extension-email-marketing

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npx skills add caffeinelabs/skills --skill extension-email-marketing

Documentation

SKILL.md

npx skills add ...

Documentation

SKILL.md

Send personalised marketing emails to subscribers with an unsubscribe link.

npx skills add caffeinelabs/skills --skill extension-email-marketing

Documentation

SKILL.mdView source

Email — Marketing

Marketing email extension for Caffeine AI.

Overview

This skill adds direct marketing email support with subscriber management, topic-based subscriptions, and automatic unsubscribe links. Requires email verification before users can receive marketing emails.

Backend

This component is for sending direct marketing emails and managing subscribers to marketing topics.

Users MUST have verified their email address AND MUST be subscribed to a marketing topic before they can receive marketing emails on that topic
Marketing emails MUST contain an unsubscribe link which will unsubscribe the user from the given topic
This component depends on the extension-email-verification for verifying email addresses, be sure to check that too.

Use the prefabricated module mo:caffeineai-email-marketing/subscribers.mo which cannot be modified.
Marketing email subscribers MUST be handled solely through this subscribers module
Do NOT also store a subscribed status against user profiles

module {
  public type State = {
    var topics : Map.Map<Nat, TopicRecord>;
    var topicsByName : Map.Map<Text, Nat>;
  };
 
  // Add a new topic by name or get an existing topic if it already exists. Returns the topic ID.
  public func addTopic(state : State, name : Text) : Nat;
 
  // Rename a topic. Returns false if a topic with the new name already exists or the topic ID does not exist.
  public func renameTopic(state : State, topicId : Nat, newName : Text) : Bool;
 
  // Remove a topic. Also removes all subscribers from that topic.
  public func removeTopic(state : State, topicId : Nat);
 
  // List all topics (id, name).
  public func listTopics(state : State) : [Topic];
 
  // Get a topic ID by name
  public func getTopicId(state : State, name : Text) : ?Nat;
 
  // Get a topic name by ID
  public func getTopicName(state : State, topicId : Nat) : ?Text;
 
  // Add a subscriber to a topic. Returns false if the topic doesn't exist
  public func add(state : State, topicId : Nat, email : Text) : Bool;
 
  // Remove a subscriber from a topic
  public func remove(state : State, topicId : Nat, email : Text);
 
  // Remove a subscriber from all topics
  public func removeFromAllTopics(state : State, email : Text);
 
  // List all subscribers alongside their verification status for a given topic. Returns null if the topic doesn't exist.
  public func list(state : State, verifiedEmails : VerifiedEmails.State, topicId : Nat) : ?[(Text, Bool)];
 
  // List all verified subscribers for a given topic. Returns null if the topic doesn't exist.
  public func verified(state : State, verifiedEmails : VerifiedEmails.State, topicId : Nat) : ?[Text];
 
  // Return whether a subscriber is subscribed to a topic
  public func isSubscribed(state : State, topicId : Nat, email : Text) : Bool;
 
  // List all topics a subscriber is subscribed to.
  public func listTopicsForSubscriber(state : State, email : Text) : [Topic];
 
  // Returns the count of subscribers for a given topic
  public func count(state : State, topicId : Nat) : Nat;
 
  // Returns the count of verified subscribers for a given topic
  public func verifiedCount(state : State, verifiedEmails : VerifiedEmails.State, topicId : Nat) : Nat;
};

To handle the unsubscribe link

Use the prefabricated module caffeineai-email-marketing/unsubscribeMixin.mo which cannot be modified.

