and multipart/form-data in both directions.

use curlite::Multipart;

let response = curlite::post("https://example.com/upload?debug=1")
    .header("Authorization", "Bearer secret")
    .multipart(
        Multipart::new()
            .text("description", "quarterly report")
            .file("file", "q3.pdf", mime::APPLICATION_PDF, std::fs::read("q3.pdf")?),
    )
    .send()?;

println!("{}", response.status());
for part in response.parts()? {
    println!("{}: {} bytes", part.name, part.body.len());
}

Bodies are body(mime, bytes), form(pairs) or multipart(..); everything else (query, header, timeout, follow_redirects) is on the builder. Responses are read into memory and expose status(), headers(), body(), text(), form() and parts().

The params module adds a parameter model for services that exchange named values and files, where the body format follows from the parameters: one body parameter is sent raw, several text parameters as a form, anything with a file as multipart. Responses parse back into the same model. This is the interface of the CPEE process engine.

TLS and linking

TLS comes from libcurl. By default the system libcurl is linked dynamically, with whatever TLS library it was built against. The static-curl, static-ssl and rustls features are passed through to the curl crate to build and link libcurl statically instead.

Why libcurl

Most Rust HTTP clients are async and bring a runtime with them. That is the right choice for servers, but for a small program that makes a few calls, or for many small processes on one machine, it mostly adds binary size and setup cost. curlite keeps the client itself small and leaves the heavy lifting to libcurl, which is probably already on the machine and whose TLS library can be chosen at build time.

License

Licensed under either of Apache License, Version 2.0 or MIT license at your option.