Terms of Service (8 October 2026, superseded)

Last Updated: 8 October 2026 · Previous versions

If you have a paid Business or Enterprise subscription, our Standard Terms also apply to you.

EVENTCATALOG LTD ("EVENTCATALOG", "WE", "US"), A COMPANY REGISTERED IN ENGLAND AND WALES (COMPANY NUMBER 15764703), OWNS AND OPERATES THE SOFTWARE AND SERVICES DESCRIBED AT WWW.EVENTCATALOG.DEV. THESE TERMS OF SERVICE (THE "TERMS") APPLY TO ANY ORGANISATION THAT PURCHASES A COMMERCIAL LICENSE, STARTS A PAID PROGRAMME, OR OTHERWISE ENTERS INTO A PAID RELATIONSHIP WITH EVENTCATALOG ("YOU", "YOUR").

PLEASE READ THESE TERMS CAREFULLY. BY COMPLETING A PURCHASE, SIGNING AN ORDER, OR CONTINUING TO PAY FEES AFTER ANY UPDATE TO THESE TERMS, YOU ACCEPT THEM. IF YOU DO NOT ACCEPT THESE TERMS, DO NOT PURCHASE A COMMERCIAL LICENSE. YOUR RIGHTS UNDER THE BUSINESS SOURCE LICENSE ARE UNAFFECTED EITHER WAY.

Business Use Only. Commercial Licenses are sold to organisations for business use. By agreeing to these Terms, you confirm you are purchasing in a business capacity, not as a consumer, and that you have authority to bind your organisation.

Custom Terms. These Terms apply to all Commercial Licenses purchased online or by invoice. We provide a Trust pack on request (security overview, standard security questionnaire, DPA, tax forms and insurance certificate). If you need your own contract, redlines, custom questionnaires, vendor registration or custom payment terms, that is part of the Enterprise plan; contact hello@eventcatalog.dev.

1. How the licenses fit together​

a. Three layers. EventCatalog is available in three ways, and it is important to understand which one applies to you:

1. EventCatalog v4 and earlier is open source under the MIT License. These Terms do not apply to it.
2. EventCatalog v5 and later is source-available under the Business Source License 1.1 with an Additional Use Grant (together, the "BSL"), published in the LICENSE file of the EventCatalog repository. The BSL lets Eligible Users (as defined there) use the Software in production for free, and lets everyone read, modify, fork, redistribute and make non-production use of it.
3. A Commercial License (these Terms, together with your Order) is required for production use of v5 and later by organisations that are not Eligible Users under the BSL. It also provides the support, notifications and commercial assurances described below.

b. These Terms add to the BSL, never subtract from it. Nothing in these Terms limits any right you have under the BSL or, for earlier versions, the MIT License. If any provision of these Terms would restrict a right the BSL grants, the BSL prevails and that provision does not apply to that right.

c. Guidance. Our published licensing guidance at eventcatalog.dev/license-faq explains who qualifies as an Eligible User and how the BSL works in practice. The license FAQ is guidance only. It does not form part of these Terms or change the license, and if anything in it conflicts with the license or these Terms, the license and these Terms apply.

2. Definitions​

a. "Software" means EventCatalog version 5.0 or later, as published by EventCatalog, including any updates we release.

b. "Commercial License" means the license granted under Section 3 for the term of your subscription.

c. "Organisation" has the meaning given in the BSL: a legal entity together with all of its Affiliates (entities that control it, that it controls, or that are under common control with it, at more than 50% ownership), subject to the exceptions in the BSL for government-owned entities and investment-fund portfolio companies.

d. "Authorized Users" means employees, contractors and agents of your Organisation, and of any client for whom you hold a license under Section 3(d), whom you allow to use the Software.

e. "Team" means a group of up to about 10 people in your Organisation who work together day to day and read or edit your catalog most months, for example teams building the services you document, teams integrating with them, and the architects or platform team maintaining the catalog. People who look occasionally, and automated systems and AI agents acting for your Organisation, are not counted separately.

f. "Licensed Teams" means the number of Teams stated in your Order.

g. "Plan" means the Business plan or the Enterprise plan, as stated in your Order and described on the Website.

h. "Enterprise Features" means federation (connecting multiple catalogs into one organisation-wide view) and any other capability the Website identifies as available on the Enterprise plan.

i. "Order" means your online purchase through the Website, a signed order form, an invoice you have accepted, or similar, which together with these Terms forms the agreement between you and EventCatalog.

j. "License Key" means the signed license.jwt file or equivalent token we issue to you.

k. "Website" means www.eventcatalog.dev and its subdomains, and EventCatalog Cloud (eventcatalog.cloud), our license key and billing portal.

l. "Success Programme" means the fixed-fee, fixed-term programme described on the Website and in your Order, in which we work with one of your teams to establish a defined workflow in your catalog.