The MixinEmailUnsubscribe module handles calls to the unsubscribe link to unsubscribe an email address from a topic.

import MixinEmailUnsubscribe "mo:caffeineai-email-marketing/unsubscribeMixin";

For sending direct marketing emails from the backend

This component depends on the email component for sending email addresses.
Use the sendMarketingEmail function.
This MUST be used alongside the subscribers.mo module and unsubscribeMixin.mo module
The recipients argument is an array of email addresses, where for each email an optional array of substitution name/value pairs can be specified.
- These substitutions allow the email to be personalised for each recipient.
- If the email body contains the substitution name in double curly braces it is replaced by the substitution value in the email to that recipient.
It returns a Result which is #ok if the email is sent successfully otherwise #err(error) with the error text.
Ensure the placeholder text {{UNSUBSCRIBE_URL}} is appended to the htmlBody if not already present. This will be replaced automatically by the system with a specific unsubscribe url for each recipient.

module {
  public type BroadcastEmailRecipient = {
    email : Text;
    substitutions : ?[(Text, Text)];
  };
 
  public type SendResult = {
    #ok;
    #err : Text;
  };
 
  public func sendMarketingEmail(
    topicId : Nat,
    fromUsername : Text,
    recipients : [BroadcastEmailRecipient],
    subject : Text,
    htmlBody : Text,
  ) : async SendResult;
};

Example usage for an app which can send marketing emails to users who are subscribed to topics managed by the admin

import Array "mo:core/Array";
import Runtime "mo:core/Runtime";
import Option "mo:core/Option";
import Principal "mo:core/Principal";
import Iter "mo:core/Iter";
import Map "mo:core/Map";
import Set "mo:core/Set";
import Text "mo:core/Text";
import AccessControl "mo:caffeineai-authorization/access-control";
import MixinAuthorization "mo:caffeineai-authorization/MixinAuthorization";
import EmailClient "mo:caffeineai-email/emailClient";
import MixinEmailUnsubscribe "mo:caffeineai-email-marketing/unsubscribeMixin";
import EmailSubscribers "mo:caffeineai-email-marketing/subscribers";
import MixinEmailVerification "mo:caffeineai-email-verification/verificationMixin";
import VerifiedEmails "mo:caffeineai-email-verification/verifiedEmails";
 
actor {
  public type UserProfile = {
    name : Text;
    email : Text;
  };
 
  // Include authorization component
  let accessControlState : AccessControl.AccessControlState;
  include MixinAuthorization(accessControlState, null);
 
  // Store a map of caller principal to UserProfile
  let userProfiles : Map.Map<Principal, UserProfile>;
 
  // Store a set of emails for uniqueness check
  let emails : Set.Set<Text>;
 
  // Stores which emails are verified
  let verifiedEmails : VerifiedEmails.State;
 
  // In this example we use a single hardcoded topic.
  // In general there could be CRUD endpoints for the admin to manage email subscription topics.
  transient let newsletterTopic = "Newsletter";
 
  // Store the email subscribers per topic
  let emailSubscribers : EmailSubscribers.State;
 
  // Include this mixin to handle the unsubscribe link which updates the EmailSubscribers state
  include MixinEmailUnsubscribe(emailSubscribers);
 
  // Include this mixin to handle the verification link which updates the VerifiedEmails state
  include MixinEmailVerification(verifiedEmails);
 
  func getUserInternal(caller : Principal) : UserProfile {
    userProfiles.get(caller) ?? Runtime.trap("User profile does not exist!");
  };
 
  public shared ({ caller }) func registerUser(name : Text, email : Text) : async () {
    // Check if the user already exists
    if (userProfiles.containsKey(caller)) {
      Runtime.trap("User already registered");
    };
    // Check if the email is already used
    if (emails.contains(email)) {
      Runtime.trap("Email already taken");
    };
    // Add a user record
    userProfiles.add(
      caller,
      {
        name;
        email;
      },
    );
    emails.add(email);
    // Subscribe the user to the Newsletter topic by default
    let topicId = EmailSubscribers.getTopicId(emailSubscribers, newsletterTopic)
      ?? Runtime.trap("Newsletter topic not found");
    ignore EmailSubscribers.add(emailSubscribers, topicId, email);
    // Send a verification email
    let result = await EmailClient.sendVerificationEmail(
      "no-reply",
      [email],
      "Welcome to Our Service",
      "Hello " # name # ",<br><br>Thank you for registering with our service.<br><br>Please <a href=\"{{VERIFICATION_URL}}\">click here</a> to verify your email address.<br><br>By clicking on the verification link you also agree to sign-up to the monthly Newsletter which you can unsubscribe from at any time.<br><br>Best regards,<br>The Team",
    );
    switch (result) {
      case (#ok) {};
      case (#err(error)) {
        Runtime.trap("Failed to send verification email: " # error);
      };
    };
  };
 
