ActionMattermostUpdated September 2026

How do I post to a Mattermost channel?

Short answer: You can send mattermost channel message in Mattermost by hand from its own interface, but it won’t repeat itself. On TinyCommand, add the Mattermost Send Mattermost Channel Message action to a workflow, map its 3 inputs from any upstream app, and it runs automatically every time the trigger fires. No code, and a free tier to start.

Send Mattermost Channel Message in Mattermost — start free All 7 Mattermost actions

Send Mattermost Channel Message in Mattermost — start free

Inputs

The fields this action accepts.

Every field can be mapped from an upstream trigger, AI step, table row, or hard-coded literal.

Field	Type	Required	Description
Channel ID channel_id	string	Required	Channel ID. Example: abcdef1234567890
Message message	string	Required	Message text (supports Markdown)
Thread Root ID root_id	string	Optional	Post ID to reply to (creates a threaded reply)

Sample request

{
  "channel_id": "e.g. abcdef1234567890",
  "message": "e.g. Build #42 deployed successfully :white_check_mark:",
  "root_id": "e.g. post123abc"
}

Returns

{
  "id": "post123",
  "message": "Build deployed!",
  "create_at": 1700000000000,
  "channel_id": "abcdef123"
}

Use these fields in downstream nodes for routing, logging, or error handling.

Triggered by

Apps that pair well as the trigger for Send Mattermost Channel Message.

Any of these apps can fire this action as part of a workflow.

Google Sheets → Mattermost

2 Google Sheets triggers

HubSpot → Mattermost

18 HubSpot triggers

FAQ

Questions about Send Mattermost Channel Message.

What does the Send Mattermost Channel Message action do in Mattermost?

Posts a message to a specific channel with optional attachments (Slack-attachment-style cards). The base hook for "external event → post to team channel" workflows.

What inputs does Send Mattermost Channel Message require?

Required: Channel ID, Message. Every input accepts a static value or a variable from any upstream node in your workflow.

Can I use dynamic inputs from earlier workflow nodes?

Yes. Any field on this action can pull values from upstream nodes, whether that's a form response, a trigger payload, an AI output, or a lookup result.

What happens if Mattermost returns an error?

The run history shows the failed step with its input and the error message Mattermost returned, so you can fix the input and run the workflow again. Automatic retries are built into HTTP steps only, where you can also set your own retry count and delay.

Does Send Mattermost Channel Message support batch operations?

Run Send Mattermost Channel Message inside a loop to process each item in an array. TinyCommand does not throttle calls for you, so for large arrays add a Delay step if you need to stay within Mattermost's rate limits.

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