Privacy Policy

1. Personal Information We Collect

• Sign-up and authentication information: We collect your email address, nickname, and password (stored in encrypted form). If you use Google or Kakao social login, we receive your email address and profile (nickname) from that provider and use them to create and authenticate your account (for Kakao, only if you have consented to providing your email address). If you use Sign in with Apple, we use the email address provided by Apple (or, if you so choose, a relay email address created by Apple) and your name for the same purpose. In these cases, the Service does not store a password.
• Content created while using the Service: Information you write or upload yourself, such as messages, letters, attached photos, bookmarks, and calendar events (title, notes, dates, and reminder settings). Of this, the text you write (DM message bodies, letter bodies and titles, comments, Feed captions, emotion notes, photo descriptions, attachment file names, questions you create, and calendar event titles and notes) is stored in the database in encrypted form (see “Security Measures” below).
• When you use the Conversation Report service: We collect the KakaoTalk chat export file (the original conversation) that you upload yourself, the email address at which you will receive the completion notice, your survey responses, and any “points you want to check” that you write yourself. The original conversation is used only for analysis and is destroyed immediately after analysis (Section 4). Your email address, your “points you want to check,” and the completed report are stored in encrypted form, and survey responses are stored as predefined answer-choice codes. This service can be used without a Syncbox account.
• When you use the AI chat “Pola”: We collect the questions you write to Pola and Pola’s answers, excerpts of original messages (DM) and letters brought into the chat, and your question usage records (Section 3). Chat records are stored in encrypted form.
• Device and notification information: We collect device tokens to send push notifications.
• Signed-in device information: To show your signed-in devices in Settings and let you sign them out remotely, we record each signed-in device’s browser and operating system information and when it was last used. This is deleted when you delete your account.
• Error diagnostic logs: When an error occurs in the app or on the server, we collect the type of error, an error description with any input content removed, the code location where the error occurred, the address (path) of the screen where it occurred, the usage environment (web, Android app, iOS app, or server), and the time and number of occurrences. If you are logged in, we also record your member identifier (a random ID); if you are not logged in, we record an irreversibly transformed value of your IP address. For certain screen display errors, we also collect the device type, screen size, and the type and time of interaction events at that moment. Content you write, such as messages and letters, is not included; these logs are used only to fix errors and are automatically destroyed after 30 days.
• App usage records: Items collected: app usage records (screens used, the type of button pressed, results of features such as sending or unlocking, error types, device type, and app version). Purpose: identifying the causes of Service errors and improving the user experience. Retention: 30 days (automatically deleted after this period, and deleted immediately when you delete your account). Content you write, such as conversations and letters, is not collected.
• Visit statistics: Screen addresses (with any part that could identify a post or conversation hidden), device and browser information, and a random visitor identifier (cookie). This is not linked to your account information. You can refuse cookies in your browser settings, and refusing them does not limit your use of the Service.
• When you use paid features: Conversation Report payments are processed through the payment agent PortOne and its partner electronic payment providers, and Syncbox+ subscriptions are processed through in-app purchase on the app stores (Google Play and App Store). The Service does not directly collect or store payment method information such as credit card numbers. The Service retains only your subscription and usage status (product, status, period of use, and whether auto-renewal is on), store transaction identifiers, and payment confirmation records (order number and payment approval result). To verify subscription status, the Service’s member identifier (a random ID) is provided to our subscription management processor (RevenueCat).

