---
title: "SHA-256 fingerprint of the FreeSign CA certificate"
method: GET
path: "/.well-known/free-sign-signing-ca.sha256.txt"
---

# SHA-256 fingerprint of the FreeSign CA certificate

`GET /.well-known/free-sign-signing-ca.sha256.txt`

## Request

- Base URL: `https://free-sign.com`
- URL: `https://free-sign.com/.well-known/free-sign-signing-ca.sha256.txt`
- Auth: none declared

Plain-text lowercase hex SHA-256 of the FreeSign CA certificate DER, followed by a trailing newline. Pair with /.well-known/free-sign-signing-ca.pem and /freesign-trust.fdf — these three surfaces together let any verifier or recipient pin / install the CA out of band, with no Worker code on their side.

## Response `200`

64-character lowercase hex SHA-256 + newline.

## Other responses

- `404`: Signing CA cert is not configured on this deployment.

---

[API](https://skmtc.dev/free-sign/apis/freesign-free-e-signature-api.md) · [All operations](https://skmtc.dev/free-sign/apis/freesign-free-e-signature-api/llms.txt) · [OpenAPI document](https://skmtc.dev/free-sign/apis/freesign-free-e-signature-api/revisions/5d8e9854ab85?raw)