  public shared ({ caller }) func addTopic(name : Text) : async Nat {
    if (not (AccessControl.hasPermission(accessControlState, caller, #admin))) {
      Runtime.trap("Unauthorized: Only admins can add topics");
    };
    EmailSubscribers.addTopic(emailSubscribers, name);
  };
 
  public shared ({ caller }) func removeTopic(topicId : Nat) : async () {
    if (not (AccessControl.hasPermission(accessControlState, caller, #admin))) {
      Runtime.trap("Unauthorized: Only admins can remove topics");
    };
    EmailSubscribers.removeTopic(emailSubscribers, topicId);
  };
 
  public shared ({ caller }) func renameTopic(topicId : Nat, newName : Text) : async () {
    if (not (AccessControl.hasPermission(accessControlState, caller, #admin))) {
      Runtime.trap("Unauthorized: Only admins can rename topics");
    };
    let success = EmailSubscribers.renameTopic(emailSubscribers, topicId, newName);
    if (not success) {
      Runtime.trap("Failed to rename topic");
    };
  };
 
  public shared ({ caller }) func subscribeToTopic(topicId : Nat) : async () {
    let userProfile = getUserInternal(caller);
    ignore EmailSubscribers.add(emailSubscribers, topicId, userProfile.email);
  };
 
  public shared ({ caller }) func unsubscribeFromTopic(topicId : Nat) : async () {
    let userProfile = getUserInternal(caller);
    EmailSubscribers.remove(emailSubscribers, topicId, userProfile.email);
  };
 
  public shared ({ caller }) func sendMarketingEmail(topicId : Nat, subject : Text, htmlBody : Text) : async () {
    if (not (AccessControl.hasPermission(accessControlState, caller, #admin))) {
      Runtime.trap("Unauthorized: Only admins can send the newsletter");
    };
    // Get the array of subscriber emails that have been verified
    let recipientEmails = EmailSubscribers.verified(emailSubscribers, verifiedEmails, topicId)
      ?? Runtime.trap("No verified subscribers found for newsletter topic");
    if (recipientEmails.size() == 0) {
      Runtime.trap("No verified subscribers found for newsletter topic");
    };
    // Ensure the email body contains the unsubscribe link placeholder
    let finalHtmlBody = if (htmlBody.contains(#text "{{UNSUBSCRIBE_URL}}")) {
      htmlBody;
    } else {
      htmlBody # "<br><br>To unsubscribe <a href=\"{{UNSUBSCRIBE_URL}}\">click here</a>";
    };
    // For each recipient specify the NAME substitution to personalise the email
    let recipients = recipientEmails.filterMap(
      func(email) {
        switch (userProfiles.values().find(func(user) { user.email == email })) {
          case (?user) { ?{ email; substitutions = ?[("NAME", user.name)] } };
          case (null) { null };
        };
      }
    );
    let result = await EmailClient.sendMarketingEmail(
      topicId,
      "no-reply",
      recipients,
      subject,
      finalHtmlBody,
    );
    switch (result) {
      case (#ok) {};
      case (#err(error)) {
        Runtime.trap("Failed to send newsletter: " # error);
      };
    };
  };
 
  public query ({ caller }) func listTopics() : async [EmailSubscribers.Topic] {
    EmailSubscribers.listTopics(emailSubscribers);
  };
 
