Payder Merchant API

Take payments, issue refunds and pay out sellers from your own platform. A small REST API, signed webhooks and a full sandbox.

What you can do

Accept payments. Create a checkout, send your buyer to a hosted Payder payment page (card or bank transfer), and get them back at your own return URL.
Refund. Refund a paid checkout in full or in part. A refund can never exceed what was paid.
Pay out. Send money to a seller's Nigerian bank account.
Stay in sync. Payder tells your server about every result with a signed webhook, retried automatically until you acknowledge it.

Your server calls POST /v1/checkouts with your order reference and amount. You get back a checkoutUrl.
You redirect the buyer to checkoutUrl. They pay on the Payder page.
Payder redirects the buyer to your returnUrl and, separately, sends payment.succeeded or payment.failed to your webhook.
Your server marks the order paid when the webhook arrives. Do not rely on the redirect alone: it can be skipped or faked by the buyer.

Everything exists twice, with separate merchants, API keys and webhook secrets, so test traffic can never touch real money.

	Sandbox	Live
Base URL	`https://sandbox-api.payder.ng/v1`	`https://api.payder.ng/v1`
Merchant ID	`mch_test_…`	`mch_live_…`
API key	`pdr_test_sk_…`	`pdr_live_sk_…`
Money	Simulated	Real
Access	After your developer account is approved	Enabled by Payder after you have tested

Keys cannot cross environments

A sandbox key is refused by the live API, and a live key by the sandbox. You will get 403 wrong_environment.

Amounts are integers in kobo. ₦1,250.00 is 125000. The currency is always NGN.
Requests and responses are JSON. Timestamps are ISO 8601 in UTC.
Every write needs an Idempotency-Key, so a retried request never creates a duplicate.
Errors always look like { "error": { "code", "message" } }.

Quickstart gets you from nothing to a signed webhook in about ten minutes. Then read Webhooks and Sandbox and testing.