# NCBI Protein Clusters E-Search

> NCBI Protein Clusters 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 2026-09-15).

Searches the NCBI Protein Clusters database and returns matching UIDs for a given query using NCBI E-utilities.

## Facts

- Endpoint: POST https://clonecho.builda.company/x402/s/ncbi-esearch-proteinclusters
- 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-protein-clusters-e-search-fedb202e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_HZV9xhIGCoydQrZxiTpWE

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-protein-clusters-e-search-fedb202e -d '<json body>'
```

Example prompt: Search the NCBI Protein Clusters database for records matching 'cytochrome oxidase' and give me the matching UIDs.

## When to prefer this

Use this endpoint when you need to programmatically search NCBI's Protein Clusters database and retrieve UIDs for downstream lookups, rather than using the NCBI web interface or building E-utilities requests manually. Ideal for bioinformatics workflows that need to identify protein cluster records by name, gene, or sequence keyword.

## Known failure modes

- Empty result set when query matches no protein clusters
- Invalid or malformed query string returns an error from NCBI E-utilities
- Rate limiting or timeout if NCBI upstream is slow or unavailable
- Payment failure returns 402 before the request is forwarded
- Ambiguous query terms may return large UID sets without ranking

## How this service works

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

## Output

A JSON response containing NCBI Protein Cluster UIDs that match the submitted search query, following the standard E-utilities ESsearch response format.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/ncbi-protein-clusters-e-search-fedb202e/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)