The agreement

Who you are agreeing with

Sparkline is run by Alexander Ivashkin, an individual — not a company. There is no registered entity behind it, no support department and no account manager. Everything on this page, and every question you have about it, reaches the same person at hello@ivashkin.dev.

Throughout this page, we means that person and you means whoever holds the account.

What Sparkline does

You send numbers to a URL and Sparkline draws them. Each chart has two URLs: a write key, which is a secret, and a read code, which is not. The API reference is the full description of both, and it is part of these terms in the sense that it is what the service actually promises to do.

A chart's read code is public. Anyone who has it can open the chart, fetch its SVG and read its JSON, from any website, without signing in — that is what makes a chart embeddable, and it is not a setting. Treat a chart's title, its series names and its numbers as things you have published. If you would not put them on a web page, do not put them in a chart.

Your account

Give a real email address: it is how you sign in, how you get back in when you cannot, and the only way we can reach you about your plan. You are responsible for your password and for every write key on your account. A write key is a secret in a URL, so anything holding it can write to that chart — if one leaks, rotate it from the chart's own page, which invalidates the old one immediately.

You must be old enough to enter into a contract where you live. Sparkline is not built for children and is not directed at them.

What you may not do with it

• Nothing unlawful, and nothing that infringes somebody else's rights.
• No personal data about other people in a chart — not in a title, not in a series name, not in the numbers. A chart is public to anyone with its code, so a chart is the wrong place for it, and we have no way to protect what you publish there.
• No using the write endpoints as a load generator. They are rate limited per key; working around that limit, rather than staying inside it, is the line.
• No probing, scraping or interfering with other people's accounts, charts or keys.
• No reselling Sparkline as your own service. Embedding your charts in your own product is exactly what it is for; putting a wrapper around it and charging for it is not.

Plans, limits and what expires

There is Free and there is Premium. What each allows — how many charts, how many samples a chart keeps, how many series it carries — is on the pricing page, which is read out of the same place the service enforces and is part of these terms. The numbers are not repeated here: terms that carry their own copy of a number are terms that can be out of date about it.

A chart is a window, not an archive. Each one keeps the most recent samples up to its capacity and drops the oldest as new ones arrive. That is the product working as intended, not data loss, and Sparkline is not a backup of anything. If you need the history, keep it where it came from.

When Premium ends — because it was cancelled, or because a payment stopped — nothing happens for 7 days. Everything keeps working, and you are warned by email. After that the account goes back to free, and anything above the free limits is deleted: charts past the free count, and samples past the free capacity. Cancelling before the date you have already paid for changes nothing until that date arrives.

Paying

Payments are taken by Paddle, who are the merchant of record for every sale. That means your contract for the payment itself is with Paddle: they charge your card, they handle tax, and their own terms apply to that part. Sparkline never sees your card details.

A subscription renews on its own until it is cancelled. The price you see at checkout is the price, in your currency and with whatever tax applies; anything quoted elsewhere on this site is a starting point. You can cancel from your account page at any time, and there are 14 days to change your mind about any charge — see the refund policy, which is part of these terms.

Who owns what

Your charts and your numbers are yours. We do not claim any ownership of them and we do not sell them, mine them or train anything on them. You give us permission to store them, process them and show them to whoever has the read code — which is only what is needed to run the service you asked for.

Sparkline itself — the site, the renderer, the name and the mark — stays ours. The privacy policy says exactly what is stored about you and who else ever sees it.

Uptime, changes and endings

There is no uptime guarantee. Sparkline is one process on one server, run carefully but without a rota, and it will occasionally be down. If a chart is load-bearing for something that matters, do not let it be the only thing watching.

We may change the service. Changes that take something away from Premium will be emailed to the address on the account first, and if you do not want to continue on the new terms you can cancel and ask for the unused part of what you paid back.

You can stop whenever you like: cancel the subscription, or email us to have the account and everything in it deleted. We can suspend or close an account that is being used against the rules above, that has not paid, or that is putting the service at risk — and unless it is urgent or unlawful, we will say why and give you a chance to fix it first. If we close an account that has done nothing wrong, the unused part of what you paid comes back.

Liability

Sparkline is provided as it is. Within what the law where you live allows, there is no warranty that it will be available, accurate or fit for any particular purpose, and we are not liable for lost profits, lost data or anything else that follows on from using it.

Where we are liable, that liability is limited to what you actually paid for Sparkline in the twelve months before whatever went wrong — which for most accounts is nothing, because most accounts are free.

None of that removes rights you have that cannot be removed. If you are a consumer, your local consumer-protection law applies whatever this page says, and it wins where the two disagree.

If something goes wrong between us

This page deliberately does not impose a country's law or a court in a city you have never been to. Email hello@ivashkin.dev first — Sparkline costs a few dollars a month and almost anything can be sorted out in one reply. If it cannot be, you keep whatever rights and whatever venue the law where you live gives you.

Changes to these terms

When this page changes, the date at the top changes with it. A change that materially affects a paying account is emailed to the address on that account before it takes effect. Carrying on using Sparkline after a change is how you accept it; if you would rather not, cancel.