# ISBNdb

**Canonical:** https://apis.io/providers/isbndb/  
**Website:** https://isbndb.com  
**APIs profiled:** 8

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.

## Kin Score — 43.1 / 100 (developing)

Scored 2026-08-20 under rubric 0.12.0. Trend: flat (+0.0 from 43.1).

| Facet | Score |
|---|---|
| Discoverability | 74.1 |
| Contract Quality | 56.6 |
| Governance | 9.8 |
| Contract Governance | 9.8 |
| Operational Transparency | 31.6 |
| Developer Ergonomics | 28.6 |
| Commercial Clarity | 50.0 |
| Access Clarity | 50.0 |

Regulatory layer — **Education & Research**: 31.5 (matched via tags).

## Agent readiness — 29.1 (agent-aware)

| Dimension | Value |
|---|---|
| Spec Presence | yes |
| Agentic Access | derived |
| Reversibility Documented | no |
| MCP Server | no |
| Auth Clarity | yes |
| Idempotency | no |
| Error Semantics | no |
| OpenAPI Examples | no |
| Rate Limit Signal | documented |
| Event Surface Described | no |
| Agent Skills | no |
| Well Known Catalog | no |
| Consent Identity | no |
| Agent Card | no |
| Dry Run Mode | no |

## Access

Paid · Self-serve signup — onboarding: self-serve, pricing: paid, trial: no (confidence: high).

## APIs (8)

- **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

## Agentic access (1)

- **Isbndb Agentic Access** — 16 operations · 1 acting

## Security (2)

- **Isbndb Authentication** — apiKey · 1 scheme
- **Isbndb Domain Security** — TLSv1.3 · DMARC

## Plans (1)

- **Isbndb Plans Pricing**

## Tags

Books, ISBN, Publishing, Metadata, Library, Bibliography

---

Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/providers/isbndb/). Scores are computed from the provider's own public artifacts under a published rubric.