3. Commercial License​

a. Grant. For the term of your subscription, and subject to payment of the fees, EventCatalog grants your Organisation a non-exclusive, non-transferable, worldwide license to install, run and make production use of the Software for your Organisation's own purposes, in any number of catalogs, environments and instances, by any number of Authorized Users within your Licensed Teams (or, on the Enterprise plan, as stated in your Order).

b. What each Plan includes. Every Plan includes every feature, integration, generator and capability of the Software for documenting your architecture, at the time of purchase and released during your term. The Business plan does not include production use of Enterprise Features; the Enterprise plan does. This Section describes the scope of the Commercial License only and does not limit any right you have under the BSL.

c. One license for your Organisation. One Commercial License covers your Organisation as defined above, priced by the number of Licensed Teams. You do not need separate licenses for subsidiaries, catalogs, or development, staging and production environments. A subsidiary may instead buy its own Commercial License covering only its own Teams.

d. Client work. If you are a consultancy, agency or vendor, a Commercial License held by your client covers your work for that client. Your own Commercial License covers work for your own Organisation; it does not cover your clients unless your Order expressly says so.

e. What you may not do. You may not: (i) use the Software to provide third parties with access to it, or to catalogs built with it, as a hosted, managed or multi-tenant service, whether or not for a fee, except as the BSL permits or as your Order expressly allows; (ii) share your License Key with, or use it on behalf of, any organisation outside your Organisation or a client covered under Section 3(d); (iii) misrepresent your eligibility or your number of Teams; or (iv) remove or alter EventCatalog's copyright and license notices in the Software. These restrictions mirror the BSL and apply in addition to it; they do not limit your right under the BSL to read, modify, fork or redistribute the Software.

f. Modifications. You may modify the Software, as the BSL allows. Modifications are at your own risk: support and the warranty in Section 11 do not cover problems caused by changes you make.

4. Evaluation, grace periods and coming into compliance​

a. Evaluation. Every Organisation gets one 60-day evaluation of the Software under the BSL, with nothing held back, starting from its first production use. This is governed by the BSL, not by these Terms, and we may extend it in writing.

b. Your builds keep working. The Software never stops building, and we never disable a deployed catalog, when an evaluation ends or a license lapses. It shows a reminder instead. Continued production use outside the BSL's free-use terms after the applicable grace period is a breach of the BSL, not a technical failure.

c. Grace periods. The BSL gives you 30 days after your evaluation ends, or after you stop being an Eligible User, to purchase a Commercial License or stop production use. Organisations that grow past the BSL's revenue or funding thresholds get 90 days' grace before that. These periods are set by the BSL and summarised on the licensing FAQ.

d. If you've been using the Software without a license. If you make production use of the Software without being an Eligible User and without a Commercial License, and did not know that a license was required, the BSL treats your past use as permitted provided you purchase a Commercial License or stop within 30 days of becoming aware. We would rather you became a customer than worried about it. This does not apply to offering the Software as a hosted service.

5. Teams, self-certification and renewal​

a. Self-certification. When you purchase, you tell us how many Teams you expect to use the Software during the term, and you confirm that your Organisation is not an Eligible User under the BSL. We do not audit you. You confirm that what you tell us is accurate to the best of your knowledge.

b. Fixed for the term. Your price does not change during a term, however your use grows. You may move to a larger band or to the Enterprise plan at any time during the term by agreement, with the difference pro-rated.

c. Renewal review. Before each renewal we review with you how the Software is being used, including the number of Teams using it and how your catalog has grown, drawing on the information in Section 6. Your Plan, Licensed Teams and fees for the next term reflect that review and the prices published on the Website at the time.

d. Multi-year terms. If your Order is for more than one year, the review in Section 5(c) takes place on each anniversary, and your Licensed Teams and fees for the following year are adjusted to match, subject to any discount or cap stated in your Order.

e. Acquisitions and mergers. If your Organisation acquires, is acquired by, or merges with another organisation during the term, your Commercial License continues on its existing terms until renewal. Tell us about the change, and at renewal the combined Organisation's Teams are reviewed together. If the other organisation already holds a Commercial License, we will consolidate the two at the next renewal rather than charge twice.

f. Misrepresentation. If you knowingly understate your number of Teams or misstate your eligibility, we may invoice the difference for the current and any prior terms and, if unpaid within 30 days, treat it as a material breach.

