77trust / 100

Invoice Preflight

by Invoice Preflight in Markets & finance

x402 APIPassing, checked 4 h ago

Check invoice amounts, purchase details and line items; return match, discrepancy or needs_review with evidence.

POST

https://mcp.dropenginehq.com/api/invoice-preflight

Price: $0.065; per call in USDC
Uptime: 100%; last 30 days
Response time: 496 ms; 610 ms slowest 5%
Last check: Passed; 4 h ago, next any minute now

Run a free test call How to call it

Reliability

All checks passedSome failedAll failedNot checked

Status and outage history · Atom feed · Watch with other listings

How to call it

POST https://mcp.dropenginehq.com/api/invoice-preflight

Each call costs $0.065 in USDC on Base, paid with the request over x402.

Run a free test callOne unpaid request, the way an agent sends it. You see the payment challenge it gets back. Nothing is charged.

Example request

From the listing.

POST https://mcp.dropenginehq.com/api/invoice-preflight
content-type: application/json

{
  "document_xml": "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<Invoice xmlns=\"urn:oasis:names:specification:ubl:schema:xsd:Invoice-2\" xmlns:cac=\"urn:oasis:names:specification:ubl:schema:xsd:CommonAggregateComponents-2\" xmlns:cbc=\"urn:oasis:names:specification:ubl:schema:xsd:CommonBasicComponents-2\">\n  <cbc:ID>INV-8821</cbc:ID>\n  <cbc:DocumentCurrencyCode>USD</cbc:DocumentCurrencyCode>\n  <cac:OrderReference><cbc:ID>PO-8841</cbc:ID></cac:OrderReference>\n  <cac:AccountingSupplierParty><cac:Party><cac:PartyLegalEntity><cbc:RegistrationName>Example Ltd</cbc:RegistrationName></cac:PartyLegalEntity></cac:Party></cac:AccountingSupplierParty>\n  <cac:TaxTotal><cbc:TaxAmount currencyID=\"USD\">24.00</cbc:TaxAmount></cac:TaxTotal>\n  <cac:LegalMonetaryTotal><cbc:TaxExclusiveAmount currencyID=\"USD\">100.00</cbc:TaxExclusiveAmount><cbc:PayableAmount currencyID=\"USD\">124.00</cbc:PayableAmount></cac:LegalMonetaryTotal>\n  <cac:InvoiceLine><cbc:ID>1</cbc:ID><cbc:LineExtensionAmount currencyID=\"USD\">60.00</cbc:LineExtensionAmount><cac:Item><cbc:Name>Service A</cbc:Name></cac:Item></cac:InvoiceLine>\n  <cac:InvoiceLine><cbc:ID>2</cbc:ID><cbc:LineExtensionAmount currencyID=\"USD\">40.00</cbc:LineExtensionAmount><cac:Item><cbc:Name>Service B</cbc:Name></cac:Item></cac:InvoiceLine>\n</Invoice>",
  "expected": {
    "currency": "USD",
    "purchase_order": "PO-8841",
    "supplier_name": "Example Ltd",
    "total": "124.00"
  }
}

Parameters

Parameter	Type	Required	Description
`document_base64`	string	No	Base64 encoded PDF, PNG, or JPEG (up to 10 MB, 3 pages for this tool).
`document_url`	string	No	Public HTTPS URL to a PDF, PNG, or JPEG (up to 10 MB, 3 pages for this tool).
`document_xml`	string	No	UBL Invoice XML document, up to 1 MB.
`expected`	object	No
`mime_type`	string	No	One of: application/pdf, image/png, image/jpeg.

Example response

The provider's example. We can't check it without paying.

