Trello

This connector uses the Trello REST API v1.

Setup:

1. Sign in to Trello → go to https://trello.com/power-ups/admin → + New to create a Power-Up (this is just the modern way to mint API keys).
2. After creation, open the Power-Up → API key section → copy the API key.
3. Below it, click Token → authorize the Power-Up → copy the generated user Token.
4. Set:
   • TRELLO_API_KEY = the Power-Up key (a long alphanumeric)
   • TRELLO_TOKEN = the user token (much longer)

Authentication: query-string ?key=${TRELLO_API_KEY}&token=${TRELLO_TOKEN} on every request. The token is per-user — actions are attributed to that user. To act as a different user, mint a separate token via their Trello account.

Hierarchy: Workspace (Organization) → Board → List → Card. Cards have members[], labels[], checklists[], attachments[], comments (= actions of type commentCard).

ID format: 24-character hex (e.g. abc123def456789012345678). Boards / lists / cards / members all use this format. Discover board IDs via trello_list_my_boards → list IDs via trello_get_board_lists → card IDs via trello_list_cards_in_list.

fields parameter: virtually every endpoint accepts ?fields=all or ?fields=comma,separated,list. Default returns a sensible subset — for full payloads pass fields=all.

Position values: lists and cards have a pos (float) for ordering. pos=top or pos=bottom shortcuts work for moves; otherwise pass an explicit number between the neighbors' positions.

Labels: are board-level. A label has color (green/yellow/orange/red/purple/blue/sky/lime/pink/black/null) + name. Cards reference labels by their ID. Use trello_list_board_labels to discover IDs.

Attachments: upload via multipart not supported in single call. Use URL attachments via the url parameter — Trello fetches it.

Webhooks out of scope.

Rate limits: 100 req per 10 sec per API key, 300 per 10 sec per token. Returns 429 with X-Rate-Limit-Api-Key-Remaining header.

Out of scope here: Power-Up actions, custom fields (Power-Up only), board backgrounds, voting, plugin data, butler automations.