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

# Agent

> An agent should be able to think and act.

In AgentScope, an agent is an **independent** entity that can receive outside information, process it, and take actions to achieve specific goals.

To achieve this, an agent is abstracted into two main methods:

| Method        | Description                                                                                       |
| ------------- | ------------------------------------------------------------------------------------------------- |
| **`reply`**   | Handle incoming messages, reason about the current state, and generate responses.                 |
| **`observe`** | Receive external information and update the agent's internal state without generating a response. |

During the `reply` process, the agent reasons based on the current state and takes actions accordingly — this is the "ReAct" (Reasoning + Acting) paradigm.

<Frame>
  <img src="https://mintlify.s3.us-west-1.amazonaws.com/agentscope-ai-786677c7/versions/1.0.21/en/images/agent.png" alt="The reasoning-acting loop in replying" />
</Frame>

<Info>
  The `observe` method is useful for injecting context into the agent's memory without triggering a reply, such as updating environment state or injecting background knowledge.
</Info>