chore(mcp): migrate to rmcp (#2700)

* client struct definition

* clean up unused code

* adds mechanism for checking if server is alive

* prefetches prompts if applicable

* fixes agent swap

fixes agent swap

* only applies process group leader promo for unix

* removes unused import for windows

* renames abstractions for different stages of mcp config

Author: dingfeli

Cargo.lock

@@ -129,6 +129,7 @@ winnow = "=0.6.2"
 winreg = "0.55.0"
 schemars = "1.0.4"
 jsonschema = "0.30.0"
+rmcp = { version = "0.6.0", features = ["client", "transport-child-process"] }
 
 [workspace.lints.rust]
 future_incompatible = "warn"

Cargo.toml

@@ -15,12 +15,6 @@ workspace = true
 default = []
 wayland = ["arboard/wayland-data-control"]
 
-[[bin]]
-name = "test_mcp_server"
-path = "test_mcp_server/test_server.rs"
-test = true
-doc = false
-
 [dependencies]
 amzn-codewhisperer-client.workspace = true
 amzn-codewhisperer-streaming-client.workspace = true
@@ -123,6 +117,7 @@ whoami.workspace = true
 winnow.workspace = true
 schemars.workspace = true
 jsonschema.workspace = true
+rmcp.workspace = true
 
 [target.'cfg(unix)'.dependencies]
 nix.workspace = true

crates/chat-cli/Cargo.toml

@@ -17,6 +17,7 @@ use crate::cli::chat::{
 
 #[deny(missing_docs)]
 #[derive(Debug, PartialEq, Args)]
+/// Arguments for the clear command that erases conversation history and context.
 pub struct ClearArgs;
 
 impl ClearArgs {

crates/chat-cli/src/cli/chat/cli/clear.rs

@@ -31,6 +31,12 @@ How it works
 Compaction will be automatically performed whenever the context window overflows.
 To disable this behavior, run: `q settings chat.disableAutoCompaction true`"
 )]
+/// Arguments for the `/compact` command that summarizes conversation history to free up context
+/// space.
+///
+/// This command creates an AI-generated summary of the conversation while preserving essential
+/// information, code, and tool executions. It's useful for long-running conversations that
+/// may reach memory constraints.
 pub struct CompactArgs {
     /// The prompt to use when generating the summary
     prompt: Vec<String>,

crates/chat-cli/src/cli/chat/cli/compact.rs

@@ -38,6 +38,7 @@ Notes:
 • Agent rules apply only to the current agent 
 • Context changes are NOT preserved between chat sessions. To make these changes permanent, edit the agent config file."
 )]
+/// Subcommands for managing context rules and files in Amazon Q chat sessions
 pub enum ContextSubcommand {
     /// Display the context rule configuration and matched files
     Show {
@@ -52,17 +53,20 @@ pub enum ContextSubcommand {
         #[arg(short, long)]
         force: bool,
         #[arg(required = true)]
+        /// Paths or glob patterns to remove from context rules
         paths: Vec<String>,
     },
     /// Remove specified rules
     #[command(alias = "rm")]
     Remove {
+        /// Paths or glob patterns to remove from context rules
         #[arg(required = true)]
         paths: Vec<String>,
     },
     /// Remove all rules
     Clear,
     #[command(hide = true)]
+    /// Display information about agent format hooks (deprecated)
     Hooks,
 }
 

crates/chat-cli/src/cli/chat/cli/context.rs

@@ -15,7 +15,9 @@ use crate::cli::chat::{
 
 #[deny(missing_docs)]
 #[derive(Debug, PartialEq, Args)]
+/// Command-line arguments for the editor functionality
 pub struct EditorArgs {
+    /// Initial text to populate in the editor
     pub initial_text: Vec<String>,
 }
 

crates/chat-cli/src/cli/chat/cli/editor.rs

@@ -286,6 +286,7 @@ Notes:
 • 'conversation_start' hooks run on the first user prompt and are attached once to the conversation history sent to Amazon Q
 • 'per_prompt' hooks run on each user prompt and are attached to the prompt, but are not stored in conversation history"
 )]
+/// Arguments for the hooks command that displays configured context hooks
 pub struct HooksArgs;
 
 impl HooksArgs {

crates/chat-cli/src/cli/chat/cli/hooks.rs

@@ -14,6 +14,10 @@ use crate::cli::chat::{
     ChatState,
 };
 
+/// Arguments for the MCP (Model Context Protocol) command.
+///
+/// This struct handles MCP-related functionality, allowing users to view
+/// the status of MCP servers and their loading progress.
 #[deny(missing_docs)]
 #[derive(Debug, PartialEq, Args)]
 pub struct McpArgs;

crates/chat-cli/src/cli/chat/cli/mcp.rs

@@ -60,10 +60,11 @@ impl ModelInfo {
         self.model_name.as_deref().unwrap_or(&self.model_id)
     }
 }
+
+/// Command-line arguments for model selection operations
 #[deny(missing_docs)]
 #[derive(Debug, PartialEq, Args)]
 pub struct ModelArgs;
-
 impl ModelArgs {
     pub async fn execute(self, os: &Os, session: &mut ChatSession) -> Result<ChatState, ChatError> {
         Ok(select_model(os, session).await?.unwrap_or(ChatState::PromptUser {