6. License Keys and telemetry​

a. License Keys. We issue a License Key for your Organisation. It is a signed token verified locally by the Software using a public key built into it. The Software does not contact our servers to validate it, and it works in air-gapped environments. If you still use a Starter or Scale license key issued before version 5.0, the Software checks that key online at build time by sending it to our license service, which, as with any web request, receives the request time and IP address. No catalog content is sent.

b. Expiry. License Keys expire at the end of your subscription term. When a key is within 30 days of expiry, or has expired, the Software shows a reminder. It continues to build and run.

c. Telemetry. By default, the Software sends usage telemetry when you run development, build and create commands. It includes the organisation name from your configuration, a randomly generated catalog ID, the Software version, the command run, whether a license is present and its type, plan and feature flags, generator names, counts of the resource types in your catalog (for example, the number of services and events), a one-way hash of your catalog files, and operating system and Node.js versions. The IP address of the machine running the build is visible to the receiving service. It never sends the names or content of your services, events, schemas, documentation or diagrams, nor any data about the people using your catalog. Telemetry is not anonymous, because the organisation name and catalog ID can identify your Organisation. It is sent to our analytics provider, Simple Analytics, and then copied into PostHog by a scheduled job. Telemetry is used to understand adoption and improve the Software. From v5, it can be turned off with EVENTCATALOG_TELEMETRY_DISABLED=1, DO_NOT_TRACK=1 or telemetry: false in eventcatalog.config.js. Further detail is in our Privacy Policy.

d. Account information. We collect and process the contact and billing information you give us when you purchase, together with your self-certified eligibility and number of Teams, to manage your license. This is handled under our Privacy Policy, which also lists our subprocessors in its Subprocessors section.

e. If we stop trading. If EventCatalog Ltd ever stops trading, the Software you have installed keeps working, and License Keys already issued (including offline keys) continue to work for the versions they cover. No further development or support would be provided.

7. Support and updates​

a. Support. All Commercial License holders receive support by email at support@eventcatalog.dev, Monday to Friday, 9 AM to 5 PM UK time, with a target first response within 3 business days on the Business plan and within 1 business day on the Enterprise plan. Support covers installation, configuration, upgrade assistance, feature guidance and bug reports. It does not cover custom development, training beyond our published documentation, third-party software, or issues caused by your modifications to the Software.

b. Security notifications. We will notify you by email of security vulnerabilities in the Software that we assess as high or critical, together with the fixed version, as soon as reasonably practicable after a fix is available.

c. Updates. We make updates available through our usual distribution channels (currently npm). You are responsible for installing them on your own infrastructure. We follow Semantic Versioning: minor and patch releases are backwards-compatible; major releases may include breaking changes, which we document with migration guidance.

d. Supported versions. Support covers the latest major version of the Software. When a new major version is released, the previous major version receives critical security fixes only, for 3 months. Older versions may continue to be used but are not supported.

e. Enterprise support. On the Enterprise plan we also provide: (i) a target first response within 1 business day for all support requests, with critical issues worked on until a fix or workaround is available; and (ii) a private Slack or Discord channel for support, if you want one. Because the Software is self-hosted, we do not provide an uptime commitment; our service levels cover how quickly we respond. Security fixes are handled as described in Section 7(b).

Service levels apply during support hours, and targets are commitments of effort, not guarantees of outcome. If we repeatedly miss them, your remedy is as stated in your Order.

f. Success Programme. If your Order includes the Success Programme, we will provide the scoping, working sessions, check-ins and written readout described on the Website for the programme's fixed term. The programme fee is credited against the first year of a Commercial License purchased within 30 days of the programme ending, as stated in your Order. The Success Programme is a professional service with a fixed scope; it does not include development work or open-ended consultancy.

