Evaluate a proposed payment against a structured, caller-supplied policy and opt
Evaluate a proposed payment against a structured, caller-supplied policy and optional recipient sanctions screening, before execution. Returns ALLOW, REQUIRE_APPROVAL, or BLOCK with reasons, plus a signed OCD PREFLIGHT receipt anyone can independently verify. Policy evaluation only: OCD never holds, moves, or authorizes funds. The wallet, PayBox, or x402 client independently authorizes execution afterward; an ALLOW here does not guarantee it will proceed.
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://mcp.onchaindiligence.com/x402/preflight-payment
| Category | Code and developer |
|---|---|
| Provider host | mcp.onchaindiligence.com |
| Networks | eip155:8453 |
| Payment schemes | exact |
| Self-reported calls, 30 days | 2 from 2 payers (the provider's figure, not ours) |
Our checks, last 30 days
| Day | Result | HTTP | Asked | Time |
|---|---|---|---|---|
| 2026-09-24 | valid payment request | 402 | $0.01 | 654 ms |
Example input (from the provider)
{
"body": {
"action": {
"amount": "1.00",
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"kind": "PAYMENT",
"network": "eip155:8453",
"recipient": "0x000000000000000000000000000000000000dEaD",
"resource": "https://service.example/api",
"sender": null
},
"options": {
"screen_recipient_sanctions": true
},
"policy": {
"allowed_assets": [
"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"
],
"allowed_networks": [
"eip155:8453"
],
"allowed_resource_origins": [
"https://service.example"
],
"expected_recipient": null,
"max_amount": "5.00"
},
"references": {
"mandate_digest": null
}
},
"bodyType": "json",
"method": "POST",
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"properties": {
"action": {
"type": "object"
},
"options": {
"type": "object"
},
"policy": {
"type": "object"
},
"references": {
"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"
},
"output": {
"properties": {
"example": {
"properties": {
"checks": {
"type": "array"
},
"decision": {
"properties": {
"authorized": {
"type": [
"boolean",
"null"
]
},
"reasons": {
"items": {
"type": "string"
},
"type": "array"
},
"status": {
"enum": [
"ALLOW",
"REQUIRE_APPROVAL",
"BLOCK",
"UNKNOWN"
],
"type": "string"
}
},
"type": "object"
},
"receipt": {
"description": "Complete onchaindiligence.public-action-receipt.v1 envelope.",
"type": "object"
}
},
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}