2. Purposes of Use

• For account authentication, including sign-up, login, and identity verification.
• To provide core Service features, such as messages and letters.
• To send push notifications and notification emails when new messages or letters arrive (both can be turned off in Settings).
• To send a push notification at the time you set when you add a reminder to a calendar event (to both of you for an “Us” event, and to the owner for a personal event).
• To provide paid subscription features and manage subscription status.
• To use error diagnostic logs to find and fix Service errors and operate the Service reliably.
• If you end the connection, to retain the records up to the time of ending so that both people can view and download them for a set period, and to send notice emails before the viewing period ends.
• If you use Pola, to answer your questions and let you view your chat records again.
• If you apply for the Conversation Report service, to analyze the uploaded conversation, generate the report, and notify you by email of its completion or failure.
• Conversations you upload or import (KakaoTalk chats uploaded to the Conversation Report, KakaoTalk chats imported into the app, and messages brought into Pola) are used only for the features the Service describes (the Conversation Report, your shared DMs, analysis and monthly reports, and Pola chats), and are never used to train AI models or to develop the Service. (effective 2026-11-15)

3. AI Topic Analysis and the AI Chat “Pola” (Optional Features)

AI Topic Analysis

• This is an optional feature, offered as part of the paid features, that operates only when both people have consented in Settings. You can turn it off in Settings at any time; when you do, the topic analysis results are deleted right away. Monthly reports you have already received remain.
• What is processed: The bodies of letters (Weekly, Q&A, and Piece letters) and letter comments, as well as Feed captions and Feed comments. DM conversations are included only if you have agreed to analysis that covers DMs, and disappearing messages are not included.
• Relationship temperature: If you turn on DM analysis, each day’s conversation mood is summarized as a temperature compared with your usual, with a short reason, and shown on the calendar. Turning it off deletes it right away.
• Imported KakaoTalk chats: KakaoTalk chats imported into the app are analysed, like other messages (DM), only when both of you have turned on DM analysis. As an exception, if both of you agree to use the monthly report pass, that one report analyses the messages (DM) and the imported KakaoTalk chat from the month you chose. Deleting the imported chat also deletes the report made with that pass.
• How it is processed: Excerpts of the records above are sent to the API of our AI processing provider (Anthropic) to generate topic classifications and summaries, question suggestions, letter material summaries (Weekly letters and Piece letters), and weekly activity ideas. The content sent is processed on commission under terms that it will not be used to train AI models.
• What is stored: No original text is newly stored during analysis; only the analysis results (topic names and summaries, suggested questions, letter material summaries, and weekly activity ideas) are stored in encrypted form. Topics that may be sensitive are displayed only if both people have separately turned this on together.

AI Chat “Pola”

• Pola is a generative AI chat feature that answers your questions based on the conversations between the two of you. It is available when you yourself have turned on the DM consent; your partner’s consent is not required. (effective 2026-11-15)
• What is processed: Original messages (DM) that you pick or bring in by date, messages from the last 7 days read when a chat starts or resumes after a long break, new messages the two of you have sent since the chat last read them (each time you ask a question), letters you attach, and the questions you write to Pola. If you request a “month analysis,” the original messages from the last 30 days are also processed. Pola also refers to your two names, the number of days you have been together, last week’s record counts, a numeric summary of your usual conversation patterns (calculated from the last 30 days of messages), monthly reports and topic summaries, and, if you turn on the memory feature, what Pola remembers and summaries of your other Pola chats. Disappearing messages and deleted messages are not brought in.
• How it is processed: The content above is sent to the API of our AI processing provider (Anthropic) to generate answers. The content sent is processed on commission under terms that it will not be used to train AI models.
• What is stored: Pola chat records (questions and answers, original messages brought into the chat and the recent messages read when the chat started, and month analysis summaries), chat titles, and, if you turn on the memory feature, a summary of conversation tendencies that Pola remembers and per-chat summaries are stored in encrypted form. Messages already brought into a chat remain in that Pola chat until you delete it, even if they are later deleted or disappear from your DMs. Only you can see your Pola chats; your partner cannot see them or even that they exist. Your partner can see only the chats you choose to show them; if a chat you show contains sensitive content such as health information, your partner will see it too, so please check before showing.
• Crisis-signal detection (optional): only if you separately consent, when crisis signals such as self-harm are detected during a chat, we mark that chat so we can show you information about support services and leave that chat out of Pola’s memory. Because this mark may be sensitive information about health, we ask for this consent separately from other consents. You can turn it off in Settings at any time, which also deletes existing marks. You can also turn a mark off in the chat, and it is deleted together with the chat. Records of questions used free of charge in a chat marked as a crisis are used only to check the daily limit and processing costs and are deleted within three days, except when the same question also has a charge or refund record, in which case they remain with that record.
• Question usage records: We store your remaining question count, the time and number of questions used or received, the processing cost per question, and whether you have already received the free trial (chat content is not included). While you are viewing a Pola chat, we also record when you last viewed it so we don’t send you answer notifications.

