How much does a pdf-metadata call cost?

$0.005 per call, paid in USDC on Base via x402, with no account and no API key.

What does pdf-metadata return?

A JSON object with 13 top-level fields: source_url, bytes, version, pages, encrypted, title, author, subject, keywords, creator, producer, creation_date and modification_date. The example on this page is a real call over documents/metadata-brochure.pdf.

What happens when a pdf-metadata call fails?

The tool answers with a typed JSON error from the errors table. Payment is settled only after the tool has produced its result; a call that fails inside the tool is never settled. A 503 upstream_unavailable can follow a settled call; the x402 payments guide covers it, 429, 402 and an uncertain 500.

catalogue / tools / Documents / PDF Metadata API

PDF Metadata API

Reads a PDF's page count, document-info fields, version and encryption flag without rendering it.

Endpoint: POST /v1/pdf-metadata
Price: $0.005 per call
Family: Documents
Docs: /docs/pdf-metadata

01When to use it

Reading a PDF trailer needs a real PDF parser and a hardened fetch: an agent that pulls the URL itself walks past every SSRF control, and carrying a PDF library per call is not something an agent does inline.

When not to use it

The input is over 25 MB (26,214,400 bytes): pdf-metadata answers too_large (413).
The destination needs more than 25 s to answer: the call ends with upstream_timeout (424).
The destination is on a private or local network: the network guard refuses it with blocked_target (403).

02Parameters

Field	Type	Required	Description
url	string	yes	Absolute http(s) URL of the PDF, up to 2048 characters; redirects are followed, the body must start with %PDF-, and an encrypted file is still described without being decrypted.

03Limits

Limit	Value
Size cap	25 MB (26,214,400 bytes)
Timeout	25 s

04Example

The published example of pdf-metadata, verbatim: the request body and the response it returns.

Request

POST /v1/pdf-metadata
content-type: application/json
payment-signature: <base64 x402 payload>

{
  "url": "https://grist.tools/samples/documents/metadata-brochure.pdf"
}

Response

200 OK
payment-response: <base64 settlement receipt>

{
  "source_url": "https://grist.tools/samples/documents/metadata-brochure.pdf",
  "bytes": 1010,
  "version": "1.7",
  "pages": 1,
  "encrypted": false,
  "title": "Sample Brochure",
  "author": "Grist Samples",
  "subject": "Public test document",
  "keywords": "sample metadata test",
  "creator": "grist.tools",
  "producer": "grist.tools",
  "creation_date": "2000-01-01T00:00:00.000Z",
  "modification_date": "2000-01-01T00:00:00.000Z"
}

Sample file: documents/metadata-brochure.pdf. One-page PDF whose info dictionary sets title, author, subject and keywords, with dates, creator and producer pinned by pdf-lib.

In the sample itself, the PDF 1.7 file has 3 top-level objects, 1 object stream among them, and a cross-reference stream; inflated, its streams declare 1 page with MediaBox 0 0 420 300, base font Helvetica and 2 text runs at 18 and 11 pt, the first reading "Sample Brochure".

Response field	Type	In the example
source_url	string	"https://grist.tools/samples/documents/metadata-brochure.pdf"
bytes	number	1010
version	string	"1.7"
pages	number	1
encrypted	boolean	false
title	string	"Sample Brochure"
author	string	"Grist Samples"
subject	string	"Public test document"
keywords	string	"sample metadata test"
creator	string	"grist.tools"
producer	string	"grist.tools"
creation_date	string	"2000-01-01T00:00:00.000Z"
modification_date	string	"2000-01-01T00:00:00.000Z"

