import type { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js';
import type { GetPromptResult } from '@modelcontextprotocol/sdk/types.js';
import { z } from 'zod';
import { type IconInfo, withDefaultIcons } from './tools/shared.js';
const HELP_PROMPT_NAME = 'get-help';
const HELP_PROMPT_TITLE = 'Get Help';
const HELP_PROMPT_DESCRIPTION = 'Return the filesystem-mcp usage instructions.';
function filterInstructionsByTopic(
instructions: string,
topic: string
): string {
const normalized = topic.trim().toLowerCase();
if (!normalized) return instructions;
const sections = instructions.split(/\n(?=## )/u);
const match = sections.find((sec) =>
sec.toLowerCase().startsWith(`## ${normalized}`)
);
if (match !== undefined) return match;
const available = sections
.filter((sec) => sec.startsWith('## '))
.map((sec) => sec.split('\n')[0]?.replace(/^##\s*/u, '') ?? '')
.filter(Boolean)
.join(', ');
return `Section '${topic}' not found. Available sections: ${available}\n\n${instructions}`;
}
export function registerGetHelpPrompt(
server: McpServer,
instructions: string,
iconInfo?: IconInfo
): void {
const baseConfig = withDefaultIcons(
{ title: HELP_PROMPT_TITLE, description: HELP_PROMPT_DESCRIPTION },
iconInfo
);
server.registerPrompt(
HELP_PROMPT_NAME,
{
...baseConfig,
argsSchema: {
topic: z
.string()
.optional()
.describe(
'Section heading prefix to filter (e.g. "error handling strategy"). Omit for full instructions.'
),
},
},
({ topic }): GetPromptResult => {
const text = topic
? filterInstructionsByTopic(instructions, topic)
: instructions;
return {
description: HELP_PROMPT_DESCRIPTION,
messages: [
{
role: 'user',
content: {
type: 'text',
text,
},
},
],
};
}
);
}
