# Label a card

`PUT https://evohub.io/api/v1/board/cards/{cardID}/labels/{labelID}`

Part of the [Board API](https://docs.evohub.io/board.md) reference · operationId `addCardLabel`.

Puts one of the board's labels on the card. Adding a label the card
already carries changes nothing.

Requires the `board:card:write` scope.

## Authorization

Any one of:

- `bearerKey`
- `headerKey`

Where:

- `bearerKey`: HTTP Bearer — An EvoHub API key (`evohub_…`) as a bearer token.
- `headerKey`: API key in the header `X-API-Key` — An EvoHub API key (`evohub_…`).

## Path parameters

- `cardID` (string, required, example `crd_9f2e4d6c8b0a1e3f5d7c9b1a3e5f7d90`): The card's ID.
- `labelID` (string, required, example `lbl_0a1b2c3d4e5f46a7b8c9d0e1f2a3b4c5`): The label's ID.

## Responses

### 204 — The card carries the label.

### 401 — No API key was sent, or it is unknown, revoked or expired (`UNAUTHORIZED`).

Content type: `application/json`

Type: `Error`

- `error` (object, required)
  - `code` (string, required, example `NOT_FOUND`)
  - `message` (string, required, example `not found`)
  - `request_id` (string)

### 403 — The key lacks the scope this endpoint needs (`FORBIDDEN`).

Content type: `application/json`

Type: `Error`

- `error` (object, required)
  - `code` (string, required, example `NOT_FOUND`)
  - `message` (string, required, example `not found`)
  - `request_id` (string)

### 404 — The card is not one the caller can see, or the label is not on its board (`NOT_FOUND`).

Content type: `application/json`

Type: `Error`

- `error` (object, required)
  - `code` (string, required, example `NOT_FOUND`)
  - `message` (string, required, example `not found`)
  - `request_id` (string)

### 429 — Too many requests (`RATE_LIMITED`). Wait for `Retry-After` seconds.

Headers:

- `Retry-After` (integer): Seconds to wait before retrying.

Content type: `application/json`

Type: `Error`

- `error` (object, required)
  - `code` (string, required, example `NOT_FOUND`)
  - `message` (string, required, example `not found`)
  - `request_id` (string)

### 500 — Something went wrong on EvoHub's side (`INTERNAL_ERROR`). Retry later.

Content type: `application/json`

Type: `Error`

- `error` (object, required)
  - `code` (string, required, example `NOT_FOUND`)
  - `message` (string, required, example `not found`)
  - `request_id` (string)

## Example request

```bash
curl -X PUT 'https://evohub.io/api/v1/board/cards/crd_9f2e4d6c8b0a1e3f5d7c9b1a3e5f7d90/labels/lbl_0a1b2c3d4e5f46a7b8c9d0e1f2a3b4c5' \
  -H 'Authorization: Bearer <TOKEN>'
```