Struct ToolCallLoggingLayer 

pub struct ToolCallLoggingLayer { /* private fields */ }

Tower layer that adds audit logging for tool call requests.

This layer intercepts tools/call requests and emits structured tracing events with the tool name, execution duration, and result status. Non-tool-call requests pass through with zero overhead.

Events are emitted with tracing target mcp::tools, which can be used for filtering in your tracing subscriber configuration.

Example

use tower_mcp::{McpRouter, StdioTransport};
use tower_mcp::middleware::ToolCallLoggingLayer;

let router = McpRouter::new().server_info("my-server", "1.0.0");

let mut transport = StdioTransport::new(router)
    .layer(ToolCallLoggingLayer::new());

Implementations

impl ToolCallLoggingLayer

pub fn new() -> Self

Create a new tool call logging layer with default settings (INFO level).

pub fn level(self, level: Level) -> Self

Set the log level for tool call events.

Default is INFO.

Trait Implementations

impl Clone for ToolCallLoggingLayer

fn clone(&self) -> ToolCallLoggingLayer

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ToolCallLoggingLayer

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for ToolCallLoggingLayer

fn default() -> Self

Returns the “default value” for a type.

impl<S> Layer<S> for ToolCallLoggingLayer

type Service = ToolCallLoggingService<S>

The wrapped service

fn layer(&self, inner: S) -> Self::Service

Wrap the given service with the middleware, returning a new service that has been decorated with the middleware.

impl Copy for ToolCallLoggingLayer