Example response, 99 lines

{
  "checks": [
    {
      "actual": "Example Ltd",
      "expected": "Example Ltd",
      "field": "supplier_name",
      "status": "match"
    },
    {
      "actual": "PO-8841",
      "expected": "PO-8841",
      "field": "purchase_order",
      "status": "match"
    },
    {
      "actual": "USD",
      "expected": "USD",
      "field": "currency",
      "status": "match"
    },
    {
      "actual": "124.00",
      "expected": "124.00",
      "field": "total",
      "status": "match"
    },
    {
      "actual": "100.00",
      "calculated": "100.00",
      "field": "line_items_sum",
      "status": "match"
    },
    {
      "actual": "124.00",
      "calculated": "124.00",
      "field": "subtotal_plus_tax",
      "status": "match"
    }
  ],
  "decision": "match",
  "evidence": [
    {
      "field": "number",
      "source": "Invoice/ID",
      "text": "INV-8821"
    },
    {
      "field": "supplier_name",
      "source": "Invoice/AccountingSupplierParty/Party/PartyLegalEntity/RegistrationName",
      "text": "Example Ltd"
    },
    {
      "field": "purchase_order",
      "source": "Invoice/OrderReference/ID",
      "text": "PO-8841"
    },
    {
      "field": "currency",
      "source": "Invoice/DocumentCurrencyCode",
      "text": "USD"
    },
    {
      "field": "subtotal",
      "source": "Invoice/LegalMonetaryTotal/TaxExclusiveAmount",
      "text": "100.00"
    },
    {
      "field": "tax",
      "source": "Invoice/TaxTotal/TaxAmount",
      "text": "24.00"
    },
    {
      "field": "total",
      "source": "Invoice/LegalMonetaryTotal/PayableAmount",
      "text": "124.00"
    }
  ],
  "invoice": {
    "currency": "USD",
    "line_items": [
      {
        "amount": "60.00",
        "description": "Service A"
      },
      {
        "amount": "40.00",
        "description": "Service B"
      }
    ],
    "number": "INV-8821",
    "purchase_order": "PO-8841",
    "subtotal": "100.00",
    "supplier_name": "Example Ltd",
    "tax": "24.00",
    "total": "124.00"
  },
  "source_sha256": "924b90ef73afa563db0e69f5f512e96e8041e9c6e192748011f1a8a809469fed",
  "warnings": []
}

Call it from code

The curl command shows the payment challenge. The JavaScript and Python versions pay and call, and never pay more than $0.065.

curl: see the payment challenge

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i -X POST 'https://mcp.dropenginehq.com/api/invoice-preflight' \
  -H 'content-type: application/json' \
  --data-raw '{"document_xml":"<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<Invoice xmlns=\"urn:oasis:names:specification:ubl:schema:xsd:Invoice-2\" xmlns:cac=\"urn:oasis:names:specification:ubl:schema:xsd:CommonAggregateComponents-2\" xmlns:cbc=\"urn:oasis:names:specification:ubl:schema:xsd:CommonBasicComponents-2\">\n  <cbc:ID>INV-8821<\/cbc:ID>\n  <cbc:DocumentCurrencyCode>USD<\/cbc:DocumentCurrencyCode>\n  <cac:OrderReference><cbc:ID>PO-8841<\/cbc:ID><\/cac:OrderReference>\n  <cac:AccountingSupplierParty><cac:Party><cac:PartyLegalEntity><cbc:RegistrationName>Example Ltd<\/cbc:RegistrationName><\/cac:PartyLegalEntity><\/cac:Party><\/cac:AccountingSupplierParty>\n  <cac:TaxTotal><cbc:TaxAmount currencyID=\"USD\">24.00<\/cbc:TaxAmount><\/cac:TaxTotal>\n  <cac:LegalMonetaryTotal><cbc:TaxExclusiveAmount currencyID=\"USD\">100.00<\/cbc:TaxExclusiveAmount><cbc:PayableAmount currencyID=\"USD\">124.00<\/cbc:PayableAmount><\/cac:LegalMonetaryTotal>\n  <cac:InvoiceLine><cbc:ID>1<\/cbc:ID><cbc:LineExtensionAmount currencyID=\"USD\">60.00<\/cbc:LineExtensionAmount><cac:Item><cbc:Name>Service A<\/cbc:Name><\/cac:Item><\/cac:InvoiceLine>\n  <cac:InvoiceLine><cbc:ID>2<\/cbc:ID><cbc:LineExtensionAmount currencyID=\"USD\">40.00<\/cbc:LineExtensionAmount><cac:Item><cbc:Name>Service B<\/cbc:Name><\/cac:Item><\/cac:InvoiceLine>\n<\/Invoice>","expected":{"currency":"USD","purchase_order":"PO-8841","supplier_name":"Example Ltd","total":"124.00"}}'

