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Pre API Hook

This function is called before any API call is being made to your backend from our frontend SDK. You can use this to change the request body / url / header or any other request property.

import ThirdPartyPasswordless from "supertokens-auth-react/recipe/thirdpartypasswordless";

contactMethod: "EMAIL", // This example will work with any contactMethod.
preAPIHook: async (context) => {
let url = context.url;

// is the fetch config object that contains the header, body etc..
let requestInit = context.requestInit;

let action = context.action;
if (action === "EMAIL_EXISTS") {

} else if (action === "PASSWORDLESS_CONSUME_CODE") {

} else if (action === "PASSWORDLESS_CREATE_CODE") {

} else if (action === "PASSWORDLESS_RESEND_CODE") {

} else if (action === "PHONE_NUMBER_EXISTS") {


// events such as sign out are in the
// session recipe pre API hook (See the info box below)
return {
requestInit, url

Reading custom request information in the backend#

Visit this page to learn how to read custom headers etc from the request on the backend.

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