diff --git a/src/errors.js b/src/errors.js
index 3c6cd27..023ba59 100644
--- a/src/errors.js
+++ b/src/errors.js
@@ -5,6 +5,13 @@ class ChallengedUsedError extends Error {
     }
 }
 
+class AlreadyUsedError extends Error {
+    constructor(message) {
+        super(message);
+        this.name = "AlreadyUsedError"
+    }
+}
+
 class InvalidSignatureError extends Error {
     constructor(message) {
         super(message);
@@ -27,8 +34,7 @@ class NotFoundError extends Error {
 }
 
 module.exports = {
-    ChallengedUsedError,
+    AlreadyUsedError,
     InvalidSignatureError,
-    AppInvitedUsedError,
     NotFoundError
 };
\ No newline at end of file
diff --git a/src/public/javascript/invite.js b/src/public/javascript/invite.js
index 1521ccf..89e9b09 100644
--- a/src/public/javascript/invite.js
+++ b/src/public/javascript/invite.js
@@ -10,40 +10,51 @@ window.onload = function () {
 
 async function acceptInvite() {
 
-    if (!window.nostr) {
-        console.log("No Nostr extension found.");
-        return { success: false, error: "No Nostr extension detected." };
+    let challengeResponse;
+    try {
+        challengeResponse = await fetch('/api/signup/nostr-challenge', {
+            method: 'GET',
+            headers: {
+                'Content-Type': 'application/json'
+            }
+        });
+    } catch (error) {
+        console.log(`Something went wrong: ${error}`);
+        return;
     }
 
+    const { challenge } = await challengeResponse.json();
 
+    let pubkey;
     try {
-        const challengeResponse = await fetch("/api/signup/nostr-challenge");
-        if (!challengeResponse.ok) throw new Error("Failed to fetch challenge");
-        const { challenge } = await challengeResponse.json();
+        pubkey = await window.nostr.getPublicKey();
+    } catch (error) {
+        document.querySelector('#rejected-nostr-nudges').style.display = 'block';
+        return;
+    }
+    const event = {
+        kind: 22242,
+        created_at: Math.floor(Date.now() / 1000),
+        tags: [["challenge", challenge]],
+        content: "Sign this challenge to authenticate",
+        pubkey: pubkey
+    };
 
-        const pubkey = await window.nostr.getPublicKey();
+    let signedEvent;
+    try {
+        signedEvent = await window.nostr.signEvent(event);
+    } catch (error) {
+        document.querySelector('#rejected-nostr-nudges').style.display = 'block';
+        return;
+    }
 
-        const event = {
-            kind: 22242,
-            created_at: Math.floor(Date.now() / 1000),
-            tags: [["challenge", challenge]],
-            content: "Sign this challenge to authenticate",
-            pubkey: pubkey
-        };
+    const verifyResponse = await fetch("/api/signup/nostr-verify", {
+        method: "POST",
+        headers: { "Content-Type": "application/json" },
+        body: JSON.stringify(signedEvent),
+    });
 
-        const signedEvent = await window.nostr.signEvent(event);
+    if (verifyResponse.status === 200) {
 
-        const verifyResponse = await fetch("/api/signup/nostr-verify", {
-            method: "POST",
-            headers: { "Content-Type": "application/json" },
-            body: JSON.stringify(signedEvent),
-        });
-
-        if (verifyResponse.status === 200) {
-
-        }
-
-
-
-    } catch (error) { }
+    }
 }
\ No newline at end of file
diff --git a/src/routes/apiRoutes.js b/src/routes/apiRoutes.js
index cf0943d..384de44 100644
--- a/src/routes/apiRoutes.js
+++ b/src/routes/apiRoutes.js
@@ -1,5 +1,4 @@
 const express = require('express');
-const crypto = require("crypto");
 
 const invitesService = require('../services/invitesService');
 const nostrService = require('../services/nostrService');
@@ -9,17 +8,48 @@ const errors = require('../errors');
 const router = express.Router();
 
 router.get('/signup/nostr-challenge', async (req, res) => {
+    console.log("I'm heeeere")
     const inviteUuid = req.cookies.inviteUuid;
 
-    const signUpChallenge = await invitesService.createSignUpChallenge(
-        inviteUuid
-    )
+    let signUpChallenge;
+    try {
+        signUpChallenge = await invitesService.createSignUpChallenge(
+            inviteUuid
+        )
+    } catch (error) {
+        if (error instanceof errors.NotFoundError) {
+            return res.status(404).json({
+                success: false,
+                message: 'Could not find invite with that id.'
+            })
+        }
 
-    const relatedNostrChallenge = await nostrService.getNostrChallenge(
-        signUpChallenge.nostr_challenge_uuid
-    )
+        if (error instanceof errors.AlreadyUsedError) {
+            return res.status(410).json({
+                success: false,
+                message: 'That invite has already been used.'
+            })
+        }
 
