Struct McpBackendClient 

pub struct McpBackendClient { /* private fields */ }

Client for MCP backends, holding the bounded backend-session table.

Implementations

impl McpBackendClient

pub fn new(client: Client) -> Self

Build a client on top of the gateway’s shared HTTP client.

pub fn cached_sessions(&self) -> usize

Number of cached backend sessions (for tests and metrics).

pub fn forget_agent_session(&self, agent_session: &str)

Forget every backend session opened for agent_session.

pub async fn initialize( &self, endpoint: &BackendEndpoint, ) -> Result<BackendSession, McpError>

Run the initialize handshake against endpoint.

pub async fn session( &self, agent_session: &str, backend: &str, endpoint: &BackendEndpoint, ) -> Result<BackendSession, McpError>

The cached session for (agent_session, backend), opening one on first use. Concurrent callers share a single handshake.

pub async fn request( &self, agent_session: &str, backend: &str, endpoint: &BackendEndpoint, body: &[u8], request_id: &Value, ) -> Result<(u16, Vec<u8>, Option<String>), McpError>

Send one JSON-RPC request and return the matching JSON-RPC response bytes. body is forwarded verbatim; request_id is its id.

Returns (http_status, response_bytes). A non-success HTTP status other than a session-expiry 404 is returned as-is with the body the backend sent, so the caller can record it.

pub async fn list_tools( &self, agent_session: &str, backend: &str, endpoint: &BackendEndpoint, ) -> Result<Vec<Value>, McpError>

Collect every tool a backend advertises through tools/list, following nextCursor pagination within fixed bounds.