Terms of Service

These Terms of Service (the “Terms”) are a binding agreement between you and MatWorld Inc., a California corporation (“MatWorld”, “we”, “us”), governing your use of the website at matworld.ai, the application programming interfaces that serve it, and every feature they expose (together, the “Service”).

You accept these Terms by creating an account, by ticking the acceptance box at sign-up or at checkout, or by using the Service. If you use the Service on behalf of a company or other organisation, you represent that you are authorised to bind it, and “you” includes that organisation.

Our Privacy Policy and Cookie & Local Storage Notice describe how we handle information and are incorporated by reference.

The Service is built for engineers and other professionals working with material data. You must be at least 16 years old to use it, and at least 18 to hold a paid subscription. You may not use the Service if you are barred from doing so under the laws of your jurisdiction or under the export-control rules in section 8.

MatWorld is a reference database of engineering material properties with each value linked to its published source, together with tools that work on that data: a browser and datasheets, a material selector, regulatory screening, side-by-side comparison, plain-English search, export of material cards for computer-aided engineering (CAE) solvers, and a calibration workbench that fits constitutive models to test curves you upload.

What each plan includes is stated on the pricing page at the time you subscribe. In summary: browsing, property values, and source citations are available to everyone; interactive curves, the selector, regulatory screening, and calibration set-up require a free account; plain-English search, comparison, CAE export, and running calibration fits are part of Pro. We may add, change, or retire features. Any feature may be paused for incident response. Pro also includes agent access: your own AI agents may query the Service through our Model Context Protocol (MCP) server, using a personal key you generate in Settings or by signing in with your account, within the limits in section 7. There is no other programmatic interface.

Sign-in is operated by Clerk. You are responsible for keeping your credentials confidential and for all activity under your account. Tell us promptly at matworldai@gmail.com if you believe your account has been compromised.

A Team plan is purchased by one account holder (the “owner”) for a fixed number of seats. The owner distributes a redeem link, is responsible for who uses it, may revoke any member at any time, and is the only party we bill or refund. Seats are personal: one person per seat, no sharing of credentials. If a Team subscription ends, every member on a team-provided seat returns to the free plan at the end of the paid period.

• Processor. Payments are processed by Stripe. Card details are entered on Stripe’s pages and never reach MatWorld’s servers.
• Automatic renewal. Pro and Team plans are monthly subscriptions. They renew automatically on the same day of each month as your original purchase, at the price shown at checkout, until you cancel. You consent to the renewal charge by completing checkout.
• Cancel any time. You can cancel from Settings → Billing, which opens the Stripe billing portal, or by emailing us. Cancellation takes effect at the end of the billing period you have already paid for: you keep access until then, and you are not charged again.
• No refunds. Fees are non-refundable. We do not prorate or credit partial billing periods, including when you cancel, downgrade, or stop using the Service. Where the law of your jurisdiction requires a refund we cannot exclude, we will honour it.
• Price changes. We will notify you by email at least 30 days before any price change takes effect on a renewal. Continuing past that renewal accepts the new price.
• Failed payments. If a renewal payment fails we will email you with a link to update your payment method. If it is not resolved, the subscription ends and your account returns to the free plan.
• Taxes. Prices exclude any taxes we are required to collect, which are shown at checkout where applicable.

What the data is. Property values, curves, compositions, regulatory flags, and descriptions on the Service are reference information reproduced from third-party published sources. Each is shown with its source and, where the source states them, its table or figure, test conditions, and statistical basis. MatWorld did not generate, test, measure, or certify any of it and has not independently verified it. Transcription, digitisation, unit conversion, property inheritance between related grades, and text written by AI can all introduce errors.

Not design allowables, not qualification. CAE export cards, Advanced Mode selections, digitised curves, comparison results, selector plots, and calibration decks are computed from that reference data and from inputs you supply. They are engineering aids. They are not design allowables, not qualified material data, and not a substitute for testing to the specification that governs your application. A calibration verdict (PASS, WARN, or REJECT) is an automated check of how well a model fits the curve you uploaded; it endorses no model for any use.

Safety-critical use. The Service is not designed for use where an error in the data could lead to death, personal injury, or severe physical or environmental damage. If you use it in such a context, you do so only after independently qualifying the data for that purpose, and MatWorld accepts no responsibility for the outcome.

No professional relationship. Nothing on the Service is engineering advice. No engineer–client, fiduciary, or advisory relationship is created. MatWorld is not a manufacturer, supplier, or testing laboratory of any material.

Regulatory screening. Compliance flags are derived by matching a material’s recorded composition against published substance lists. They are a screening aid to help you decide what to check, not a compliance determination or a legal opinion.

Sources’ own terms. Where a source imposes conditions (for example attribution under a Creative Commons licence, or a distribution statement), those conditions travel with the data and you are responsible for honouring them. MatWorld is not responsible for the content of any source.

