# Set an issue's labels

> Replace the labels of an issue or a pull request with these; an empty list takes them all off.

<div class="g1t-endpoint"><span class="g1t-method" data-method="put">PUT</span><code>/repos/{owner}/{name}/issues/{number}/labels</code></div>

The same rules as [`add_issue_labels`](/reference/api/issues/add-issue-labels/). Returns its labels now.

- **Authentication:** Required. Send an [access token](/reference/api/#authentication) as `Authorization: Bearer`.
- **MCP tool:** [`issue`](/reference/mcp/#issue) with `action` `set_labels`, and the same inputs
- **Scope:** An access token needs [`issues:write`](/guides/authentication/#scopes).

## Path parameters

| Name | Type | Required | Description |
| --- | --- | --- | --- |
| `owner` | string | Yes | The workspace that owns the repository. |
| `name` | string | Yes | The repository's name. |
| `number` | integer | Yes | The number shown after the #. Issues and pull requests share one sequence. |

## Body parameters

Send a JSON object. Names are `snake_case`, as in responses; the `camelCase` spelling is accepted too.

| Name | Type | Required | Description |
| --- | --- | --- | --- |
| `labels` | array of strings | Yes | Label names, e.g. ["bug", "help wanted"]. Names the repository does not have yet are created for someone with the Write role. |

## Example request

```sh
curl -X PUT https://api.g1t.sh/repos/flagon-io/hello/issues/12/labels \
  -H "Authorization: Bearer $G1T_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "labels": [
      "bug"
    ]
  }'
```

## Example response

A successful request answers `200` with:

```json
[
  "bug"
]
```

## Errors

A failed request answers with one of these statuses and a body like `{"error": {"code": "not_found", "message": "Repository not found."}}`. See [errors](/reference/api/#errors).

| Status | Code | When |
| --- | --- | --- |
| 401 | `unauthenticated` | A token is required, or the one sent is not valid. |
| 403 | `forbidden` | The token is valid but not allowed to do this, such as a member-only change or an agent token outside its repository. |
| 404 | `not_found` | It does not exist, or you cannot see it. |
| 409 | `conflict` | The request conflicts with the current state. |
| 422 | `invalid` | The input is not valid. `message` says which field and why. |