Anchor a SHA-256 payload hash (64 lowercase hex chars) into a Merkle batch on Ba
Anchor a SHA-256 payload hash (64 lowercase hex chars) into a Merkle batch on Base mainnet. Payment: $0.001 USDC per submission (batch-settled). Returns anchor_id (202); poll status_url for Merkle proof + on-chain tx hash.
Answeringour last check, 2026-10-03
1 of 1checks answered this week
1020 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://x402.fairseal.io/v2/anchor
| Category | Market data |
|---|---|
| Provider host | x402.fairseal.io |
| Networks | eip155:8453 |
| Payment schemes | exact |
| Self-reported calls, 30 days | 0 from 0 payers (the provider's figure, not ours) |
Our checks, last 30 days
| Day | Result | HTTP | Asked | Time |
|---|---|---|---|---|
| 2026-10-03 | valid payment request | 402 | $0.001 | 1020 ms |
Example input (from the provider)
{
"body": {
"metadata": {
"label": "my-document-v1",
"purpose": "proof_of_existence"
},
"payload_hash": "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
"tier": "batch"
},
"bodyType": "json",
"method": "POST",
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"properties": {
"metadata": {
"description": "Optional metadata (max 1KB). Stored with receipt.",
"type": "object"
},
"payload_hash": {
"description": "SHA-256 hex of content to anchor (64 lowercase hex chars)",
"pattern": "^[0-9a-f]{64}$",
"type": "string"
},
"tier": {
"description": "batch (default, ~60s) or realtime (pro key required)",
"enum": [
"batch",
"realtime"
],
"type": "string"
}
},
"required": [
"payload_hash"
],
"type": "object"
},
"bodyType": {
"enum": [
"json",
"form-data",
"text"
],
"type": "string"
},
"method": {
"enum": [
"POST"
],
"type": "string"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method",
"bodyType",
"body"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}