Emfakt Developer API

Use the Emfakt Developer API to submit invoices, check invoice state, and download UPO XML through the versioned /v1 API. This guide covers the core developer flow: authenticate, submit a sandbox invoice, poll for the result, and retrieve UPO when it is available.

Base URL

The current public API version is 1.0.0.

The sandbox API is available at:

Base URL
https://api-sandbox.emfakt.com/v1

All examples in this guide use this base URL.

Request-Id

Every public API response includes a server-generated Request-Id response header for support and diagnostics.

Client-supplied Request-Id values are ignored. Use the value returned by the API when reporting a failed request.

Response header
Request-Id: req_0Y9a6cW9xQz9xwWzYxA0fY

Authentication surfaces

Emfakt has two separate authentication surfaces.

  • Control-plane APIJWT access token

    Used for setup and owner operations, including account creation, login, organizations, and developer API-key management. This guide summarizes the setup calls needed to create a test key.

  • Developer APIdeveloper API key

    Used by external integrations. Core invoice calls use Authorization: Bearer sk_test_... for sandbox mode or Authorization: Bearer sk_live_... for live mode when live mode is enabled for the deployment.

API key modes

Use sk_test_... keys for deterministic sandbox behavior. Sandbox invoice submission is local to the product and does not call real KSeF TEST, DEMO, or production systems.

sk_live_... represents live API-key mode, but live submission is deployment-gated. Live calls require live mode to be enabled and organization KSeF TOKEN credentials to be stored through the control plane.

Core developer flow

The docs cover the first invoice integration path:

  1. Create or obtain a developer API key.
  2. Submit a sandbox invoice with POST /v1/invoices.
  3. Poll GET /v1/invoices/{id} for status.
  4. Retrieve persisted UPO XML from GET /v1/invoices/{id}/upo when upo_available is true.

Start with the Quickstart, then read Authentication, Idempotency, and Invoices.

Other API areas

Beyond the developer invoice flow, the API includes control-plane setup and management endpoints and a webhooks model. See Webhooks and events for event delivery, the event catalog, and delivery records.

There is no public event-list or event-replay API in the current public surface.