Sellat

sellat.app · 2 paid endpoints · listed 2026-10-27

Timestamp and notarize any file or data by its SHA-256 hash: blockchain proof of existence and document integrity, anchored on Polygon in minutes and attested on Bitcoin (OpenTimestamps); blockchain notarization, not a notary act. Returns proof_id, certificate, proof.json and evidence ZIP, verifiable without Sellat. Use when you must prove that exact data existed by now and is intact.

livelast check 14 h ago

100%valid x402 answers, 72 h

$0.93USDC received on Base, 7 days

2distinct payers, 7 days

55.3score (0-100)

Paid endpoints

Method	Endpoint	Price	Networks
POST	sellat.app/api/v2/proofs Timestamp and notarize any file or data by its SHA-256 hash: blockchain proof of existence and document integrity, anchored on Polygon in minutes and attested o	$0.01	Base
POST	sellat.app/api/v2/proofs/:id/qualified eIDAS qualified electronic timestamp (RFC 3161 .tsr) on a Sellat proof, issued in seconds by an EU qualified trust service provider on the EU trusted list. Lega	$0.90	Base

Latest checks

When	Endpoint	HTTP	ms	Result
14 h ago	sellat.app/api/v2/proofs	402	307	valid x402 v2 terms

Income on Base (7 days)

Day		Transfers	USDC
2026-10-26		4	$0.93

Is this your API?

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<a href="https://logicnodes.io/observatory/p/sellat.app"><img src="https://logicnodes.io/observatory/badge/sellat.app.svg" alt="x402 status"></a>

Claim it for free with x402_provider_claim (sign with your payout address), and get an alert within minutes when it stops answering with x402_monitor_create ($5 for 30 days). Both work over MCP (https://logicnodes.io/mcp/v2) or POST https://logicnodes.io/v1/tools/<tool>.

Income is all USDC received by the provider's payout address on Base, whatever the source. Score: 0-100: 50 x share of checks in the last 72 h that returned valid x402 payment terms + 30 x min(1, log10(1 + USDC received in 7 days) / 4) + 20 x min(1, log10(1 + distinct payers in 7 days) / 3). A provider never checked scores on income only; income is all USDC received by its payout address on Base, whatever the source. JSON: /v1/observatory/providers/sellat.app