diff --git a/OAuth2-Backend-Approach.md b/OAuth2-Backend-Approach.md
index e47fa13..d220a89 100644
--- a/OAuth2-Backend-Approach.md
+++ b/OAuth2-Backend-Approach.md
@@ -46,8 +46,8 @@ A way for the `user` to tell `google` to give an access to `myapp` app
# 1. Get Code
-1. Frontend **GET** to Google `https://accounts.google.com/o/oauth2` with callback url
-2. Google **302** to Backend `https://myapp/api/auth/callback` with authorization code
+1. Frontend **Navigate** to Google `https://accounts.google.com/o/oauth2` with a callback url
+2. Google **Redirect** to Backend callback url `https://myapp/api/auth/callback` with authorization code
### 1. Front **GET** to Google
@@ -83,10 +83,10 @@ Content-Length: 0
# 2. Exchange Code with Token
1. Backend **POST** the `code` to Google `https://oauth2.googleapis.com/token`
-2. Google **response** to Backend with an `access_token` and a `refresh token`
-3. Backend **response** to Frontend with the `access_token` in a `cookie`
+2. Google **Response** to Backend with an `access_token` and a `refresh token`
+3. Backend **Redirect** to Frontend with the `access_token` in a `cookie`
-### 1. Backend **POST** the `code` to Google
+### 1. Backend **POST** the code to Google
```sh
POST https://oauth2.googleapis.com/token
@@ -99,8 +99,7 @@ client_secret=PASS1234&
redirect_uri=https://myapp/callback
```
-### 2. Google **response** to Backend
-
+### 2. Google **Response** to Backend
```js
{
@@ -114,7 +113,7 @@ redirect_uri=https://myapp/callback
### 3. Backend **Redirect** to Frontend success page
-This redirect will place a cookie in the browser that contains the access token
+This redirect will place a **cookie** in the browser that contains the **access token**
```bash
HTTP/1.1 302 Found
@@ -124,7 +123,6 @@ Set-Cookie: access_token=ya29.a0AfH6SMC8Op6zkVX-VoA; HttpOnly; Secure; Max-Age=3
-
2. POST send the authorization code to https://oauth2.googleapis.com/token
3. POST response the access & refresh tokens
4. Redirect to Fronend success page with a cookie contains the access token
-
@@ -187,6 +184,8 @@ app.get('/callback', async (req, res) => {
});
```
+The `redirect_uri` in the token exchange `POST` request needs to match EXACTLY the same `redirect_uri` that was used in the initial authorization request to Google. It's part of OAuth2 security verification.
+