Light Book Terms of Service
Effective: May 27, 2026 · Last updated: June 11, 2026
1. Introduction
Welcome to Light Book (the "Service" or "App"). The Service is developed and operated by Ningbo Tangxiaoyuan Technology Co., Ltd. ("we", "us", "our"). These Terms of Service ("Terms") form a binding agreement between you and us regarding your use of the Service.
Please read these Terms carefully before using the Service. By registering for or using the Service, you confirm that you have read, understood and agreed to be bound by these Terms in their entirety. If you do not agree, please stop using the Service immediately.
2. Description of the Service
Light Book is a multi-purpose application combining an AI assistant, personal notes, file management and image generation. Key features include:
- AI conversation: chat, Q&A and writing assistance powered by third-party large language models, including DeepSeek, Alibaba Tongyi Qianwen, OpenRouter aggregated providers, and Cloudflare AI Gateway.
- Notebooks and notes: create, edit and organise your personal notes.
- Files ("My Files"): upload, download, share and manage files; storage is provided by Alibaba Cloud Object Storage Service (OSS).
- Image generation: generate or edit images from prompts via Cloudflare Gemini Image, OpenRouter image models and other third-party services.
- Memory: with your authorisation, the Service automatically extracts personal preferences from your conversations to provide a more coherent experience.
- Third-party backup: after you actively bind a GitHub or Baidu Netdisk account, the Service backs up your notes to your own third-party storage account, on a schedule or on manual demand.
- Subscriptions: a free tier with basic quotas; a Pro tier offering higher quotas and advanced features, purchased through Apple In-App Purchase.
You understand and agree that, to continuously improve the Service, diagnose issues and optimise your experience, we collect behavioural-analytics information from your use of the Service (such as in-app events, app version and device model). The scope, purposes, sharing and your withdrawal rights are described in our Privacy Policy.
3. Account Registration and Security
- You register with an email address, an email verification code, and a password. Your password is stored as a one-way hash (bcrypt) and cannot be recovered in plain text.
- You are responsible for safeguarding your account credentials and for all activity that occurs under your account. Please contact us immediately if you suspect any unauthorised access.
- By registering you represent that you are at least 14 years old; that the information you provide is true, accurate and lawful; and that you are not impersonating any other person.
4. User Content and Licence
- Ownership: you retain ownership and all intellectual-property rights in the conversations, notes, files, images and other materials you create, upload or generate via the Service ("User Content").
- Licence to us: solely to the extent necessary to provide the Service, you grant us a worldwide, royalty-free, non-exclusive licence to:
- forward your conversations and attachments to the third-party LLM providers listed above so that responses can be generated;
- store your files, notes and generated images on Alibaba Cloud OSS;
- where you have opted in, automatically extract and store memory information to personalise subsequent conversations;
- perform necessary technical processing such as compression, thumbnail generation and caching.
This licence terminates immediately when you delete the relevant content or close your account.
- No use for AI model training: the licence granted above does not include using your User Content (conversations, notes, files, images) to train any AI model. We commit that we will not proactively use your User Content to train any AI model operated by us. When a conversation invokes a third-party AI model to generate a response, whether the third party uses that data for training or improvement is governed by their own terms of service — see "Special notice on AI model training" in §3 of the Privacy Policy and the third-party sharing list in §4 of the Privacy Policy. If you do not want your conversation content to potentially be used for training by any third party, please avoid sending sensitive personal or commercial-secret content, or contact us to request that we evaluate adding "no-train" paid model options.
- Compliance: you are solely responsible for your User Content and represent that it does not infringe any third-party rights and does not violate any applicable law.
5. Prohibited Conduct
You agree not to:
- violate any law or regulation, public policy or social interest in the People's Republic of China or any other applicable jurisdiction;
- use the AI features to generate or disseminate obscene, violent, terror-related, fraudulent, infringing or otherwise harmful content;
- harass, defame or harm other people;
- obtain or attempt to obtain other users' accounts, personal information or data without authorisation;
- scrape, crawl or use automated agents to extract data at scale;
- reverse-engineer, decompile or attempt to circumvent any technical limitation of the Service;
- abuse free quotas, fabricate transactions or evade billing;
- otherwise harm the legitimate rights of us or any third party.
We may suspend or terminate your access for any breach, without prejudice to any further legal remedies.
