Licensing FAQ

v5 and later use the Business Source License 1.1 (BSL), with an Additional Use Grant that makes production use free for most people. The SDK, CLI, connectors, linter, diff, visualiser, breaking-changes and create-eventcatalog packages, and the example catalogs, stay MIT. The generators, integrations and plugins we publish are MIT too. There are no separate plugin licenses and no plugin trials. See the license.

v4 and earlier are MIT open source, forever. v5 is source-available: you can read, run, modify, fork and contribute to the code, but organisations over the free-use thresholds need a commercial license for production use. The BSL isn’t an OSI-approved open-source license, and we don’t call it one.

Nothing is taken away. v4 stays MIT forever, and you can keep using, forking and building on it. v4 now gets critical security fixes only, for 6 months after v5 is released, then reaches end of life. No new features or other fixes go into v4; new work happens in v5.

Yes. Each release series (a major or minor version with all its patches and pre-releases) becomes MIT four years after it first ships. If 5.1 first ships in March 2027, all of 5.1 becomes MIT in March 2031.

You do. Your documentation, schemas, diagrams and configuration aren’t part of the licensed software, and the BSL places no conditions on them.

• Individuals, for their own personal projects
• Organisations with under $10M in annual revenue and under $10M in funding raised
• Anyone documenting a public open-source project
• Schools and universities, for teaching and research
• Any organisation during its 60-day evaluation

Your whole group’s gross revenue for its most recently completed financial year, from consolidated accounts where they exist. Banks and insurers use the nearest equivalent measure of total income. No completed year yet? Use your projected first-year revenue. Convert other currencies to US dollars at that year’s average rate.

All outside equity investment your group has taken since it was formed, at the amounts invested, including priced rounds, convertible notes and SAFEs. Revenue, grants, bank loans and other debt don’t count, so a bootstrapped or grant-funded company has zero funding for this test.

Your group’s: every company that controls you, that you control, or that is under common control with you (more than 50% ownership). One commercial license can cover the whole group. Two exceptions: companies aren’t grouped just because the same government owns them, or because the same investment fund owns them without consolidating their accounts. So a state-owned or private-equity portfolio company is judged on its own group.

Each public body counts on its own (a ministry, department, agency, local authority or health trust), not the wider government. Use the greater of your annual income and your annual budget.

The same $10M test applies, using the greater of your total income (including grants and donations) and your annual budget. Grants don’t count as funding. Most charities and non-profits are under the threshold.

Teaching and academic research are free at any school, college or university recognised by its country’s education authorities. Documenting the institution’s own IT systems uses the revenue and funding tests, like any other organisation.

You get 90 days’ grace, with nothing changing, then 30 more days to buy a commercial license. The 90 days start from the earliest of: the end of the financial year in which your revenue reached $10M, the date your total funding raised reached $10M, or the date an acquisition or merger took your group over either threshold.

Your client’s status decides. If they qualify for free use or hold a commercial license, your work for them is covered, whether you build, customise, host or hand over the catalog. You can rely on what they tell you in writing, unless you know it’s wrong. Your own internal catalog is judged on your own revenue and funding.

Yes. Production use is any catalog your teams, contractors or automated systems (including AI agents) use or rely on to document, discover, understand or govern your systems, whether it’s internal, private or public. Building or validating a catalog in CI counts too.

If it documents your real systems and anyone relies on it, yes, whatever you call it: POC, pilot, evaluation or sandbox. Once your real architecture is in a catalog people look at, your 60-day evaluation has started. That’s what the evaluation is for.

Trying EventCatalog with sample, test or throwaway content nobody relies on, and developing, testing or contributing to EventCatalog itself. That’s free for everyone, with no time limit.

No. Agents working for your organisation, such as Copilot, Cursor, Claude or your own agents reading the catalog over MCP or llms.txt, are part of your use. They don’t affect whether you need a commercial license, and they don’t count towards your price.

Every organisation, including all its group companies, gets one 60-day evaluation of the full product, starting from its first production use of any v5 release. Upgrading, reinstalling or creating another catalog doesn’t restart it.

Your builds keep working. We never break your catalog or pipeline. You’ll see a reminder and have 30 more days to buy a license or stop using it: 90 days in total from first production use. Need longer? If you have a sponsor, success criteria and a decision date, contact us. Extensions are confirmed in writing.

If you didn’t know, and had no reason to know, that you needed a license, buy one or stop within 30 days of finding out, and your past use is treated as permitted. This doesn’t apply if you offered EventCatalog as a hosted service to third parties (see below), or if in-product reminders had already told you a license was needed.

Strictly, your combined group has used its evaluation, but email us and we’ll normally agree a fresh one in writing. The one-per-organisation rule stops groups cycling evaluations between subsidiaries; it isn’t meant to penalise acquisitions.

Optional hands-on help rolling out EventCatalog: $6,000 for six months. We work with one team on one workflow, agree success criteria and check in every few weeks. The fee is credited against your first year if you buy a commercial license within 30 days of the programme ending. Learn more.

Your license key: a signed token in a file called license.jwt. Put it in the root of your catalog, or store it anywhere and set the EC_LICENSE environment variable to the file’s path. EventCatalog reads it to show your license details and expiry.

Free users confirm their eligibility on EventCatalog Cloud and get a key in about a minute. Commercial customers get a key with their license. To buy Business, place an order: we send your order form and invoice within 1 business day, and your key as soon as it’s paid.

