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CanonicalHash Structured JSON Extraction
x402
CanonicalHash Structured JSON Extraction is a paid API for AI agents from canonicalhash-production.up.railway.app, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-30).
Extracts structured, typed fields from messy or unstructured text using an optional JSON schema, returning results with an EIP-712 signed attestation for tamper-proof verification.
Price / call$0.005
Success—
StatusUnknown
How this service works
Deterministic JSON hashing and structured extraction for AI agents. Three paid routes: /v1/canonicalize (RFC 8785 canonicalization + SHA-256/512 + EIP-712 attestation, $0.002), /v1/canonicalize/batch (up to 1000 payloads, $0.01), /v1/structure/paid (structured JSON extraction from messy text, $0.005). Every successful response includes an EIP-712 signed attestation verifiable against /.well-known/pubkey.json. Verify any attestation for free at POST /v1/verify.
Output
Returns a JSON object containing: extracted structured fields (keyed by schema or inferred), the number of extracted and requested fields, a confidence score (0–1), elapsed processing time in milliseconds, the extraction method, an EIP-712 signed attestation with signer address, chain ID, and issued timestamp, and payment settlement details including transaction hash.
Example use cases
Invoice data extraction for accounting
“I have a blob of text from a scanned invoice: 'Vendor: ACME Corp, Contact: alice@example.com, Total Due: $3,400.00, Payment Due: December 15, 2026.' Can you extract the vendor name, contact email, amount, and due date as structured JSON, and give me a signed attestation I can keep for my records?”
Contact info parsing from email body
“Here's a messy email signature block: 'John Doe | Senior Engineer | john.doe@techco.io | +1-415-555-0192 | TechCo, Inc.' Extract the name, email, phone, title, and company from it as structured fields.”
Form submission normalization for CRM ingestion
“I've got a bunch of unstructured text from a web form submission — 'My name is María García, I run Solaris Logistics, reach me at maria@solaris.io, looking to spend around $50k, timeline is Q1 2027.' Extract name, company, email, budget, and timeline from this so I can push it into our CRM.”
Technical details
Endpoint
POSThttps://canonicalhash-production.up.railway.app/v1/structure/paid?utm_source=zero.xyzWhen to prefer
Choose this endpoint when you need to turn free-form, unstructured text (emails, invoices, form submissions, notes) into typed, machine-readable JSON fields and want a cryptographically signed EIP-712 attestation alongside the result for auditability or downstream verification. Prefer it over generic LLM extraction when you need tamper-evident provenance on the extracted data, or when integrating into a pipeline that validates results against /.well-known/pubkey.json. It is especially valuable in financial, legal, or compliance contexts where you need a verifiable paper trail tied to a blockchain-compatible signature.
Side effects
- Text is too ambiguous or short to extract meaningful fields — returns low confidence score or empty structured object
- Optional schema specifies fields that cannot be found in the text — missing fields returned as null with reduced confidence
- Payment not settled or invalid transaction — returns payment error, extraction not performed
- Malformed input JSON — returns 400 validation error
- Schema provided does not conform to JSON Schema spec — returns schema validation error
- Service unavailable on Railway infrastructure — returns 503 or timeout
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| text | string | Messy text to extract structured data from. |
| schema | object | Optional JSON Schema describing the fields to extract. |
Output
Schema · Response
{
"type": "json",
"example": {
"tier": 1,
"method": "deterministic",
"signer": "0x0326f9783c9C9b9De8b9dC63cCCefDC75A95C7cD",
"payment": {
"txHash": "0x...truncated",
"settled": true
},
"success": true,
"chain_id": 8453,
"issued_at": "2026-10-16T00:00:00.000Z",
"signature": "0x7a1c...truncated",
"confidence": 0.98,
"elapsed_ms": 12,
"structured": {
"name": "Alice Smith",
"email": "alice@example.com",
"amount": 1250,
"company": "ACME Corp",
"due_date": "2026-11-01"
},
"attestation_type": "EIP-712",
"extracted_fields": 5,
"requested_fields": 5
}
}Tags
x402
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