HTTP Request formurlencoded problem


I’m new to Elixir and I come from the world Javascript

To learn the language, I decided to redo a reverse API that I had done a few days ago in JS.

import fetch from 'node-fetch' 

export default class Authentification {
    async login() {
        return (await fetch("", {
            "headers": {
                "accept": "application/json, text/plain, */*",
                "accept-language": "fr-FR,fr;q=0.9,en-US;q=0.8,en;q=0.7",
                "content-type": "application/x-www-form-urlencoded",
                "sec-fetch-dest": "empty",
                "sec-fetch-mode": "cors",
                "sec-fetch-site": "same-site"
            "referrer": "",
            "referrerPolicy": "no-referrer-when-downgrade",
            "body": "data={\n    \"identifiant\": \"" + process.env.USERNAME + "\",\n    \"motdepasse\": \"" + process.env.PASSWORD + "\"\n}",
            "method": "POST",
            "mode": "cors"

My problem being that I’m trying to do a code style but I get an error message from the api telling me that the body is incorrect, I don’t really know how to do it, could you direct me?

Would you have a good resource to understand Elixir and the OTP? I come from the imperative world and I have a lot of pain making effective code in Elixir.

  def main() do "", "{\"body\": data={\"identifiant\": \"secret\"\n    \"motdepasse\": \"secret\"\n}}", [{"Content-Type", "application/x-www-form-urlencoded"}]

I would first try and reproduce your Node.JS code with curl on the command line. It helps establish a baseline with which to compare.

That being said, I noticed that in your Node code you have process.env.USERNAME as a value for "identifiant" and that you hardcoded "" secret for its value in the Elixir code. Are both identical? (Same goes for "password"). Of course, don’t post users and passwords here, I am just making sure.


process.env.USERNAME == "SECRET" // true 

I don’t think you want the body part here - that was from the JS, not something that should be sent to the API.

The data= bit here is weird, but matches the observed behavior and the behavior described in this post:

The format this is expecting is odd; it appears to be a URL-encoded payload containing exactly one key data containing incompletely-escaped JSON. Prettified from that login page’s source:

        if ( && "object" == typeof {
   = $sessionStorage.token;
            var replacer = function(key, value) {
                return "string" == typeof value ? (value = value.replace(/%/g, "%25"),
                value = value.replace(/&/g, "%26"),
                value = value.replace(/\+/g, "%2B")) : value
              , strVal = JSON.stringify(, replacer, 4);
   = "data=" + strVal
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