4. Retention and Destruction

• Viewing after ending the connection: If you end the connection with your partner, both people can view the records up to the time of ending, read-only, and download them free of charge for 6 months from the date the connection ended. We send notice emails 30 days and 7 days before the viewing period ends (the 7-day notice only if you have not downloaded, deleted, unsubscribed, or taken similar action in the meantime), and you can opt out of these notice emails via the link in the email.
• When the viewing period ends, that user’s viewing access ends, and the Feed posts, photos, and Feed comments that user posted are destroyed (including the partner’s comments on those Feed posts). If, when ending the connection, the user chose “Leave my photos and Feed with my partner,” they remain for the partner’s viewing period. Letters and messages that user sent to the partner may remain with the recipient for the recipient’s viewing period. In no case are they retained for more than 2 years from the date the connection ended, and users can check the maximum retention date of what they wrote in Past records in Settings.
• Once both people’s viewing access has ended, all remaining data in that space, including messages, letters, and photos, is destroyed.
• During the viewing period, you may choose End my access (ends only your viewing access immediately, under the rules above) or Delete what I wrote (immediately and permanently destroys the letters, messages, photos, Feed posts, comments, and reactions you wrote, as well as your partner’s comments and reactions on your letters and Feed posts, and also ends your viewing access), and you may also permanently delete items you wrote one by one. In these cases, the items are destroyed immediately without the 12-month retention described below. However, copies of passages or conversations that your partner has saved to their own Bookmarks remain for your partner’s viewing period.
• If the two people reconnect within the viewing period, they continue from their existing records as they were.
• If the last user leaves a space that is not connected to anyone, all data in that space is permanently deleted immediately, with no retention period, and cannot be recovered.
• An account created on or after October 23, 2026 that has never been connected with a partner is deleted without separate notice once 90 days have passed since both its sign-up and its last use, and its information is destroyed with it.
• Transitional provision: Information of users who left a relationship before the effective date of this policy (2026-10-13) is retained for up to 12 months from the date they left and then destroyed, in accordance with the previous provisions.
• If you delete individual content (messages, letters, posts, comments, etc.) in the app, that content immediately disappears from the screen and is not shown again, but it is kept on the server for up to 12 months from the date of deletion for error recovery and legal response, and is then completely destroyed. Disappearing messages (messages that disappear from the screen a set time after being read) are destroyed on the same basis. Data in retention remains subject to the encryption policy and is never shown again on any screen, in search, or in exports.
• Calendar events are destroyed immediately when you delete them, without the 12-month retention above. If you delete your account (withdraw), your personal (“Me”) events are deleted with it, and the shared “Us” events follow the same rules as the other records in that space. After a connection ends, when your viewing ends or you choose Delete what I wrote, your events and the “Us” events you created are destroyed as well.
• Pola chat records in a couple space (effective 2026-11-15) are retained until you delete them. You can delete chats one at a time or all at once in Settings, and turning off the memory feature immediately deletes what Pola remembered and the per-chat summaries. Deleting a single chat does not remove that chat if you showed it to your partner, or what has already been reflected in Pola’s memory. Chats you showed your partner are removed when you delete all Pola records, and what is reflected in memory is removed when you turn off memory or delete all records. If you turn off topic analysis consent or its DM consent, new analysis stops and your past Pola records stay until you delete them (effective 2026-11-15), and if you delete your account (withdraw), your Pola records are deleted immediately. If you end the connection, the Pola records from that connection are deleted when your viewing period ends. Question usage records (Section 3) remain even if you delete your Pola records, and are destroyed together with your other account information when you delete your account (withdraw).
• A waiting space (a space the inviter uses alone while waiting for the other person to join) closes if the other person does not join within 7 days of the invitation. We will let you know 2 days before it closes, and you can download your records then. When it closes, we delete the conversation originals uploaded to that space (imported KakaoTalk conversations, including photos and videos) and other records such as letters, photos and events, and move only your Pola chat records to your personal page. (effective 2026-11-15)
• Pola chat records on your personal page are deleted 30 days after the later of your last Pola chat and the day they were moved to your personal page. We will let you know 7 days before deletion. You can delete them yourself at any time before then. If you use Pola only (counseling based on a conversation you upload without connecting as a couple), we keep the uploaded conversation original for up to 30 days from upload, and delete Pola chat records on the same basis as the personal page. (effective 2026-11-15)
• Completed reports from the Conversation Report (conversation analysis service) are destroyed 7 days after completion, and the original conversation used for analysis is destroyed immediately after analysis. Where no analysis takes place, such as when you stop after payment without starting the analysis, the original conversation is destroyed within 48 hours at most. However, if you link a completed report to your Syncbox account, that report is excluded from the 7-day destruction, kept in your account, and remains viewable in the app (the web link itself expires after 7 days). Reports kept in your account are destroyed together with your account when you delete it (withdraw).

