refactor: Simplify MCP code around Client, Server and Gateway concepts

.aether/settings.json

@@ -31,8 +31,7 @@
                 "${HOME}/.agents/rules",
                 "--rules-dir",
                 "${WORKSPACE}/.agents/rules"
-              ],
-              "input": null
+              ]
             }
           }
         }

.aether/skills/rust/error-handling.md

@@ -19,8 +19,6 @@ use thiserror::Error;
 
 #[derive(Debug, Error)]
 pub enum AgentError {
-    #[error("MCP error: {0}")]
-    McpError(#[from] mcp_utils::client::McpError),
     #[error("LLM error: {0}")]
     LlmError(#[from] llm::LlmError),
     #[error("IO error: {0}")]

README.md

@@ -136,21 +136,23 @@ Use `aether-agent-core` as a Rust library to build your own agent in ~25 lines.
        mcp::mcp,
    };
    use llm::providers::anthropic::AnthropicProvider;
+   use aether_core::mcp::McpConfig;
    use std::io::{self, Write};
 
    #[tokio::main]
    async fn main() -> Result<(), Box<dyn std::error::Error>> {
        // 1. Create a provider (reads ANTHROPIC_API_KEY from env)
        let llm = AnthropicProvider::new(None);
 
-       // 2. Spawn MCP tool servers from one or more mcp.json files
-       let mut mcp_runtime = mcp(".").from_json_files(&["mcp.json"])?.spawn().await?;
-       let snapshot = mcp_runtime.block_until_ready().await.ok_or("MCP bootstrap aborted")?;
+       // 2. Spawn MCP tool servers from an mcp.json file
+       let config = McpConfig::from_json_file("mcp.json")?;
+       let mcp = mcp(".").with_config(config)?.spawn()?;
+       mcp.ready().await;
 
        // 3. Build and spawn the agent
        let (tx, mut rx, _handle) = agent(llm)
            .system_prompt(Prompt::file("AGENTS.md", "."))
-           .tools(mcp_runtime.handle().clone(), snapshot.tool_definitions())
+           .mcp(mcp)
            .spawn()
            .await?;
 

crates/aether-cli/Cargo.toml

@@ -29,7 +29,7 @@ name = "aether"
 path = "src/main.rs"
 
 [features]
-testing = ["acp_utils/testing", "mcp_utils/testing"]
+testing = ["acp_utils/testing", "mcp_utils/testing", "aether-core/testing"]
 
 [dependencies]
 aether-auth = { path = "../aether-auth", version = "0.1.17", features = ["keyring"] }
@@ -40,7 +40,7 @@ aether-project = { path = "../aether-project", version = "0.5.58" }
 aether-telemetry = { path = "../aether-telemetry", version = "0.3.13" }
 llm = { package = "aether-llm", path = "../llm", features = ["bedrock", "codex"], version = "0.9.13" }
 mcp_utils = { package = "aether-mcp-utils", path = "../mcp-utils", version = "0.7.13" }
-mcp-servers = { package = "aether-mcp-servers", path = "../mcp-servers", features = ["all"], version = "0.8.4" }
+mcp-servers = { package = "aether-mcp-servers", path = "../mcp-servers", features = ["subagents"], version = "0.8.4" }
 wisp = { package = "aether-wisp", path = "../wisp", version = "0.7.14" }
 ratatui = { workspace = true }
 acp_utils = { package = "aether-acp-utils", path = "../acp-utils", features = ["websocket"], version = "0.5.13" }
@@ -49,7 +49,6 @@ clankerdiff-core = { workspace = true }
 clankerdiff-protocol = { workspace = true }
 clankerdiff-server = { workspace = true }
 aether-lspd = { path = "../aether-lspd", version = "0.3.3" }
-rmcp = { workspace = true, features = ["client", "elicitation", "server", "transport-streamable-http-client-reqwest"] }
 thiserror = { workspace = true }
 tokio = { workspace = true, features = ["rt", "rt-multi-thread", "macros", "sync", "io-util", "net", "fs", "time", "signal", "process"] }
 tokio-tungstenite = { workspace = true }

crates/aether-cli/README.md

@@ -153,7 +153,7 @@ The `mcp.json` file configures MCP tool servers:
 - **coding** — Filesystem tools (read, write, bash, etc.) plus optional auto-read rules from configured `--rules-dir` paths
 - **skills** — Slash commands and reusable prompts loaded from the configured `--dir` paths
 