05Call it from code

JavaScript

// pdf-metadata: $0.005 per call, paid in USD Coin on eip155:8453 via x402
// Install: npm install @x402/fetch@2 @x402/evm@2 viem@2
// Save as client.mjs (ES module, Node 18+), export EVM_PRIVATE_KEY with the paying wallet's key in your shell, then run: node client.mjs
// The wrapper reads the 402 (payment-required), signs and retries with payment-signature.
import { wrapFetchWithPayment, x402Client, decodePaymentResponseHeader } from '@x402/fetch'
import { ExactEvmScheme } from '@x402/evm/exact/client'
import { privateKeyToAccount } from 'viem/accounts'

const account = privateKeyToAccount(process.env.EVM_PRIVATE_KEY)
const client = new x402Client().register('eip155:8453', new ExactEvmScheme(account))
const fetchWithPayment = wrapFetchWithPayment(fetch, client)

const body = {
  "url": "https://grist.tools/samples/documents/metadata-brochure.pdf"
}

const res = await fetchWithPayment('https://grist.tools/v1/pdf-metadata', {
  method: 'POST',
  headers: { 'content-type': 'application/json' },
  body: JSON.stringify(body),
})
console.log(res.status, await res.json())
const settle = res.headers.get('payment-response')
if (settle) console.log(decodePaymentResponseHeader(settle).transaction)

Python

# pdf-metadata: $0.005 per call, paid in USD Coin on eip155:8453 via x402
# Install: pip install "x402[requests,evm]>=2.24,<3"
# The session reads the 402 (payment-required), signs and retries with payment-signature.
import os
from eth_account import Account
from x402 import x402ClientSync
from x402.http import decode_payment_response_header
from x402.http.clients.requests import x402_requests
from x402.mechanisms.evm.exact import register_exact_evm_client
from x402.mechanisms.evm.signers import EthAccountSigner

account = Account.from_key(os.environ["EVM_PRIVATE_KEY"])
client = x402ClientSync()
register_exact_evm_client(client, EthAccountSigner(account), networks="eip155:8453")
session = x402_requests(client)

payload = {
    "url": "https://grist.tools/samples/documents/metadata-brochure.pdf"
}

res = session.post("https://grist.tools/v1/pdf-metadata", json=payload)
print(res.status_code, res.json())
settle = res.headers.get("payment-response")
if settle:
    print(decode_payment_response_header(settle).transaction)

curl

# pdf-metadata: $0.005 per call, paid in USD Coin on eip155:8453 via x402
# 1. Unpaid call: HTTP 402, the requirements in the payment-required header (base64 JSON) and in the body.
curl -i -X POST 'https://grist.tools/v1/pdf-metadata' -H 'content-type: application/json' -d '{"url":"https://grist.tools/samples/documents/metadata-brochure.pdf"}'

# 2. Same call with the signed payment (an EIP-3009 authorization, EIP-712 signed: it cannot be
#    typed by hand). x-payment is accepted as the v1 alternative. HTTP 200 carries payment-response.
curl -i -X POST 'https://grist.tools/v1/pdf-metadata' -H 'content-type: application/json' -H 'payment-signature: <base64 x402 payload>' -d '{"url":"https://grist.tools/samples/documents/metadata-brochure.pdf"}'

06Errors

Code	HTTP	For this service
invalid_input	400	The body does not match the schema; its fields are url.
blocked_target	403
unreachable_target	424
upstream_timeout	424
unsupported_content_type	415
too_large	413
unprocessable	422
internal	500

Input that is rejected before the tool runs (malformed JSON, schema mismatch, body over the size limit) is never charged.

When each code is raised, and what it means for payment: /docs/pdf-metadata.

07Questions

How much does a pdf-metadata call cost?: $0.005 per call, paid in USDC on Base via x402, with no account and no API key.
What does pdf-metadata return?: A JSON object with 13 top-level fields: source_url, bytes, version, pages, encrypted, title, author, subject, keywords, creator, producer, creation_date and modification_date. The example on this page is a real call over documents/metadata-brochure.pdf.
What happens when a pdf-metadata call fails?: The tool answers with a typed JSON error from the errors table. Payment is settled only after the tool has produced its result; a call that fails inside the tool is never settled. A 503 upstream_unavailable can follow a settled call; the x402 payments guide covers it, 429, 402 and an uncertain 500.

08Related

Documents guide