> ## Documentation Index
> Fetch the complete documentation index at: https://docs.etherfuse.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Introduction

> The Etherfuse REST API — base URLs, auth, and conventions.

The Etherfuse API is organized around **REST**. It has predictable, resource-oriented URLs, accepts and returns JSON, and uses standard HTTP verbs and response codes. Every endpoint on the pages that follow includes a live **"Try it"** playground and copy-paste code samples.

## Two API surfaces

The reference is split into two groups:

* **Ramp API** (`/ramp/*`) — the authenticated partner operations: onboarding, quotes, orders, swaps, customers, wallets, KYC, webhooks, and organizations. Requires an [API key](/authentication). Start with [List assets](/api-reference/assets/list-assets).
* **Lookup API** (`/lookup/*`) — **public** reference data: exchange rates, stablebonds, bond costs, and country codes. No API key required. Start with [List stablebonds](/api-reference/lookup/list-stablebonds).

## Base URLs

| Environment    | Base URL                         |
| -------------- | -------------------------------- |
| **Sandbox**    | `https://api.sand.etherfuse.com` |
| **Production** | `https://api.etherfuse.com`      |

Build and test against the sandbox first — see [Initial Setup](/initial-setup). The endpoints are identical across environments; only the base URL and API key differ.

## Authentication

Send your API key in the `Authorization` header — with **no `Bearer` prefix**. Full details and the sandbox-vs-production key rules are in [Authentication](/authentication).

```bash theme={null}
curl https://api.sand.etherfuse.com/ramp/assets \
  -H "Authorization: <your_api_key>"
```

## Conventions

<CardGroup cols={2}>
  <Card title="Errors" icon="circle-exclamation" href="/errors">
    Standard HTTP status codes (400, 401, 403, 404, 409, 5xx) with a human-readable message.
  </Card>

  <Card title="Pagination" icon="layer-group" href="/pagination">
    `POST` list endpoints take `{pageNumber, pageSize, filters}` and return a page envelope.
  </Card>

  <Card title="Idempotency" icon="rotate" href="/idempotency">
    You supply resource UUIDs; reusing one returns `409` instead of creating a duplicate.
  </Card>

  <Card title="Webhooks" icon="bell" href="/webhooks">
    Signed, real-time events for orders, swaps, KYC, and bank accounts.
  </Card>
</CardGroup>

## Use the spec directly

[Download `openapi.json`](https://api.etherfuse.com/openapi.json) to import into Postman or Insomnia, or to generate a client. Prefer natural language? Connect the [MCP server](/mcp-overview).