  // Admin function to list topic subscribers and whether the email is verified or not
  public query ({ caller }) func listSubscribers(topicId : Nat) : async [(Text, Bool)] {
    if (not (AccessControl.hasPermission(accessControlState, caller, #admin))) {
      Runtime.trap("Unauthorized: Only admins can list topic subscribers");
    };
    EmailSubscribers.list(emailSubscribers, verifiedEmails, topicId).get([]);
  };
 
  public query ({ caller }) func isCallerSubscribedToTopic(topicId : Nat) : async Bool {
    let userProfile = getUserInternal(caller);
    EmailSubscribers.listTopicsForSubscriber(emailSubscribers, userProfile.email).find(
      func(topic) { topic.id == topicId }
    ).isSome();
  };
 
  public query ({ caller }) func isCallerEmailVerified() : async Bool {
    let userProfile = getUserInternal(caller);
    VerifiedEmails.contains(verifiedEmails, userProfile.email);
  };
};

The migration chain head — newsletterTopic is transient, so the migration repeats the topic literal instead of referencing it:

import Map "mo:core/Map";
import Set "mo:core/Set";
import AccessControl "mo:caffeineai-authorization/access-control";
import EmailSubscribers "mo:caffeineai-email-marketing/subscribers";
import VerifiedEmails "mo:caffeineai-email-verification/verifiedEmails";
 
module {
  type UserProfile = {
    name : Text;
    email : Text;
  };
 
  type NewActor = {
    accessControlState : AccessControl.AccessControlState;
    userProfiles : Map.Map<Principal, UserProfile>;
    emails : Set.Set<Text>;
    verifiedEmails : VerifiedEmails.State;
    emailSubscribers : EmailSubscribers.State;
  };
 
  public func migration(_old : {}) : NewActor {
    {
      accessControlState = AccessControl.initState();
      userProfiles = Map.empty<Principal, UserProfile>();
      emails = Set.empty<Text>();
      verifiedEmails = VerifiedEmails.new();
      emailSubscribers = EmailSubscribers.new(["Newsletter"]);
    };
  };
};

npx skills add caffeinelabs/skills --skill extension-email-marketing

Documentation

SKILL.md

Send personalised marketing emails to subscribers with an unsubscribe link.

npx skills add caffeinelabs/skills --skill extension-email-marketing

Documentation

SKILL.mdView source

Email — Marketing

Marketing email extension for Caffeine AI.

Overview

Backend

This component is for sending direct marketing emails and managing subscribers to marketing topics.

Users MUST have verified their email address AND MUST be subscribed to a marketing topic before they can receive marketing emails on that topic
Marketing emails MUST contain an unsubscribe link which will unsubscribe the user from the given topic
This component depends on the extension-email-verification for verifying email addresses, be sure to check that too.

Use the prefabricated module mo:caffeineai-email-marketing/subscribers.mo which cannot be modified.
Marketing email subscribers MUST be handled solely through this subscribers module
Do NOT also store a subscribed status against user profiles

module {
  public type State = {
    var topics : Map.Map<Nat, TopicRecord>;
    var topicsByName : Map.Map<Text, Nat>;
  };
 
  // Add a new topic by name or get an existing topic if it already exists. Returns the topic ID.
  public func addTopic(state : State, name : Text) : Nat;
 
  // Rename a topic. Returns false if a topic with the new name already exists or the topic ID does not exist.
  public func renameTopic(state : State, topicId : Nat, newName : Text) : Bool;
 
  // Remove a topic. Also removes all subscribers from that topic.
  public func removeTopic(state : State, topicId : Nat);
 
  // List all topics (id, name).
  public func listTopics(state : State) : [Topic];
 
  // Get a topic ID by name
  public func getTopicId(state : State, name : Text) : ?Nat;
 
  // Get a topic name by ID
  public func getTopicName(state : State, topicId : Nat) : ?Text;
 
  // Add a subscriber to a topic. Returns false if the topic doesn't exist
  public func add(state : State, topicId : Nat, email : Text) : Bool;
 
  // Remove a subscriber from a topic
  public func remove(state : State, topicId : Nat, email : Text);
 
  // Remove a subscriber from all topics
  public func removeFromAllTopics(state : State, email : Text);
 
