# NCBI E-utilities PubMed Central Full-Text Article Search

> NCBI E-utilities PubMed Central Full-Text Article Search is a paid API for AI agents from clonecho.builda.company, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-15).

Searches PubMed Central full-text articles using NCBI E-utilities and returns matching article UIDs for a given query string.

## Facts

- Endpoint: POST https://clonecho.builda.company/x402/s/ncbi-esearch-pmc
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/ncbi-e-utilities-pubmed-central-full-text-article-search-63a4f5db
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_TWZeYe7-HIlOhyPIiJ-1u

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-e-utilities-pubmed-central-full-text-article-search-63a4f5db -d '<json body>'
```

Example prompt: Search PubMed Central for full-text articles about CRISPR gene editing and give me the article UIDs I can use to pull the papers.

## When to prefer this

Use this endpoint when you need to search PubMed Central's full-text article database and retrieve article UIDs for biomedical, life science, or medical research queries. Prefer this over general web search when you specifically need open-access PMC full-text article identifiers compatible with NCBI E-utilities workflows for downstream content retrieval.

## Known failure modes

- Empty result set when query matches no PMC articles (returns zero UIDs)
- Malformed or missing query parameter returns an error or empty response
- NCBI E-utilities rate limits may cause transient failures under high request volume
- Very broad queries may return large UID lists that are difficult to paginate
- Spelling errors or non-standard terminology may yield poor or zero results

## How this service works

Search PubMed Central full-text articles and return matching UIDs for query {q} via E-utilities. Query: ?q= Returns JSON.

## Output

Returns a JSON object containing matching PubMed Central article UIDs (PMCIDs) for the given search query, along with metadata such as result count — suitable for downstream retrieval of full article content via NCBI E-utilities.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/ncbi-e-utilities-pubmed-central-full-text-article-search-63a4f5db/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)