Three modes over the same event structure
Three modes over the same event structure. In preimage mode the caller supplies a public key and the event fields; the answer holds the exact NIP-01 serialisation, the SHA-256 event id derived from it and the 32 bytes to sign, so the caller signs locally and no secret key ever crosses the connection.
Answeringour last check, 2026-10-10
1 of 1checks answered this week
1190 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
POST https://nostr.halowerk.com/event-sign
| Category | Everything else |
|---|---|
| Provider host | nostr.halowerk.com |
| 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 |
|---|---|---|---|---|
| 2026-10-10 | valid payment request | 402 | $0.001 | 1190 ms |
Example input (from the provider)
{
"body": {
"mode": "preimage",
"pubkey": "beispiel"
},
"bodyType": "json",
"method": "POST",
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"additionalProperties": false,
"properties": {
"content": {
"default": "",
"description": "Event content.",
"maxLength": 64000,
"type": "string"
},
"created_at": {
"description": "Unix seconds. Left out, the current time is used.",
"minimum": 0,
"type": "integer"
},
"event": {
"description": "The complete event to check. Only used in verify mode.",
"type": "object"
},
"kind": {
"default": 1,
"description": "NIP-01 event kind. 1 is a text note, 30023 a long-form article.",
"maximum": 65535,
"minimum": 0,
"type": "integer"
},
"mode": {
"default": "preimage",
"description": "preimage: caller signs locally. ephemeral: single-use key generated here. verify: check a complete event.",
"enum": [
"preimage",
"ephemeral",
"verify"
],
"type": "string"
},
"pubkey": {
"description": "Public key as hex or npub. Required in preimage mode, ignored otherwise.",
"type": "string"
},
"tags": {
"description": "NIP-01 tags, each an array of strings, for example [\"t\",\"bitcoin\"].",
"items": {
"items": {
"type": "string"
},
"type": "array"
},
"maxItems": 200,
"type": "array"
}
},
"type": "object"
},
"bodyType": {
"enum": [
"json",
"form-data",
"text"
],
"type": "string"
},
"method": {
"enum": [
"POST",
"PUT",
"PATCH"
],
"type": "string"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method",
"bodyType",
"body"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}