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

# Shared Entities & Parameters

> Your agent's ontology — the structured vocabulary available across all tools

The Shared Entities section represents your agent's ontology — the structured vocabulary of entities and parameters available across all tools. This is where you define the common objects and attributes that your agent understands and operates on.

## Entities

Entities are the structured domain objects your agent works with. They define the "nouns" of your agent's world and are reusable across all tools.

Common examples:

* **User Profile** — customer identity, preferences, and account details
* **Transactions** — payment records, amounts, dates, and statuses
* **Credit Cards** — card details, limits, and states
* **Products** — items, services, pricing, and availability

Entities are automatically populated from API responses, ensuring your agent always works with current data.

## Parameters

Parameters are the attributes of entities — the properties that describe and differentiate them. Each parameter has:

| Property        | Description                                       |
| --------------- | ------------------------------------------------- |
| **Name**        | Identifier for the parameter                      |
| **Type**        | Data type: string, number, date, enum, or boolean |
| **Description** | What the parameter represents                     |
| **Value**       | Current or expected value                         |
| **Use**         | Designation as input, output, or both             |

The parameter type determines which operators are available for use in constraints and activation logic:

* **String** — Is, Is not, Contains, Has any value, About, Does not have any value
* **Number** — More than, Less than, Between, Equals, Has any value
* **Enum** — Is, Is not, Has any value, Is empty
* **Date** — Before, After, Between, Has any value, Is, Is not
* **Boolean** — Is true, Is false

## How Shared Entities Are Used

Shared entities and parameters are referenced throughout your agent's configuration:

* **Tools** use them to define required information and activation logic
* **Constraints** reference them in WHEN conditions to evaluate state
* **Integrations** map API response fields to entity parameters
* **Responses** use them to present dynamic information to users

By defining entities at the shared level, you ensure consistency across all tools and avoid duplication.