---
title: "Refresh access token"
method: POST
path: "/auth-api/v2/authenticate/refresh"
tags: ["Authentication"]
---

# Refresh access token

`POST /auth-api/v2/authenticate/refresh`

A [renewed access token](https://help.smartling.com/hc/en-us/articles/1260805176849) that can be attached to the header of any API request.
Refreshing does not reset the session: it only issues a new token pair within the session's remaining lifetime, which is capped to 12 hours. As the session nears that limit, `expiresIn` and `refreshExpiresIn` shrink to whatever time is left, and can eventually reach zero even though the refresh token hasn't expired. A shrinking `refreshExpiresIn` across repeated refreshes is a sign the session is ending: call `/auth-api/v2/authenticate` again to start a new session, rather than refreshing more often.

## Request body

- AuthenticationRefreshRequest
  - `refreshToken` string, required — The refresh token returned from a previous authentication request.

## Response `200`

OK

- AuthenticationResponse
  - `response` object, required
    - `code` 'SUCCESS', required — Indicates whether the response was successful or what error has occured.
    - `data` Authentication
      - `accessToken` string, required — Contains the security credentials for a login session and identifies the user.
      - `expiresIn` integer — TTL (time-to-live) in seconds for the access token. This value can be smaller than usual as the underlying session approaches its maximum lifespan; see `refreshExpiresIn` below.
      - `refreshExpiresIn` integer — TTL (time-to-live) in seconds for the refresh token. This value is tied to the token pair's underlying session, which has a fixed maximum lifespan of 12 hours regardless of how many times the pair is refreshed. As the session nears that limit, `refreshExpiresIn` shrinks toward zero rather than resetting to its usual value, even though the refresh token itself hasn't expired. A shrinking value is a signal to call `/auth-api/v2/authenticate` again and start a new session, rather than continue refreshing.
      - `refreshToken` string, required — A kind of token that can be used to obtain a renewed access token.
      - `tokenType` 'Bearer' — The access token type.

## Other responses

- `400` — Provided request parameters are invalid.
- `401` — Provided credentials are not valid.
- `429` — Too many simultaneous API requests.
- `500` — Unexpected error

---

[API](https://skmtc.net/smartling/apis/smartling-rest-api-reference.md) · [All operations](https://skmtc.net/smartling/apis/smartling-rest-api-reference/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/smartling/smartling-rest-api-reference/revisions/2a73d11e9b98/schema)