Trait ToolHandler 

pub trait ToolHandler: Send + Sync {
    // Required methods
    fn tool(&self) -> Tool;
    fn call<'life0, 'async_trait>(
        &'life0 self,
        invocation: ToolInvocation,
    ) -> Pin<Box<dyn Future<Output = Result<ToolResult, Error>> + Send + 'async_trait>>
       where Self: 'async_trait,
             'life0: 'async_trait;
}

A client-defined tool with its handler logic.

Implement this trait for each tool you expose to the Copilot agent. The struct is a named type — visible in stack traces and navigable via “go to definition” — unlike closure-based alternatives.

Example

use github_copilot_sdk::tool::{schema_for, tool_parameters, JsonSchema, ToolHandler};
use github_copilot_sdk::{Error, Tool, ToolInvocation, ToolResult};
use serde::Deserialize;
use async_trait::async_trait;

#[derive(Deserialize, JsonSchema)]
struct GetWeatherParams {
    /// City name
    city: String,
    /// Temperature unit
    unit: Option<String>,
}

struct GetWeatherTool;

#[async_trait]
impl ToolHandler for GetWeatherTool {
    fn tool(&self) -> Tool {
        Tool {
            name: "get_weather".to_string(),
            namespaced_name: None,
            description: "Get weather for a city".to_string(),
            parameters: tool_parameters(schema_for::<GetWeatherParams>()),
            instructions: None,
            ..Default::default()
        }
    }

    async fn call(&self, inv: ToolInvocation) -> Result<ToolResult, Error> {
        let params: GetWeatherParams = serde_json::from_value(inv.arguments)?;
        Ok(ToolResult::Text(format!("Weather in {}: sunny", params.city)))
    }
}

Required Methods

fn tool(&self) -> Tool

The tool definition sent to the CLI during session creation.

fn call<'life0, 'async_trait>( &'life0 self, invocation: ToolInvocation, ) -> Pin<Box<dyn Future<Output = Result<ToolResult, Error>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait,

Handle a tool invocation from the agent.

Implementors