Crate agent_client_protocol_cookbook 

Cookbook of common patterns for building ACP components.

This crate contains guides and examples for the three main things you can build with ACP:

• Clients - Connect to an existing agent and send prompts
• Proxies - Sit between client and agent to add capabilities (like MCP tools)
• Agents - Respond to prompts with AI-powered responses

See the agent_client_protocol::concepts module for detailed explanations of the concepts behind the API.

Building Clients

A client connects to an agent, sends requests, and handles responses. Use Client.builder() to build connections.

• one_shot_prompt - Send a single prompt and get a response (simplest pattern)
• connecting_as_client - More details on connection setup and permission handling

Building Proxies

A proxy sits between client and agent, intercepting and optionally modifying messages. The most common use case is adding MCP tools. Use Proxy.builder() to build proxy connections.

Important: Proxies don’t run standalone—they need the agent-client-protocol-conductor to orchestrate the connection between client, proxies, and agent. See running_proxies_with_conductor for how to put the pieces together.

• global_mcp_server - Add tools that work across all sessions
• per_session_mcp_server - Add tools with session-specific state
• filtering_tools - Enable or disable tools dynamically
• reusable_components - Package your proxy as a ConnectTo for composition
• running_proxies_with_conductor - Run your proxy with an agent

Building Agents

An agent receives prompts and generates responses. Use Agent.builder() to build agent connections.

• building_an_agent - Handle initialization, sessions, and prompts
• reusable_components - Package your agent as a ConnectTo
• custom_message_handlers - Fine-grained control over message routing

Modules

building_an_agent

Pattern: Building an agent.

connecting_as_client

Pattern: Connecting as a client.

custom_message_handlers

Pattern: Custom message handlers.

filtering_tools

Pattern: Filtering which tools are available.

global_mcp_server

Pattern: Global MCP server in handler chain.

one_shot_prompt

Pattern: You Only Prompt Once.

per_session_mcp_server

Pattern: Per-session MCP server with workspace context.

reusable_components

Pattern: Defining reusable components.

running_proxies_with_conductor

Pattern: Running proxies with the conductor.