• The app — the desktop app, the web editor, and the dgmo command-line tool. Free. No account. Your diagrams are files you own.
• Diagrammo Cloud — optional. You sign in, we store your diagrams so a team can reach them, and some of it costs money.

If you have never signed in, most of this page is about a service you do not use.

Who you are agreeing with

The Services are provided by Diagrammo LLC, a limited liability company formed in Colorado, United States. “Diagrammo”, “we” and “us” mean that company. “You” means the person using the Services — or, if you are using them for an organisation, that organisation, and you are telling us you are allowed to agree on its behalf.

“The Services” means the Diagrammo desktop app, the web editor at online.diagrammo.app, the dgmo command-line tool, the MCP server, Diagrammo Cloud, and the diagrammo.app website.

Using the Services means you accept these terms. If you don’t accept them, don’t use them — no hard feelings, and the file formats are plain text either way.

The software, and what you may do with it

The app and the web editor

The desktop app and the web editor are proprietary software, licensed to you free of charge. The licence is personal, non-exclusive and non-transferable. Install it on any device you own or use.

You may not redistribute it, rent it, sell it, or pass it off as yours. You may not reverse-engineer, decompile or disassemble it, or make derivative works of it — except where the law where you live gives you that right regardless of what a licence says, in which case the law wins and we are not going to argue.

The open-source parts

The dgmo library and command-line tool, the MCP server, and the framework integrations are open source under the MIT License. Use, modify and redistribute them on those terms. Where the MIT License and this page disagree about those packages, the MIT License wins.

The app and the web editor bundle third-party open-source software, each under its own licence — the full list is here.

Your diagrams are yours

You own everything you create with Diagrammo. We claim no ownership of your diagrams, and nothing here transfers any of your rights to us.

To host something, we need your permission to host it — so when you put a diagram in Diagrammo Cloud, you give us a licence to store it, copy it, transmit it and display it back solely in order to run the service for you: to serve it to you and the people you have given access to, to hold it briefly in a cache so it loads quickly, and — if and only if you choose to show a diagram on the web — to serve it publicly.

That licence is narrow and it is not open-ended:

• It exists only to operate the Services. It is not a licence to publish your work, market with it, or show it to anyone you have not given access to.
• It ends when you delete the content, subject to the deletion window below and to caches that expire on their own.
• We do not train AI on your diagrams, and no model of ours or anyone else’s is shown them by us. Diagrammo’s AI features run on your own machine with your own key.
• We do not sell your content or your data. What we store and why is set out on the Privacy page, which is part of this agreement.

In exchange, you are telling us that you have the right to the content you upload, and that it doesn’t break the rules below.

Diagrammo Cloud accounts

Your email address is your identity. Sign-in links go to it, so whoever controls that mailbox controls the account — keep it secure, and tell us if you think somebody else has got in.

Diagrams live in spaces. A space has one owner and any number of members, and members hold one of three roles:

Role	What it means
Viewer	Can read the diagrams in the space. Always free, on every plan, however many of them there are
Editor	Can create and change diagrams in the space. This is the role a paid plan is priced by
Admin	The space’s owner. Invites people, changes roles, removes members, deletes the space

Two limits worth knowing before you build around them, both true as of 9 August 2026:

• A space cannot change hands. There is no ownership transfer, and the owner cannot leave their own space. If a space needs to belong to somebody else, that is a manual job — email us.
• The owner is the only admin. Admin cannot be granted to another member.

The app and the web editor keep a local copy of a space’s diagrams on your device so you can work offline. That copy is yours and it is not encrypted by us — it relies on your operating system’s disk encryption. If you are removed from a space, the app deletes that space’s local copy the next time it runs.

Showing a diagram on the web

This is the one action on the whole service that cannot be quietly undone, so it gets its own section.

When you show a diagram on the web, it becomes a genuinely public web page. Anyone with the link can read it. There is no sign-in, no password and no allowlist in front of it, other services may fetch it directly, and search engines may index it. Treat it exactly as you would treat posting the diagram publicly anywhere else — because that is what it is.

