Terms of Service

The legal entity and service provider for PaperLens, LitLink, litlink.cc, the browser extension, account portal, and related paid services is Yisigao (Beijing) Technology Co., Ltd.

When users register for, use, or purchase PaperLens services, they are contracting with Yisigao (Beijing) Technology Co., Ltd., unless a checkout page identifies a Merchant of Record such as Paddle for a specific payment transaction.

You must use a real, reachable email address to register and you are responsible for your account, password, devices, sessions, and activity under your account.

You may not mass-register, impersonate others, share, resell, rent, or transfer accounts, license keys, paid entitlements, AI quota, or access credentials.

If you notice abnormal sign-ins, unauthorized access, or account-security risks, update your password, remove abnormal sessions, and contact support.

PaperLens provides academic page enhancement, journal metrics, citation signals, full-text links, saved libraries, cloud sync, export, Zotero integration, AI reading, selection translation/summarization, PubMed query enhancement, and related features. The actual feature set is the one shown in the current website, extension, checkout, and account portal.

Journal metrics, citations, full-text links, and third-party metadata may come from public databases, publisher pages, or third-party services. They may be delayed, missing, inaccurate, or changed. Before making formal research, submission, purchasing, clinical, legal, or management decisions, verify the original sources and your institution's rules.

AI output is only an aid for reading, translation, summarization, and search suggestions. It is not medical, legal, investment, ethics-review, submission, or research-conclusion advice.

You must use PaperLens legally, reasonably, and without abuse. You may not attack, scan, bypass limits, scrape unauthorized data, interfere with service availability, break publisher pages, or infringe others' rights.

Do not use PaperLens to upload, store, copy, export, or send content to third-party models unless you have the right to do so. You are responsible for following your institution's rules, database terms, publisher terms, and browser-store policies.

If an account presents abuse, fraud, illegal activity, infringement, payment risk, or security risk, we may restrict, suspend, or terminate the relevant account, order, or service access.

Plans, prices, billing cycles, trials, AI quota, device limits, and entitlements are governed by the purchase page, checkout page, order record, and account portal shown at the time of purchase.

International checkout is not open yet. When it opens, international payments may be processed through Paddle or another international checkout provider shown on the live checkout page.

When checkout is processed by Paddle, Paddle.com or its affiliates may act as the Merchant of Record and may handle order processing, tax calculation, payment-related customer support, and refunds. The merchant, tax, currency, and settlement information shown at checkout controls that purchase.

Digital access is usually delivered automatically after payment confirmation. If a system issue prevents activation, we will verify the order and either activate access, extend the entitlement, or handle the case under the Refund Policy.

We may change features, prices, entitlements, or access methods due to product iteration, compliance, security, third-party service changes, or cost changes. Material changes will be announced on the website, account portal, or by email where appropriate.

Trials, gifts, student prices, coupons, and promotional entitlements may have separate rules. Unless expressly stated, they cannot be redeemed for cash, transferred, or split across accounts.

PaperLens software, interfaces, brand, documents, icons, design, code, and service content are protected by intellectual-property laws. Except as allowed by law or expressly authorized by us, you may not copy, modify, distribute, reverse engineer, or create derivative services from them.

You retain your rights in content you save, upload, export, or submit, but you grant us the limited rights needed to provide the service, sync data, process requests, troubleshoot issues, and maintain security.

If you submit suggestions, feedback, or bug reports, we may use them to improve PaperLens without compensation, but that does not transfer ownership of your original research content to us.

To the extent permitted by law, PaperLens is provided as is and as available. We do not guarantee that every site, metric, citation, AI output, or third-party link will always be accurate, complete, continuous, or fit for a specific purpose.

We will reasonably help investigate disruptions or errors caused by networks, browsers, publisher page changes, third-party APIs, payment providers, model services, user configuration, institutional access, or force majeure, but we are not liable for indirect losses beyond what applicable law requires.

These Terms, the Privacy Policy, and the Refund Policy together govern your use of PaperLens. If checkout, refund, or entitlement descriptions conflict, the checkout page, order record, and the more specific policy language control.

We may update these Terms. Updated terms will be posted on the website, and material changes may be announced by page notice or email. Continued use means you accept the updated Terms.