The deal, in plain words.

Who you are dealing with

Lyndran is made and operated by Mainspring. In this document “we” and “us” mean Mainspring; “you” means the person using Lyndran, or the organisation you are using it on behalf of.

Using the app or this website means you accept these terms. If you do not, the honest answer is: do not install it.

Young software means young software

Lyndran is young software, and this is the plainest place on the site to say so. We ship it because we would rather have you in it than have you wait.

Expect: tasks that fail halfway, plans that misread what you asked, results that need checking, and updates that change how something behaves. Features can appear and disappear. Saved tools may need rebuilding across versions.

Check the work. Lyndran hands back a designed result, not a guarantee. Where the output matters — a ledger, a contract comparison, a booking — read it before you act on it, exactly as you would read a colleague’s draft.

Your licence

We grant you a personal, non-exclusive, revocable licence to install and run Lyndran on Macs you own or control, for your own purposes and for the work of the organisation you belong to. Commercial use is fine. That is the whole point of it.

What the licence does not cover: reselling Lyndran or offering it as a service to others; removing or obscuring the marks and notices; decompiling or reverse engineering the application to build a competing product; or redistributing modified builds under our name. The app and everything in it — the code, the design, Lyn, the carrot — stays ours.

The tools you build inside Lyndran, and the results it produces for you, are yours. We claim no ownership of your work and no licence to use it.

The press is yours — and so is what follows

The entire design of this product rests on one boundary: Lyndran can prepare a change, but nothing is committed until you have been shown the finished thing and pressed a button on it. Messages come out as drafts. A payment is lined up and stops, with the amount read off the page and shown to you. A click on anything that sends, submits, buys, pays, orders, posts, publishes or deletes is caught in Rust and turned into a panel that waits for you.

There is one exception and you should read it before you rely on the sentence above. Lyndran can send an email — after it has shown you every recipient, the subject and the entire body on a card in front of you, and after you have pressed send on that card. Your press is the approval; the press on the mail application’s own Send button is Lyndran’s, and it happens only after yours. A sent email cannot be recalled by us or by the app. If you would rather it never sent anything at all, do not press send on that card — the draft is still there and is still yours. The security page sets out what guards it: five recipients at most, no bcc anywhere in the code, and no standing “always allow” for it, ever.

That boundary is what makes the product safe. It also decides where responsibility sits. When you press the button, you are the one taking the action. You are responsible for reading what is on the panel — we show you the full text of a message, not a summary, precisely so that the reading is possible — and for what happens after.

Where a task is reversible, Lyndran keeps a one-press undo. Some things are not reversible: money that has moved, a message that has arrived, a form a website has already processed. Undo cannot follow those out into the world, and we do not pretend otherwise.

The same applies to a standing “always allow.” Granting one is your decision to stop being asked. Actions that cannot be undone are never eligible for it, by design — but for those that are, the grant is real, and it applies until you take it back.

What you must not use it for

Running an agent on your own machine, in your own logged-in browser, does not grant you rights you did not already have. So:

• Only point it at things you are entitled to access. Your accounts, your files, your company’s systems where you have permission.
• No breaking the law with it — fraud, harassment, stalking, infringement, or building anything designed to harm someone.
• No defeating access controls. Do not use Lyndran to get around a paywall, a rate limit, a login, a robots policy, or a bot check. It is not built for that and we will not help make it so.
• No mass unsolicited messaging. The approval rule exists so a person reads every message that goes out in their name, in full, before it goes; using it to fire off thousands is against the point and against these terms.
• No reselling the output as a service that competes with Lyndran itself.
• Respect other people’s privacy. If a task will read material about someone else, you need a proper basis for that, and it is yours to have, not ours.

If you use Lyndran on behalf of an organisation, you are confirming you are allowed to agree to this on its behalf, and that installing an agent on that machine is permitted where you work.

Model keys and third parties

Lyndran can run on your own model provider key. If you supply one, it stays on your machine, the requests go from your Mac to that provider directly, and their terms and their bill apply to you, not to us. Keep the key safe; a key in an agent is still a key.

When Lyndran drives your browser or another app, you are still bound by those services’ terms. Lyndran clicks the same buttons a person clicks; it does not launder the rules.

Carrots, memberships, refunds

Fresh thinking costs credits we call carrots, each worth cents. Replaying a tool you already built costs nothing, and scheduled runs of a saved tool cost nothing. That is not a promotion; it is how the pricing works, because a replay does not spend a model call.

Today, nothing is charged. Memberships are not open. If you bring your own key, the free tier is free in the plain sense of the word — you pay your provider for the thinking and you pay us nothing.

When memberships do open we will publish the prices before they apply, and no existing user will be silently moved onto a paid plan. We are not promising a date, because we do not have one worth promising. If you have bought carrots and something on our side prevented you spending them, write to us and we will sort it out; unused credits on a cancelled membership are refundable at our discretion and we intend to be generous rather than clever about it.

Availability and changes

There is no uptime guarantee. The app itself keeps working offline for anything that does not need fresh thinking — saved tools, scheduled runs, reminders — but planning a new task needs a model, and a model needs a connection.

We may change, suspend or withdraw parts of the service. If a change materially reduces what you get, we will say so rather than let you discover it. We may update these terms; the effective date at the top moves when we do, and continuing to use Lyndran after that means the new version applies.

No warranty

Lyndran is provided as is. To the fullest extent the law allows, we make no warranties of any kind — express or implied — including merchantability, fitness for a particular purpose, non-infringement, or that the software will be uninterrupted, secure, or free of error.

In particular, we do not warrant that a plan the model produces will be correct, or that a result will be accurate. Language models are wrong sometimes. The consent boundary exists because that is true, not in spite of it.

Limits of liability

To the extent the law allows, we are not liable for indirect or consequential losses, lost profits, lost business, lost data, or the cost of substitute services. Our total liability to you for any claim connected with Lyndran is limited to the greater of the amount you paid us in the twelve months before the claim, or fifty euros.

Nothing here excludes liability that cannot lawfully be excluded — including for death or personal injury caused by negligence, or for fraud. If you are a consumer, your statutory rights are unaffected by anything on this page.

Ending it

You can stop at any moment: delete the app, and press forget everything about me first if you want the local store gone with it. Nothing is held hostage on a server, because nothing of yours is on one.

We can suspend or end your access if you break these terms in a way that is serious or repeated, or if we have to stop offering the service. Where it is reasonable to warn you first, we will.

Law, and how to reach us

These terms are governed by the law of the country in which Mainspring is established, and the courts there have jurisdiction. If you are a consumer, this does not deprive you of the protection of the mandatory rules of the country you live in, and you may bring proceedings there.

If any part of this is found unenforceable, the rest stands. Failing to enforce something once is not a waiver of it.

Questions about any of this: ertansoftwaresolutions@gmail.com. See also the privacy policy and the security architecture.