No. A v5 key is verified offline against a public key built into EventCatalog, so it works air-gapped and your architecture never leaves your infrastructure. Older Starter or Scale keys issued before v5 are still checked online at build time, and we’ll swap one for an offline key on request. Separately, by default EventCatalog sends usage telemetry, such as the organisation name from your configuration, a random catalog ID, the version and counts of the resources in your catalog, but never the content of your catalog. You can turn it off; see our Privacy Policy.

Your catalog keeps building. You’ll see a reminder with the days remaining, and renewing replaces the file. We never lock you out of your own documentation.

No. One key covers your whole organisation: every catalog, every environment, and everyone in the teams you count, with no per-user limit. Your team count is part of your agreement; the key doesn’t count or enforce it.

No. Eligibility and team count are self-certified. We trust you. Before each renewal we review your team count with you, using a list of the teams you counted, by name.

Not without a separate agreement, whether or not you charge. You can’t give third parties access to EventCatalog, or to catalogs built with it, as a hosted, managed or multi-tenant service, on its own or inside another product. There’s no automatic grace period here: if we notify you, you have 30 days to stop or agree terms. That applies only once, and past use isn’t forgiven.

Yes, as a bespoke service, if the catalog documents that client’s systems and the client qualifies or holds a commercial license. You can’t turn it into a standardised or self-service hosting product. For example:

• One dedicated instance for one client, as part of your engagement: fine.
• The same set-up for several clients, each a separate bespoke engagement: fine.
• “Managed EventCatalog hosting” that anyone can sign up for: needs an agreement.
• Your SaaS product shows each customer a catalog of their own events, powered by EventCatalog: needs an agreement.
• One multi-tenant catalog for every company in your own group: fine. Your group isn’t a third party.
• Free-of-charge hosting for catalogs that document only open-source projects: fine.

Yes, always. You can make a catalog of your own systems public for customers, partners or anyone else.

Yes. The SDK and other MIT packages are open source, so you can build and sell tools, generators, plugins and integrations with them. The restriction only covers hosting EventCatalog itself for others.

Only if the vendor’s agreement with us expressly covers its customers. Otherwise your own status applies, as if you’d installed EventCatalog yourself. Ask the vendor, or ask us.

Yes, please do. You sign our Contributor License Agreement with EventCatalog Ltd once, through the pull request check. You keep the copyright in your work and give us a license to include it in EventCatalog.

Yes. v4 forks are MIT. v5 forks stay under the BSL, so the same free-use rules apply. Forks can’t use the EventCatalog name or logo.

It depends on how many teams use EventCatalog. Business has three published bands: Team, $5,995 a year for up to 5 teams; Department, $11,995 for 6 to 15 teams; and Division, $19,995 for 16 to 30 teams. Above 30 teams, you move to Enterprise, which starts at $24,995 a year and scales with the number of teams, agreed with you. It is for organisations that want federation, a signed Enterprise Agreement with the contract changes they propose reviewed, procurement and security reviews, and faster support, at any size. A team is a standing group under one lead, like a squad, product team or platform team, and it counts if anyone in it uses EventCatalog as part of their work. See every band on the pricing page, or buy Business.

A team is a standing group that works together under one lead, like a squad, product team or platform team. It counts if anyone in it uses EventCatalog as part of their work, reading or contributing, whether or not the team owns anything in the catalog. A department counts as the teams inside it. Someone occasionally opening a link another team shared doesn’t make their team count. Using EventCatalog through an AI assistant counts the same as using it directly, but CI pipelines and other automation never add a team. People outside your organisation with read-only access, such as partners, suppliers or clients, don’t count. Count them the way your organisation already does. You tell us your number, and we review it together at renewal.

Yes. You can give people outside your organisation, such as partners, suppliers and clients, read-only access to your catalogs for your own business. They don’t count towards your team count, and you’re responsible for how they use it.

Yes. The generators, integrations and plugins we publish are open source under the MIT License, and every paid plan covers using them with EventCatalog in production. There are no separate plugin licenses and no plugin trials. EventCatalog itself is under the BSL: if your organisation qualifies for free use (under $10M in revenue and under $10M raised) or is in its 60-day evaluation, you can use EventCatalog with all of them in production, with no contract, procurement or support.

Organisations that qualify for Free Use get every feature free, including federation, every generator and every plugin, as is, with no contract and no support. Business gives you the right to use EventCatalog in production above the thresholds, without federation, plus email support (first response within 3 business days) and our Terms of Service. Business does not include federation in production. Our DPA forms part of every paid contract, and the Security Pack and an insurance certificate are available on request. On a paid plan, federation is Enterprise only. Enterprise adds production use of federation, a team count agreed with you, a first response within 1 business day, a dedicated contact, an optional private Slack or Discord channel in your workspace, an optional monthly call, and a signed Enterprise Agreement, with the contract changes you propose reviewed.

Ask for our Security Pack: a security overview, our standard security questionnaire and tax forms. Our DPA, covering support data, forms part of every paid contract, and an insurance certificate is available on request, alongside the license and our Terms of Service. We can invoice. Your own purchasing terms don’t apply. A signed Enterprise Agreement, review of the contract changes you propose, your own questionnaires and vendor registration are part of the Enterprise plan.

Yes. This page is guidance only. It doesn’t form part of the license or the Terms of Service, and it doesn’t change either of them. If this page differs from the license, the license applies. For paying customers, the Terms of Service apply to the paid subscription. We give commercial customers at least 90 days’ notice of material changes to those terms.