> For the complete documentation index, see [llms.txt](https://doc.duaer.com/zh/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://doc.duaer.com/zh/getting-started/spectrum.md).

# 在 Duaer 里按 USI 取谱

在 Duaer 里按 USI 取公开质谱的峰列表。一次成功查询用 1 额度。
## 能拿到什么

Duaer 数据市场里的「Spectrum by USI」一次成功查询 1 额度，查不到结果也算一次。

结果里的峰列表可直接交给 MassBank 谱图或 MASST。

逐步处理未知特征见 [用 Duaer 注释未知特征](/zh/getting-started/metabolic-dark-matter.md)。

## 在画布里检索

1. 打开节点创建器，选 Duaer 数据 → Spectrum by USI。
2. 填 USI（以 mzspec: 开头）。
3. Limit 默认 10，最大 20。执行。

成功扣 1 额度；输入为空或来源失败不扣。

## 用 API 调用

- GET https://api.duaer.com/v1/data/spectrum?...
- Authorization: Bearer <Duaer key>

下方是与「复制技能」相同的英文技能。

## 调用技能（英文）

与数据市场「复制技能」一致。

```
---
name: duaer-spectrum
description: >-
  Fetch the peaks of a public mass spectrum by its USI through Duaer.
  One successful search uses 1 Duaer credit.
---

# Duaer spectrum by USI

Fetch a public MS/MS spectrum by its Universal Spectrum Identifier (USI) through the GNPS resolver with a Duaer key.

## Call

`GET https://api.duaer.com/v1/data/spectrum?usi=mzspec:GNPS:GNPS-LIBRARY:accession:CCMSLIB00005435737`

Header: `Authorization: Bearer <Duaer key>`

Use an account key or a model API key.

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

- `usi` — required. A USI that starts with `mzspec:` (GNPS, MassIVE, MetaboLights, and other public repositories).

## Result

One item with `source`, `title`, `url` (spectrum viewer), `summary`, `usi`, `precursorMz`, `charge`, `peakCount`, `peaks` (`mz:intensity` pairs), and `splash`.
Pass `peaks` to https://skills.duaer.com/massbank.md, or the `usi` to https://skills.duaer.com/masst.md.
To work an unannotated feature step by step, follow https://skills.duaer.com/metabolic-dark-matter.md.

## Credits

One successful search uses 1 credit, including a search that finds no match.
Empty input, a failed source, or no remaining credits uses 0.
No remaining credits returns 402 and does not search.
A missing key returns 401.

```
## Questions

### Duaer 的 Spectrum by USI 检索扣多少额度？

一次成功扣 1 额度，查不到结果也算一次；输入为空或来源失败不扣。

## 相关

- [用 Duaer 注释未知特征（代谢暗物质）](https://doc.duaer.com/zh/getting-started/metabolic-dark-matter.md)
- [在 Duaer 里匹配 MassBank 谱图](https://doc.duaer.com/zh/getting-started/massbank.md)
- [在 Duaer 里用 MASST 搜谱图](https://doc.duaer.com/zh/getting-started/masst.md)