关于Places API会话令牌有效期及过期处理的技术问询

Hey there! Let's break down your questions about the Google Maps AutocompleteSessionToken, based on the platform's official guidelines and practical implementation best practices:

1. How long is an AutocompleteSessionToken valid? #

An AutocompleteSessionToken is tied to a single user browser session—meaning it stays valid as long as the user keeps the tab/browser open and active for their address autocomplete flow. It doesn't have a fixed time limit like 1 hour or 12 hours, nor is it permanent (it expires when the tab is closed, the page is refreshed, or the browser session ends).

For billing purposes, the monthly session limits reset each billing cycle, but that's separate from the token's individual validity period.

2. What happens if you send a request with an expired session token? How to avoid errors when a user returns to an open page later? #

• Expired token behavior: When you send a request with an expired AutocompleteSessionToken, the Google Maps API will treat that request as a new, standalone session. This means it won't be grouped under the original session for billing, and you'll be charged per-request instead of per-session.
• Handling long-open pages: If your backend session data is still valid but the AutocompleteSessionToken has expired (since it's tied to the browser session), here are steps to prevent autocomplete errors:
  • Regenerate a new AutocompleteSessionToken whenever the user resumes interaction with the autocomplete field—like when they click into the input, start typing, or switch back to the tab after it's been in the background.
  • Don't rely solely on your backend's session state to track the token's validity. Instead, implement checks that trigger token refresh on user engagement (e.g., listening for focus or visibilitychange events on the input element).
  • If you notice API requests are being charged per-request instead of per-session (via your billing dashboard or API response metadata), immediately swap in a fresh token for subsequent requests.

内容的提问来源于stack exchange，提问作者jbhelfrich