> For the complete documentation index, see [llms.txt](https://docs.emudhradigital.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.emudhradigital.com/documentation/esign-v2-online-aadhaar-ekyc.md).

# eSign v2 (Online Aadhaar eKYC)

**eSign v2** provides on-demand, Aadhaar-based electronic signatures under CCA eSign API 2.1 — no enrolment required. Signers authenticate with Aadhaar OTP / T-OTP, fingerprint, iris or face, and a one-time DSC is issued for each transaction.

In this section:

* **eSign v2 Overview** — capabilities and when to use eSign v2
* **Authentication Modes** — OTP, T-OTP, fingerprint, iris and face
* **Integration Models** — Web, Web-to-App, App-to-App and SDK, with the platform support matrix
* **Signing Flow** — end-to-end transaction sequence
* **API Specification** — request and response XML
* **Error Codes** — ESP error codes and handling