HTTP requests in Rust

I started my vesync-rs library - which makes HTTP calls to the VeSync API - by using reqwest:

[dependencies]
 reqwest = { version = "0.10", features = ["blocking", "json"] } 

Then I had both POST and GET requests, such as:

// POST request to the login route:
let client = reqwest::blocking::Client::new();
let response = client
    .post(&build_path("/vold/user/login"))
    .json(&request)
    .send()
    .map_err(|_e| ())?;

let account: AccountResponse = response.json().map_err(|_e| ())?;

// ...

// GET all known devices
let client = reqwest::blocking::Client::new();
let response = client
	.get(&build_path("/vold/user/devices"))
	.header("tk", &self.account.tk)
	.header("accountid", &self.account.accountID)
	.send()
	.map_err(|_e| ())?;

let devices: Vec<dto::Device> = response.json().map_err(|_e| ())?;

I discovered that attohttpc is quite a bit smaller, which fits my project’s needs better, so I switched my Cargo.toml:

[dependencies]
attohttpc = { version = "0.14.0", features = ["json"] }

And the POST and GET requests changed only slightly:

// POST request to the login route:
let response = attohttpc::post(&build_path("/vold/user/login"))
    .json(&request) // set the request body (json feature required)
    .map_err(|_e| ())?
    .send()
    .map_err(|_e| ())?;

let account: AccountResponse = response.json().map_err(|_e| ())?;

// GET all known devices
let response = attohttpc::get(&build_path("/vold/user/devices"))
	.header("tk", &self.account.tk)
	.header("accountid", &self.account.accountID)
	.send()
	.map_err(|_e| ())?;

let devices: Vec<dto::Device> = response.json().map_err(|_e| ())?;

The build went from 106 components to 62 components just with this one change. I believe Serde is responsible for the majority of those. I’m looking into nanoserde, though its features aren’t neary on-par with Serde.