Toolpaper

Send JSON with cURL in Rust

Paste a curl command that sends JSON and get idiomatic Rust code. We pick the right serialization for reqwest and set the correct Content-Type.

Quick answer

To convert a cURL command to Rust, paste it into the Toolpaper workbench below. It parses the command in your browser and emits idiomatic Rust code — headers, query string, request body, authentication (Bearer, Basic, API key), and cookies are all wired up automatically. No data is uploaded; conversion is fully client-side.

Prefer a different target? See the full cURL to Rust reference, or jump to the same guide in JavaScript, Node.js, or Python.

InputcURL command
MethodPOST·Headers1·Body40 B· Chars 132
OutputRust · reqwest(blocking)
// Cargo.toml: reqwest = { version = "0.12", features = ["json", "blocking", "gzip", "brotli"] }
use reqwest::blocking::Client;
use reqwest::header::{HeaderMap, HeaderName, HeaderValue};
use std::str::FromStr;

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let client = Client::builder().redirect(reqwest::redirect::Policy::none()).build()?;
    let mut headers = HeaderMap::new();
    headers.insert(HeaderName::from_str("content-type")?, HeaderValue::from_str("application/json")?);

    let mut req = client.post("https://api.example.com/users").headers(headers);
    req = req.body("{\"name\":\"Ada\",\"email\":\"ada@example.com\"}");
    let resp = req.send()?;
    println!("{}", resp.text()?);
    Ok(())
}
Inspect

Example

A representative curl command for this scenario. Paste your own above to convert an exact match.

curl input
curl -X POST https://api.example.com/users \
  -H "Content-Type: application/json" \
  -d '{"name":"Ada","email":"ada@example.com"}'

Implementation notes

  • Content-Type is detected from -H headers first, then inferred from the body shape when the header is missing.
  • JSON bodies are parsed and re-emitted through reqwest's serializer so quoting stays consistent with what the server expects.
  • Charset directives on Content-Type (e.g. application/json; charset=utf-8) survive the round trip.

Common mistakes

  • Setting Content-Type manually and then also using reqwest's helper — you end up with duplicate headers or the wrong one wins.
  • Mixing form encoding with JSON headers — the server rejects with 400 and it's easy to miss in code review.
  • Trusting the browser DevTools "Copy as cURL" to preserve charset — it often drops it. Clean panel restores common defaults.

Common questions

How is JSON encoded in the generated Rust?
Toolpaper detects Content-Type: application/json and emits idiomatic reqwest JSON serialization (json= for requests, Response.json for Go, etc.).
Does it preserve Content-Type?
Yes. The Content-Type header is honored and matched against the body so serialization stays consistent.
Is anything uploaded?
No. Parsing and generation happen entirely in your browser.

More payload types in Rust

Rust hub →

form-urlencoded in Rust

/how-to/send-form-with-curl-in-rust

multipart form-data in Rust

/how-to/send-multipart-with-curl-in-rust

XML in Rust

/how-to/send-xml-with-curl-in-rust

GraphQL in Rust

/how-to/send-graphql-with-curl-in-rust

The same guide in other languages

All guides →

In JavaScript

/how-to/send-json-with-curl-in-javascript

In Node.js

/how-to/send-json-with-curl-in-node

In Python

/how-to/send-json-with-curl-in-python

In Go

/how-to/send-json-with-curl-in-go

In PHP

/how-to/send-json-with-curl-in-php

In Ruby

/how-to/send-json-with-curl-in-ruby

In Java

/how-to/send-json-with-curl-in-java

In Kotlin

/how-to/send-json-with-curl-in-kotlin

Full Rust reference on the cURL to Rust hub, or open the main converter for all 18 targets.