Cookie Policy
Last Updated: October 13, 2026
AgentStack believes in transparency about the collection and use of data. This policy provides information about how and when we use cookies.
What is a Cookie?
Cookies are small text files sent to your computer or mobile device which enable features and functionality. They are unique to your account or your browser. Session-based cookies last only while your browser is open and are automatically deleted when you close it. Persistent cookies last until you or your browser delete them or until they expire.
Does AgentStack Use Cookies?
Yes. AgentStack uses both session-based and persistent cookies, as well as similar technologies. We use both first-party cookies (set by us) and third-party cookies (set by our service providers).
How We Use Cookies
Some cookies are associated with your account to remember that you are logged in and which organisation you belong to. Other cookies are not tied to your account but are unique and allow us to carry out analytics and customisation.
Categories of Use
Authentication: If you are signed into the Service, cookies help us show you the right information and personalise your experience.
Security: We use cookies to enable and support security features, and to help detect malicious activity.
Preferences and Features: Cookies help remember your preferences and provide you with features and customised content.
Performance, Analytics, and Research: Cookies help us learn how well our platform performs. We use cookies to understand, improve, and research products, features, and services.
Cookie Details
Strictly Necessary Cookies
These cookies are necessary for the website to function and cannot be switched off. They are usually only set in response to actions made by you, such as logging in or filling in forms. You can set your browser to block these cookies, but that will cause some parts of the site to not work. Most of these cookies hold only a random identifier, such as a session token. The Help Center sign-in cookie (hc_session_<siteId>) holds the email address the visitor verified, so that the Help Center site can keep them signed in. Its value is signed, so it cannot be changed without detection, and it is HttpOnly, so scripts on the page cannot read it.
| Cookie | Type | Purpose |
|---|---|---|
| Session / auth cookies | First party | Authentication and session management |
Stripe (__stripe_mid, __stripe_sid) | Third party | Payment processing and fraud prevention |
Help Center sign-in (hc_session_<siteId>) | First party | Keeps a visitor signed in to a private Help Center site for up to 30 days |
Analytics Cookies
These cookies allow us to count visits and traffic sources so we can measure and improve the performance of our platform. They help us know which pages are the most and least popular and see how visitors move around the site. If you do not allow these cookies, we will not know when you have visited our site and will not be able to monitor its performance.
| Cookie | Type | Purpose |
|---|---|---|
PostHog (ph_*) | Third party | Product analytics and usage tracking |
PostHog analytics is on by default, and our website has no setting to turn it off. To stop it, block or delete cookies and site data for agentstack.build in your browser (see below), or email us to object (see "Contact").
A Help Center can be served on agentstack.build or on a customer's own domain; its cookies, such as hc_session_<siteId>, are first party to the site that serves it. Help Centers used to set a cookie named hc_visitor_id, a random id kept for up to 1 year. We no longer set it. When a browser that still holds it uses Help Center search or article feedback on agentstack.build, our server deletes it. On a customer's own domain we cannot delete it for you, so delete it in your browser settings.
Widget Storage
When a business adds the AgentStack chat widget to its website, the widget stores items such as the ones below in your browser. These are not cookies: they are browser storage (localStorage and sessionStorage), and they are not sent to us automatically with each request the way cookies are. The chat window runs in a frame. Usually that frame is served from agentstack.build, and a website at another address cannot read the items the frame stores. On a Help Center that AgentStack hosts for a business, including one on the business's own domain, the frame is served from the Help Center's own address, so its items are stored for that website and its pages can read them. A small script that loads the widget also stores a few items on the website itself. In the names below, <publicId> is the public id of the business's AgentStack agent and <sessionId> is the id of one conversation.
localStorage stays in your browser until it is removed by the widget or you clear it. sessionStorage is deleted when you close the browser tab.
