From 65e173aa85250d819d2e5022f7690d1e3788d1a0 Mon Sep 17 00:00:00 2001
From: abroa01 <142853163+abroa01@users.noreply.github.com>
Date: Sat, 2 Nov 2024 16:08:13 -0400
Subject: [PATCH] Update README.md

Adding a sequence diagram that includes high level understanding of the flow
---
 README.md | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/README.md b/README.md
index bde5d95..4b71eff 100644
--- a/README.md
+++ b/README.md
@@ -13,3 +13,34 @@ This starts a webserver on localhost, allows someone to connect, then connects t
 
 * https://docs.webchartnow.com/resources/system-specifications/fhir-application-programming-interface-api/oauth-2.0-tutorial/
 * https://docs.enterprisehealth.com/resources/system-specifications/fhir-application-programming-interface-api/oauth-2.0-tutorial/
+
+
+## Sequence Diagram 
+
+```mermaid
+sequenceDiagram
+    actor U as User
+    participant N as Node.js Server
+    participant O as OAuth2 Server (.well-known)
+
+    U ->> N: Access Node.js server
+    N ->> O: Request OpenID configuration (.well-known/openid-configuration)
+    O -->> N: Return configuration (auth & token endpoints)
+
+    N ->> O: Generate login link using authorization endpoint
+    O -->> N: Send login link back
+    N ->> U: Show login link to user
+
+    U ->> O: User clicks login link (Authorization URL)
+    O ->> U: Prompt User for Authentication
+    U -->> O: User Authenticates
+
+    O ->> U: Redirect to Node.js Server with Authorization Code
+    U ->> N: Send Authorization Code to Node.js Server
+
+    N ->> O: Exchange Authorization Code for Access Token
+    O -->> N: Return Access Token
+
+    N ->> U: Respond with Access Token or Success Message
+
+```