Yield3

Privacy policy

Last updated 5 September 2026

Who we are

PolySmarter is operated by Yield3 Insight Limited, a company registered in England and Wales under number 15272863, with its registered office at Unit 1e, Bromsgrove House, 88 Bromsgrove Street, Birmingham, England, B5 6AJ. Yield3 Insight Limited is the data controller for the information described here.

For any privacy question, or to exercise the rights set out below, write to web3flyer@gmail.com.

What the extension handles

PolySmarter handles the following, in order to provide the read-only analytics you ask it for.

  1. The market you are looking at, and the ones you watch. The event slug, market slug or condition ID taken from the Polymarket URL; a limited set of on-device market snapshots used for the “since your last view” feature; and the market identifiers for any Watch you create.
  2. A small amount of text from the page. On an event with several outcomes, the extension reads the event title and the outcome names shown in the trade widget — at most six short lines — so it can tell which outcome you are looking at. That text stays on your device: it passes from the page to the extension's own background script and back to the panel, and is never transmitted to us or to anyone else. The extension does not read prices, order sizes, forms, cookies or local storage from the page, and it cannot read your Polymarket account, wallet, balance, positions, orders or trading history.
  3. Your settings. Language, theme, panel mode, width, hypothetical trade size, display preferences, breakeven limit and Watch conditions. General settings may be synchronised by Chrome Sync between your own browsers; Watch conditions and market snapshots stay on the device.
  4. Installation and licence. A randomly generated installation identifier, which is not derived from anything about you and is replaced if you clear the extension's local data or reinstall; a licence key issued by us, cached plan state, and one-time sign-in handoff data. The licence key is stored locally and is not synchronised by Chrome Sync. On our side we store only a SHA-256 digest and a short prefix of that key, never the key itself.
  5. Account information, only if you sign in. If you choose to sign in with Google, we receive your Google subject identifier, your verified email address and whether that address is verified. We request only openid and email. We do not request your Google profile, Gmail, Drive or offline access, and we store no Google refresh token.
  6. Subscription information, only if you subscribe. Stripe customer, subscription and event identifiers, subscription status, the price you are on and renewal or termination timing. Card numbers and bank details are handled by Stripe directly; neither the extension nor we ever receive them.
  7. Request and security records. The market identifier, installation identifier, extension version and, when you are signed in, your licence, sent with each API request; together with the IP address, user agent, request time, request identifier, rate-limit counters and security-audit entries that our servers record automatically.

Why we handle it

To identify the market you selected; to return public market data and derived analytics; to calculate hypothetical execution results; to remember your settings and Watch conditions; to send the notifications you asked for; to verify whether you are on Free or Pro; to administer subscriptions; to enforce rate limits and prevent abuse; to protect accounts and service security; to troubleshoot faults; and to keep the service reliable.

We do not use any of it for personalised or retargeted advertising, for assessing creditworthiness or lending, or to build profiles unrelated to what the extension does, and we do not sell it.

Our lawful bases under UK data protection law are: performance of our contract with you (running the extension, your account and your subscription); our legitimate interests in keeping the service secure, available and free of abuse; and our legal obligations, principally the retention of accounting records.

Who else sees it

These are the only third parties involved, and each acts as our processor or as an independent controller for its own service:

Google
Sign-in, if you choose it (OpenID Connect), and cloud hosting for our servers.
Stripe
Payment processing and the billing portal, if you subscribe.

We use no advertising network, no analytics provider, no error-monitoring service, no email or CRM provider and no content delivery network. If that ever changes, this page changes with it.

We may also disclose information where we are legally required to, where it is necessary to protect the security of the service or the rights of others, or in connection with a corporate transaction, subject to any consent the law requires.

Our servers are hosted in the United States. Where personal data is transferred out of the United Kingdom or the European Economic Area, we rely on the safeguards our providers make available, including standard contractual clauses.

How long we keep it

On your device
Settings, Watch conditions, market snapshots and the licence key stay until you clear them or uninstall the extension. Settings can be cleared from the extension's Settings page; removing the extension removes all of it.
Account and subscription records
Kept while your account exists. Billing and accounting records are kept for six years after the end of the financial year they relate to, as UK company law requires.
Server logs
Written to size-capped files that rotate automatically, so older entries are discarded as new ones are written. They are not archived and not sent to any third-party logging service.

Your rights

You may ask us for a copy of the personal data we hold about you, ask us to correct it, ask us to delete it, ask us to restrict or object to how we use it, and ask for it in a portable form. Where we rely on consent you may withdraw it at any time.

To close your account and have its records deleted, write to web3flyer@gmail.com from the address you signed in with. We act on deletion requests promptly and confirm when it is done. Records we are legally required to retain — chiefly billing records — are kept for the period described above and then deleted.

You do not need to contact us to remove what the extension keeps on your device: the Settings page clears stored market snapshots and Watch conditions, and uninstalling removes all of it.

If you are unhappy with how we have handled your data you can complain to the UK Information Commissioner's Office at ico.org.uk.

Google user data

Our use of information received from Google APIs will adhere to the Chrome Web Store User Data Policy, including the Limited Use requirements.

Children

PolySmarter is not directed at children and is not for anyone under 18. We do not knowingly handle the personal data of children.

Changes

If we change what we handle or why, we will update this page and move the date at the top. Where a change materially affects how your data is used, we will make it visible in the extension rather than relying on you to re-read this page.