5. Provision to Third Parties and Outsourcing of Processing

The Service processes personal information through the external providers listed below, and does not sell personal information or provide it to third parties for advertising purposes.

• Supabase — We outsource account authentication, the database, and storage of files such as photos (Supabase uses Amazon Web Services infrastructure).
• Vercel — We outsource hosting and running of the Service website and app.
• Google · Kakao · Apple (social login) — If you choose easy login, that provider performs login authentication and provides the Service with your email and profile (nickname) to the extent you have consented.
• Resend — We outsource sending of Service-related emails, such as authentication and notification emails.
• Plausible Analytics — We outsource aggregation of visit statistics for the Conversation Report information page. It does not use cookies and does not collect information that identifies individuals.
• Google Analytics — We outsource aggregation of visit statistics for each screen of the Service.
• PortOne and partner electronic payment providers (PG) — We outsource payment processing for paid features (such as the Conversation Report). Payment method information is processed directly by the payment agent and is not provided to the Service.
• Google Play · Apple App Store — If you subscribe to Syncbox+ in the app, we outsource in-app purchase processing. Payment method information is processed directly by each store and is not provided to the Service.
• RevenueCat — We outsource payment verification for store subscriptions and subscription status management. The Service’s member identifier (a random ID) and store purchase information are provided.
• Apple — We outsource notification delivery for the iPhone app (Apple Push Notification service).
• Anthropic — We outsource analysis processing in three cases: (1) excerpts of records if you have consented to AI topic analysis (Section 3), (2) the original conversation and survey responses if you have applied for the Conversation Report service, and (3) your questions and the original messages and letters brought in if you use the AI chat “Pola” (Section 3). In each case, the content sent is processed under terms that it will not be used to train AI models, and Anthropic deletes what it receives within 30 days (except where needed to address usage policy violations or required by law). (effective 2026-11-15)

6. Transfer of Personal Information Overseas

The Service transfers personal information overseas as described below. Transfers take place over information and communications networks at the time you use the Service, and the retention period is the same as the destruction criteria in Section 4.

