---
ref: tool:trello/add-card-comment
name: Add a comment to a card
company: company:trello
workflows: []
access: [api]
tags: [capability:manage-tasks, category:project-management, has:api]
docs: https://developer.atlassian.com/cloud/trello/rest/api-group-cards/#api-cards-id-actions-comments-post
updated: 2026-09-27
---

# Add a comment to a card

Adds a comment with the text you pass to a card and returns the comment action.

## Set up

Use the first option your agent supports.

### API (official)

- Base URL: https://api.trello.com/1
- Endpoint: `POST /cards/{id}/actions/comments`
- Auth: OAuth; sign in when the agent asks
- Docs: https://developer.atlassian.com/cloud/trello/rest/

Before doing anything else, make one read-only call to confirm access.

## Rules

- Ask the user before anything that sends messages, costs money, or changes data.
- Never print API keys.