Trello

Overview

The Trello API exposes boards, lists, cards, members, and activity for the kanban project-management tool. Public boards are readable without a key (verified live — the Trello Development Roadmap board returns JSON anonymously); private data and writes need an API key + token (OAuth-style).

Quick Start

A public board — no key needed (verified live):

curl "https://api.trello.com/1/boards/4d5ea62fd76aa1136000000c"

{
  "id": "4d5ea62fd76aa1136000000c",
  "name": "Trello Development Roadmap",
  "desc": "## Welcome to the Trello Roadmap! ...",
  "url": "https://trello.com/b/nC8QJJoZ/trello-development-roadmap"
}

Lists on the board:

curl "https://api.trello.com/1/boards/4d5ea62fd76aa1136000000c/lists"

Cards in a list (public data, no key):

curl "https://api.trello.com/1/lists/{listId}/cards"

With key + token (private boards, writes):

curl "https://api.trello.com/1/boards/{boardId}?key=YOUR_KEY&token=YOUR_TOKEN"

Authentication

• Anonymous: public boards/lists/cards are readable without a key (verified).
• API key + token: generate at trello.com/power-ups/admin (or the developer site) — required for private data and mutations (create cards, move lists…).
• Token is user-scoped; treat it like a password.

Rate Limits & Notes

• Public reads are effectively unlimited; authenticated calls have per-key limits (check the docs).
• Board/List/Card IDs are stable alphanumeric strings.
• Use ?cards=open&card_fields=name and similar to trim responses.
• The API is RESTful with /1/ prefix; webhooks available for real-time updates.

FAQ

Is Trello API free? Yes — public reads are keyless; key+token is free for most use.

Do I need a token? Only for private boards and writes — public data is readable anonymously.

How do I get a key? trello.com/power-ups/admin → create a power-up → copy the API key.