# NCBI Structure (MMDB) Database Search via E-utilities

> NCBI Structure (MMDB) Database Search via E-utilities is a paid API for AI agents from clonecho.builda.company, paid per call via x402, $0.02/call, status down (last checked 2026-08-24).

Searches the NCBI Structure (MMDB) database using a text query and returns matching UIDs via the E-utilities API.

## Facts

- Endpoint: POST https://clonecho.builda.company/x402/s/ncbi-esearch-structure
- Price: $0.02/call
- Payment: x402
- Status: down
- Last checked: 2026-08-24
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/ncbi-structure-mmdb-database-search-via-e-utilities-d2d95b88
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_gsC-w9N_m_FafTJWM4IgH

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-structure-mmdb-database-search-via-e-utilities-d2d95b88 -d '<json body>'
```

Example prompt: Search the NCBI Structure (MMDB) database for 'hemoglobin' and give me the matching structure UIDs.

## When to prefer this

Use this endpoint when you need to programmatically search NCBI's Molecular Modeling Database (MMDB) for 3D structure records by keyword or entity name and retrieve their UIDs for downstream lookups. Prefer this over manual NCBI web searches when automating structural biology workflows or when you need machine-readable UIDs to pass into further NCBI E-utilities calls.

## Known failure modes

- Empty result set if no structures match the query term
- Query string with special characters may need URL encoding
- NCBI E-utilities rate limiting if called too frequently
- Network timeout if NCBI upstream is slow
- Invalid or malformed query returns zero results

## How this service works

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

## Output

Returns a JSON object containing MMDB UIDs matching the query, typically including a count of results and a list of integer identifiers referencing 3D molecular structure records in the NCBI MMDB database.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/ncbi-structure-mmdb-database-search-via-e-utilities-d2d95b88/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)