Timestamp SHA-256 hashes in Bitcoin with OpenTimestamps
Timestamp SHA-256 hashes in Bitcoin with OpenTimestamps: returns a standard .ots proof per hash (pending, complete within hours), verifiable without us
Answeringour last check, 2026-10-21
1 of 1checks answered this week
379 msmedian answer time
$0.05listed price per call
$0.05price 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
POST https://stampthisfile.com/v1/stamps
| Category | Everything else |
|---|---|
| Provider host | stampthisfile.com |
| Networks | eip155:8453 |
| Payment schemes | exact |
| Self-reported calls, 30 days | 2 from 2 payers (the provider's figure, not ours) |
Our checks, last 30 days
| Day | Result | HTTP | Asked | Time |
|---|---|---|---|---|
| 2026-10-21 | valid payment request | 402 | $0.05 | 379 ms |
Example input (from the provider)
{
"body": {
"hashes": [
"b94d27b9934d3e08a52e52d7da7dabfac484efe37a5380ee9088f7ace2efcde9"
]
},
"bodyType": "json",
"method": "POST",
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"properties": {
"hashes": {
"description": "Each hash costs the unit price; send each once",
"items": {
"description": "SHA-256 of the file, hex",
"pattern": "^[0-9a-fA-F]{64}$",
"type": "string"
},
"maxItems": 100,
"minItems": 1,
"type": "array"
},
"webhook": {
"properties": {
"signing_key": {
"description": "Optional Standard Webhooks secret (whsec_\u2026) to also sign deliveries with HMAC (v1)",
"type": "string"
},
"url": {
"description": "https URL that receives stamps.completed / stamps.failed",
"format": "uri",
"type": "string"
}
},
"required": [
"url"
],
"type": "object"
}
},
"required": [
"hashes"
],
"type": "object"
},
"bodyType": {
"enum": [
"json"
],
"type": "string"
},
"headers": {
"additionalProperties": {
"type": "string"
},
"type": "object"
},
"method": {
"enum": [
"POST"
],
"type": "string"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method",
"bodyType",
"body"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}