• Supabase Inc. (United States · data storage region: India, Amazon Web Services infrastructure) — Account information, content you write, and attached files. For database and file storage.
• Vercel Inc. (United States · execution region: India) — Request information processed in the course of using the Service. For website and app hosting.
• Anthropic PBC (United States) — Excerpts of records if you have consented to AI topic analysis or the monthly report pass, the original conversation and survey responses if you have applied for the Conversation Report service, and your questions and the original messages and letters brought in if you use the AI chat “Pola” (including your own messages contained in them when your partner uses Pola or imports a KakaoTalk chat). (effective 2026-11-15)For analysis processing; the recipient deletes the content it receives within 30 days (except where needed to address usage policy violations or required by law).
• Resend, Inc. (United States) — Email addresses and the content of emails sent. For sending authentication and notification emails.
• Plausible Analytics (European Union) — Access records for the Conversation Report information page (excluding personally identifiable information). For aggregating visit statistics.
• Google LLC (United States) — Account identification information if you choose social login (for login authentication), and device tokens and notification content if you turn on app notifications (for sending push notifications).
• Google LLC (United States) — Screen visit records. For aggregating visit statistics; retained for 2 months.
• RevenueCat, Inc. (United States) — If you subscribe in the app, your member identifier (a random ID) and store purchase information (product, transaction identifier, and subscription period). For subscription payment verification and status management.
• Apple Inc. (United States) — Account identification information if you choose Sign in with Apple, device notification tokens and notification content for the iPhone app, and App Store subscription payment information. For login authentication, sending notifications, and payment processing.

You may refuse the overseas transfer. However, because the transfers above are essential to providing the Service, if you wish to refuse, you may contact us at the address below or stop using the Service (withdraw). Because AI topic analysis, Pola, and the Conversation Report are optional features, no overseas transfer for those purposes takes place if you do not use them.

If you do not want your messages transferred when your connected partner uses Pola, you can request this by email (privacy@oursyncbox.com). We apply the request after verifying your identity; once applied, Pola stops analyzing your conversations for your partner. (effective 2026-11-15)

7. Your Rights

You may at any time export your letters and calendar events from the Settings screen, or withdraw your account to stop the processing of your personal information. Even after ending the connection, during the viewing period you can download your records free of charge, end your viewing, or delete what you wrote from Past records in Settings. To request any other access, correction, or deletion of your personal information, please contact us at the address below.

8. Rights of Data Subjects Who Are Not Members (effective 2026-11-15)

Conversations that users upload or import may contain information about people who are not members of the Service (such as the other person in the chat or people mentioned in it). Non-members may also request confirmation of processing, access, suspension of processing, or deletion of a conversation containing their information by email at privacy@oursyncbox.com. After confirming that the requester is the person who appears in the conversation, we will notify them of the result within 10 days of receiving the request. Original conversations uploaded to the Conversation Report are destroyed right after analysis, so they may no longer exist.

9. Restriction on Use by Children Under 14

The Service is not intended for children under the age of 14 and does not accept sign-ups from such users.

10. Business Information and Contact

• Business name: Syncbox (싱크박스)
• Representative: Jiyoon Yeo
• Privacy inquiries: privacy@oursyncbox.com

11. Security Measures

• Communications are encrypted with HTTPS, and passwords are stored in a form that cannot be decrypted.
• The text you write (DM message bodies, letter bodies and titles, comments, Feed captions, emotion notes, photo descriptions, attachment file names, questions you create, and calendar event titles and notes) is encrypted on the server (server-side encryption) and stored in the database. As a result, even if the database itself were leaked, that content would exist only in encrypted form. However, this is not end-to-end encryption (E2EE), and the Service can decrypt the content to the extent necessary to provide the Service (for example, search, export, and troubleshooting).
• Photos, videos, audio, and attached files shared in the app are encrypted and stored with a different key for each couple.
• Only where strictly necessary, such as to resolve a user inquiry, the operator may view photos and audio, recording the reason for viewing and keeping a log.

12. Changes to This Policy

This policy may be revised in line with changes to the Service, and any changes will be announced by updating the effective date on this page.