API Reference

Base URL

Base URL

https://stampapi.veristamp.in/api/v1

POST /timestamp

Submit a file hash for timestamping and receive a signed cryptographic receipt. The file itself is never transmitted — only the hash is sent.

Request

HTTP

POST /api/v1/timestamp Content-Type: application/json

hashstring

required

Hex-encoded SHA-256 digest of the file (64 hex characters).

noncestring

required

Base64url-encoded random 16-byte nonce. Generate a fresh nonce per request to prevent brute-force matching of the leaf hash.

filenamestring

optional

Original filename. Metadata only — not part of the cryptographic proof.

sizenumber

optional

File size in bytes. Metadata only — not part of the cryptographic proof.

Example request

{
  "hash": "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
  "nonce": "xK9mP2vL8nQ4wR7j",
  "filename": "contract.pdf",
  "size": 2048576
}

Response (200 OK)

{
  "receipt": {
    "veristamp_version": "1.0",
    "type": "veristamp.receipt",
    "receipt_id": "vst_r_7f3a2b1c",
    "issued_at": "2026-06-05T12:00:00.000Z",
    "hash": {
      "algorithm": "SHA-256",
      "value": "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"
    },
    "nonce": "xK9mP2vL8nQ4wR7j",
    "issuer": {
      "name": "Veristamp",
      "key_id": "vst_sign_2026_q2_01"
    },
    "signature": {
      "algorithm": "Ed25519",
      "value": "aBcDeFgHiJkLmNoPqRsTuVwXyZ..."
    },
    "verification": {
      "public_key_registry": "https://stamp.veristamp.in/.well-known/veristamp-keyring.json",
      "verifier": "https://stamp.veristamp.in/verify"
    },
    "transparency": {
      "log": "https://stamp.veristamp.in/transparency",
      "current_root": "https://roots.veristamp.in/.well-known/veristamp-roots/current.json",
      "monthly_archive": "https://roots.veristamp.in/.well-known/veristamp-roots/2026-06.json",
      "yearly_archive": "https://roots.veristamp.in/.well-known/veristamp-roots/2026.json",
      "status": "pending_next_root"
    }
  }
}

Error responses

Status	Code	Description
400	BAD_REQUEST	Invalid request body — not valid JSON or unrecognized fields
400	MISSING_NONCE	Nonce is missing or shorter than 16 bytes
400	INVALID_HASH_FORMAT	Hash is not a valid 64-character hex string
400	UNSUPPORTED_HASH_ALGORITHM	Only SHA-256 is supported
429	RATE_LIMITED	Returned by Cloudflare WAF before the Worker is invoked.
503	SERVICE_UNAVAILABLE	Internal service error — retry later

Error responses follow a consistent format:

{
  "error": {
    "code": "MISSING_NONCE",
    "message": "Human-readable description of the error"
  }
}

Keyring

The current keyring containing all active and retired public keys is available as a static file — no API call needed:

URL

https://stamp.veristamp.in/.well-known/veristamp-keyring.json

The keyring supports conditional requests via ETag/If-None-Match headers and can be cached indefinitely for offline verification. See the Keyring reference for the full structure and verification guide.