Basic implementation of ACP agent interface using Amazon Q CLI agent

The following features are supported:
- New Session setup ("session/new")
- Basic chat ("session/prompt" & "session/update")
- Using built-in tool like fs_read and fs_write ("tool_call")
- Request tool call permission ("session/request_permission")

We use Symposium ACP as it provides a nicer interface to write non-blocking ACP agent

The main method is handle_prompt_request:
- submit the request to the agent
- poll agent update events, convert them to ACP events, and send them back to ACP client
- tell ACP client that the request is completed

You can test this implementation using acp_client: cargo run -p agent -- acp-client ./target/debug/agent

Author: erbenmo

.gitignore

@@ -50,3 +50,5 @@ book/
 
 run-build.sh
 .amazonq/
+
+chat.log

Cargo.lock

@@ -8,6 +8,7 @@ version.workspace = true
 license.workspace = true
 
 [dependencies]
+agent-client-protocol = "0.7.0"
 amzn-codewhisperer-client.workspace = true
 amzn-codewhisperer-streaming-client.workspace = true
 amzn-consolas-client.workspace = true
@@ -55,6 +56,7 @@ rmcp = { version = "0.8.0", features = ["client", "transport-async-rw", "transpo
 rusqlite.workspace = true
 rustls.workspace = true
 rustls-native-certs.workspace = true
+sacp = "0.1"
 schemars = "1.0.4"
 semver.workspace = true
 serde.workspace = true

crates/agent/Cargo.toml

@@ -0,0 +1,40 @@
+# Agent-Client-Protocol (ACP)
+
+This is an implementation of ACP agent interface using Amazon Q CLI agent
+
+## Features
+
+### Supported
+- New Session setup ("session/new")
+- Basic chat ("session/prompt" & "session/update")
+- Using built-in tool like fs_read and fs_write ("tool_call")
+- Request tool call permission ("session/request_permission")
+
+### Not Supported
+- Tool call update ("tool_call_update" as part of "session/update")
+- Auth
+- Slash commands
+- MCP
+- Cancel
+- Session reload
+
+## Usage
+
+### Run ACP Agent (Standalone)
+```bash
+cargo run -p agent -- acp
+
+# Test it with:
+{"jsonrpc":"2.0","id":0,"method":"initialize","params":{"protocolVersion":1}}
+```
+
+### Run ACP Client (for testing)
+```bash
+# Build agent first
+cargo build -p agent
+
+# Run interactive test client
+cargo run -p agent -- acp-client ./target/debug/agent
+```
+
+The test client automatically launch the ACP Agent. It provides a REPL interface for sending prompts to the agent and automatically approves tool permissions.