ISBNdb website screenshot

ISBNdb

ISBNdb is the world's largest book database REST API providing access to metadata for over 110 million books and publications. Search by ISBN (ISBN-10 or ISBN-13), title, author, publisher, or subject to retrieve up to 19 data points per book including cover images, publication dates, descriptions, and real-time pricing. The API supports bulk lookups of up to 1,000 ISBNs per request on eligible plans.

ISBNdb publishes 8 APIs on the APIs.io network, including Author API, Books API, Feed API, and 5 more. Tagged areas include Books, ISBN, Publishing, Metadata, and Library.

The ISBNdb catalog on APIs.io includes 1 JSON-LD context and 1 Spectral governance ruleset.

ISBNdb’s developer surface includes authentication, documentation, pricing, engineering blog, and 7 more developer resources.

🌐 Visit website 📡 Source on GitHub
47.9/100 developing ▬ flat Agent 31/100 agent aware Full breakdown ↓
scored 2026-07-28 · rubric v0.6
AccessPaidSelf serve
8 APIs
BooksISBNPublishingMetadataLibraryBibliography

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-07-28 · rubric v0.6
Composite quality — 47.9/100 · developing
Contract Quality 15.1 / 25
Developer Ergonomics 4.3 / 20
Commercial Clarity 10.0 / 20
Operational Transparency 4.1 / 13
Governance 7.0 / 12
Discoverability 7.4 / 10
Agent readiness — 31/100 · agent aware
Machine-Readable Contract 18 / 18
Agentic Access Contract 10 / 10
MCP Server 0 / 12
Machine-Readable Auth 10 / 10
Idempotency 0 / 9
Stable Error Semantics 0 / 8
Request/Response Examples 0 / 7
Rate-Limit Signaling 7 / 7
Typed Event Surface 0 / 6
Agent Skills 0 / 5
Well-Known Catalog 0 / 4
Consent & Bot Identity 0 / 3
A2A Agent Card 0 / 8
Dry-Run / Simulate Mode 0 / 4
Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. This rating is computed from github.com/api-evangelist/isbndb: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

APIs 8

Individual APIs this provider publishes, each with its own machine-readable definition.

ISBNdb Author API

Author endpoints

ISBNdb Books API

Book endpoints

ISBNdb Feed API

Feed endpoints for incremental sync

ISBNdb Key API

API key management

ISBNdb Publisher API

Publisher endpoints

ISBNdb Search API

Legacy search endpoints (deprecated)

ISBNdb Stats API

Database statistics

ISBNdb Subject API

Subject endpoints

Scroll for all 8

Pricing Plans 1

Published pricing tiers and plan structures.

Isbndb Plans Pricing

5 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Isbndb Rate Limits

10 limits

RATE LIMITS

FinOps 1

Cost, billing, and metering signals for API financial operations.

Isbndb Finops

FINOPS

Semantic Vocabularies 1

JSON-LD contexts and semantic vocabularies used across these APIs.

Isbndb Context

2 classes · 33 properties

JSON-LD

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

ISBNdb API Rules

5 rules · 4 warnings 1 info

SPECTRAL

JSON Schema 1

Standalone JSON Schema definitions for this provider's data models.

Book

26 properties

JSON SCHEMA

Examples 4

Example request and response payloads for these APIs.

Author Details Response

6 fields

EXAMPLE

Book Get Response

1 fields

EXAMPLE

Books Bulk Request

1 fields

EXAMPLE

Books Search Response

3 fields

EXAMPLE

Security Posture 2

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Isbndb Authentication

apiKey · 1 scheme

SECURITY

Isbndb Domain Security

TLSv1.3 · DMARC

SECURITY

Agentic Access 1

Recommended x-agentic-access execution contracts for AI agents.

Isbndb Agentic Access

16 operations · 1 acting

16 operations · 1 acting

AGENTIC

Resources

Documentation 1

Reference material describing how the API behaves

Documentation
Documentation

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess
AgenticAccess

Access & Security 2

Authentication, authorization, and security posture

DomainSecurity
DomainSecurity
 Authentication
Authentication

Operate 1

Status, limits, changes, and where to get help

RateLimits
RateLimits

Commercial 3

Pricing, plans, and the legal terms of use

Pricing
Pricing
 Plans
Plans
 FinOps
FinOps

Company 2

The organization behind the API

Website
Website
 Blog
Blog

Other 1

Properties that don't map to a standard resource type

X
X

Source (apis.yml)

