Terms of Service
1. The service
OpenCITE is a meta-search over third-party open-access scholarly, library, museum and archive databases, available at citation.today as a free website and as a paid API and MCP server. We retrieve, deduplicate and relay records and format citations. We do not own the underlying records and do not guarantee their completeness or accuracy. Sources may be added, changed or removed at any time.
2. Web search and subscriptions
Searching on the website is free for up to 10 searches per day. Signing in with Google adds a saved library and search history synced to your account. Signing in does not include API credits; see section 3.
- Student ($5/month) and Pro ($10/month) are subscriptions processed by Stripe, priced in US dollars, that renew monthly until cancelled. Both remove the daily web search limit and include a monthly API credit allowance (Student 500, Pro 1,000) that tops the balance up each calendar month and does not accumulate.
- Manage your subscription yourself from Plans → Manage billing (a Stripe-hosted page): cancel, switch between Student and Pro, update your payment method or billing details, and download invoices and receipts.
- Cancelling stops the next renewal; you keep the plan until the end of the period you have paid for, then the account returns to the free plan. Upgrading from Student to Pro takes effect immediately and charges the prorated difference; downgrading from Pro to Student takes effect at the next renewal.
- Student is for enrolled students. We may move an account that misuses it to another plan.
3. API credits and pay as you go
- API and MCP calls are metered in credits: one credit per search or citation-graph call (
/api/search,/api/citations,/api/workswith a citation direction), and one tenth of a credit per reference verified (/api/verify), per identifier resolved (/api/ids) or per work fetched without a graph. Charges are prorated by the share of the eligible sources that actually answered; calls where fewer than about half of the eligible sources answered, or where every upstream source failed, are free. - Pay as you go is a subscription with no base fee, processed by Stripe and priced in US dollars: 1,000 calls per calendar month are included, further usage is billed at $2.50 per 1,000 calls ($0.25 per 1,000 verifications or identifier lookups), invoiced monthly in arrears to the card on file. You set a monthly spending cap (default $25) in Developers → Billing; metered calls stop when the cap is reached. Usage is reported to the billing system daily, so calls near the end of a period may appear on the next invoice. If a payment fails, metered calls pause until the card is updated; purchased credits still work. Cancel at any time from Plans → Manage billing; usage up to cancellation is still invoiced.
- Credit packs are one-time purchases processed by Stripe, priced in US dollars. Credits do not expire. Spending order is: the monthly allowance of your plan, then purchased credits, then pay-as-you-go usage.
- Some purchases are sold through Link, a Stripe service, which is then the seller of record and handles sales tax, VAT or GST, receipts and payment support; the checkout page says so when this applies. Your use of OpenCITE is still governed by these terms.
- There are no free API credits. Reference verification is free up to 25 references per day per caller (per IP address, or per account), with no account or card required; everything else requires a plan or credits.
- Monthly allowances (Student, Pro, pay as you go) reset at the start of each calendar month and do not accumulate; purchased credits are unaffected.
- API keys are shown once and stored only as a hash. You are responsible for keeping keys secret; usage on a key is billed to the owning account. You can revoke keys at any time.
- A pack purchase moves a free account to the machine tier (all sources, higher rate limit for API calls). Neither packs nor pay as you go remove the daily web search limit. Rate limits protect the service and the upstream sources and may change.
4. Refunds
See the Refund Policy. In short: unused credits from a pack can be refunded within 14 days of purchase; a refund removes the pack's credits.
5. Acceptable use
- Do not circumvent rate limits, credit metering or plan gating, share one key across unrelated users to avoid buying credits, or create multiple accounts to multiply free allowances.
- Do not use the service to rebuild or redistribute an upstream database wholesale, or in violation of an upstream source's terms.
- Do not use the service for unlawful purposes or to harass, defraud or harm others.
We may suspend or terminate accounts that violate these terms.
6. Content and attribution
Records are third-party metadata. Each API result names the source database that served it. Verify citations against the original before relying on them. If you believe content relayed through OpenCITE infringes your rights, see the contact page for takedown requests.
7. No warranty; limitation of liability
The service is provided "as is" and "as available", without warranties of any kind, including completeness, accuracy, availability or fitness for a particular purpose. To the maximum extent permitted by law, our total liability for any claim relating to the service is limited to the amount you paid us in the twelve months before the claim.
8. Source code
These terms govern use of the hosted service. The OpenCITE source code is published separately under a source-available license that does not permit operating a hosted or commercial deployment; the MCP client package is MIT-licensed.
9. Changes and law
We may update these terms; the effective date above changes when we do, and continued use after a change is acceptance. These terms are governed by the laws of the State of Delaware, USA. Nothing here limits consumer rights that cannot be waived under your local law.