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SignalHarness Content Fingerprint
x402
SignalHarness Content Fingerprint is a paid API for AI agents from signalharness.ai, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-14).
Computes a SHA-256 cryptographic fingerprint and byte-count of submitted content (HTML, JSON, text, or base64 binary) with normalization metadata for deduplication and integrity verification.
Price / call$0.005
Success—
StatusUnknown
How this service works
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Output
Returns a JSON object containing: a SHA-256 hash of the raw content, a normalized SHA-256 hash (after applying a normalization strategy), the raw byte count, the normalization method name, the normalized content length, and a replay flag indicating if this is a repeated computation. Also includes a payment receipt with execution metadata, timing, and settlement reference.
Example use cases
Deduplication of scraped web pages
“I'm scraping a bunch of web pages and want to avoid processing duplicates — can you fingerprint this HTML and give me a SHA-256 so I can compare it against pages I've already processed? Here's the HTML: '<html><body><p>Welcome to our site</p></body></html>'”
JSON payload change detection
“Has this JSON configuration object changed since last time? Compute a fingerprint for it so I can store the hash and compare next time: {"version":"2.1","features":["alpha","beta"],"enabled":true}”
Text document integrity verification
“I need to prove this contract text hasn't been tampered with — generate a SHA-256 fingerprint for this text so I can record it: 'This agreement is entered into as of January 1, 2025 between Party A and Party B...'”
Technical details
Endpoint
POSThttps://signalharness.ai/api/agent/services/content_fingerprint/invokeWhen to prefer
Choose this endpoint when you need a cryptographic fingerprint of arbitrary content (HTML, JSON, text, or binary) for deduplication, change detection, caching keys, or integrity verification — especially in agent workflows requiring per-call micropayment via x402/USDC. Prefer this over ad-hoc client-side hashing when you need server-side normalization (e.g., stripping whitespace from HTML before hashing) to ensure semantically equivalent content produces the same fingerprint.
Side effects
- Input content exceeds 65,536 character/byte limit — request rejected
- No valid content field provided (html, json, text, or base64 all absent) — validation error
- Invalid base64 encoding pattern — schema validation failure
- Payment failure or insufficient USDC balance — 402 Payment Required
- Malformed JSON body — 400 Bad Request
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| html | string | |
| json | — | |
| text | string | |
| type | string | |
| base64 | string |
Output
Schema · Response
{
"type": "json",
"example": {
"replay": false,
"result": {
"type": "example",
"sha256": "0000000000000000000000000000000000000000000000000000000000000000",
"byteCount": 0,
"normalization": "example",
"normalizedLength": 0,
"normalizedSha256": "0000000000000000000000000000000000000000000000000000000000000000"
},
"status": "succeeded",
"receipt": {
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"usage": [],
"status": "succeeded",
"network": "eip155:8453",
"artifacts": [],
"endedAtMs": 0,
"latencyMs": 0,
"paymentId": "example-payment",
"receiptId": "example-receipt",
"requestId": "example-request",
"serviceId": "content_fingerprint",
"executionId": "example-execution",
"startedAtMs": 0,
"amountAtomic": "5000",
"resultSha256": "3861c2f5ca83c78359f3fc168c79d4dab10e7dc1d28858e724e9f33d397cb3b1",
"serviceVersion": "1.0.0",
"settlementReference": "0x0000000000000000000000000000000000000000000000000000000000000000"
},
"artifacts": [],
"requestId": "example-request",
"executionId": "example-execution"
}
}Tags
x402
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