import { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js';
import { z } from 'zod';
import { RECIPES, REPO_COOKBOOK_PATH, loadCookbook, type Recipe } from './howto.js';
export function registerHowtoGetTool(server: McpServer): void {
server.registerTool(
'gerbil_howto_get',
{
title: 'Get Gerbil Recipe by ID',
description:
'Fetch a single cookbook recipe by its ID. Returns the full recipe with code, ' +
'imports, notes, and related recipes. Use after gerbil_howto with compact: true ' +
'to retrieve only the recipes you need.',
annotations: {
readOnlyHint: true,
idempotentHint: true,
},
inputSchema: {
id: z
.string()
.describe('Recipe ID to fetch (e.g. "json-parse", "hash-table-basics")'),
cookbook_path: z
.string()
.optional()
.describe(
'Absolute path to a JSON cookbook file with additional recipes to merge',
),
},
},
async ({ id, cookbook_path }) => {
// Load all recipes (built-in + repo + optional external)
let recipes: Recipe[] = [...RECIPES];
const sources = [REPO_COOKBOOK_PATH];
if (cookbook_path) sources.push(cookbook_path);
for (const src of sources) {
const external = loadCookbook(src);
if (external.length > 0) {
const externalIds = new Set(external.map((r) => r.id));
recipes = recipes.filter((r) => !externalIds.has(r.id));
recipes.push(...external);
}
}
const recipe = recipes.find((r) => r.id === id);
if (!recipe) {
return {
content: [
{
type: 'text' as const,
text: `Recipe "${id}" not found. Use gerbil_howto to search for recipes.`,
},
],
isError: true,
};
}
const sections: string[] = [];
const versionTag = recipe.gerbil_version ? ` [${recipe.gerbil_version}]` : '';
const testedTag =
recipe.valid_for && recipe.valid_for.length > 0
? ` (tested: ${recipe.valid_for.map((v) => { const m = v.match(/^(v\d+\.\d+)/); return m ? m[1] : v; }).filter((v, i, a) => a.indexOf(v) === i).join(', ')})`
: '';
if (recipe.deprecated) {
sections.push(`## [DEPRECATED]${versionTag} ${recipe.title}`);
if (recipe.superseded_by) {
sections.push(`Superseded by: "${recipe.superseded_by}"`);
}
} else {
sections.push(`## ${recipe.title}${versionTag}${testedTag}`);
}
sections.push(`ID: ${recipe.id}`);
sections.push(`Tags: ${recipe.tags.join(', ')}`);
if (recipe.imports.length > 0) {
sections.push(`Imports: ${recipe.imports.join(' ')}`);
}
sections.push('```scheme');
sections.push(recipe.code);
sections.push('```');
if (recipe.notes) {
sections.push(`Note: ${recipe.notes}`);
}
if (recipe.related && recipe.related.length > 0) {
sections.push(`Related: ${recipe.related.join(', ')}`);
}
return {
content: [{ type: 'text' as const, text: sections.join('\n') }],
};
},
);
}
