---
title: "Issue a c_nonce for the credential proof"
method: POST
path: "/v1/nonce"
tags: ["OpenID4VCI Protocol"]
---

# Issue a c_nonce for the credential proof

`POST /v1/nonce`

OpenID4VCI nonce endpoint. Public, unauthenticated. Mints a fresh single-use `c_nonce` that the holder must embed in the proof JWT presented to the credential endpoint. The c_nonce is consumed when the proof is verified and expires after 60 seconds. The request body is empty.

## Request body

- object

## Response `200`

A single-use challenge nonce.

- object
  - `c_nonce` string — The challenge nonce. Place it in the `nonce` claim of the holder proof JWT sent to POST /v1/credential. Single-use — consumed on successful proof verification.
  - `c_nonce_expires_in` integer — Nonce lifetime in seconds. Always 60.

## Changes

- **2026-06-30** `1ee4908e9af4` — 1 breaking
  - request body became required

[Change history](https://skmtc.dev/didit-protocol/apis/didit-credentials-api/changes/v1/nonce/post.md)

---

[API](https://skmtc.dev/didit-protocol/apis/didit-credentials-api.md) · [All operations](https://skmtc.dev/didit-protocol/apis/didit-credentials-api/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/didit-protocol/didit-credentials-api/revisions/1c34704cfbbb/schema)