Simple blocking HTTP POST request using Rust

The reqwest crate provides all the capabilities to send HTTP requests.

In this example we are using the reqwest crate to send an HTTP POST request to https://httpbin.org/.

The curl command

This is the same command as executed using curl.

curl -X POST -d "text=Hello World!" http://httpbin.org/post

This is the result:

{
  "args": {},
  "data": "",
  "files": {},
  "form": {
    "text": "Hello World!"
  },
  "headers": {
    "Accept": "*/*",
    "Content-Length": "17",
    "Content-Type": "application/x-www-form-urlencoded",
    "Host": "httpbin.org",
    "User-Agent": "curl/8.2.1",
    "X-Amzn-Trace-Id": "Root=1-65b22590-3ba351816c46408426023f1b"
  },
  "json": null,
  "origin": "46.120.9.250",
  "url": "http://httpbin.org/post"
}

Dependencies

In order to be able to send a blocking request we need to add that feature, and in order to be able to parse the returned JSON data we had to add the json feature.

[package]
name = "simple-blocking-http-post-reqwest"
version = "0.1.0"
edition = "2024"

[dependencies]
reqwest = { version = "0.11.23", features = ["blocking", "json"] }
serde_json = "1.0.111"

The code

We can pass the parameters in the form method as a bunch of key-value pairs from a HashMap.

use reqwest::blocking::Client;
use std::collections::HashMap;

fn main() {
    let client = Client::new();
    let params = HashMap::from([
        ("text", "Hello World!"),
    ]);

    match client.post("http://httpbin.org/post").form(&params).send() {
        Ok(resp) => {
            let data:  serde_json::Value = resp.json().unwrap();
            println!("{:#?}", data);
        },
        Err(err) => eprintln!("{}", err),
    }
}

The result

This is the resulting data from the request.

#![allow(unused)]
fn main() {
Object {
    "args": Object {},
    "data": String(""),
    "files": Object {},
    "form": Object {
        "text": String("Hello World!"),
    },
    "headers": Object {
        "Accept": String("*/*"),
        "Content-Length": String("19"),
        "Content-Type": String("application/x-www-form-urlencoded"),
        "Host": String("httpbin.org"),
        "X-Amzn-Trace-Id": String("Root=1-65b225c3-1cfb5c6440c0d3014b818197"),
    },
    "json": Null,
    "origin": String("46.120.9.250"),
    "url": String("http://httpbin.org/post"),
}
}

• reqwest
• HTTP
• POST
• form