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If you're unable to use [OAuth2](../../api/oauth2.md), you can use a personal access token to authenticate with the [GitLab API](../../api/README.md#personalproject-access-tokens).
You can also use personal access tokens with Git to authenticate over HTTP or SSH. Personal access tokens are required when [Two-Factor Authentication (2FA)](../account/two_factor_authentication.md) is enabled. In both cases, you can authenticate with a token in place of your password.
- GitLab runs a check at 01:00 AM UTC every day to identify personal access tokens that will expire in under seven days. The owners of these tokens are notified by email.
- In GitLab Ultimate, administrators may [limit the lifetime of personal access tokens](../admin_area/settings/account_and_limit_settings.md#limiting-lifetime-of-personal-access-tokens-ultimate-only).
- In GitLab Ultimate, administrators may [toggle enforcement of personal access token expiry](../admin_area/settings/account_and_limit_settings.md#optional-enforcement-of-personal-access-token-expiry-ultimate-only).
For examples of how you can use a personal access token to authenticate with the API, see the following section from our [API Docs](../../api/README.md#personalproject-access-tokens).
GitLab also offers [impersonation tokens](../../api/README.md#impersonation-tokens) which are created by administrators via the API. They're a great fit for automated authentication as a specific user.
| `read_user` | [GitLab 8.15](https://gitlab.com/gitlab-org/gitlab-foss/-/merge_requests/5951) | Allows access to the read-only endpoints under `/users`. Essentially, any of the `GET` requests in the [Users API](../../api/users.md) are allowed. |
| `api` | [GitLab 8.15](https://gitlab.com/gitlab-org/gitlab-foss/-/merge_requests/5951) | Grants complete read/write access to the API, including all groups and projects, the container registry, and the package registry. |
| `read_api` | [GitLab 12.10](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/28944) | Grants read access to the API, including all groups and projects, the container registry, and the package registry. |
| `read_registry` | [GitLab 9.3](https://gitlab.com/gitlab-org/gitlab-foss/-/merge_requests/11845) | Allows to read (pull) [container registry](../packages/container_registry/index.md) images if a project is private and authorization is required. |
| `sudo` | [GitLab 10.2](https://gitlab.com/gitlab-org/gitlab-foss/-/merge_requests/14838) | Allows performing API actions as any user in the system (if the authenticated user is an admin). |
| `read_repository` | [GitLab 10.7](https://gitlab.com/gitlab-org/gitlab-foss/-/merge_requests/17894) | Allows read-only access (pull) to the repository through `git clone`. |
| `write_repository` | [GitLab 11.11](https://gitlab.com/gitlab-org/gitlab-foss/-/merge_requests/26021) | Allows read-write access (pull, push) to the repository through `git clone`. Required for accessing Git repositories over HTTP when 2FA is enabled. |