  // List all subscribers alongside their verification status for a given topic. Returns null if the topic doesn't exist.
  public func list(state : State, verifiedEmails : VerifiedEmails.State, topicId : Nat) : ?[(Text, Bool)];
 
  // List all verified subscribers for a given topic. Returns null if the topic doesn't exist.
  public func verified(state : State, verifiedEmails : VerifiedEmails.State, topicId : Nat) : ?[Text];
 
  // Return whether a subscriber is subscribed to a topic
  public func isSubscribed(state : State, topicId : Nat, email : Text) : Bool;
 
  // List all topics a subscriber is subscribed to.
  public func listTopicsForSubscriber(state : State, email : Text) : [Topic];
 
  // Returns the count of subscribers for a given topic
  public func count(state : State, topicId : Nat) : Nat;
 
  // Returns the count of verified subscribers for a given topic
  public func verifiedCount(state : State, verifiedEmails : VerifiedEmails.State, topicId : Nat) : Nat;
};

To handle the unsubscribe link

Use the prefabricated module caffeineai-email-marketing/unsubscribeMixin.mo which cannot be modified.

The MixinEmailUnsubscribe module handles calls to the unsubscribe link to unsubscribe an email address from a topic.

import MixinEmailUnsubscribe "mo:caffeineai-email-marketing/unsubscribeMixin";

For sending direct marketing emails from the backend

This component depends on the email component for sending email addresses.
Use the sendMarketingEmail function.
This MUST be used alongside the subscribers.mo module and unsubscribeMixin.mo module
The recipients argument is an array of email addresses, where for each email an optional array of substitution name/value pairs can be specified.
- These substitutions allow the email to be personalised for each recipient.
- If the email body contains the substitution name in double curly braces it is replaced by the substitution value in the email to that recipient.
It returns a Result which is #ok if the email is sent successfully otherwise #err(error) with the error text.
Ensure the placeholder text {{UNSUBSCRIBE_URL}} is appended to the htmlBody if not already present. This will be replaced automatically by the system with a specific unsubscribe url for each recipient.

module {
  public type BroadcastEmailRecipient = {
    email : Text;
    substitutions : ?[(Text, Text)];
  };
 
  public type SendResult = {
    #ok;
    #err : Text;
  };
 
  public func sendMarketingEmail(
    topicId : Nat,
    fromUsername : Text,
    recipients : [BroadcastEmailRecipient],
    subject : Text,
    htmlBody : Text,
  ) : async SendResult;
};

Example usage for an app which can send marketing emails to users who are subscribed to topics managed by the admin

import Array "mo:core/Array";
import Runtime "mo:core/Runtime";
import Option "mo:core/Option";
import Principal "mo:core/Principal";
import Iter "mo:core/Iter";
import Map "mo:core/Map";
import Set "mo:core/Set";
import Text "mo:core/Text";
import AccessControl "mo:caffeineai-authorization/access-control";
import MixinAuthorization "mo:caffeineai-authorization/MixinAuthorization";
import EmailClient "mo:caffeineai-email/emailClient";
import MixinEmailUnsubscribe "mo:caffeineai-email-marketing/unsubscribeMixin";
import EmailSubscribers "mo:caffeineai-email-marketing/subscribers";
import MixinEmailVerification "mo:caffeineai-email-verification/verificationMixin";
import VerifiedEmails "mo:caffeineai-email-verification/verifiedEmails";
 
actor {
  public type UserProfile = {
    name : Text;
    email : Text;
  };
 
  // Include authorization component
  let accessControlState : AccessControl.AccessControlState;
  include MixinAuthorization(accessControlState, null);
 
  // Store a map of caller principal to UserProfile
  let userProfiles : Map.Map<Principal, UserProfile>;
 
  // Store a set of emails for uniqueness check
  let emails : Set.Set<Text>;
 
  // Stores which emails are verified
  let verifiedEmails : VerifiedEmails.State;
 
  // In this example we use a single hardcoded topic.
  // In general there could be CRUD endpoints for the admin to manage email subscription topics.
  transient let newsletterTopic = "Newsletter";
 