8. Fees and payment​

a. Fees. Fees are set by your Plan and number of Licensed Teams, using the prices published on the Website at the time of purchase or renewal, or as stated in your Order. Fees are payable annually in advance.

b. Taxes. Fees exclude VAT and other applicable taxes, which are your responsibility, except taxes on EventCatalog's net income.

c. Payment. You may pay by card at checkout or by invoice. Invoices are due within 30 days of the invoice date unless your Order says otherwise. Overdue invoices accrue interest at the rate set by the Late Payment of Commercial Debts (Interest) Act 1998. If invoiced fees remain unpaid 30 days after the due date, we may suspend your Commercial License until paid; the Software itself keeps running.

d. Refunds. Fees are non-refundable except as stated in Sections 11 and 13 or where required by law.

9. Term and renewal​

a. Term. Your subscription starts on the date in your Order and runs for one year unless your Order says otherwise.

b. Renewal. Subscriptions renew automatically for successive one-year terms unless either party gives written notice at least 30 days before the renewal date. To cancel, email support@eventcatalog.dev.

c. Price changes. We may change the published prices for our Plans and bands. A change takes effect for you at your next renewal, and we will give you at least 60 days' notice before it does. Your price never changes mid-term.

d. Existing customers at the launch of v5. If you held an EventCatalog subscription before the release of version 5.0, your existing price is honoured until your first renewal after the v5 release, and any later increases to move you to the published price for your Plan and Licensed Teams are capped as stated on the Website or in your Order.

10. Your data and your content​

a. You own your content. Your documentation, schemas, diagrams, configuration and everything else you create with the Software are yours. They are not part of the Software and neither the BSL nor these Terms places any condition on them.

b. Self-hosted. You install and run the Software on your own infrastructure. You are responsible for its security, backups, access control and legal compliance. Other than the telemetry in Section 6(c), the online license check in Section 6(a) for older keys, and the account information in Section 6(d), we do not access, store or process your data, and we have no visibility of your catalog content. We act as an independent controller for the account, license and billing information we hold, as described in our Privacy Policy. If your organisation needs a data processing agreement, one is available on request.

c. Support access. If you give us access to your environment to resolve a support issue, we access only what is needed, for as long as needed, under the confidentiality obligations in Section 14, and we delete anything we obtained within 30 days of resolution.

11. Warranties​

a. Limited warranty. We warrant that, for 90 days from purchase, the Software will substantially conform to its published documentation. Your exclusive remedy is for us to use commercially reasonable efforts to fix the non-conformity or, if we cannot within a reasonable time, to refund the fees for the affected period.

b. Disclaimer. EXCEPT AS EXPRESSLY PROVIDED IN THESE TERMS, THE SOFTWARE AND SERVICES ARE PROVIDED "AS IS" AND EVENTCATALOG DISCLAIMS ALL OTHER WARRANTIES AND CONDITIONS, EXPRESS, IMPLIED OR STATUTORY, INCLUDING WARRANTIES OF MERCHANTABILITY, SATISFACTORY QUALITY, FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT, TO THE MAXIMUM EXTENT PERMITTED BY LAW. WE DO NOT WARRANT THAT THE SOFTWARE WILL BE ERROR-FREE OR UNINTERRUPTED.

12. Limitation of liability​

a. NEITHER PARTY IS LIABLE FOR ANY INDIRECT, INCIDENTAL, SPECIAL, CONSEQUENTIAL OR EXEMPLARY DAMAGES, OR FOR LOSS OF PROFITS, REVENUE, GOODWILL OR DATA, ARISING OUT OF OR IN CONNECTION WITH THESE TERMS, EVEN IF ADVISED OF THE POSSIBILITY.

b. EVENTCATALOG'S TOTAL LIABILITY UNDER OR IN CONNECTION WITH THESE TERMS IS LIMITED TO THE FEES YOU PAID IN THE 12 MONTHS BEFORE THE CLAIM, EXCEPT THAT FOR CLAIMS UNDER SECTION 13(a) IT IS LIMITED TO THREE TIMES THOSE FEES.

c. Exceptions. Nothing in these Terms limits or excludes liability for fraud or fraudulent misrepresentation, for death or personal injury caused by negligence, or for anything that cannot be limited or excluded under applicable law.

