> Index: [llms.txt](https://skills.duaer.com/llms.txt). This skill: https://skills.duaer.com/ligands.md

---
name: duaer-ligands
description: >-
  Look up PDBe chemical component (CCD) ligands through Duaer. One successful search uses 1 Duaer credit.
---

# Duaer ligands

Look up PDBe chemical component (CCD) ligands through Duaer. One successful search uses 1 Duaer credit.

## Call

`GET https://api.duaer.com/v1/data/ligands?words=ATP&limit=10`

Header: `Authorization: Bearer <Duaer key>`

Use an account key or a model API key.

Get a Duaer key: https://skills.duaer.com/keys.md

- Provide `words` or `id` as a CCD chemical component id (1–3 characters). Comma-separate several ids.
- `words` — CCD id such as ATP or HEM.
- `id` — optional. Same as words; combine for a batch.
- `limit` — optional. From 1 to 20. Default 10.

## Result

Each item includes `source`, `title`, `url`, and `summary`, plus the fields named on this skill.

## Credits

One successful search uses 1 credit.
An empty search, a failed search, a compound that matches nothing, or no remaining credits uses 0.
No remaining credits returns 402 and does not search.
A missing key returns 401.

## Related skills

- [Search protein structures in Duaer](https://skills.duaer.com/structures.md)
- [Search compounds in Duaer](https://skills.duaer.com/compounds.md)
- [Search crossrefs in Duaer](https://skills.duaer.com/crossrefs.md)
- [Search metabolites in Duaer](https://skills.duaer.com/metabolites.md)