CoinsSend API Examples

These examples implement the verified public contract from openapi.json.

Examples

• PHP invoice
• Node.js invoice
• Python invoice
• PHP static wallet
• Node.js static wallet
• Python static wallet
• Node.js withdrawal and webhook receiver

Shared Signing Rules

1. Build the request object using strings for monetary values.
2. Encode it with the PHP-compatible canonical JSON rules documented in Authentication.
3. Sign base64(canonical_body).
4. Send the same canonical string as the HTTP request body.
5. Use legacy MD5 only when no timestamp header is sent.
6. For withdrawals, send Timestamp and use timestamped HMAC-SHA256.

Run client implementations against signature-test-vectors.json. Keep merchant API keys in backend secrets; none of these examples belongs in browser code.

Write Safety

The public API does not accept a general Idempotency-Key request header. Invoice order_id uniqueness rejects a duplicate with 409, but does not replay the first response. Withdrawals and static-wallet creation must not be blindly retried after an unknown outcome. Provider-card creation only reuses an already-active order.

Error bodies are not universal: authentication errors return {"error":"..."}; endpoint errors normally return status and message; validation returns errors, status, and message.