Attribute Macro prompt 

#[prompt]

Marks an async function as an MCP prompt handler and generates a companion {fn_name}_prompt_def() function that returns a mcp::PromptDef.

Attributes

• name = "..." — Prompt name (defaults to function name with - instead of _)
• description = "..." — Optional description
• arguments = ["arg1", "arg2:required", "arg3:optional"] — Optional argument list

Examples

Basic prompt:

use mcp_kit::prelude::*;

#[prompt(name = "greeting", description = "Generate a greeting message")]
async fn greeting(_req: GetPromptRequest) -> McpResult<GetPromptResult> {
    Ok(GetPromptResult::new(vec![
        PromptMessage::user_text("Hello! How can I help you today?")
    ]))
}

Prompt with arguments:

use mcp_kit::prelude::*;

#[prompt(
    name = "code-review",
    description = "Generate a code review",
    arguments = ["code:required", "language:optional"]
)]
async fn code_review(req: GetPromptRequest) -> McpResult<GetPromptResult> {
    let code = req.arguments.get("code").cloned().unwrap_or_default();
    let lang = req.arguments.get("language").cloned().unwrap_or_else(|| "unknown".into());
     
    Ok(GetPromptResult::new(vec![
        PromptMessage::user_text(format!("Review this {lang} code:\n\n```{lang}\n{code}\n```"))
    ]))
}