---
title: "List By Category"
method: GET
path: "/api/v1/dropdowns/{category}"
tags: ["dropdowns"]
---

# List By Category

`GET /api/v1/dropdowns/{category}`

Return active dropdowns for a specific category.

Valid categories include ``machining_process``, ``material``,
``finishing``, and ``coating``.  Returns a 400 for unknown categories.

Optional ``?material_id=X`` filters ``coating`` results to only
coatings compatible with that material (per ``VALID_COATING_COMBINATIONS``).
Ignored for non-coating categories. Empty list = "no coatings
available for this material" — the frontend uses that signal to
disable the coating select.

## Path parameters

- `category` string, required

## Query parameters

- `material_id` string, uuid, nullable

## Response `200`

Successful Response

- DropdownResponse[]
  - `id` string, uuid, required
  - `category` string, required
  - `label` string, required
  - `value` string, required
  - `sort_order` integer, required

## Other responses

- `422` — Validation Error

---

[API](https://skmtc.dev/prototyping/apis/prototyping-io-api.md) · [All operations](https://skmtc.dev/prototyping/apis/prototyping-io-api/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/prototyping/prototyping-io-api/revisions/f4a0079fbb57/schema)