Stop showing revokes it, but not instantly and not everywhere:

• Our own records stop serving it immediately.
• Copies already held in the content-delivery cache can go on answering for up to five minutes.
• Nothing we can do reaches a copy somebody else has already saved, screenshotted, cached or archived.

You are responsible for what you publish this way, and for having the right to publish it.

Paid plans

Paid plans are not on sale as of 9 August 2026. This section is what will govern them when they are, and it changes nothing for you until you actually subscribe.

What is free. An account with no subscription can hold up to 25 diagrams, show up to 5 of them on the web, and own up to 25 spaces, with one editor per space. Viewers are unlimited and free at every tier — a space that many people read but one person writes never costs anything.

What you pay for. A subscription is priced per editor, per month. It belongs to a person, not to a space: it counts the distinct editors across every space you own, wherever they are. Viewers are never counted. The current price is shown on the pricing page and again at checkout before you commit, and that is the price that binds.

A subscription raises the ceilings to 1,000 diagrams, 250 shown on the web, 250 owned spaces, and as many editors as you pay for.

Renewal. Subscriptions renew automatically each month until cancelled. Adding or removing editors is done through the billing portal, and our payment provider works out any mid-cycle proration.

Cancelling. Cancel from the Billing button on your account page, which opens the payment provider’s portal — the same number of clicks as subscribing, and you never have to email anyone to be allowed to leave.

What happens when a subscription ends is deliberately gentle, and we want it in writing:

• Nothing is deleted, hidden or made read-only. Not one diagram, not one space.
• You return to the free ceilings going forward only. Anything you already created above them stays exactly as it is, and stays yours — you simply can’t add more until you are under the limit or subscribed again.
• Editors already in your spaces keep working. The limit applies to adding new ones.
• Your export always works, subscription or no subscription. Diagrams are plain text.

If a payment fails, we do not lock you out. Access continues while the payment provider retries in the normal way. Only when the subscription is actually cancelled do you return to the free tier — and, as above, nothing is destroyed when that happens.

Refunds. There is no automated refund button. Email us and we will sort it out — we would rather refund somebody who is unhappy than argue about ten dollars. Nothing here takes away a refund or cancellation right the law where you live gives you.

Tax and receipts. Prices exclude any sales tax, VAT or GST, which is added where it applies. Receipts and invoices come from the payment provider, and card details go to them and never touch our servers.

Price changes. If we change the price of a plan you are on, we will tell you before it takes effect, and it applies from your next renewal — so you always have a full cycle to cancel instead.

What you may not do

Don’t use Diagrammo to store, publish or send anything that:

• infringes someone’s copyright, trademark or other rights
• is unlawful, defamatory, or sexualises children
• harasses, threatens or doxxes somebody
• contains malware, or is designed to phish or defraud
• you don’t have the right to put there

And don’t attack the service itself: no attempts to break authentication or reach another tenant’s data, no probing for vulnerabilities without asking us first, no scraping the service wholesale, and no reselling access to it as your own product.

There are technical limits, and they are not negotiable by usage. Requests are rate-limited per address and per account, and there is a daily ceiling on writes. They exist to keep one account from degrading the service for everyone; automating around them is a breach of this section.

If you find a security problem, tell us at security@diagrammo.app. We will not pursue anyone who reports a genuine flaw in good faith and gives us a reasonable chance to fix it before going public.

Copyright complaints and takedowns

If you believe something hosted on Diagrammo Cloud infringes your copyright, email dmca@diagrammo.app with:

• what work you say is infringed
• the link to the material you want removed
• your contact details
• a statement that you believe in good faith the use is not authorised, and that the information in your notice is accurate and you are the rights holder or authorised to act for them

We will look at every notice and remove or disable access to material where the complaint is well-founded.

If your content is removed and you believe that was a mistake, reply and tell us why. We will pass your response to the complainant and may restore the material.

