> ## Documentation Index
> Fetch the complete documentation index at: https://yn-c9bb3266.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.
# API overview
> One JSON-over-HTTPS REST API for payments across 100+ providers and every major method.
One JSON-over-HTTPS REST API to orchestrate payments across 100+ providers and every major payment method, in any country Yuno supports. Standard HTTP verbs, predictable URLs, JSON in and out โ if you've used Stripe, this will feel familiar.
## Where to start
Make your first checkout session against sandbox in under 5 minutes.
Browse by capability or jump straight to the endpoint reference below.
## Install and call
Sandbox: `https://api-sandbox.y.uno` ยท Production: `https://api.y.uno`
A trivial auth-bearing call to confirm your credentials reach the API. List one customer โ side-effect free, returns `200 OK`.
```bash theme={"theme":{"light":"github-dark","dark":"github-dark"}}
curl "https://api-sandbox.y.uno/v1/customers?limit=1" \
-H "public-api-key: $YUNO_PUBLIC_API_KEY" \
-H "private-secret-key: $YUNO_PRIVATE_SECRET_KEY"
```
```js theme={"theme":{"light":"github-dark","dark":"github-dark"}}
const res = await fetch("https://api-sandbox.y.uno/v1/customers?limit=1", {
headers: {
"public-api-key": process.env.YUNO_PUBLIC_API_KEY,
"private-secret-key": process.env.YUNO_PRIVATE_SECRET_KEY,
},
});
console.log(await res.json());
```
```python theme={"theme":{"light":"github-dark","dark":"github-dark"}}
import os, requests
res = requests.get(
"https://api-sandbox.y.uno/v1/customers?limit=1",
headers={
"public-api-key": os.environ["YUNO_PUBLIC_API_KEY"],
"private-secret-key": os.environ["YUNO_PRIVATE_SECRET_KEY"],
},
)
print(res.json())
```
```go theme={"theme":{"light":"github-dark","dark":"github-dark"}}
req, _ := http.NewRequest("GET", "https://api-sandbox.y.uno/v1/customers?limit=1", nil)
req.Header.Set("public-api-key", os.Getenv("YUNO_PUBLIC_API_KEY"))
req.Header.Set("private-secret-key", os.Getenv("YUNO_PRIVATE_SECRET_KEY"))
res, err := http.DefaultClient.Do(req)
```
List endpoints return a JSON array of resource objects directly โ no envelope. An empty account returns `[]`.
```json theme={"theme":{"light":"github-dark","dark":"github-dark"}}
[
{
"id": "c9d0e1f2-3a4b-5c6d-7e8f-9a0b1c2d3e4f",
"merchant_customer_id": "cust-internal-001",
"first_name": "Maria",
"last_name": "Silva",
"email": "maria.silva@example.com",
"country": "BR",
"created_at": "2026-05-11T14:32:01.482Z",
"updated_at": "2026-05-11T14:32:01.482Z"
}
]
```
## Build with Yuno
Hosted checkout sessions that render Yuno's SDK and route across providers.
Direct API payments for custom UIs and headless flows.
Vault payment methods for one-click checkout and merchant-initiated transactions.
Subscriptions with retry logic and dunning built in.
Country-specific installment plans for cards.
Hosted, single-use checkout URLs you can send by email or chat.
Onboard recipients and split payouts across multiple parties.
Open accounts and move funds via Banking as a Service.
## Reference and tools
The two required headers and how to keep secrets server-side.
Sandbox vs production base URLs and isolation guarantees.
Business keys that make retries safe across every resource.
The error envelope, the full code catalog, and how to retry safely.
Endpoint registration, signature verification, and lifecycle events.
Web, iOS, Android, Flutter, and framework component libraries.
See [Conventions](/api-reference/conventions/pagination) for pagination, status codes, rate limits, and async result behavior.
## For AI coding agents
The full machine-readable contract. Drop into openapi-generator, Stainless, or any compatible client generator.
Plain-markdown index of every documentation page and OpenAPI endpoint, ready for RAG or context loading.
Connect Claude Code, Cursor, or any MCP-compatible tool to read these docs and call the API in one session.
Combined, these let an agent both read this documentation and call the API in the same session.
## Changelog
New endpoints, field additions, and behavior changes.
How Yuno ships changes and what counts as breaking.