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FractalAI x402 Seal — Post-Quantum Provenance Attestation
x402
FractalAI x402 Seal — Post-Quantum Provenance Attestation is a paid API for AI agents from fractalai.net.co, paid per call via x402, $0.05/call, status unknown (last checked 2026-09-13).
Creates a post-quantum cryptographic provenance seal (Dilithium/ML-DSA) over content, optionally anchored on-chain, with drand-sourced randomness for timestamping.
Price / call$0.05
Success—
StatusUnknown
How this service works
The first AI-native Layer 1 blockchain built from scratch in Rust. Post-quantum cryptography (CRYSTALS-Dilithium), Proof of Fractal Work consensus, WASM smart contracts, and 460+ RPC endpoints. Mine FRAC tokens with fractal analysis instead of hash puzzles.
Output
Returns a JSON object containing: a provenance 'seal' object with version, content_hash, drand_round, drand_randomness, sealed_at timestamp, algorithm, base64-encoded Dilithium-2 signature, and public key; an optional on-chain 'anchor' with attestation_hash, block_number, and permalink; a 'served_signature' with an offline-verifiable ML-DSA-65 (NIST FIPS 204) signature, its public key, and the exact signed_message bytes; a 'payment' settlement receipt; and a 'verify_drand_at' URL for independently re-checking the drand round.
Example use cases
Legal document timestamping
“I need to create a tamper-proof, post-quantum signed seal proving this contract existed today — give me a drand-backed attestation with an on-chain anchor and an ML-DSA-65 signature I can verify offline in court.”
AI-generated content provenance
“I'm publishing an AI-generated report and need a quantum-resistant provenance seal so auditors can verify the exact content hash and timestamp without trusting any third-party server — can you get that seal from FractalAI with a drand round and Dilithium signature?”
Dataset integrity for compliance
“Before I submit this training dataset to our compliance team, seal it with a post-quantum cryptographic attestation tied to a public drand randomness round so we have an immutable, verifiable proof of exactly what was in the dataset at submission time.”
Technical details
Endpoint
POSThttps://fractalai.net.co/api/x402/sealWhen to prefer
Choose this endpoint when you need post-quantum resistant content attestation with public verifiability via drand randomness, especially when offline verification (no callback to any server) is required. Prefer over traditional SHA/ECDSA timestamping when quantum-attack resistance is a concern, when you need both a chain anchor and an offline-verifiable signature in a single call, or when your compliance framework requires NIST FIPS 204 (ML-DSA) signatures.
Side effects
- Payment not settled — x402 payment flow incomplete, returns 402 with payment requirements
- Content too large or malformed — seal generation fails
- drand network unavailable — randomness round cannot be fetched, seal may be delayed
- On-chain anchoring unavailable — anchor field returns advisory note but seal remains valid
- Signature verification failure on client side — must use exact signed_message bytes, not reconstructed
- Invalid public key format — base64 decoding errors for ML-DSA-65 key (1952 bytes expected)
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| kind | string | Optional provenance kind: "dataset" | "training" | "content" (informational label recorded in the seal). |
| anchor | boolean | Optional (default true): also anchor the seal hash on-chain (VAID-1) for a public, tamper-evident record. Failure to anchor never fails the seal. |
| issuer | string | Optional declaring party (recorded, informational). |
| content | string | Arbitrary UTF-8 content to seal; we seal sha256(content). Provide content OR content_hash. |
| content_hash | string | A sha256 hex digest you already computed (e.g. of a dataset or training artifact); sealed as-is. Privacy-preserving — the content never leaves you. |
Output
Schema · Response
{
"type": "json",
"schema": {
"type": "object",
"required": [
"seal"
],
"properties": {
"seal": {
"type": "object",
"description": "The re-verifiable provenance seal: { version, content_hash, drand_round, drand_randomness, sealed_at, algorithm, signature (base64 Dilithium-2), public_key }."
},
"anchor": {
"type": "object",
"description": "On-chain anchor receipt (attestation_hash, block_number, permalink) or a note if anchoring was unavailable. Advisory — the seal is valid without it. The anchor is Dilithium-2 (ML-DSA-44), bound to the node."
},
"payment": {
"type": "object",
"description": "Settlement receipt (scheme, network, asset, txHash, payer, settled)."
},
"verify_drand_at": {
"type": "string",
"description": "URL to independently re-check the drand round on drand.sh."
},
"served_signature": {
"type": "object",
"description": "Self-contained, OFFLINE-verifiable Dilithium-3 / ML-DSA-65 (NIST FIPS 204) signature over the canonical seal bytes: { algorithm: \"ml-dsa-65\", algorithm_label, digest (sha256 hex signed), signature (base64 ML-DSA-65, 3309 bytes), public_key (base64, 1952 bytes), signed_message (the EXACT UTF-8 bytes signed = \"FRACTALAI-x402-served-v1\\nx402-seal\\n<digest>\", route-separated, 3 lines) }. Additive — verify with ml_dsa65.verify(b64(signature), utf8(signed_message), b64(public_key)); pass signed_message verbatim, do not reconstruct it."
}
}
},
"example": {
"seal_id": "…",
"permalink": "https://fractalai.net.co/attestation/0x…",
"attestation_hash": "0x…",
"served_signature": {
"algorithm": "ml-dsa-65"
}
}
}Tags
x402
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