Privacy Policy

The legal entity responsible for operating PaperLens, LitLink, litlink.cc, the browser extension, account portal, and related services covered by this Privacy Policy is Yisigao (Beijing) Technology Co., Ltd.

In this Privacy Policy, PaperLens, we, us, and our refer to Yisigao (Beijing) Technology Co., Ltd., except where a checkout page or third-party provider page identifies a separate Merchant of Record or payment processor for a specific transaction.

Account information: email address, display name, institution, email-verification status, password hash, sign-in status, plan, entitlements, orders, invoice requests, and refund requests.

Security information: IP address, request time, device/session identifiers, abnormal-access records, email-delivery logs, bot-check results, and risk-control logs.

Product information: extension settings, saved papers, libraries, folders, tags, export records, sync status, Zotero connector status, email preferences, and research-assistance content you choose to save or submit.

Page and search context: to provide extension features on supported academic sites, the browser extension may read visible paper titles, authors, journals, DOI, PMID, abstracts, selected text, search terms, visible links, and page metadata.

We use information for registration, login, email verification, password reset, account security, cloud sync, research libraries, paid entitlements, order payment, invoices, refunds, customer support, and service notices.

We use information to identify papers on pages, show journal metrics and citations, add full-text links, export records, save to Zotero, provide selection translation/summarization, and provide AI-assisted reading.

We use information to troubleshoot issues and prevent mass registration, credential stuffing, fraud, abusive requests, unauthorized access, and payment risk.

When you use AI reading, translation, summarization, or PubMed query enhancement, text you submit or select and the necessary context may be sent to PaperLens backend services or to third-party model providers you configure.

Do not submit confidential, sensitive, institution-restricted, or publisher-restricted content unless you have the right to do so. AI output may be inaccurate and should be verified against the original paper and authoritative sources.

We do not use AI content to sell personal information. For troubleshooting, security audit, and quota accounting, we may store necessary request records, usage counts, and error information.

Email services are used to send registration verification, password reset, account-security, and order notices.

Cloudflare Turnstile or similar security services may be used to detect automated risk in registration, login, password reset, and similar requests.

International payments may be processed by Paddle or another international checkout provider shown on the live checkout page. We do not store full card numbers. We store only the order, transaction status, entitlement activation, and reconciliation information needed for service delivery.

Browser stores, hosting providers, logging services, and model providers may process necessary data within their role. We limit sharing where practical and expect providers to handle data under applicable rules.

The website uses cookies or local storage to maintain login status, language preference, security sessions, bot-check status, and account experience.

The browser extension may store settings, cache, paper-operation state, and runtime data locally. After you sign in, the libraries and preferences you choose to sync may be synced with our server.

PaperLens's use of information received from Google APIs or Chrome extension permissions will adhere to the Chrome Web Store User Data Policy, including the Limited Use requirements, and will be limited to providing or improving the disclosed user-facing features.

You can manage some local and synced data through browser settings, extension settings, or the account portal. Removing local data may affect extension behavior or sign-in status.

We keep personal information only for as long as needed to provide the service, fulfill transactions, maintain security audits, handle disputes, meet tax obligations, and comply with law.

We use encrypted transport, access controls, audit logs, least-privilege access, and security monitoring to protect data, but no internet service can guarantee absolute security.

If a data-security incident may affect your rights, we will notify you through the website, email, or another reasonable channel as required by applicable law.

You may request access, correction, deletion, export, account-data deletion, marketing or product-email opt-out, or withdrawal of non-essential processing permissions.

Registration verification, password reset, order, refund, security, and service-essential notices usually cannot be unsubscribed from because they are directly tied to account and transaction safety.

To exercise rights, contact customer@litlink.tech. To protect accounts, we may need to verify your identity.

PaperLens is mainly intended for research, education, and professional users. Minors should use it only with guardian consent and guidance.

As international payments, model services, cloud services, and browser-store distribution evolve, your data may be processed by overseas providers where necessary. We will handle this under applicable rules and protections.

When this Privacy Policy changes, we will update the date on the website. Material changes may be announced by page notice or email.