par.diff

diff --git a/examples/oauth.ts b/examples/par.ts
index cc6d632..110d820 100644
--- a/examples/oauth.ts
+++ b/examples/par.ts
@@ -37,15 +37,16 @@ const code_verifier = oauth.generateRandomCodeVerifier()
 const code_challenge = await oauth.calculatePKCECodeChallenge(code_verifier)
 let state: string | undefined
 
+// Pushed Authorization Request & Response (PAR)
+let request_uri: string
 {
-  // redirect user to as.authorization_endpoint
-  const authorizationUrl = new URL(as.authorization_endpoint!)
-  authorizationUrl.searchParams.set('client_id', client.client_id)
-  authorizationUrl.searchParams.set('redirect_uri', redirect_uri)
-  authorizationUrl.searchParams.set('response_type', 'code')
-  authorizationUrl.searchParams.set('scope', 'api:read')
-  authorizationUrl.searchParams.set('code_challenge', code_challenge)
-  authorizationUrl.searchParams.set('code_challenge_method', code_challenge_method)
+  const params = new URLSearchParams()
+  params.set('client_id', client.client_id)
+  params.set('redirect_uri', redirect_uri)
+  params.set('response_type', 'code')
+  params.set('scope', 'api:read')
+  params.set('code_challenge', code_challenge)
+  params.set('code_challenge_method', code_challenge_method)
 
   /**
    * We cannot be sure the AS supports PKCE so we're going to use state too. Use of PKCE is
@@ -53,9 +54,33 @@ let state: string | undefined
    */
   if (as.code_challenge_methods_supported?.includes('S256') !== true) {
     state = oauth.generateRandomState()
-    authorizationUrl.searchParams.set('state', state)
+    params.set('state', state)
+  }
+
+  const response = await oauth.pushedAuthorizationRequest(as, client, params)
+  let challenges: oauth.WWWAuthenticateChallenge[] | undefined
+  if ((challenges = oauth.parseWwwAuthenticateChallenges(response))) {
+    for (const challenge of challenges) {
+      console.error('WWW-Authenticate Challenge', challenge)
+    }
+    throw new Error() // Handle WWW-Authenticate Challenges as needed
   }
 
+  const result = await oauth.processPushedAuthorizationResponse(as, client, response)
+  if (oauth.isOAuth2Error(result)) {
+    console.error('Error Response', result)
+    throw new Error() // Handle OAuth 2.0 response body error
+  }
+
+  ;({ request_uri } = result)
+}
+
+{
+  // redirect user to as.authorization_endpoint
+  const authorizationUrl = new URL(as.authorization_endpoint!)
+  authorizationUrl.searchParams.set('client_id', client.client_id)
+  authorizationUrl.searchParams.set('request_uri', request_uri)
+
   // now redirect the user to authorizationUrl.href
 }