-Set `"deferTools": true` on a server to keep its schemas out of the model-visible tool definitions. Use `aether mcp --help` to discover deferred servers, then `aether mcp <server> --help` and `aether mcp <server> <tool> --help` to inspect tools and schemas. Invoke a tool with `--json '{...}'` or a JSON object on stdin. To partition tools, use `"deferTools": { "include": [...], "exclude": [...] }`; patterns are exact MCP-local names or trailing-`*` prefixes, and `exclude` wins.
+Set `"deferTools": true` on a server to keep its schemas out of the model-visible tool definitions. Use `aether mcp --help` to discover deferred servers, then `aether mcp <server> --help` and `aether mcp <server> <tool> --help` to inspect tools and schemas. Invoke a tool with `--json '{...}'` or a JSON object on stdin. To partition tools, use `"deferTools": { "include": [...], "exclude": [...] }`; entries are exact MCP-local names, trailing-`*` prefixes, or annotation matchers such as `{ "readOnly": true }`, and `exclude` wins.
 
 ## Slash Commands
 

crates/aether-cli/src/acp/mod.rs

@@ -1,14 +1,11 @@
 pub(crate) mod agent;
-#[cfg(any(test, feature = "testing"))]
-pub(crate) mod fake_prompt_mcp;
 pub(crate) mod protocol;
 pub mod server;
 pub(crate) mod session;
 pub(crate) mod state;
 #[cfg(any(test, feature = "testing"))]
 pub mod testing;
 
-pub use protocol::map_mcp_prompt_to_available_command;
 pub use session::hooks::{IdleHook, SessionHooks};
 
 use crate::acp::state::{AcpState, AcpStateConfig};

crates/aether-cli/src/acp/protocol/commands.rs

@@ -1,22 +1,17 @@
 use agent_client_protocol::schema::v2::{self as acp, AvailableCommandInput, TextCommandInput};
-use rmcp::model::Prompt as McpPrompt;
+use mcp_utils::gateway::ServerPrompt;
 
-/// Converts an MCP Prompt to an ACP `AvailableCommand`
-///
-/// Strips the MCP namespace from the prompt name (e.g., "`coding__web`" -> "web")
-/// and creates a slash command that clients can invoke.
-pub fn map_mcp_prompt_to_available_command(prompt: &McpPrompt) -> acp::AvailableCommand {
-    let command_name = prompt.name.split("__").last().unwrap_or(prompt.name.as_ref()).to_string();
+pub(crate) fn available_commands(prompts: &[ServerPrompt]) -> Vec<acp::AvailableCommand> {
+    prompts.iter().map(|listed| available_command(&listed.prompt)).collect()
+}
 
+fn available_command(prompt: &mcp_utils::model::Prompt) -> acp::AvailableCommand {
     let hint = prompt
         .arguments
         .as_ref()
         .and_then(|args| args.iter().find(|a| a.name.as_str() == "ARGUMENTS").and_then(|a| a.description.as_deref()))
         .unwrap_or("optional arguments");
-
-    let input = Some(AvailableCommandInput::Text(TextCommandInput::new(hint)));
-
     let description = prompt.description.clone().unwrap_or_else(|| "No description available".to_string());
-
-    acp::AvailableCommand::new(command_name, description).input(input)
+    acp::AvailableCommand::new(&prompt.name, description)
+        .input(Some(AvailableCommandInput::Text(TextCommandInput::new(hint))))
 }