ISBN Validation

Check an ISBN-10 or ISBN-13 and its checksum, and convert ISBN-10 to ISBN-13.

Pay by wallet (x402) isbn-validate

Example

Input

{
  "isbn": "978-0-13-468599-1"
}

Answer

{
  "type": "ISBN-13",
  "valid": true,
  "isbn13": "9780134685991",
  "ean_prefix": "978",
  "isbn_input": "978-0-13-468599-1",
  "isbn_cleaned": "9780134685991"
}

Inputs

Field	Type	Required	What it is
`isbn`	string	Yes	ISBN-10 or ISBN-13 (e.g. 978-3-16-148410-0)

Output fields

How reliably each field appears in a successful answer.

Field	Type	Appears
`type`	string	Always (present in every successful answer)
`valid`	boolean	Always (present in every successful answer)
`isbn13`	string	Always (present in every successful answer)

How to call it

The same tool through each route. MCP clients reach it through Strale’s server at https://api.strale.io/mcp; the call below is what the agent sends.

# Needs an API key. max_price_cents caps what this call may cost.
curl -X POST https://api.strale.io/v1/do \
  -H "Authorization: Bearer $STRALE_API_KEY" \
  -H 'Content-Type: application/json' \
  -d '{
    "capability_slug": "isbn-validate",
    "inputs": {
      "isbn": "978-0-13-468599-1"
    },
    "max_price_cents": 2
  }'

{
  "tool": "strale_execute",
  "arguments": {
    "slug": "isbn-validate",
    "inputs": {
      "isbn": "978-0-13-468599-1"
    },
    "max_price_cents": 2
  }
}

import { Strale } from "straleio";

const strale = new Strale({ apiKey: process.env.STRALE_API_KEY! });
const result = await strale.do({
  capability_slug: "isbn-validate",
  inputs: {
    "isbn": "978-0-13-468599-1"
  },
  max_price_cents: 2,
});

import os
from straleio import Strale, DoRequest

strale = Strale(api_key=os.environ["STRALE_API_KEY"])
result = strale.do(DoRequest(
    capability_slug="isbn-validate",
    inputs={
        "isbn": "978-0-13-468599-1",
    },
    max_price_cents=2,
))

# No account. The first request answers 402 with the price in USDC;
# an x402 client pays it from your wallet and repeats the request.
curl -i 'https://api.strale.io/x402/v2/isbn-validate?isbn=978-0-13-468599-1'

Limitations

A valid ISBN does not confirm a publication exists
Validates ISBN-10 and ISBN-13 format and check digits — does not verify the ISBN is assigned to an actual publication
What to do instead: Check the ISBN against the publisher’s catalogue to confirm the publication.