  // Store the email subscribers per topic
  let emailSubscribers : EmailSubscribers.State;
 
  // Include this mixin to handle the unsubscribe link which updates the EmailSubscribers state
  include MixinEmailUnsubscribe(emailSubscribers);
 
  // Include this mixin to handle the verification link which updates the VerifiedEmails state
  include MixinEmailVerification(verifiedEmails);
 
  func getUserInternal(caller : Principal) : UserProfile {
    userProfiles.get(caller) ?? Runtime.trap("User profile does not exist!");
  };
 
  public shared ({ caller }) func registerUser(name : Text, email : Text) : async () {
    // Check if the user already exists
    if (userProfiles.containsKey(caller)) {
      Runtime.trap("User already registered");
    };
    // Check if the email is already used
    if (emails.contains(email)) {
      Runtime.trap("Email already taken");
    };
    // Add a user record
    userProfiles.add(
      caller,
      {
        name;
        email;
      },
    );
    emails.add(email);
    // Subscribe the user to the Newsletter topic by default
    let topicId = EmailSubscribers.getTopicId(emailSubscribers, newsletterTopic)
      ?? Runtime.trap("Newsletter topic not found");
    ignore EmailSubscribers.add(emailSubscribers, topicId, email);
    // Send a verification email
    let result = await EmailClient.sendVerificationEmail(
      "no-reply",
      [email],
      "Welcome to Our Service",
      "Hello " # name # ",<br><br>Thank you for registering with our service.<br><br>Please <a href=\"{{VERIFICATION_URL}}\">click here</a> to verify your email address.<br><br>By clicking on the verification link you also agree to sign-up to the monthly Newsletter which you can unsubscribe from at any time.<br><br>Best regards,<br>The Team",
    );
    switch (result) {
      case (#ok) {};
      case (#err(error)) {
        Runtime.trap("Failed to send verification email: " # error);
      };
    };
  };
 
  public shared ({ caller }) func addTopic(name : Text) : async Nat {
    if (not (AccessControl.hasPermission(accessControlState, caller, #admin))) {
      Runtime.trap("Unauthorized: Only admins can add topics");
    };
    EmailSubscribers.addTopic(emailSubscribers, name);
  };
 
  public shared ({ caller }) func removeTopic(topicId : Nat) : async () {
    if (not (AccessControl.hasPermission(accessControlState, caller, #admin))) {
      Runtime.trap("Unauthorized: Only admins can remove topics");
    };
    EmailSubscribers.removeTopic(emailSubscribers, topicId);
  };
 
  public shared ({ caller }) func renameTopic(topicId : Nat, newName : Text) : async () {
    if (not (AccessControl.hasPermission(accessControlState, caller, #admin))) {
      Runtime.trap("Unauthorized: Only admins can rename topics");
    };
    let success = EmailSubscribers.renameTopic(emailSubscribers, topicId, newName);
    if (not success) {
      Runtime.trap("Failed to rename topic");
    };
  };
 
  public shared ({ caller }) func subscribeToTopic(topicId : Nat) : async () {
    let userProfile = getUserInternal(caller);
    ignore EmailSubscribers.add(emailSubscribers, topicId, userProfile.email);
  };
 
  public shared ({ caller }) func unsubscribeFromTopic(topicId : Nat) : async () {
    let userProfile = getUserInternal(caller);
    EmailSubscribers.remove(emailSubscribers, topicId, userProfile.email);
  };
 
