Verifiable timestamp (trustless proof-of-existence / freshness proof)
Verifiable timestamp (trustless proof-of-existence / freshness proof): bind a hash to a drand round for an anti-backdating receipt — proves data existed no earlier than a public instant, with no trusted timestamp authority. Privacy: stamp an opaque sha256 digest.
Answeringour last check, 2026-09-24
1 of 1checks answered this week
232 msmedian answer time
$0.001listed price per call
$0.001price it asked us
Paid test badge: not yet. The checks above are free: we call the tool without paying and read the payment request it sends back. The Verified badge needs paid calls whose answers match the promised output, and nobody can buy a badge.
Endpoint
GET https://touchstone.locomot.io/timestamp
| Category | Everything else |
|---|---|
| Provider host | touchstone.locomot.io |
| Networks | eip155:8453 |
| Payment schemes | exact |
| Self-reported calls, 30 days | 1 from 1 payers (the provider's figure, not ours) |
Our checks, last 30 days
| Day | Result | HTTP | Asked | Time |
|---|---|---|---|---|
| 2026-09-24 | valid payment request | 402 | $0.001 | 232 ms |
Example input (from the provider)
{
"method": "GET",
"queryParams": {
"data": "i decided X before the match",
"op": "stamp"
},
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"method": {
"enum": [
"GET",
"HEAD",
"DELETE"
],
"type": "string"
},
"queryParams": {
"properties": {
"data": {
"description": "text to stamp (sha256'd)",
"type": "string"
},
"hash": {
"description": "OR a 64-hex sha256 digest (private)",
"type": "string"
},
"op": {
"description": "operation; default stamp",
"enum": [
"stamp",
"verify"
],
"type": "string"
},
"round": {
"description": "pin a drand round; verify requires it",
"type": "integer"
}
},
"type": "object"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method"
],
"type": "object"
},
"output": {
"properties": {
"beacon": {
"type": "object"
},
"claim": {
"type": "string"
},
"commitment": {
"type": "string"
},
"deterministic_given_round": {
"type": "boolean"
},
"digest": {
"type": "string"
},
"digest_source": {
"type": "string"
},
"engine": {
"type": "string"
},
"not_earlier_than": {
"type": "string"
},
"op": {
"type": "string"
},
"proof": {
"type": "object"
},
"round": {
"type": "integer"
},
"round_time_utc": {
"type": "string"
}
},
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}