> ## Documentation Index
> Fetch the complete documentation index at: https://developers.authlete.com/llms.txt
> Use this file to discover all available pages before exploring further.

# How Authlete Determines Token Duration

> Technical information on how Authlete determines token duration based on Authlete 3.0.

<Info>
  For **Authlete 2.x** documentation, see [2.x version](/v2/configuration-reference/token-lifecycle-policies/how-to-calculate-token-duration).
</Info>

## Overview

Authlete 3.0 calculates the effective token duration by evaluating configurations at multiple levels. The final duration is determined based on the following priority order:

1. **Service Level**: If no other duration is specified, the service-level token duration is used.
2. **Scope Level**: If the token duration is configured for any of the requested scopes, it overrides the service-level duration. Authlete uses the shortest duration among all requested scopes.
3. **Client Level**: If a token duration is set for the requesting client, it overrides both the service-level and scope-level durations.

This ensures that the token's lifetime reflects the most granular and specific configuration available.

***

## Token Duration Calculation Process

1. **Service Level**:
   * Authlete starts with the token duration configured at the service level.
2. **Scope Level**:
   * If the request includes scopes with configured durations, Authlete selects the shortest duration among those scopes.
3. **Client Level**:
   * If the requesting client has a configured token duration, it takes precedence over both service-level and scope-level durations.

***

### Example

| Level           | Token Duration (seconds) |
| --------------- | ------------------------ |
| Service         | 86,400                   |
| Scope (`read`)  | 3,600                    |
| Scope (`write`) | 600                      |
| Client          | 300                      |

**Scenario 1**: Request without scopes → Token duration is `86,400` (service level).\
**Scenario 2**: Request with `read` scope → Token duration is `3,600` (scope level).\
**Scenario 3**: Request with `write` scope → Token duration is `600` (scope level).\
**Scenario 4**: Request with `read` and `write` scopes → Token duration is `600` (shortest scope-level duration).\
**Scenario 5**: Request by a client with configured duration → Token duration is `300` (client level overrides all).

***

## See Also

* [Token Duration Per Scope](/configuration-reference/tokens-and-claims/token-duration-per-scope)
* [Token Duration Per Client](/configuration-reference/tokens-and-claims/token-duration-per-client)