Struct MCPClient 

pub struct MCPClient { /* private fields */ }

Client for communicating with MCP tool providers over any transport.

Implementations

impl MCPClient

pub async fn spawn( command: &str, args: &[&str], env: &HashMap<String, String>, ) -> Result<Self>

Spawn an MCP server as a child process and talk to it over stdio.

pub fn connect_http( url: &str, headers: &HashMap<String, String>, allow_env: &[String], ) -> Result<Self>

Connect to an MCP server over HTTP.

pub fn set_refresher(&mut self, refresher: Arc<dyn BearerRefresher>)

Attach a refresher used to re-authenticate on a mid-session 401.

Only the HTTP transport acts on it; stdio ignores it. The daemon sets this for an OAuth-backed HTTP server so a long run whose token expires keeps working.

pub async fn from_config(config: &MCPServerConfig) -> Result<Self>

Build a client for a configured server, over whichever transport the entry describes.

Callers above this point - discovery, execution, the tool registry - never learn which one it turned out to be.

pub async fn from_config_with_auth( config: &MCPServerConfig, auth_header: Option<(String, String)>, allow_env: &[String], ) -> Result<Self>

Self::from_config with a resolved Authorization header injected for an HTTP server.

auth_header is the (name, value) pair from crate::OAuthClient::authorization_header; it is layered on top of the config’s static headers (and wins on a clash, since a live token should override a stale hard-coded one). Ignored for stdio servers, which carry no HTTP headers.

pub async fn connect(&mut self) -> Result<()>

Connect to the MCP server by sending initialize and initialized messages.

pub async fn list_tools(&mut self) -> Result<Vec<ToolMetadata>>

List available tools from the server, following nextCursor pagination.

tools/list is a paginated operation. Reading only the first response silently exposes just the first page of a large server’s catalogue, so this loops until the server stops returning a cursor, bounded by an internal page limit so a server that returns a cursor forever can’t spin the loop.

pub async fn call_tool( &mut self, name: &str, arguments: Value, ) -> Result<ToolResult>

Call a tool on the server.

pub async fn shutdown(&mut self) -> Result<()>

Shutdown the MCP server.

Always succeeds: a dead or unresponsive server must never block cleanup.

pub fn capabilities(&self) -> Option<&ServerCapabilities>

Get the server capabilities (available after connect).

pub fn protocol_version(&self) -> Option<&str>

The protocol revision agreed with the server (available after connect).

pub fn cached_tools(&self) -> &[ToolMetadata]

Get the cached tool list.