Sunlight
The Universal Card-On-File API
If you are part of Sunlight (or you are a YC founder who looks at Sunlight and thinks that is the kind of business I run), you probably do not have time for a six-month SEO agency contract. Seoable was built for that. Audit your site, queue 100 ready-to-publish posts, and run it all from your AI assistant.
About Sunlight
Sunlight is an API to change the card-on-file with apps and subscription services. Fintechs use Sunlight to automatically make their cards top-of-wallet as soon as they're issued. Merchants, service providers and subscriptions-based businesses everywhere now offer their customers the ability to save a debit/credit card on file, so they can pay their bills on time, buy in one click, or earn rewards. In 2021, 79% of consumers worldwide reported already having at least one payment card saved with a service or being open to doing so. In recent years, card-issuing as-a-service has become mainstream: any company can now start their own card business in a matter of weeks. Last year, the number of new payment cards issued was at an all-time high. For users, however, switching banks or opening a new card now comes with an additional hurdle: they need to update their payment info across the internet. On the other side of that equation, card issuers have no visibility or control over the card-on-file updating process, and as a result struggle to get their new users to switch their spend from their old card to the new one, leading to low conversion rates and missed revenue opportunities. Until Sunlight. With our universal get-your-card-on-file API, FIs can now offer their users, at any point in their journey, a quick and easy way to update their debit/credit card info everywhere they shop or pay online, without ever leaving their Apps. The Sunlight API works on every platform that has a card-on-file option (think Uber, Amazon, Netflix, DoorDash, Starbucks and so many more…), is as seamless as a Plaid connection, and always gets the card number and CVV code right on the first try!
Quick facts
- YC Batch
- Summer 2022
- Founded
- 2021
- Headquarters
- New York
- Team size
- 6
- Industry
- Fintech • Fintech
- Tags
- fintech, payments, b2b, api
- Website
- www.sunlightapi.com
Founders
Why founders like Sunlight use Seoable
- Ship without an agency. Audit your site and queue 100 posts in one afternoon. No briefs to write, no calls to take.
- Drive it from Claude or Cursor. Seoable is MCP-first. Your assistant can run audits, queue posts, and pull reports without you opening a dashboard.
- Pay per piece, not per seat. Credits instead of monthly seats. Buy what you need, when you need it.
- SEO that includes AI engines. Our audits check what ChatGPT, Claude, Perplexity, Gemini, DeepSeek, and Grok already say about you, not just Google.