# Revocation

`Revoke()` implements logout: it clears cookies, invalidates the current Access Token immediately, and expires the Refresh ID after 5 seconds.

## Flow

| # | Step | On failure |
|---|---|---|
| 1 | Send `Set-Cookie` headers clearing `access_token` and `refresh_id` (regardless of what follows) | — |
| 2 | Read the Refresh ID | Missing → `400 data_missing` |
| 3 | Read `refresh:<id>` | Absent → `401 unauthorized`; Redis error → `500 failed_to_get` |
| 4 | Read its TTL | `TTL ≤ 0` → `401 unauthorized` |
| 5 | `MULTI`: set `refresh:<id>` TTL to 5 seconds and write `revoke:<accessToken>` (TTL `AccessTokenExpires`) | `500 failed_to_store` |

On success the result is `200` with `Success` set to `true`.

## Example

```go
mux.HandleFunc("POST /logout", func(w http.ResponseWriter, r *http.Request) {
	result := auth.Revoke(w, r)
	if !result.Success && result.StatusCode >= 500 {
		http.Error(w, result.Error, result.StatusCode)
		return
	}
	w.WriteHeader(http.StatusNoContent)
})
```

A `400`/`401` means the session no longer exists and the cookies are already cleared, which is a completed logout from the user's view, so the example treats only 5xx as an error.

## Boundaries

| Case | Behavior |
|---|---|
| Refresh ID kept for 5 seconds | Within 5 seconds of revocation, a request carrying the same Refresh ID (for example via `X-Refresh-ID`) and no Access Token can still refresh |
| Scope | Only the Access Token in the request is invalidated; the same user's sessions on other devices are unaffected |
| No Access Token sent | `revoke:` is still written (with an empty key), and the Refresh ID still expires |
| Logging out twice | The second call returns `400 data_missing` because the cookies are already cleared |

See step 2 of [Verification Flow](/verification) for how a revoked token is rejected.