# x402 v2 sends the challenge base64-encoded in the PAYMENT-REQUIRED header (v1 sends it in the body).
# To read the header:
curl -sS -g -o /dev/null -D - -X POST 'https://mcp.dropenginehq.com/api/invoice-preflight' \
  -H 'content-type: application/json' \
  --data-raw '{"document_xml":"<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<Invoice xmlns=\"urn:oasis:names:specification:ubl:schema:xsd:Invoice-2\" xmlns:cac=\"urn:oasis:names:specification:ubl:schema:xsd:CommonAggregateComponents-2\" xmlns:cbc=\"urn:oasis:names:specification:ubl:schema:xsd:CommonBasicComponents-2\">\n  <cbc:ID>INV-8821<\/cbc:ID>\n  <cbc:DocumentCurrencyCode>USD<\/cbc:DocumentCurrencyCode>\n  <cac:OrderReference><cbc:ID>PO-8841<\/cbc:ID><\/cac:OrderReference>\n  <cac:AccountingSupplierParty><cac:Party><cac:PartyLegalEntity><cbc:RegistrationName>Example Ltd<\/cbc:RegistrationName><\/cac:PartyLegalEntity><\/cac:Party><\/cac:AccountingSupplierParty>\n  <cac:TaxTotal><cbc:TaxAmount currencyID=\"USD\">24.00<\/cbc:TaxAmount><\/cac:TaxTotal>\n  <cac:LegalMonetaryTotal><cbc:TaxExclusiveAmount currencyID=\"USD\">100.00<\/cbc:TaxExclusiveAmount><cbc:PayableAmount currencyID=\"USD\">124.00<\/cbc:PayableAmount><\/cac:LegalMonetaryTotal>\n  <cac:InvoiceLine><cbc:ID>1<\/cbc:ID><cbc:LineExtensionAmount currencyID=\"USD\">60.00<\/cbc:LineExtensionAmount><cac:Item><cbc:Name>Service A<\/cbc:Name><\/cac:Item><\/cac:InvoiceLine>\n  <cac:InvoiceLine><cbc:ID>2<\/cbc:ID><cbc:LineExtensionAmount currencyID=\"USD\">40.00<\/cbc:LineExtensionAmount><cac:Item><cbc:Name>Service B<\/cbc:Name><\/cac:Item><\/cac:InvoiceLine>\n<\/Invoice>","expected":{"currency":"USD","purchase_order":"PO-8841","supplier_name":"Example Ltd","total":"124.00"}}' \
  | grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decode

JavaScript: pay and call

// npm i @x402/fetch @x402/evm viem
import { wrapFetchWithPayment, x402Client } from "@x402/fetch";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

// Pays at most $0.065 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.065" });
registerExactEvmScheme(client, { signer: privateKeyToAccount(process.env.EVM_PRIVATE_KEY) });
const pay = wrapFetchWithPayment(fetch, client);

// Not sure it's safe to pay? ToolVet checks it first for $0.005. Pay for that from a separate
// client: this one is capped at $0.065 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fmcp.dropenginehq.com%2Fapi%2Finvoice-preflight&method=POST
const res = await pay("https://mcp.dropenginehq.com/api/invoice-preflight", {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify({
    "document_xml": "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<Invoice xmlns=\"urn:oasis:names:specification:ubl:schema:xsd:Invoice-2\" xmlns:cac=\"urn:oasis:names:specification:ubl:schema:xsd:CommonAggregateComponents-2\" xmlns:cbc=\"urn:oasis:names:specification:ubl:schema:xsd:CommonBasicComponents-2\">\n  <cbc:ID>INV-8821<\/cbc:ID>\n  <cbc:DocumentCurrencyCode>USD<\/cbc:DocumentCurrencyCode>\n  <cac:OrderReference><cbc:ID>PO-8841<\/cbc:ID><\/cac:OrderReference>\n  <cac:AccountingSupplierParty><cac:Party><cac:PartyLegalEntity><cbc:RegistrationName>Example Ltd<\/cbc:RegistrationName><\/cac:PartyLegalEntity><\/cac:Party><\/cac:AccountingSupplierParty>\n  <cac:TaxTotal><cbc:TaxAmount currencyID=\"USD\">24.00<\/cbc:TaxAmount><\/cac:TaxTotal>\n  <cac:LegalMonetaryTotal><cbc:TaxExclusiveAmount currencyID=\"USD\">100.00<\/cbc:TaxExclusiveAmount><cbc:PayableAmount currencyID=\"USD\">124.00<\/cbc:PayableAmount><\/cac:LegalMonetaryTotal>\n  <cac:InvoiceLine><cbc:ID>1<\/cbc:ID><cbc:LineExtensionAmount currencyID=\"USD\">60.00<\/cbc:LineExtensionAmount><cac:Item><cbc:Name>Service A<\/cbc:Name><\/cac:Item><\/cac:InvoiceLine>\n  <cac:InvoiceLine><cbc:ID>2<\/cbc:ID><cbc:LineExtensionAmount currencyID=\"USD\">40.00<\/cbc:LineExtensionAmount><cac:Item><cbc:Name>Service B<\/cbc:Name><\/cac:Item><\/cac:InvoiceLine>\n<\/Invoice>",
    "expected": {
      "currency": "USD",
      "purchase_order": "PO-8841",
      "supplier_name": "Example Ltd",
      "total": "124.00"
    }
  }),
});
console.log(res.status, await res.text());