  public shared ({ caller }) func sendMarketingEmail(topicId : Nat, subject : Text, htmlBody : Text) : async () {
    if (not (AccessControl.hasPermission(accessControlState, caller, #admin))) {
      Runtime.trap("Unauthorized: Only admins can send the newsletter");
    };
    // Get the array of subscriber emails that have been verified
    let recipientEmails = EmailSubscribers.verified(emailSubscribers, verifiedEmails, topicId)
      ?? Runtime.trap("No verified subscribers found for newsletter topic");
    if (recipientEmails.size() == 0) {
      Runtime.trap("No verified subscribers found for newsletter topic");
    };
    // Ensure the email body contains the unsubscribe link placeholder
    let finalHtmlBody = if (htmlBody.contains(#text "{{UNSUBSCRIBE_URL}}")) {
      htmlBody;
    } else {
      htmlBody # "<br><br>To unsubscribe <a href=\"{{UNSUBSCRIBE_URL}}\">click here</a>";
    };
    // For each recipient specify the NAME substitution to personalise the email
    let recipients = recipientEmails.filterMap(
      func(email) {
        switch (userProfiles.values().find(func(user) { user.email == email })) {
          case (?user) { ?{ email; substitutions = ?[("NAME", user.name)] } };
          case (null) { null };
        };
      }
    );
    let result = await EmailClient.sendMarketingEmail(
      topicId,
      "no-reply",
      recipients,
      subject,
      finalHtmlBody,
    );
    switch (result) {
      case (#ok) {};
      case (#err(error)) {
        Runtime.trap("Failed to send newsletter: " # error);
      };
    };
  };
 
  public query ({ caller }) func listTopics() : async [EmailSubscribers.Topic] {
    EmailSubscribers.listTopics(emailSubscribers);
  };
 
  // Admin function to list topic subscribers and whether the email is verified or not
  public query ({ caller }) func listSubscribers(topicId : Nat) : async [(Text, Bool)] {
    if (not (AccessControl.hasPermission(accessControlState, caller, #admin))) {
      Runtime.trap("Unauthorized: Only admins can list topic subscribers");
    };
    EmailSubscribers.list(emailSubscribers, verifiedEmails, topicId).get([]);
  };
 
  public query ({ caller }) func isCallerSubscribedToTopic(topicId : Nat) : async Bool {
    let userProfile = getUserInternal(caller);
    EmailSubscribers.listTopicsForSubscriber(emailSubscribers, userProfile.email).find(
      func(topic) { topic.id == topicId }
    ).isSome();
  };
 
  public query ({ caller }) func isCallerEmailVerified() : async Bool {
    let userProfile = getUserInternal(caller);
    VerifiedEmails.contains(verifiedEmails, userProfile.email);
  };
};

The migration chain head — newsletterTopic is transient, so the migration repeats the topic literal instead of referencing it:

import Map "mo:core/Map";
import Set "mo:core/Set";
import AccessControl "mo:caffeineai-authorization/access-control";
import EmailSubscribers "mo:caffeineai-email-marketing/subscribers";
import VerifiedEmails "mo:caffeineai-email-verification/verifiedEmails";
 
module {
  type UserProfile = {
    name : Text;
    email : Text;
  };
 
  type NewActor = {
    accessControlState : AccessControl.AccessControlState;
    userProfiles : Map.Map<Principal, UserProfile>;
    emails : Set.Set<Text>;
    verifiedEmails : VerifiedEmails.State;
    emailSubscribers : EmailSubscribers.State;
  };
 
  public func migration(_old : {}) : NewActor {
    {
      accessControlState = AccessControl.initState();
      userProfiles = Map.empty<Principal, UserProfile>();
      emails = Set.empty<Text>();
      verifiedEmails = VerifiedEmails.new();
      emailSubscribers = EmailSubscribers.new(["Newsletter"]);
    };
  };
};

extension-email-marketing

Documentation

Documentation

extension-email-marketing

Documentation

Email — Marketing

Overview

Backend

This component is for sending direct marketing emails and managing subscribers to marketing topics.

To subscribe users to marketing topics and manage lists of subscribers

To handle the unsubscribe link

For sending direct marketing emails from the backend

Example usage for an app which can send marketing emails to users who are subscribed to topics managed by the admin

Documentation

Documentation

Email — Marketing

Overview

Backend

This component is for sending direct marketing emails and managing subscribers to marketing topics.

To subscribe users to marketing topics and manage lists of subscribers

To handle the unsubscribe link

For sending direct marketing emails from the backend

Example usage for an app which can send marketing emails to users who are subscribed to topics managed by the admin