Pull attributes or push interventions

Signals calculates attributes and stores them in the Profiles Store. Your application gets those values in one of two ways. It can pull attribute values when it needs them, through a service. Or it can subscribe to interventions, and Signals pushes a payload to it when a user meets the criteria you defined.

Pull suits decisions your application makes at a moment it controls, such as rendering a page or answering a chatbot message. Push suits reactions to user behavior that can happen at any time, such as a user hesitating over a cart. Many applications use both: pull to personalize what the user sees, push to react when something changes.

How each pattern works

Both patterns start the same way. A tracker sends events, Signals calculates attributes from them, and the Profiles Store holds the latest values. They differ in who starts the exchange.

When your application pulls attributes:

1. Your application decides it needs attribute values, for example when a page loads
2. It asks Signals for the values of a service, or of an attribute group, for one attribute key ID, such as the current domain_sessionid
3. Signals returns the current values from the Profiles Store
4. Your application uses the values in its own logic

When Signals pushes interventions:

1. Your application subscribes to interventions for one or more attribute key IDs, such as the current domain_userid and domain_sessionid
2. Signals updates attribute values as events arrive
3. Signals checks each update against the criteria of your published interventions
4. The first time a user meets an intervention's criteria, Signals sends the intervention payload to the subscribed application
5. Your application acts on the payload

An intervention is sent only the first time its criteria are met, not every time an attribute changes. Subscriptions are by attribute key ID, not by intervention, so a subscription receives every intervention that targets that ID.

Compare pull and push

This table summarizes the differences.

	Pull: services and attribute groups	Push: interventions
Who starts it	Your application, when it requests values	Signals, when criteria are met
What your application receives	Current attribute values	An intervention payload
Decision logic	In your application code	In the intervention criteria, defined in Signals
How often	Every request returns current values	Once, the first time the criteria are met
How to receive it	Retrieve attributes with the Python SDK, Node.js SDK, or Signals API	Subscribe with the Python SDK, the browser tracker plugin, or the Signals API
Versioning	A service pins specific attribute group versions	Criteria use the latest published version of each attribute group

Agents can also pull: an agent can read attribute groups and agentic contexts as tools through the Signals MCP server.

Example

An online store calculates product_view_count_last_10_min for each session, in an attribute group with the domain_sessionid attribute key.

With pull, the product page calls a service when it loads and reads the session's product_view_count_last_10_min. If the value is high, the page shows a "Recently viewed" panel. The application decides what to do, and it asks again on the next page load.

With push, the store defines an intervention with the criteria product_view_count_last_10_min >= 5 and a name, such as discount_offer, that the page recognizes. The browser subscribes to interventions for the current domain_sessionid. When the fifth product view arrives, Signals updates the attribute, sees that the criteria are met, and sends the payload: the intervention name plus the attribute values you chose to send with it. The page recognizes discount_offer and shows the offer, whose content lives in the page, not in the intervention. Signals doesn't send it again for that session.

For an ecommerce app that reacts to interventions, see Implement real-time interventions.

Related concepts

These pages cover the parts of each pattern in more detail:

• Services explain why production applications should pull through a service rather than directly from attribute groups
• Interventions cover rule-based and direct interventions, targeting, and subscriptions
• Attribute keys are the IDs that both patterns use to identify the user, session, or other entity
• The subscription delivery example walks through the send-once rule with two interventions