We terminate repeat infringers. An account that is the subject of repeated well-founded copyright complaints will be closed. This is a policy we actually apply, not a sentence we keep here for decoration.

Suspension, termination and getting your data out

You can leave whenever you like, and you can do it yourself. Deleting your account takes two deliberate acts through two channels: you type your own email address in the app, and then you open the link we send you and press the button on the page it opens. The link is good for a day. Opening it is not enough on its own — mail scanners follow links, so nothing happens until somebody presses the button.

What follows is irreversible, and it takes your diagrams and their stored files with it. If you would rather we did it, or you want your work exported first, email hello@diagrammo.app and we will.

We can suspend or close an account that breaches these terms, that is being used to attack or abuse the service, or where we are legally required to. Except where the abuse is ongoing or we have no choice, we will tell you what the problem is and give you a chance to fix it first.

What we keep, and for how long:

• We keep only the current version of each diagram. Saving replaces the copy before it — there is no version history, and nothing here to restore an earlier draft from.
• A deleted diagram or space is recoverable for 7 days — you can restore it yourself from the trash — after which it is destroyed for real: database rows and stored files both. Until it clears, a deleted diagram still counts towards what your plan lets you hold, so emptying the trash is what frees the room.
• The security activity log is deliberately tamper-evident, so rather than delete those entries when an account closes, we sever your account ID from them. What is left records that something happened without recording that you did it.

The full retention table is on the Privacy page.

Availability, and what we don’t promise

We work hard to keep Cloud up and we do not publish an uptime guarantee, because a number on a marketing page is not something we are prepared to owe you in a court. There is no service-level agreement, no credit scheme, and no promise that the service will be uninterrupted or error-free.

We may change, add or remove features. If we ever discontinue Diagrammo Cloud altogether, we will give you reasonable notice and time to export everything — and because diagrams are plain text you already hold locally, you would not be waiting on us to get your work out.

Warranties

The Services are provided “as is” and “as available”, without warranty of any kind, express or implied — including the implied warranties of merchantability, fitness for a particular purpose, and non-infringement.

We do not warrant that the Services will meet your requirements, that they will be available at any particular moment, or that any diagram will render exactly as you expect. Where the law where you live gives you warranty rights that cannot be excluded, they apply and this section does not touch them.

Limitation of liability

To the fullest extent the law allows:

• Neither of us is liable to the other for indirect, incidental, special, consequential or punitive damages, or for lost profits, lost revenue, or lost or corrupted data, however caused.
• Our total liability for any and all claims arising out of the Services is capped at the greater of the fees you actually paid us in the twelve months before the claim arose, or US$100.

For most people that cap is one hundred dollars, and we would rather say so plainly than bury it. Diagrammo is inexpensive or free, and the price reflects the fact that we are not underwriting your business.

None of this applies to liability that cannot legally be limited — fraud, wilful misconduct, death or personal injury caused by negligence, and any right you have under consumer law where you live.

Your responsibility for your content

You agree to cover us for claims brought against us because of content you put into the Services or published from them — a copyright complaint about a diagram you uploaded, for instance — and for claims arising from your breach of these terms. We will tell you promptly about any such claim, let you take charge of defending it, and not settle it without asking you.

This is about your content and your conduct, and nothing else. It is not a general indemnity for us being sued over our own product.

Privacy

What we collect, what we don’t, how long we keep it and how to get it deleted is on the Privacy page, which forms part of this agreement. In short: the app collects optional, opt-out diagnostics carrying no diagram content and no personal identifiers; Cloud stores your email address, your display name if you set one, and the diagrams you push to a space.

The MCP server (@diagrammo/dgmo-mcp)

The Diagrammo MCP server runs locally inside your AI client and does not transmit your diagrams, or anything else, to us or to any third party. All rendering happens on your machine. It has no telemetry and makes no outbound network requests of its own.

Two of its tools have side effects worth knowing about:

• share_diagram and open_in_app encode your diagram into a diagrammo.app URL. The encoded diagram sits in the URL fragment — after the # — and is never sent to our servers, because fragments are client-only by HTTP design. We see that a page was loaded, not what was in it.
• preview_diagram and generate_report write self-contained HTML files to your operating system’s temp directory and open them in your browser. Nothing is uploaded.