6. Third-Party Backup — Special Terms
- Activation: third-party backup (GitHub / Baidu Netdisk) is off by default and is enabled only after you actively complete the OAuth flow at Settings → Sync & Backup.
- Data flow: during a backup run, your note bodies, attachments (images / files) and other user content are uploaded over an encrypted channel from our server directly to your own third-party account (a private GitHub repository / your Baidu Netdisk authorized directory). No other third party is involved.
- Credential handling: the OAuth access token (and, for Baidu, the refresh token) is stored on our server encrypted with AES-256-GCM, decrypted only at backup-run time, and never disclosed to any third party.
- Responsibility for your third-party account: you understand and agree that the backup destination (GitHub / Baidu Netdisk) account is owned and managed by you, and that its availability, storage quota, account security and pricing are the responsibility of the respective third party. We are not liable for backup failures, data loss, or data corruption resulting from third-party service outages, account suspension, insufficient storage, network failures, or other causes outside our control.
- Unbinding: you may unbind at any time from within the app. Upon unbinding, we immediately delete the stored OAuth credentials for that destination, stop further backup runs, and make a best-effort call to the corresponding platform's revoke-grant API. Backup content already uploaded to your third-party account will not be auto-deleted by us; you may manage it on GitHub / Baidu Netdisk.
- Not a primary store: backup is provided as additional redundancy. The authoritative copy of your notes remains on our server. Please do not rely on third-party backup as the only safeguard for your data.
7. AI-Generated Content Disclaimer
- Conversation, Q&A and image outputs are produced automatically by third-party AI models. The outputs may be inaccurate, incomplete or biased and do not constitute professional advice (including but not limited to medical, legal, financial or investment advice).
- You alone are responsible for evaluating AI-generated content and for any decisions you make based on it.
- We make no express or implied warranty regarding the quality, accuracy or availability of any third-party AI model output.
8. Subscriptions and Billing
- Free tier: available immediately upon registration. Includes monthly quotas for conversation tokens, file storage and image generation.
- Pro subscription: purchased via Apple In-App Purchase and renewed monthly or annually. Prices are displayed in the App Store and prevail over any other source.
- Auto-renewal:
- Your subscription will automatically renew within 24 hours before expiry and the fee will be charged to your Apple ID.
- You may view, change or cancel your subscription at any time in iOS Settings → Apple ID → Subscriptions.
- Cancellations take effect from the next billing cycle. Fees already paid for the current cycle are non-refundable, unless required by applicable law.
- Refund requests must be submitted via Apple; we cannot directly process refunds for Apple in-app purchases.
9. Service Availability and Changes
- We will make reasonable efforts to keep the Service running, but we do not guarantee uninterrupted or error-free operation. We are not liable for outages caused by force majeure, scheduled maintenance or third-party service disruptions.
- We reserve the right to modify, suspend or discontinue any feature, interface, pricing or policy of the Service. For material changes we will provide reasonable advance notice through in-app notifications, email or similar channels.
- These Terms may be revised from time to time. Revisions take effect upon publication. Continued use of the Service constitutes acceptance of the revised Terms.
10. Limitation of Liability
To the maximum extent permitted by applicable law:
- the Service and all content are provided on an "as-is" and "as-available" basis, without any express or implied warranty;
- we are not liable for any indirect, incidental, special, consequential or punitive damages arising from your use of or inability to use the Service, including loss of profits, data or goodwill;
- our aggregate liability to you under these Terms shall not exceed the greater of (a) the total subscription fees actually paid by you to us in the 12 months preceding the event giving rise to the claim, or (b) CNY 100.
11. Termination
- By you: you may close your account at any time via "Me → Delete Account" in the App. Upon closure, all of your account data, conversations, notes, files and generated content will be permanently deleted and cannot be recovered.
- By us: we may suspend or terminate your account immediately if you breach these Terms or applicable law.
- Provisions of these Terms relating to intellectual property, limitation of liability and dispute resolution survive termination.
12. Governing Law and Disputes
- These Terms are governed by the laws of mainland China, without regard to its conflict-of-laws principles.
- Any dispute arising from these Terms or the Service shall first be resolved through friendly negotiation. If negotiation fails, either party may bring the dispute before the competent People's Court located at the domicile of Ningbo Tangxiaoyuan Technology Co., Ltd.
13. Contact Us
For any questions or feedback regarding these Terms, please contact us: