# Yeeld > Yeeld builds credit-card surcharging infrastructure for merchants and platforms in the > United States and Canada, and provides payments consulting and development services. > The Yeeld Surcharging API is a real-time rules engine: a caller sends a transaction > amount plus payment-method details and receives the surcharge amount that jurisdictional > law and card-network rules permit, or zero where surcharging is prohibited. Yeeld does > not process payments, store card data, or provide legal advice. Founded by ex-Stripe > staff; headquartered in Chicago, Illinois. > GENERATED BY API EVANGELIST, NOT PUBLISHED BY YEELD. Yeeld serves no /llms.txt > (https://theyeeld.com/llms.txt and https://docs.theyeeld.com/llms.txt both returned 404 > on 2026-08-28). This file is assembled from Yeeld's public documentation and marketing > pages plus this repository's artifacts, and every claim in it is traceable to a URL > listed below. It is a third-party profile; correct it by opening an issue on > https://github.com/api-evangelist/yeeld. ## Products - [Surcharging API](https://theyeeld.com/products/surcharging-api): Server-side surcharge calculation for platforms and merchants running custom checkouts. Works alongside Stripe, Adyen, Checkout.com and other processors that permit surcharging; no processor change required. - [Yeeld Surcharging for Stripe](https://theyeeld.com/products/yeeld-surcharging-for-stripe): Stripe App Marketplace app that adds surcharging to Stripe Checkout Sessions and Payment Links with one line of code. Not available for Payment Intents, Terminal or Connect through the app. - [YeeldPay](https://theyeeld.com/products/yeeld-pay): No-code branded hosted checkout built on Stripe Elements, with surcharging and disclosures enabled by configuration. ## Documentation - [Docs home](https://docs.theyeeld.com/): Seven published pages; server-rendered and crawlable. - [Getting started overview](https://docs.theyeeld.com/getting-started/overview): What the rules engine handles — jurisdictional enforcement, rate calculation, disclosure support, refund and tax guidance. - [Integrations overview](https://docs.theyeeld.com/integrations): Choose the merchant model or the platform/marketplace model; determines whether the Yeeld-Account header is required. - [Merchant integration guide](https://docs.theyeeld.com/integrations/merchant): Four-phase flow — calculate, update the PSP total, display the surcharge line item, confirm. - [Platforms and marketplaces guide](https://docs.theyeeld.com/integrations/platforms-and-marketplaces): Sub-merchant is merchant of record; pass the sub-merchant's Yeeld account ID in the Yeeld-Account header on every call. - [Compliance overview](https://docs.theyeeld.com/compliance/overview): Three governing layers — jurisdictional law, card-network rules, merchant configuration. Strictest applicable rule always wins; no override. - [Yeeld Stripe App overview](https://docs.theyeeld.com/yeeld-stripe-app/overview) ## API facts - Base host: https://api.theyeeld.com — a live first-party JSON API (Fastify on Yeeld's own AWS load balancer). Established by probe on 2026-08-28; Yeeld's docs do not state a base URL and no route names are published. - Authentication: per-account API key. Platforms additionally send the `Yeeld-Account` header carrying the sub-merchant's Yeeld account ID. - Error envelope observed unauthenticated: `{"message": ..., "error": ..., "statusCode": ...}`. Not RFC 9457 problem+json. - Endpoint reference, request/response schemas and the sandbox are NOT public. The Surcharging API FAQ states: "Is there a sandbox or API docs? Yes. Contact us to get access." - No OpenAPI, Swagger, GraphQL SDL, AsyncAPI, gRPC .proto or WSDL is served on any Yeeld host. No MCP server and no A2A agent card. - No published rate limits, quotas or throttling headers. - No versioning policy, deprecation policy, SLA, status page or changelog. - No client libraries in npm, PyPI, RubyGems or crates.io. ## Behavioural rules an agent should know - Surcharging applies to eligible CREDIT card transactions only. Debit, prepaid, ACH and bank transfers are never surcharged. - In a jurisdiction where surcharging is prohibited, Yeeld returns a $0 surcharge rather than an error. Handle zero as a normal, expected result. - If the shopper changes payment method after a calculation, re-call the API and re-sync the PSP transaction total, or the authorization will mismatch the displayed total. - The surcharge must be displayed to the shopper as a distinct line item before the final payment button. - Yeeld names California, New York and Mississippi as jurisdictions where its own docs tell merchants to consult legal counsel before enabling surcharging. ## Services - [Services](https://theyeeld.com/services): Payments advisory, platforms and embedded finance, billing and recurring revenue (Stripe Billing Specialist Partner), integration development, billing migrations, custom reports. ## Pricing - [Stripe app pricing](https://theyeeld.com/products/yeeld-surcharging-for-stripe): No upfront install fee. Yeeld charges a percentage of surcharge revenue successfully collected; if no surcharges are collected, nothing is owed. Rate adjusts by volume each billing period. Billed monthly in arrears. No rate card is published — pricing is set during onboarding. ## Company - [About](https://theyeeld.com/about) — Chicago, IL; founded by ex-Stripe employees. - [Customers](https://theyeeld.com/customers) - [Blog](https://theyeeld.com/blog) — RSS at https://theyeeld.com/feed/ - [Contact](https://theyeeld.com/contact) — info@theyeeld.com; support@theyeeld.com - [LinkedIn](https://www.linkedin.com/company/theyeeld) - [Privacy policy](https://theyeeld.com/legal/privacy-policy) - [Terms of use](https://theyeeld.com/legal/terms-of-use) ## Optional - [Stripe App Marketplace listing](https://marketplace.stripe.com/apps/yeeld) - [YeeldPay signup](https://theyeeld.com/yeeld-pay-signup)