/**
* Manager for MCP prompt definitions
*/
import type { Prompt, PromptArgument, GetPromptResult, PromptMessage } from "@modelcontextprotocol/sdk/types.js"
import type { PromptDefinition } from "./prompt-types"
export interface PromptsManagerConfig {
prompts?: PromptDefinition[]
}
/**
* Manages prompt definitions and handles prompt-related MCP requests
*/
export class PromptsManager {
private prompts: Map<string, PromptDefinition> = new Map()
constructor(config: PromptsManagerConfig) {
if (config.prompts) {
for (const prompt of config.prompts) {
this.addPrompt(prompt)
}
}
}
/**
* Add a prompt definition
*/
addPrompt(prompt: PromptDefinition): void {
if (!prompt.name) {
throw new Error("Prompt name is required")
}
if (!prompt.template) {
throw new Error(`Prompt "${prompt.name}" requires a template`)
}
this.prompts.set(prompt.name, prompt)
}
/**
* Remove a prompt by name
*/
removePrompt(name: string): boolean {
return this.prompts.delete(name)
}
/**
* Get all prompts in MCP format for listing
*/
getAllPrompts(): Prompt[] {
return Array.from(this.prompts.values()).map((def) => this.toMCPPrompt(def))
}
/**
* Get a specific prompt with arguments applied
*/
getPrompt(name: string, args?: Record<string, string>): GetPromptResult {
const def = this.prompts.get(name)
if (!def) {
throw new Error(`Prompt not found: ${name}`)
}
// Validate required arguments
if (def.arguments) {
for (const arg of def.arguments) {
if (arg.required && (!args || args[arg.name] === undefined)) {
throw new Error(`Missing required argument: ${arg.name}`)
}
}
}
// Render the template with arguments
const renderedText = this.renderTemplate(def.template, args || {})
const messages: PromptMessage[] = [
{
role: "user",
content: {
type: "text",
text: renderedText,
},
},
]
return {
description: def.description,
messages,
}
}
/**
* Check if a prompt exists
*/
hasPrompt(name: string): boolean {
return this.prompts.has(name)
}
/**
* Get the count of prompts
*/
get count(): number {
return this.prompts.size
}
/**
* Convert internal prompt definition to MCP Prompt format
*/
private toMCPPrompt(def: PromptDefinition): Prompt {
const prompt: Prompt = {
name: def.name,
description: def.description,
}
if (def.arguments && def.arguments.length > 0) {
prompt.arguments = def.arguments.map(
(arg): PromptArgument => ({
name: arg.name,
description: arg.description,
required: arg.required,
}),
)
}
return prompt
}
/**
* Render a template string by replacing {{argName}} placeholders
*/
private renderTemplate(template: string, args: Record<string, string>): string {
return template.replace(/\{\{(\w+)\}\}/g, (match, argName) => {
if (args[argName] !== undefined) {
return args[argName]
}
// Return empty string for missing optional arguments
return ""
})
}
}