13. Intellectual property claims​

a. Our commitment. If a third party claims that your use of the Software in accordance with these Terms infringes its intellectual property rights, we will, at our option and expense: (i) obtain the right for you to continue using the Software; (ii) modify or replace the Software so it is non-infringing while providing substantially equivalent functionality; or (iii) if neither is commercially practicable, terminate your Commercial License and refund the prepaid fees for the unused portion of your term. You must notify us promptly in writing of any such claim and not admit liability without our written consent. This Section states our entire liability for third-party intellectual property claims.

b. Exclusions. Section 13(a) does not apply to claims arising from: modifications made by anyone other than us; use in breach of these Terms or the BSL; combination with third-party products where the claim would not arise but for the combination; use of a version other than the current version where the current version would have avoided the claim; or use of the Software without a Commercial License, which is governed solely by the BSL and provided without warranty or indemnity.

c. Your commitment. You will defend and indemnify EventCatalog against third-party claims arising from your content, your breach of these Terms, or your breach of applicable law, provided we notify you promptly, give you control of the defence, and cooperate at your expense.

14. Confidentiality​

Each party will keep the other's Confidential Information confidential and use it only to perform these Terms. "Confidential Information" means non-public business, technical or financial information disclosed under these Terms, including your eligibility, your number of Teams and anything we see during support access. It excludes information that is already known without an obligation of confidence, becomes public through no fault of the recipient, is received from a third party without restriction, or is independently developed. A party may disclose Confidential Information when legally required, after giving reasonable notice where permitted. These obligations survive for three years after termination.

15. Termination​

a. For breach. Either party may terminate these Terms on 30 days' written notice if the other commits a material breach that is not remedied within those 30 days. Non-payment, sharing your License Key outside your Organisation, and offering the Software as a hosted service without our agreement are material breaches.

b. Effect. On termination or expiry: (i) your Commercial License ends and your License Key is not renewed; (ii) your rights revert to those you have under the BSL, so if your Organisation is an Eligible User you may continue production use for free, and otherwise you must stop production use within the BSL's grace period or purchase a new Commercial License; (iii) the Software is not disabled and your deployed catalogs keep working; (iv) you pay any fees outstanding to the date of termination; and (v) your content remains yours.

c. No effect on the BSL or MIT. Termination of these Terms never affects your rights under the BSL, or under the MIT License for version 4 and earlier.

d. Survival. Sections 1, 10, 11(b), 12, 13, 14, 15 and 16 survive termination, together with any payment obligations.

16. General​

a. Dispute resolution. Before starting legal proceedings, each party will describe the dispute to the other in writing and make a good-faith effort to resolve it within 30 days. Either party may seek urgent injunctive relief at any time.

b. Governing law. These Terms are governed by the laws of England and Wales, and the courts of England and Wales have exclusive jurisdiction.

c. Publicity. We may name you as a customer on the Website unless you ask us not to at support@eventcatalog.dev; we will remove you within 30 days. EventCatalog is a registered UK trade mark of EventCatalog Ltd. You may use the EventCatalog name to refer to the Software, but not in a way that suggests we sponsor or endorse you or your product, and you may not use our logo without our written permission.

d. Force majeure. Neither party is liable for failure to perform caused by events beyond its reasonable control.

e. Assignment. You may assign these Terms to a successor to all or substantially all of your business on written notice to us. Otherwise, neither party may assign these Terms without the other's consent, except that we may assign them to an affiliate or a successor to the EventCatalog business.

f. Changes to these Terms. We may update these Terms. We will give you at least 90 days' notice of any material change by email or on the Website, and changes apply from your next renewal after that notice. We will never change these Terms to reduce the rights the BSL gives you.

g. Severability, waiver and entire agreement. If any part of these Terms is unenforceable, the rest remains in effect. A failure to enforce a right is not a waiver of it. These Terms, your Order and the BSL are the entire agreement between us about the Software and replace all prior agreements and representations. Our Privacy Policy explains how we handle personal data.

h. Notices. Notices must be in writing by email: to support@eventcatalog.dev for us, and to the email address on your account for you. Notices are treated as received on the next business day.

i. Resellers. If you buy through an authorised reseller, these Terms still apply in full. Resellers cannot change these Terms or make commitments on our behalf.

17. Contact​

EventCatalog Ltd Registered in England and Wales, company number 15764703

Licensing and sales: hello@eventcatalog.dev Support and privacy: support@eventcatalog.dev

Previous versions of these Terms are archived in our terms history.