Skip to main content


To build great applications with Symblepay APIs, you should learn about the basic design principles that form the foundation of Symblepay APIs. These principles include base elements of the data model, secured access, error handling, and more.

Using the REST API

The Symblepay API is organized around REST. You manage the resources of a Symblepay account (such as trades, user connection, webhooks) by making HTTPS requests to URLs that represent those resources.


By definition idempotence is a property of operations whereby they can be applied multiple times without changing the result beyond the initial application. As per HTTP spec all DELETE and PUT endpoints are idempotent in Symblepay.

API Keys

We handle all the authentication for your end-users through cookies or JWT keys.

For all server to server communication we require https and a valid API key.

In order to do authentication you must use an API key generated for your marketplace on the Symblepay Portal. Retrieve the API key from the Symblepay portal to get started.


To perform successful authorization provide:

-H "Authorization: Bearer {API_Key}"

Formatting rules

Working with Dates

All Symblepay endpoints expect dates and timestamps as strings in UTC (such as, "2024-02-23T00:00:00Z"). ISO 8601

Working with Monetary Amounts

The amounts should be specified as positive decimals representing how much to charge. Be aware that no thousand digit separator should be specified and decimals are converted with a "." as the decimal separator


  • Input: 'Amount: 20' equals 20 DKK.
  • Input: 'Amount: 520.50' equals 520,50 DKK.

The minimum amount is 1. The maximum amount is defined by user's daily/yearly limits.

Working with Phone numbers

All Symblepay endpoints expect phone numbers to formatted with an area code followed by a single whitespace and then the national number without whitespaces.


  • +45 12345678

Distributed tracing

Correlation IDs

A correlation ID is a unique ID assigned to every transaction. When a transaction becomes distributed across multiple services, we can follow it using the logging information. The correlation ID is passed from service to service. All services that process that specific transaction receive the correlation ID and pass it to the next service and so on so that they can log any events associated with that transaction to our centralized logs. This helps us hugely when we have to visualize and understand what has happened with this transaction across different microservices.

Using Symblepay APIs you can provide your own Correlation ID in request header:

-H "X-Correlation-Id: 3307b968-7bf8-4a14-8342-2f0011443188"

If none is provided then our systems will generate it. You will be made aware of it only during errors. If you need to contact us about a specific request, providing the correlation ID will ensure the fastest-possible resolution.