| Name | Storage | Stored by | How long it lasts | Purpose |
|---|---|---|---|---|
agentstack_visitor_<publicId> | localStorage | The chat window | Until you clear it. The widget never removes it, even when the chat is reset | A random id for your browser, used to deliver live replies and typing indicators (see below) |
agentstack_session_<publicId> | localStorage | The chat window | Replaced or removed when you start a new chat or open one from recent chats, when the website resets the chat, or when the website signs you in to or out of the chat. Otherwise until you clear it | The id of your current conversation, so the chat continues when you reload the page or come back |
agentstack_resume_token_<publicId> | localStorage | The chat window | Replaced when a new conversation is created. Removed when you start a new chat or when the website resets the chat. When the website signs you in to or out of the chat it is removed, and it is put back only if a conversation is reopened. Opening a conversation from recent chats does not remove it, so it can stay after the conversation id above names another conversation. Otherwise until you clear it | A secret token issued with a new conversation. It proves to our server that this browser started the conversation, so it can be reopened |
agentstack_sessions_<publicId> | localStorage | The chat window | Until you clear it. It keeps the ids of your 20 most recent conversations | The list of your recent conversations shown under recent chats |
agentstack_fallback_email_<publicId>_<sessionId> | localStorage | The chat window | Until you clear it. One is kept for each conversation where it was used | Records whether you answered or dismissed the request for an email address after a conversation was passed to the support team, so you are not asked again. It does not contain your email address |
lead_submitted_<publicId> | localStorage | The chat window | Until the website signs you out of the chat, or you clear it | Records that you sent the contact form, so it is not shown again |
tos_dismissed_<publicId> | localStorage | The chat window | Until you clear it | Records that you closed the terms notice, so it is not shown again |
voice-consent-<publicId> | localStorage | The chat window | Until you clear it | Records that you accepted the notice shown before your first voice message, so you are not asked again |
agentstack_<publicId>_engaged | localStorage | The website that shows the widget | Until the website signs you out of the chat, or you clear it. The widget acts on it for 7 days after it was last updated | The time you last sent a message or received a reply from the support team. For 7 days after that, the chat window is loaded in advance on each page so your conversation is ready |
agentstack_<publicId>_pending_reset | localStorage | The website that shows the widget | Removed as soon as the reset is passed to the chat window | Set when the website asks to reset the chat, so the reset still happens if you move to another page before the chat window is ready |
agentstack_<publicId>_float_shown | sessionStorage | The website that shows the widget | Until you close the browser tab | Makes the greeting message beside the chat button appear at most once per tab |
agentstack_<publicId>_auto_opened | sessionStorage | The website that shows the widget | Until you close the browser tab | Makes the chat open by itself at most once per tab, when the business has turned that on |
The visitor id (agentstack_visitor_<publicId>) is a random value created in your browser the first time the chat window loads. It does not contain your name, email address or IP address. A separate id is kept for each AgentStack agent, and the widget reads only the id for the agent it is showing. Once a conversation has started, the widget sends this id to our server, to our realtime messaging service and to the support dashboard of the business you are chatting with, so that live replies and typing indicators can reach you and the support team can see that you are in the conversation. We do not save the visitor id in our database. The conversation id, by contrast, is the id of a conversation record that we store; see our Privacy Policy.
To remove these items, clear the stored site data (often listed with cookies as "cookies and site data") in your browser settings, for the website where you used the chat and for agentstack.build, or clear all of it.
What Can You Do About Cookies?
Managing Preferences
Our website does not have a cookie preferences control. To refuse analytics cookies, use your browser settings as described below, or email us to object to analytics.
Using Your Browser
You can disable and delete cookies through your browser settings. Follow the instructions usually located within the "Help", "Tools", or "Edit" menus in your browser. Please note that disabling cookies may cause some parts of the site to not work properly.
Cookies Set in the Past
If cookies are deleted, the information collected prior to your preference change may still be used. However, we will stop using the disabled cookie to collect any further information.
Changes to This Policy
We may update this cookie policy from time to time. If we make changes, we will update the date at the top of this page.
Contact
Ray Amjad LTD (Company Number 14506459, United Kingdom)
- General support: support@agentstack.build
- Privacy and legal: legal@agentstack.build