Batch

The batch endpoint runs up to 10 GET requests in one HTTP round-trip. Useful when you'd otherwise issue a flurry of small reads.

Basic usage

const [board, lists, members] = await trello.batch.run((b) => [
  b.boards.getBoard({ id: boardId }),
  b.boards.getBoardLists({ id: boardId }),
  b.boards.getBoardMembers({ id: boardId }),
] as const);

console.log(board.name, lists.length, members.length);

The result is a tuple — each entry is typed as the return type of its corresponding call. as const preserves tuple ordering for TypeScript inference.

What it accepts

• GET requests only. Trello's batch endpoint does not accept POST/PUT/DELETE.
• Up to 10 requests per batch. Larger batches will error.
• Each request must be a call on the namespaced client passed to the builder.

Per-item error handling

If one item returns non-2xx, its individual promise rejects with Error('Batch request failed') — the rest still resolve:

try {
  const [board, missing] = await trello.batch.run((b) => [
    b.boards.getBoard({ id: validId }),
    b.boards.getBoard({ id: 'definitely-not-real' }),
  ] as const);
} catch (err) {
  // Promise.all rejects on the first failure
}

To inspect partial successes, await individual promises with Promise.allSettled:

const promises = [
  trello.boards.getBoard({ id: validId }),
  trello.boards.getBoard({ id: 'bad' }),
];
const results = await Promise.allSettled(
  await trello.batch.run(() => promises as readonly Promise<unknown>[]),
);

When NOT to use batch

• Single requests — overhead isn't worth it
• Long-running fetches (Trello has a per-batch timeout shorter than per-request)
• Mutations (PUT/POST/DELETE) — not supported

Raw batch endpoint

trello.batch.run is the high-level builder. If you need full control over the raw URL list, import the low-level run from the trello.js/batch subpath:

import { createClient } from 'trello.js/core';
import { run } from 'trello.js/batch';

const client = createClient({ apiKey, apiToken });

const responses = await run(client, {
  urls: '/boards/abc,/cards/xyz,/lists/123',
});

Returns an array of { "200": data } or { "4xx": "error message" } objects, one per URL.