apis.yml Raw ↑ 
aid: isbndb
name: ISBNdb
description: ISBNdb is the world's largest book database REST API providing access to metadata for over 110 million books
  and publications. Search by ISBN (ISBN-10 or ISBN-13), title, author, publisher, or subject to retrieve up to 19 data points
  per book including cover images, publication dates, descriptions, and real-time pricing. The API supports bulk lookups of
  up to 1,000 ISBNs per request on eligible plans.
accessModel:
  pricing: paid
  onboarding: self-serve
  trial: false
  try_now: false
  public: false
  label: Paid · Self-serve signup
  confidence: high
  source:
  - plans
  - authentication
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/isbndb.png
url: https://raw.githubusercontent.com/api-evangelist/isbndb/refs/heads/main/apis.yml
created: '2026-06-13'
modified: '2026-06-13'
specificationVersion: '0.19'
tags:
- Books
- ISBN
- Publishing
- Metadata
- Library
- Bibliography
apis:
- aid: isbndb:isbndb-author-api
  name: ISBNdb Author API
  description: Author endpoints
  humanURL: https://isbndb.com/api-documentation
  baseURL: https://api2.isbndb.com
  tags:
  - Author
  properties:
  - type: OpenAPI
    url: openapi/isbndb-author-api-openapi.yml
  - type: Documentation
    url: https://isbndb.com/api-documentation
  - type: Pricing
    url: https://isbndb.com/isbn-database
- aid: isbndb:isbndb-books-api
  name: ISBNdb Books API
  description: Book endpoints
  humanURL: https://isbndb.com/api-documentation
  baseURL: https://api2.isbndb.com
  tags:
  - Books
  properties:
  - type: OpenAPI
    url: openapi/isbndb-books-api-openapi.yml
  - type: Documentation
    url: https://isbndb.com/api-documentation
  - type: Pricing
    url: https://isbndb.com/isbn-database
- aid: isbndb:isbndb-feed-api
  name: ISBNdb Feed API
  description: Feed endpoints for incremental sync
  humanURL: https://isbndb.com/api-documentation
  baseURL: https://api2.isbndb.com
  tags:
  - Feed
  properties:
  - type: OpenAPI
    url: openapi/isbndb-feed-api-openapi.yml
  - type: Documentation
    url: https://isbndb.com/api-documentation
  - type: Pricing
    url: https://isbndb.com/isbn-database
- aid: isbndb:isbndb-key-api
  name: ISBNdb Key API
  description: API key management
  humanURL: https://isbndb.com/api-documentation
  baseURL: https://api2.isbndb.com
  tags:
  - Key
  properties:
  - type: OpenAPI
    url: openapi/isbndb-key-api-openapi.yml
  - type: Documentation
    url: https://isbndb.com/api-documentation
  - type: Pricing
    url: https://isbndb.com/isbn-database
- aid: isbndb:isbndb-publisher-api
  name: ISBNdb Publisher API
  description: Publisher endpoints
  humanURL: https://isbndb.com/api-documentation
  baseURL: https://api2.isbndb.com
  tags:
  - Publisher
  properties:
  - type: OpenAPI
    url: openapi/isbndb-publisher-api-openapi.yml
  - type: Documentation
    url: https://isbndb.com/api-documentation
  - type: Pricing
    url: https://isbndb.com/isbn-database
- aid: isbndb:isbndb-search-api
  name: ISBNdb Search API
  description: Legacy search endpoints (deprecated)
  humanURL: https://isbndb.com/api-documentation
  baseURL: https://api2.isbndb.com
  tags:
  - Search
  properties:
  - type: OpenAPI
    url: openapi/isbndb-search-api-openapi.yml
  - type: Documentation
    url: https://isbndb.com/api-documentation
  - type: Pricing
    url: https://isbndb.com/isbn-database
- aid: isbndb:isbndb-stats-api
  name: ISBNdb Stats API
  description: Database statistics
  humanURL: https://isbndb.com/api-documentation
  baseURL: https://api2.isbndb.com
  tags:
  - Stats
  properties:
  - type: OpenAPI
    url: openapi/isbndb-stats-api-openapi.yml
  - type: Documentation
    url: https://isbndb.com/api-documentation
  - type: Pricing
    url: https://isbndb.com/isbn-database
- aid: isbndb:isbndb-subject-api
  name: ISBNdb Subject API
  description: Subject endpoints
  humanURL: https://isbndb.com/api-documentation
  baseURL: https://api2.isbndb.com
  tags:
  - Subject
  properties:
  - type: OpenAPI
    url: openapi/isbndb-subject-api-openapi.yml
  - type: Documentation
    url: https://isbndb.com/api-documentation
  - type: Pricing
    url: https://isbndb.com/isbn-database
common:
- type: AgenticAccess
  url: agentic-access/isbndb-agentic-access.yml
- type: DomainSecurity
  url: security/isbndb-domain-security.yml
- type: Authentication
  url: authentication/isbndb-authentication.yml
- type: Website
  url: https://isbndb.com
- type: Documentation
  url: https://isbndb.com/api-documentation
- type: Pricing
  url: https://isbndb.com/isbn-database
- type: Blog
  url: https://isbndb.com/blog/
- type: X
  url: https://x.com/ISBNdb_com
- type: Plans
  url: plans/isbndb-plans-pricing.yml
- type: RateLimits
  url: rate-limits/isbndb-rate-limits.yml
- type: FinOps
  url: finops/isbndb-finops.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com