Advanced Trello MCP Server

Implementation Reference

• src/tools/labels.ts:166-204 (handler)

  Handler function that batch adds labels to multiple cards by iterating over 'items' array, calling Trello API POST /cards/{cardId}/idLabels for each, collecting results with Promise.all, and returning JSON stringified response or error.

  async ({ items }) => {
  	try {
  		const results = await Promise.all(
  			items.map(async (item) => {
  				const response = await fetch(
  					`https://api.trello.com/1/cards/${item.cardId}/idLabels?key=${credentials.apiKey}&token=${credentials.apiToken}`,
  					{
  						method: 'POST',
  						headers: {
  							'Content-Type': 'application/json',
  						},
  						body: JSON.stringify({
  							value: item.labelId,
  						}),
  					}
  				);
  				return await response.json();
  			})
  		);
  		return {
  			content: [
  				{
  					type: 'text',
  					text: JSON.stringify(results),
  				},
  			],
  		};
  	} catch (error) {
  		return {
  			content: [
  				{
  					type: 'text',
  					text: `Error adding labels to cards: ${error}`,
  				},
  			],
  			isError: true,
  		};
  	}
  }

• src/tools/labels.ts:158-165 (schema)

  Zod input schema defining an array of objects, each with 'cardId' (string) and 'labelId' (string).

  {
  	items: z.array(
  		z.object({
  			cardId: z.string().describe('ID of the card to add the label to'),
  			labelId: z.string().describe('ID of the label to add'),
  		})
  	),
  },

• src/tools/labels.ts:156-205 (registration)

  Direct registration of the 'add-labels' tool using server.tool(), providing name, input schema, and handler function within the registerLabelsTools function.

  server.tool(
  	'add-labels',
  	{
  		items: z.array(
  			z.object({
  				cardId: z.string().describe('ID of the card to add the label to'),
  				labelId: z.string().describe('ID of the label to add'),
  			})
  		),
  	},
  	async ({ items }) => {
  		try {
  			const results = await Promise.all(
  				items.map(async (item) => {
  					const response = await fetch(
  						`https://api.trello.com/1/cards/${item.cardId}/idLabels?key=${credentials.apiKey}&token=${credentials.apiToken}`,
  						{
  							method: 'POST',
  							headers: {
  								'Content-Type': 'application/json',
  							},
  							body: JSON.stringify({
  								value: item.labelId,
  							}),
  						}
  					);
  					return await response.json();
  				})
  			);
  			return {
  				content: [
  					{
  						type: 'text',
  						text: JSON.stringify(results),
  					},
  				],
  			};
  		} catch (error) {
  			return {
  				content: [
  					{
  						type: 'text',
  						text: `Error adding labels to cards: ${error}`,
  					},
  				],
  				isError: true,
  			};
  		}
  	}
  );

• src/index.ts:91-91 (registration)

  Top-level call to registerLabelsTools in the main MCP server setup, which in turn registers the 'add-labels' tool among others.

  registerLabelsTools(server, credentials);