Developer API · v1

Public e-invoice research and preparation API

Query the platform knowledge graph and run deterministic preparation checks without pretending to proxy credentialed authority submissions, protected registries or official acceptance decisions.

Test health endpoint OpenAPI JSON

Preparation endpoints

GET/api/health

Service health and current platform catalogue counts

GET/api/openapi

OpenAPI 3.1 description of public preparation endpoints

GET/api/v1/search?q=ksef

Search countries, formats, workflows, integrations and guides

GET/api/v1/profile/pl

Country system, formats, workflows, connectors and research boundary

GET/api/v1/connectors?country=sa

Authority and network connector capability registry

POST/api/v1/mandate

Assess recorded mandate scope from country, transaction and date

POST/api/v1/identifier

Run supported checksum or structural identifier checks

POST/api/v1/reference

Inspect UUID, IRN, CUFE, access-key and similar structures

POST/api/v1/payload

Check common fields in a JSON invoice payload

POST/api/v1/detect

Detect known invoice format signatures in a text payload

POST/api/v1/fingerprint

Create a SHA-256 digest for correlation and duplicate control

Public catalogues

Use the catalogues for navigation, research, prototypes and content integrations without scraping rendered pages.

/api/countries/api/formats/api/mandates/api/tools/api/workflows/api/integrations/api/guides

Example: mandate guidance

curl -X POST https://einvoicelab.com/api/v1/mandate   -H "content-type: application/json"   -d '{
    "country": "pl",
    "transaction": "b2b",
    "date": "2026-08-02",
    "crossBorder": false
  }'

Example: format signature detection

curl -X POST https://einvoicelab.com/api/v1/detect   -H "content-type: application/json"   -d '{"content":"<Invoice>...</Invoice>"}'

Response principles

Compliance-sensitive responses include a visible capability boundary.
Public checks are deterministic and do not claim live registry, signature or authority status.
Country profile responses include last-reviewed dates and official URLs.
Payload endpoints enforce small public limits and return JSON errors.
Do not send confidential invoice data to an API when the equivalent browser tool can run locally.