Python: pay and call

# pip install "x402[requests,evm]"
import os
from eth_account import Account
from x402 import x402ClientSync
from x402.http.clients import x402_requests
from x402.mechanisms.evm import EthAccountSigner
from x402.mechanisms.evm.exact.register import register_exact_evm_client

# Pays at most $0.065 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.065"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.post(
        "https://mcp.dropenginehq.com/api/invoice-preflight",
        json={
            "document_xml": "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<Invoice xmlns=\"urn:oasis:names:specification:ubl:schema:xsd:Invoice-2\" xmlns:cac=\"urn:oasis:names:specification:ubl:schema:xsd:CommonAggregateComponents-2\" xmlns:cbc=\"urn:oasis:names:specification:ubl:schema:xsd:CommonBasicComponents-2\">\n  <cbc:ID>INV-8821</cbc:ID>\n  <cbc:DocumentCurrencyCode>USD</cbc:DocumentCurrencyCode>\n  <cac:OrderReference><cbc:ID>PO-8841</cbc:ID></cac:OrderReference>\n  <cac:AccountingSupplierParty><cac:Party><cac:PartyLegalEntity><cbc:RegistrationName>Example Ltd</cbc:RegistrationName></cac:PartyLegalEntity></cac:Party></cac:AccountingSupplierParty>\n  <cac:TaxTotal><cbc:TaxAmount currencyID=\"USD\">24.00</cbc:TaxAmount></cac:TaxTotal>\n  <cac:LegalMonetaryTotal><cbc:TaxExclusiveAmount currencyID=\"USD\">100.00</cbc:TaxExclusiveAmount><cbc:PayableAmount currencyID=\"USD\">124.00</cbc:PayableAmount></cac:LegalMonetaryTotal>\n  <cac:InvoiceLine><cbc:ID>1</cbc:ID><cbc:LineExtensionAmount currencyID=\"USD\">60.00</cbc:LineExtensionAmount><cac:Item><cbc:Name>Service A</cbc:Name></cac:Item></cac:InvoiceLine>\n  <cac:InvoiceLine><cbc:ID>2</cbc:ID><cbc:LineExtensionAmount currencyID=\"USD\">40.00</cbc:LineExtensionAmount><cac:Item><cbc:Name>Service B</cbc:Name></cac:Item></cac:InvoiceLine>\n</Invoice>",
            "expected": {
                "currency": "USD",
                "purchase_order": "PO-8841",
                "supplier_name": "Example Ltd",
                "total": "124.00",
            },
        },
    )
    print(res.status_code, res.text)

Security scan

No findings

We scan names, descriptions and tool definitions for hidden instructions and other prompt-injection patterns.

Recent checks

When	Result	HTTP	Time	Price
4 h ago	Passed	402	495 ms	$0.065
9 h ago	Passed	402	504 ms	$0.065
13 h ago	Passed	402	496 ms	$0.065
18 h ago	Passed	402	551 ms	$0.065
22 h ago	Passed	402	537 ms	$0.065

Show 10 older checks

27 h ago	Passed	402	485 ms	$0.065
31 h ago	Passed	402	457 ms	$0.065
35 h ago	Passed	402	396 ms	$0.065
39 h ago	Passed	402	587 ms	$0.065
44 h ago	Passed	402	495 ms	$0.065
2 days ago	Passed	402	525 ms	$0.065
2 days ago	Passed	402	552 ms	$0.065
2 days ago	Passed	402	648 ms	$0.065
3 days ago	Passed	402	610 ms	$0.065
3 days ago	Passed	402	451 ms	$0.065

Trust score 77/ 100

Availability (30-day uptime)		30 / 30
Valid x402 challenge		15 / 15
Response time		7 / 10
Real paying agents (30 days)		5 / 15
Charges what it lists		10 / 10
Security scan		10 / 10
Verified owner		0 / 10

How the score works

Payment terms

Price: $0.065 per call
Listed at: $0.065
Token: USDC
Networks: Base
Pays to: 0xc769…7585

Real usage

Paying agents: 2 in 30 days
Paid calls: 3 in 30 days
Last paid call: 9 days ago

Source: x402 Bazaar settlement data.

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Show the score

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Trust score

[![ToolVet trust score](https://toolvet.app/badge/invoice-preflight-2.svg)](https://toolvet.app/s/invoice-preflight-2)