REST API
A REST API (Application Programming Interface — Representational State Transfer) is a programming interface that enables two computer systems to communicate via the HTTP protocol. In the context of document verification, a REST API allows identity verification services to be integrated directly into existing business applications.
REST architecture is based on simple principles: each resource (a document, a user, a verification) is accessible via a unique URL, and standard operations (create, read, update, delete) are performed via the corresponding HTTP methods (POST, GET, PUT, DELETE). This standardisation facilitates integration by development teams and ensures maximum interoperability between heterogeneous systems.
For businesses subject to KYC compliance obligations, the REST API is the preferred mechanism for integrating document verification services. Rather than redirecting users to a third-party platform, the business calls the API directly from its own customer journey. The document is submitted, analysed in real time, and the result (validated, rejected, pending manual review) is returned within seconds as a structured JSON response.
CheckFile's REST API offers dedicated endpoints for each stage of the verification process: document submission, data extraction, authenticity check, cross-referencing, and audit trail generation. It supports API key and OAuth 2.0 authentication, TLS encryption, and provides webhooks for asynchronous notifications. The interactive documentation allows developers to test each endpoint directly from their browser.
Regulations
Real-world examples
- 1.A fintech integrates the document verification REST API into its mobile account opening flow: the user takes a photo of their ID, the app sends the image via the API, and receives the extracted data and verification status in under 3 seconds.
- 2.An insurance broker connects their CRM to the REST API to automatically trigger an identity verification whenever a new prospect is created, without manual intervention from the compliance team.
- 3.A property rental platform uses the REST API to verify proof of address and payslips submitted by tenant applicants in real time, integrating the results directly into the application file.