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

# Overview

AgentScope offers a few protocol adapters to let an Agent talk to the outside world. Each solves a different problem:

| Extension                                                    | Protocol                                                  | Problem it solves                                                |
| ------------------------------------------------------------ | --------------------------------------------------------- | ---------------------------------------------------------------- |
| [A2A](/v2/en/integration/protocol/a2a)                       | [Agent-to-Agent](https://a2aproject.github.io/A2A/)       | Agents calling each other / composing into multi-agent workflows |
| [AG-UI](/v2/en/integration/protocol/agui)                    | [AG-UI Protocol](https://github.com/ag-ui-protocol/ag-ui) | Standardized event stream for front-end UIs                      |
| [Agent Protocol](/v2/en/integration/protocol/agent-protocol) | [Agent Protocol](https://agentprotocol.ai/)               | HTTP-based way for other systems to submit "tasks"               |

> See also [Chat Completions Web](/v2/en/integration/ecosystem/chat-completions-web): expose your Agent behind an OpenAI-compatible API.

## Choosing one

* **Stream Agent events to a front-end UI (incl. ThinkingBlock)** → AG-UI
* **Let other backend systems schedule the Agent over REST / host a remote subagent** → Agent Protocol
* **Let multiple Agents (yours or third-party) call each other** → A2A

> Layering: AG-UI is user-facing; Agent Protocol is the internal remote-subagent / task HTTP surface; A2A is external interop.