Trello - Add Comment

↩ Part of the Trello integration.

Description

Adds a comment to a Trello card (POST /cards/{id}/actions/comments). It is the simplest way to leave an audit trail on the board: what the workflow did, what it found, or why it stopped — visible to everyone who follows the card, with Trello’s own notifications.

The comment text accepts dynamic variables, so you can compose it from the output of earlier nodes.

Configuration

Field	Type	Required	Description
`credentials_id`	credentials	Yes	Trello credential
`card_id`	text	Yes	Card id
`text`	textarea	Yes	Comment text

Both card_id and text are resolved through dynamic variables ({{data.field}}).

Credentials

This node requires a Trello credential (service type trello):

Field	Description
`api_key`	Trello API key
`token`	Token generated when authorizing that key

The comment is attributed to the Trello user who owns the token.

Output

Trello returns the action it recorded, not the card:

{
  "data": {
    "id": "66ce45fa67bc89de01fa23bc",
    "type": "commentCard",
    "date": "2026-08-14T12:31:07.412Z",
    "data": {
      "text": "Shipped with tracking 1Z999AA10123456784",
      "card": { "id": "66cd34ef56ab78cd90ef12ab", "name": "Order: ACME Inc." }
    }
  },
  "_meta": {
    "moduleVersion": "1.0.0",
    "success": true,
    "id": "66cd34ef56ab78cd90ef12ab",
    "actionId": "66ce45fa67bc89de01fa23bc",
    "totalMs": 214
  }
}

_meta.actionId is the comment id, in case you want to reference it later through the HTTP node.

Usage Example

Log a result

{
  "credentials_id": "trello_ops",
  "card_id": "{{data.card_id}}",
  "text": "Shipped with tracking {{data.tracking}}"
}

Report a failure from an error branch

{
  "credentials_id": "trello_ops",
  "card_id": "{{data.card_id}}",
  "text": "Could not invoice: {{data.error.message}}"
}

Notes

If card_id or text is empty, the node stops with a validation error and nothing is posted.
Trello supports Markdown in comments (bold, lists, links), so multi-line summaries render nicely.
Mentioning a member requires their @username; the node does not resolve names to ids.
Comments cannot be edited or deleted by these nodes — post a new comment instead.

Trello - Create Card — create the card you are commenting on.
Trello - Update Card — move the card after commenting.
Trello - List Cards — comment on every card in a list via an iterator.