Integrate Changelly for Instant Crypto Swaps
Picture this: you launch a crypto service, users need to exchange coins, but holding your own liquidity is expensive and risky. Changelly is an exchange aggregator that finds the best rate and routes the deal. We connect its REST API v2 in 1–2 weeks, giving you instant exchange without capital lock-up. Our track record: 5+ years in blockchain, 20+ successful integrations with crypto exchanges. Contact us for a free project evaluation — starting at $5,000.
What Problems Does Integration with Changelly Solve?
Lack of own liquidity. Changelly does not require you to hold a balance on the platform — it routes trades through partner exchanges. You save millions on liquidity and eliminate the risk of losing it due to hacks or market fluctuations. Typical savings are 90% compared to in-house solutions.
Complexity with rates and volatility. The API returns the current rate including slippage and fees. We implement a rate lock mechanism for 30–60 seconds — typical for Changelly — so the user can confirm the deal.
Transaction status tracking. Processing can take from 30 seconds to 10 minutes. We add polling every 15 seconds and notify the user at each stage: waiting → confirming → exchanging → sending → finished.
How We Connect Changelly API in 5 Steps
- Analysis. Identify needed methods: getExchangeAmount, createTransaction, getTransactions. Study limits and errors.
- Design. Design a backend service in TypeScript with HMAC request signing (see example below). Include error handling for 400, 500, and retries.
- Implementation. Write a ChangellyClient class with methods for all calls. Integrate the frontend: pair selection, rate display, submission form.
- Testing. In test mode (parameter fix: true) run transactions without real funds. Verify amount, address, and return on error.
- Deployment. Deploy on a server, set up monitoring (Tenderly, Sentry). Guarantee stability.
Code Example: Creating a Signed Request
import crypto from 'crypto'; class ChangellyClient { private apiKey: string; private apiSecret: string; constructor(apiKey: string, apiSecret: string) { this.apiKey = apiKey; this.apiSecret = apiSecret; } private signRequest(body: object): string { const message = JSON.stringify(body); return crypto.createHmac('sha512', this.apiSecret).update(message).digest('hex'); } async getExchangeAmount(from: string, to: string, amount: string) { const body = { jsonrpc: '2.0', id: Date.now().toString(), method: 'getExchangeAmount', params: { from, to, amount }, }; const response = await fetch('https://api.changelly.com/v2', { method: 'POST', headers: { 'api-key': this.apiKey, 'sign': this.signRequest(body), 'Content-Type': 'application/json', }, body: JSON.stringify(body), }); return response.json(); } } Example getExchangeAmount Response
{ "jsonrpc": "2.0", "id": "1234", "result": { "amount": "0.0985", "currency": "eth" } } Core API Methods
| Method | Parameters | Description |
|---|---|---|
getMinAmount | from, to | Minimum exchange amount |
getExchangeAmount | from, to, amount | Rate and output amount (get exchange rate) |
createTransaction | from, to, amount, address, refundAddress | Create an exchange (create transaction Changelly) |
getTransactions | id / limit | Get transaction status (transaction status polling) |
Typical API Error Codes
| Code | Description | Action |
|---|---|---|
| 400 | Invalid parameters | Check format and values |
| 401 | Invalid signature | Reverify apiSecret |
| 403 | IP not in whitelist | Add IP in Changelly panel |
| 500 | Internal error | Retry after 5 seconds |
Comparison: Changelly vs Own Exchange
Changelly integrates 3 times faster than building your own exchange (2 weeks vs 6–8). You incur no liquidity costs and face no risk of losing it. Plus, it supports 20+ cryptocurrencies and 100+ trading pairs — expand your offering without extra expenses.
Why Choose Changelly?
Savings on liquidity. Changelly requires no prepayment — you pay only for actual exchanges. This lowers the entry barrier for startups: no need to lock up tens of thousands of dollars in stablecoins. Average operational cost savings can be up to 90% compared to an in-house platform. This makes it ideal for in-app crypto exchange and Web3 integration.
What Else Matters When Integrating?
Error handling is key. The API returns codes 400, 401, 403, 500. We implement retry logic with exponential backoff for transient failures. For authorization errors — stop and notify the admin. We also check the minimum amount (getMinAmount) before creating a transaction to avoid returns. All requests use HMAC request signing for security.
What's Included in the Work
- Integration code: Backend service in TypeScript with full coverage of all API calls.
- Documentation: Method descriptions, error handling, request examples.
- Credentials: API key and secret setup, security recommendations (e.g., IP restriction).
- Training: A 2-hour online session for your team on supporting the exchange module.
- Support: 2 weeks of technical assistance after deployment.
Timeline and Pricing
Basic functionality takes 5 to 10 business days to connect. Complex customizations (e.g., custom UI, KYC system integration) may require up to 3 weeks. Pricing starts at $5,000 for a standard integration, with custom quotes for complex projects.
Order Changelly API integration — contact us for a consultation. We guarantee transparent pricing and strict deadlines.
Official Changelly API Documentation: https://docs.changelly.com/v2