The underlying property values come from public-domain United States Government works (including MIL-HDBK-5J and MIL-HDBK-17-2F), Apache-2.0 and CC-BY licensed datasets, and other openly published sources recorded in our data ledger. The selection, curation, structuring, descriptions, compliance rules, export logic, and software are MatWorld’s, and the database as a compilation is protected where the law provides for it. MatWorld does not carry MMPDS or CMH-17 data.

We grant you a limited, revocable, non-exclusive licence to use the Service and to use the data and files you obtain through it in your own engineering work, including inside your organisation. You may not:

• scrape, crawl, bulk-download, or systematically extract the database or a substantial part of it, by hand, by automation, or through an agent connected to the MCP server;
• mirror, resell, sublicense, or redistribute the database or a substantial part of it, or build a competing dataset or service from it;
• share account credentials or a Team seat between people, or circumvent plan limits, rate limits, or access controls;
• remove source attributions or the data notices from exported files;
• use the Service to develop or train a machine-learning model on the database without our written permission;
• interfere with the Service, probe it for vulnerabilities without authorisation, or use it for anything unlawful.

Agent access. Data an agent retrieves through the MCP server is data you obtained through the Service and is covered by the licence and limits above. Keys are personal: one person, one key, never shared or embedded where others can use it. Agent calls are rate-limited and counted, plain-English queries made by an agent draw on the same daily allowance as the search box, and we may revoke a key or suspend agent access if it is used to extract the database or otherwise breaches this section. Your agent’s provider receives whatever data the agent requests on your behalf under that provider’s own terms.

Attribution required by a source’s licence (CC-BY) is carried in the exported files; keep it there.

The handbook material in the database is limited to documents marked Distribution Statement A (approved for public release, distribution unlimited). Export-controlled annexes are excluded. You remain responsible for your own obligations under the export-control and sanctions laws that apply to you, including any restriction on where and by whom the data or the files you generate may be used.

Calibration uploads. Test curves you upload to the calibration workbench are processed in memory to parse, plot, and fit them, and to render a deck. They are not stored on our servers; the only copy is in your browser’s local storage. You keep all rights in them and you confirm you are entitled to upload them.

Feedback. Suggestions, bug reports, and other feedback you send us may be used to improve the Service without obligation to you.

Material descriptions, plain-English search interpretations and reasons, and answers from the assistant are produced with the help of large language models. They can be wrong, incomplete, or confidently misleading. They are provided to help you navigate the data and are covered by section 6 in full: check the cited source before relying on anything they say.

Some jurisdictions do not allow certain warranty exclusions; in that case the exclusion applies to the greatest extent the law allows.

Nothing in these Terms excludes or limits liability that cannot be excluded or limited under applicable law, including liability for fraud, wilful misconduct, gross negligence, or death or personal injury caused by negligence where the law does not permit such a limit. You acknowledge that the pricing of the Service reflects this allocation of risk and that MatWorld would not offer the Service without it. Any claim must be brought within one year after it arises, where the law permits such a limit.

You will defend, indemnify, and hold harmless MatWorld Inc. and its officers, directors, and employees from any third-party claim, and the resulting losses, damages, and reasonable legal costs, arising out of (a) your use of material data, exports, decks, or other outputs in any design, analysis, product, or service; (b) your breach of section 6’s verification condition or of section 7; or (c) content you upload. We will notify you promptly of any such claim and cooperate reasonably in the defence.

You may stop using the Service at any time and may delete your account from Settings. We may suspend or terminate your access if you breach these Terms, if required by law, or if we discontinue the Service, and will tell you why where the law allows. On termination your right to use the Service ends; sections 6, 7, and 11 through 16 survive. Fees already paid are not refunded except where section 5 says otherwise.

These Terms are governed by the laws of the State of California, United States, without regard to its conflict-of-laws rules. Any dispute arising out of or relating to these Terms or the Service will be brought exclusively in the state and federal courts located in the State of California, and you consent to their jurisdiction. If you are a consumer resident in a jurisdiction whose law gives you mandatory rights to bring proceedings locally, nothing here removes those rights.

• Changes to these Terms. We may update these Terms. The version and effective date at the top of this page change when we do. For material changes we will email account holders at least 14 days before the new Terms take effect; continuing to use the Service after that date accepts them.
• Notices. We send notices to the email address on your account. You may send notices to matworldai@gmail.com.
• Entire agreement; severability; waiver. These Terms, the Privacy Policy, and the Cookie Notice are the entire agreement between you and MatWorld about the Service. If a provision is found unenforceable it is limited to the minimum extent necessary and the rest remains in force. A failure to enforce a provision is not a waiver.
• Assignment. You may not assign these Terms without our consent. We may assign them in connection with a merger, acquisition, or sale of assets.
• Third-party services. Clerk, Stripe, and other providers named in the Privacy Policy have their own terms for the parts of the experience they operate.