get_product

Instructions

Implementation Reference

• src/tools/get_product.ts:15-38 (handler)

  The getProductHandler function that executes the tool logic. It looks up the chain-specific adapter from the registry, calls adapter.getProduct(input.id), and returns the normalized product or throws a ToolError on failure.

  export async function getProductHandler(
    registry: AdapterRegistry,
    input: GetProductInput,
  ): Promise<NormalizedProduct | null> {
    const adapter = registry.get(input.chain);
    if (!adapter) {
      throw new ToolError(
        'adapter_not_registered',
        `No adapter registered for chain "${input.chain}"`,
        'Ensure the chain is enabled in the server configuration. For Denner, set the DENNER_JWT env var.',
      );
    }
    const r = await adapter.getProduct(input.id);
    if (!r.ok) {
      throw new ToolError(
        r.error.code,
        `Product fetch failed for ${input.chain}/${input.id}: ${r.error.code}`,
        r.error.code === 'not_found'
          ? 'The product ID may be invalid or discontinued. Re-run search_products to get a fresh ID.'
          : 'Try again later or use search_products to find an alternative.',
      );
    }
    return r.data;
  }

• src/tools/get_product.ts:6-11 (schema)

  The getProductSchema Zod schema defining the input: 'chain' (enum of supported grocery chains) and 'id' (string, min 1). Describes the tool purpose.

  export const getProductSchema = z.object({
    chain: z.enum(['migros', 'coop', 'aldi', 'denner', 'lidl', 'farmy', 'volgshop', 'ottos'])
      .describe('The grocery chain that owns this product ID.'),
    id: z.string().min(1)
      .describe('Chain-specific product identifier, e.g. Migros cumulus ID or Coop product number. Obtain via search_products.'),
  }).describe('Fetch full product details (price, size, tags, promotions) for a specific chain + product ID pair. Use after search_products to drill into a result.');

• src/index.ts:72-81 (registration)

  Registration of the 'get_product' tool in the MCP server with name, description, schema, and handler. Imported at line 25 from './tools/get_product.js'.

  {
    name: 'get_product',
    description: [
      'Fetch full product details for a specific chain + product ID pair.',
      'Returns price, brand, size, unit price, tags, category, image URL, and active promotions.',
      'Obtain product IDs from search_products. Useful for drilling into a search result.',
      'Use for "get details for this Migros product" or "what is the unit price of this item?".',
    ].join(' '),
    schema: getProductSchema,
    handler: getProductHandler,

• src/adapters/types.ts:227-231 (helper)

  The getProduct method signature in the StoreAdapter interface that all chain adapters must implement. Returns Promise<AdapterResult<NormalizedProduct | null>>.

    getProduct(id: string): Promise<AdapterResult<NormalizedProduct | null>>;
    searchStores(q: StoreQuery): Promise<AdapterResult<NormalizedStore[]>>;
    getPromotions(q: PromotionQuery): Promise<AdapterResult<NormalizedPromotion[]>>;
    findStoresWithStock?(productId: string, near?: GeoPoint): Promise<AdapterResult<StockResult[]>>;
  }