Struct McpServerManager 

pub struct McpServerManager { /* private fields */ }

Manages multiple MCP server connections behind interior mutability so per-server startup tasks can insert as they finish while synchronous consumers (has_server, all_specs) keep working.

Implementations

impl McpServerManager

pub fn new(configs: &HashMap<String, McpServerConfig>) -> Self

Empty manager pre-seeded with deterministic server-name aliases.

pub fn alias_for(&self, raw_name: &str) -> String

Sanitized alias for a raw server name (assigned at construction). Falls back to sanitizing on the fly for names outside the config set (defensive; callers always pass configured names).

pub async fn start_server( &self, name: &str, config: &McpServerConfig, ) -> Result<Vec<McpToolSpec>>

Spawn + initialize + list_tools for one server, bounded by [MCP_STARTUP_TIMEOUT]; inserts the runtime and returns the sanitized specs for the reducer’s Msg::McpServerReady.

pub fn all_specs(&self) -> Vec<(String, McpToolSpec)>

All discovered tools as (raw server name, sanitized spec) pairs, cloned out so no lock is held by the caller. Order: server name.

pub fn has_server(&self, name: &str) -> bool

True iff the named server started and has an active client, even if it advertised zero tools. Accepts raw or sanitized names.

pub fn has_servers(&self) -> bool

Check if any MCP servers are active.

pub async fn call_tool( &self, server: &str, tool: &str, arguments: &Value, ) -> Result<McpToolResult>

Call a tool on a specific server. server and tool accept sanitized names (the advertised form) or raw names (an off-script model echoing a server’s own tool listing still routes).

Concurrency

Multiple concurrent calls to the same server serialize at the transport layer (StdioTransport holds a mutex over stdin writes and uses a shared pending-response map for JSON-RPC correlation). Calls to different servers run fully in parallel. The registry read lock is dropped before awaiting the call.

pub fn format_tool_result( result: &McpToolResult, ) -> (String, Option<Vec<String>>)

Convert an MCP tool result into text suitable for a tool result message. Images are returned separately for multimodal attachment. Audio is attached through the same channel — adapters that don’t support audio will silently drop it. Resource links + embedded resources render as text so the model can follow up with another tool call.

pub async fn shutdown(&self)

Gracefully shut down all MCP servers. Sets the shutting-down flag first so straggler startup tasks reap their own clients.

pub async fn stop_server(&self, name: &str) -> bool

Stop a single named server: kill its child via the transport. The stdout-reader task then exits on EOF — no explicit abort needed. Returns true if a server matched (raw or sanitized name).

The registry entry lingers, but the client is flagged shut down, so a later call_tool to a stopped server returns a clean “has been stopped” error rather than a broken-pipe transport failure.