> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://docs.finput.com.au/api/endpoints/authentication/refresh-token/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs.finput.com.au/_mcp/server.

# Exchange a refresh token for a new token pair

POST https://api.finput.com.au/api/v1/auth/refresh
Content-Type: application/json

Returns a **new access token and a new refresh token**. The
refresh token you send is spent by this call.

**A spent token still redeems for a short grace window**
(currently 30 seconds), and returns **the same successor** the
first refresh issued. After the window it is refused with `401`.
So concurrent refreshes with one token all succeed with the same
new refresh token, and a refresh whose response was lost can be
retried promptly.

The contract a client must implement:

1. On a `401` from another endpoint, refresh once and retry the
   original request once. A `401` from this endpoint, or from
   the retried request, ends the session.
2. Store the `refresh` from the response, replacing the one you
   sent. Concurrent refreshes return the same one, so the last
   response stored wins harmlessly.
3. Single-flighting refreshes is an optimisation, not a
   requirement.
4. `429` is a rate limit, not a sign-out: back off and retry.

**Refreshing pushes back the idle timeout, never the hard cap.**
The new refresh token expires one idle period from now, or at the
cap counted from sign-in if that is sooner. The sign-in time is
carried unchanged in every rotated token, and an access token never
outlives its refresh token.

Authentication is by the refresh token in the body, not by the
`Authorization` header, so this endpoint takes no bearer token.

Rate limited per user (not per IP), so colleagues sharing an
office egress address do not share a budget.


Reference: https://docs.finput.com.au/api/endpoints/authentication/refresh-token

## Request

### Body (application/json)

This endpoint expects a RefreshRequest.

- `refresh` (string, required) — The refresh token last issued to this client — either from login or from the previous refresh.

## Response

### 200

A fresh token pair. The token you sent is spent; inside the grace window it returns this same refresh token again.

- `access` (string, optional) — A new access token.
- `refresh` (string, optional) — The successor refresh token. **Replace your stored copy with this one.** It expires one idle period from now, or at the session's hard cap from sign-in if that is sooner.

## Errors

### 401 Unauthorized Error

The refresh token is expired, revoked by logout, spent longer ago than the grace window, or invalid — or its user is inactive. The session is over: sign the user out.

- `error` (string, optional)
- `errors` (map from string to list of string, optional)

### 429 Too Many Requests Error

Too many refreshes for this user.

- `error` (string, optional)
- `errors` (map from string to list of string, optional)

## Examples

**Request**

```json
{
  "refresh": "string"
}
```

**Response**

```json
{
  "access": "string",
  "refresh": "string"
}
```

**SDK Code**

```python
import requests

url = "https://api.finput.com.au/api/v1/auth/refresh"

payload = { "refresh": "string" }
headers = {"Content-Type": "application/json"}

response = requests.post(url, json=payload, headers=headers)

print(response.json())
```

```javascript
const url = 'https://api.finput.com.au/api/v1/auth/refresh';
const options = {
  method: 'POST',
  headers: {'Content-Type': 'application/json'},
  body: '{"refresh":"string"}'
};

try {
  const response = await fetch(url, options);
  const data = await response.json();
  console.log(data);
} catch (error) {
  console.error(error);
}
```

```go
package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://api.finput.com.au/api/v1/auth/refresh"

	payload := strings.NewReader("{\n  \"refresh\": \"string\"\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(res)
	fmt.Println(string(body))

}
```

```ruby
require 'uri'
require 'net/http'

url = URI("https://api.finput.com.au/api/v1/auth/refresh")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Content-Type"] = 'application/json'
request.body = "{\n  \"refresh\": \"string\"\n}"

response = http.request(request)
puts response.read_body
```

```java
import com.mashape.unirest.http.HttpResponse;
import com.mashape.unirest.http.Unirest;

HttpResponse<String> response = Unirest.post("https://api.finput.com.au/api/v1/auth/refresh")
  .header("Content-Type", "application/json")
  .body("{\n  \"refresh\": \"string\"\n}")
  .asString();
```

```php
<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('POST', 'https://api.finput.com.au/api/v1/auth/refresh', [
  'body' => '{
  "refresh": "string"
}',
  'headers' => [
    'Content-Type' => 'application/json',
  ],
]);

echo $response->getBody();
```

```csharp
using RestSharp;

var client = new RestClient("https://api.finput.com.au/api/v1/auth/refresh");
var request = new RestRequest(Method.POST);
request.AddHeader("Content-Type", "application/json");
request.AddParameter("application/json", "{\n  \"refresh\": \"string\"\n}", ParameterType.RequestBody);
IRestResponse response = client.Execute(request);
```

```swift
import Foundation

let headers = ["Content-Type": "application/json"]
let parameters = ["refresh": "string"] as [String : Any]

let postData = JSONSerialization.data(withJSONObject: parameters, options: [])

let request = NSMutableURLRequest(url: NSURL(string: "https://api.finput.com.au/api/v1/auth/refresh")! as URL,
                                        cachePolicy: .useProtocolCachePolicy,
                                    timeoutInterval: 10.0)
request.httpMethod = "POST"
request.allHTTPHeaderFields = headers
request.httpBody = postData as Data

let session = URLSession.shared
let dataTask = session.dataTask(with: request as URLRequest, completionHandler: { (data, response, error) -> Void in
  if (error != nil) {
    print(error as Any)
  } else {
    let httpResponse = response as? HTTPURLResponse
    print(httpResponse)
  }
})

dataTask.resume()
```