Overview

The Spreadefi API lets you integrate crypto swaps and cross-chain exchanges directly into your product. With a single API key you can query supported assets, estimate rates, create exchanges and track their status in real time.

Base URL: https://api.spreadefi.io/v1

Format: all requests and responses use application/json

Auth: every request must include your API key in the X-Api-Key header

Website: spreadefi.io

1. Get your API key

API keys are issued on request only, after we review your project for compliance with our rules. Once your project is approved, you'll be granted access to the partner dashboard along with your API keys.

To apply, email partners@spreadefi.io and include a link to your project in your request. Keep your key secret - it identifies your account and your affiliate reward on every exchange.

2. Authentication

Pass your key in the X-Api-Key header on every request:

X-Api-Key: your_api_key_here

Requests without a valid key return 401 Unauthorized.

3. Your first request

List every currency Spreadefi supports:

4. The exchange flow

A typical integration is three calls:

Estimate — GET /estimate to show the user how much they will receive.

Create — POST /exchanges to open the exchange and get a deposit address.

Track — GET /exchanges/{id} (poll) to follow the status until finished.

Exchange statuses

Status	Meaning
`waiting`	Awaiting the user's deposit
`confirming`	Deposit received, waiting for network confirmations
`exchanging`	Assets are being swapped
`sending`	Funds are being sent to the recipient
`finished`	Completed successfully
`expired`	No deposit received before expiry
`failed`	Something went wrong
`refunded`	Funds returned to the refund address

5. Rate limits

The default limit is 60 requests per minute per API key. Exceeding it returns 429 Too Many Requests. Contact support for higher limits.

6. Errors

Errors use standard HTTP status codes and a JSON body:

{ "code": 401, "error": "Unauthorized", "description": "Invalid API key" }

Code	Meaning
400	Bad request
401	Invalid API key
404	Resource not found
422	Validation error
429	Rate limit exceeded
500	Internal server error

1. Get your API key#

2. Authentication#

3. Your first request#

4. The exchange flow#

Exchange statuses#

5. Rate limits#