-    res.status(200).json({ 'challenge': relatedNostrChallenge.challenge });
+        return res.status(500).json({
+            success: false,
+            message: 'Unexpected error.'
+        })
+    }
+
+    let relatedNostrChallenge;
+    try {
+        relatedNostrChallenge = await nostrService.getNostrChallenge(
+            signUpChallenge.nostr_challenge_uuid
+        )
+    } catch (error) {
+        return res.status(500).json({
+            success: false,
+            message: 'Unexpected error.'
+        })
+    }
+
+    return res.status(200).json({ 'challenge': relatedNostrChallenge.challenge });
 });
 
 
@@ -34,7 +64,7 @@ router.post("/signup/nostr-verify", async (req, res) => {
         if (error instanceof TimeoutError) {
             console.error('The challenge is outdated.');
         }
-        if (error instanceof errors.ChallengedUsedError) {
+        if (error instanceof errors.AlreadyUsedError) {
             console.error('The challenge was already used, request a new one.');
         }
         if (error instanceof errors.InvalidSignatureError) {
diff --git a/src/routes/webRoutes.js b/src/routes/webRoutes.js
index d8c0c57..fbff9d6 100644
--- a/src/routes/webRoutes.js
+++ b/src/routes/webRoutes.js
@@ -13,24 +13,23 @@ router.get('/invite/:inviteUuid', async (req, res) => {
 
     res.cookie('inviteUuid', inviteUuid, { httpOnly: true, maxAge: 86400000 });
 
+    let invite;
     try {
-
-        if (await !invitesService.appInviteExists(inviteUuid)) {
-            return res.status(404).render('error', { message: 'Invite not found' });
+        invite = await invitesService.getAppInvite(inviteUuid);
+        if (!invite) {
+            return res.status(404).render('error', { message: 'Invite not found.' });
         }
 
-        const invite = await invitesService.getAppInvite(inviteUuid);
-
         if (await invitesService.isAppInviteSpent(inviteUuid)) {
-            return res.render('invite_spent', { invite })
+            return res.status(410).render('invite_spent', { invite })
         }
 
-        return res.render('invite', { invite });
-
     } catch (error) {
         console.error('Error fetching invite:', error);
         return res.status(500).render('error', { message: 'An error occurred' });
     }
+
+    return res.render('invite', { invite });
 });
 
 router.get('/private', authMiddleware, (req, res) => {
diff --git a/src/services/invitesService.js b/src/services/invitesService.js
index 28258f2..1bacbd5 100644
--- a/src/services/invitesService.js
+++ b/src/services/invitesService.js
@@ -49,7 +49,7 @@ async function createSignUpChallenge(appInviteUuid) {
     }
 
     if (await isAppInviteSpent(appInviteUuid)) {
-        throw new errors.AppInvitedUsedError("Invite has already been used.")
+        throw new errors.AlreadyUsedError("Invite has already been used.")
     }
 
     const nostrChallenge = await nostrService.createNostrChallenge()
@@ -84,7 +84,7 @@ async function verifySignUpChallenge(signedEvent) {
     console.log(`Found this signup challenge: ${signUpChallenge}`);
 
     if (await nostrService.hasNostrChallengeBeenCompleted(challenge)) {
-        throw new errors.ChallengedUsedError("This challenge has already been used.");
+        throw new errors.AlreadyUsedError("This challenge has already been used.");
     }
     console.log(`I'm gonna verify the nostr challenge`);
     const completedNostrChallenge = await nostrService.verifyNostrChallenge(signedEvent);
diff --git a/src/services/nostrService.js b/src/services/nostrService.js
index e970e54..8a752d9 100644
--- a/src/services/nostrService.js
+++ b/src/services/nostrService.js
@@ -58,7 +58,7 @@ async function verifyNostrChallenge(signedEvent) {
 
     console.log("Checking if completed")
     if (await hasNostrChallengeBeenCompleted(challenge)) {
-        throw new errors.ChallengedUsedError("Challenge already used, request new one.");
+        throw new errors.AlreadyUsedError("Challenge already used, request new one.");
     }
 
     console.log("Checking if valid")
diff --git a/src/views/invite.ejs b/src/views/invite.ejs
index 1bfdd4d..a44c898 100644
--- a/src/views/invite.ejs
+++ b/src/views/invite.ejs
@@ -17,6 +17,9 @@
     <form onsubmit="acceptInvite();return false">
         <button id="nostr-signup" type="submit">Alta con Nostr</button>
     </form>
+    <div id="rejected-nostr-nudges" style="display:none">
+        <p>Ups, parece que no has aceptado que usemos tus claves. Si te has equivocado, puedes intentarlo de nuevo.</p>
+    </div>
     <div id="no-extension-nudges" style="display:none">
         <p>¡Atención! No se ha encontrado una extensión de Nostr en tu navegador. Puedes usar: </p>
         <ul>