openagent-mcp · handler · OpenAgentID Docs

Source: openagent-sdk/integrations/mcp/rust/src/handler.rs. SHA-256: 90e5087e39d015e22b608bba0f1550506c76121634c4718f0b82463c42463243.

This source reference follows declared modules and preserves feature attributes. It includes public declarations and implementation methods in those modules. Private-module exports and trait resolution still require the compiler; not every declaration is a crate-root import. Function bodies and constant values are omitted. Source comments describe their implementation context and are not a production deployment claim.

handler::ToolCall

A single inbound tools/call request.

meta carries the request metadata pulled from the MCP envelope — in particular meta["openagent"]["identity"] is where the auth envelope lives. The middleware reads it and never modifies it in place.

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ToolCall {
/// The tool name (e.g., `"search_web"`).

pub name: String,
/// JSON arguments the caller supplied.

#[serde(default)]
pub arguments: serde_json::Value,
/// Request metadata. Identity envelope lives at

/// `meta["openagent"]["identity"]`.

#[serde(default)]
pub meta: serde_json::Value
}

Source line: 32.

handler::ToolResult

A single outbound tool result. The middleware stamps audit metadata onto meta after the handler returns.

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ToolResult {
/// MCP content blocks (text, image, resource_link, etc).

#[serde(default)]
pub content: serde_json::Value,
/// Optional structured content (the new MCP 2025 field).

#[serde(default, skip_serializing_if = "Option::is_none")]
pub structured_content: Option<serde_json::Value>,
/// Optional `isError` flag for error responses returned via the

/// happy-path channel.

#[serde(default, skip_serializing_if = "Option::is_none")]
pub is_error: Option<bool>,
/// Result metadata. Audit metadata is stamped here on success.

#[serde(default)]
pub meta: serde_json::Value
}

Source line: 47.

handler::ToolResult::text

Build a simple text result with no metadata.

pub fn text(message: impl Into<String>) -> Self;

Source line: 65.

handler::RegisteredTool

Description of a registered tool, returned by [ToolHandler::list_tools].

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct RegisteredTool {
/// Tool name.

pub name: String,
/// Optional description for clients.

#[serde(default, skip_serializing_if = "Option::is_none")]
pub description: Option<String>
}

Source line: 78.

handler::ToolHandler

The trait every concrete server handler implements. Two methods — list_tools and call_tool — keep the surface narrow and stable across MCP SDK versions.

#[async_trait]
pub trait ToolHandler: Send + Sync {
    /// Return the tools this handler exposes.
    async fn list_tools(&self) -> Vec<RegisteredTool>;

    /// Execute a single tool call. Implementations should NOT do any
    /// authentication or authorization — that runs in the middleware
    /// before this is invoked.
    async fn call_tool(&self, call: ToolCall) -> Result<ToolResult, McpAuthError>;
}

Source line: 90.

handler::WithOpenAgent

Marker trait — anything that implements [ToolHandler] can be wrapped via [WithOpenAgent::with_openagent].

pub trait WithOpenAgent: ToolHandler + Sized {
    /// Wrap this handler with the OpenAgent middleware.
    ///
    /// ```no_run
    /// use openagent_mcp::{Config, InMemoryToolHandler, OpenAgentMiddleware, WithOpenAgent};
    /// # use std::sync::Arc;
    /// # async fn example(agent: std::sync::Arc<dyn openagent_mcp::Agent>) {
    /// let handler = InMemoryToolHandler::new();
    /// let middleware = OpenAgentMiddleware::new(Config::new(agent));
    /// let authed = handler.with_openagent(middleware);
    /// # let _ = authed;
    /// # }
    /// ```
    fn with_openagent(self, middleware: OpenAgentMiddleware) -> WrappedHandler<Self> ;
}

Source line: 102.

handler::WrappedHandler

Result of wrapping a [ToolHandler] with [OpenAgentMiddleware].

WrappedHandler itself implements [ToolHandler], so the wrapped instance is a drop-in replacement for the original — the rest of your server code keeps working unchanged.

pub struct WrappedHandler<T: ToolHandler + ?Sized> {

}

Source line: 130.

handler::InMemoryToolHandler

In-memory test handler. Useful for unit and integration tests of the middleware (and as a tiny example of what a custom handler looks like).

#[derive(Default)]
pub struct InMemoryToolHandler {

}

Source line: 173.

handler::InMemoryToolHandler::new

Create an empty handler.

pub fn new() -> Self;

Source line: 199.

handler::InMemoryToolHandler::register

pub async fn register<F, Fut>(
        &self,
        name: impl Into<String>,
        description: Option<&str>,
        handler: F,
    ) where
        F: Fn(serde_json::Value) -> Fut + Send + Sync + 'static,
        Fut: std::future::Future<Output = Result<ToolResult, McpAuthError>> + Send + 'static,;

Source line: 205.

openagent-mcp · handler

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