# ISBN Lookup: Title, Publisher, Date, Pages

> ISBN Lookup: Title, Publisher, Date, Pages is a paid API for AI agents from twin.unykorn.org, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-03).

Looks up book metadata (title, publisher, publication date, page count) by ISBN-10 or ISBN-13

## Facts

- Endpoint: POST https://twin.unykorn.org/research/isbn?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-03
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/isbn-lookup-title-publisher-date-pages-ee798630
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_nnaITZYo-AYigVH_EgAnc

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability isbn-lookup-title-publisher-date-pages-ee798630 -d '<json body>'
```

Example prompt: Can you look up the book details for ISBN 9780385333481 — I need the title, publisher, publication date, and number of pages?

## When to prefer this

Use this endpoint when you need structured bibliographic metadata (title, publisher, date, pages) for a known ISBN and want a fast, low-cost ($0.002) single-book lookup. Prefer this over broader book search APIs when you already have the ISBN and just need to resolve it to human-readable metadata. Good for enriching datasets, validating catalog entries, or answering user questions about a specific book.

## Known failure modes

- ISBN not found in database — returns empty or error response
- Malformed ISBN (wrong length or invalid check digit) — validation error
- ISBN-10 vs ISBN-13 format mismatch may return no results depending on normalization
- Out-of-print or obscure titles may have incomplete metadata (missing page count or publisher)
- Network timeout or service unavailability — HTTP 5xx error

## How this service works

ISBN lookup: title, publisher, date, pages — Genesis402 / UnyKorn Operator Network

## Output

Returns bibliographic metadata for the given ISBN including the book's title, publisher name, publication date, and total page count.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "params": {
   "type": "object",
   "properties": {
    "isbn": {
     "type": "string",
     "description": "required: ISBN-10 or ISBN-13"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "type": "isbn-lookup",
  "receipt": {
   "tx_hash": "0x<64hex>",
   "amount_usd": 0.002,
   "receipt_id": "g402-<16hex>"
  },
  "sources": [
   {
    "ok": true,
    "name": "<source>"
   }
  ],
  "limitations": "<text>",
  "generated_at": "<iso time>",
  "evidence_hash": "sha256:<64hex>"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/isbn-lookup-title-publisher-date-pages-ee798630/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from twin.unykorn.org](https://www.zero.xyz/host/twin.unykorn.org/llms.txt)