The MCP server is open source, so you can check all of that yourself.

Our name

The Diagrammo name, logo and website content belong to Diagrammo LLC. Nothing here gives you permission to use them, beyond saying truthfully that you use Diagrammo.

Changes to these terms

We may update these terms. When a change is material we will update the date at the top and say what changed in the log below — and if you are on a paid plan, a material change takes effect at your next renewal, so you can cancel instead of accepting it.

Continuing to use the Services after a change means you accept it.

The law that applies, and what happens in a dispute

These terms are governed by the laws of the State of Colorado, United States, without regard to its conflict-of-laws rules, and the courts of Colorado are where a dispute would be heard.

If you are a consumer, none of that takes away the protection of the mandatory laws of the country you live in, or your right to bring a claim in your local courts where the law gives you that right.

Talk to us first. Almost anything that would end up in a court can be sorted out by email in a day, and either of us may bring a claim in small-claims court instead. If some part of these terms turns out to be unenforceable, the rest stays in force.

Changes log

18 August 2026 — corrected the recovery window for something you delete. This page said a deleted diagram or space could be restored for 30 days; the real window became 7 days on 17 August 2026 and this page went on promising thirty for a day, which is the error being fixed here. It was wrong in the direction that matters — somebody who read it, waited three weeks and came back for a diagram would have found it already destroyed. The shortening was deliberate and came paired with a second change: a diagram in the trash now keeps counting towards what your plan lets you hold, so a long recovery window is no longer free — it is time your own deletions spend holding your allowance down. Seven days is long enough to notice a mistake and short enough that the trash cannot sit on a quarter of an account for a month. Spaces and diagrams are on the same clock. The paragraph above now says so, and adds the part that was never stated: emptying the trash is what actually frees the room.

17 August 2026 — you can now delete your own account. Until today this page said there was no self-serve button and that closing an account meant emailing us; that shipped to the web editor today, so the section on leaving now describes the real thing — type your address in the app, then press the button on the page the emailed link opens. Emailing us still works, and is still the route if you want an export first. Nothing about what we keep, or for how long, changed.

16 August 2026 — the free allowances changed. An account with no subscription used to hold 100 diagrams and show 25 of them on the web; it now holds 25 and shows 5. Nothing you already have is touched by this: both limits are checked when you create a diagram or show one on the web, never when you open or export what you already have, so an account over the new numbers keeps every diagram and every link it has already handed out, and is simply asked to delete or stop showing one before adding the next. Paid ceilings, owned spaces and the one-free-editor rule are unchanged.

16 August 2026 — corrected what this page says about version history. Cloud kept the last ten versions of every diagram until 13 August 2026, when that was switched off: nothing in the product could ever show you an older version, so those copies were your work held for a feature that did not exist. Only the current version is kept now, and saving replaces the one before it. This page went on promising ten for three days, which is the error being fixed here. The hosting licence has narrowed to match — it no longer asks your permission to keep a version history, because we do not keep one. Nothing else changed, and the 30-day window for restoring a deleted diagram is unaffected.

9 August 2026 — rewritten for Diagrammo LLC, which was formed on 8 August 2026. The previous version was a software licence written before Cloud had spaces, sharing or a price, and three things in it were wrong rather than merely thin: it said we claim no licence at all over your content, which cannot be true of a service that stores and serves it for you; it had nothing to say about subscriptions, cancellation or what happens when you stop paying; and it named no legal entity, so its limitation of liability limited the liability of a company that did not exist. This version adds the narrow hosting licence, the paid-plan section, an acceptable-use section, a copyright-complaint and repeat-infringer policy, and a liability cap tied to what you have actually paid.

June 2026 — the previous version, covering the desktop app, the web editor and the open-source packages.

Contact

Questions about these terms, or anything else: hello@diagrammo.app.