# NCBI Bookshelf E-Search

> NCBI Bookshelf E-Search is a paid API for AI agents from clonecho.builda.company, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-13).

Searches the NCBI Bookshelf biomedical-books database and returns matching UIDs for a given query via NCBI E-utilities

## Facts

- Endpoint: POST https://clonecho.builda.company/x402/s/ncbi-esearch-books
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/ncbi-bookshelf-e-search-d6f11606
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_6wiYWjBhjAOC8QmuSygP4

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 ncbi-bookshelf-e-search-d6f11606 -d '<json body>'
```

Example prompt: Can you search NCBI Bookshelf for books related to 'pharmacokinetics' and give me the matching UIDs?

## When to prefer this

Use this endpoint when you need to discover NCBI Bookshelf UIDs for biomedical or medical textbooks matching a topic or keyword — especially as a first step before fetching full book details via other NCBI E-utilities. Prefer this over general web search when you need structured NCBI identifiers for downstream processing, citation, or programmatic retrieval of book content.

## Known failure modes

- Empty result set if the query matches no books in the Bookshelf database
- Malformed or missing query parameter returns an error or empty response
- NCBI E-utilities rate limiting or downtime causes failures
- Overly broad queries return an unmanageably large list of UIDs
- Spelling errors in the query yield zero or irrelevant results

## How this service works

Search the NCBI NCBI Bookshelf biomedical-books database and return matching UIDs for query {q} via E-utilities. Query: ?q= Returns JSON.

## Output

A JSON response containing NCBI UIDs (unique identifiers) for books in the NCBI Bookshelf database that match the provided search query, along with metadata such as result count and query details returned by the E-utilities esearch endpoint.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/ncbi-bookshelf-e-search-d6f11606/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from clonecho.builda.company](https://www.zero.xyz/host/clonecho.builda.company/llms.txt)