Send a Channel Message

Prerequisites

Delegated login.
Team and channel IDs.
ChannelMessage.Send consent.

teams message send --team "$TEAM_ID" --channel "$CHANNEL_ID" --body "Hello from teams-cli" --output json

Give the post a subject line — the bold title Teams renders above the body, the same field the client offers behind "Add a subject":

teams message send --team "$TEAM_ID" --channel "$CHANNEL_ID" --subject "Release plan" --body "Details inside." --output json

Only channel root messages carry a subject. Chat messages have none, so --subject with --chat is rejected as invalid input (exit 2) before anything is sent. The subject comes back on message list and message get; human-readable lists show it in a Subject column, and JSON omits it for messages that have none.

Send an inline image:

teams message send --team "$TEAM_ID" --channel "$CHANNEL_ID" --image ./screenshot.png --output json

Attach a file. Channel attachments upload to the team's SharePoint-backed file store and require Files.ReadWrite.All.

teams message send \
  --team "$TEAM_ID" \
  --channel "$CHANNEL_ID" \
  --body "Logs attached" \
  --attach ./logs.zip \
  --output json

Verify with:

teams message list --team "$TEAM_ID" --channel "$CHANNEL_ID" --page-size 1 --output json

That listing returns thread roots only. To read the replies under a post, pass its ID with --message-id; see Read and Watch Channels.

To take a post back, soft-delete it, and restore it with message undelete. Add --reply REPLY_ID to target a reply in the thread, with the root post as the message ID:

teams message delete --team "$TEAM_ID" --channel "$CHANNEL_ID" --message "$MESSAGE_ID" --yes --output json
teams message undelete --team "$TEAM_ID" --channel "$CHANNEL_ID" --message "$MESSAGE_ID" --output json

Channel deletion needs the delegated ChannelMessage.ReadWrite scope. It is not in the default set because Microsoft marks it admin-consent required, so an administrator grants it first (teams auth consent-url --scopes ...) and you then sign in with it. A PERMISSION_DENIED on a channel target says so unless your token already carries the scope.

Inline images are capped at 3 MB each and 4 MB combined after base64 encoding. File attachments use Microsoft Graph's 250 MB simple-upload limit. See Message Attachments for storage, scope, and download details.

Prerequisites​

Prerequisites