Google Chat: Update a message — MCP tool

Google Chat MCP tool: Replaces the text of an existing message the authenticated user sent.

Technical name: update_message

What task it solves

I want to edit a Google Chat message I already sent.

Overwrites the message text (updateMask=text); the message keeps its name and thread, gains lastUpdateTime and an "Edited" marker.

When to use it

Use it to correct or extend a previously sent message instead of posting a duplicate.

What to provide

• message — required. The full message name spaces/<space>/messages/<message>.
• text — required. The new text — it REPLACES the old text entirely.

What it returns

The updated message object.

What changes in Google Chat

The message's previous text is overwritten for every member of the space. This modifies existing data; it is not a read.

Example request

Edit my last status message in spaces/AAAAAAAAAAA to say the incident is resolved.

Errors and limitations

With user authentication only the authenticated user's OWN messages can be edited — editing someone else's returns PERMISSION_DENIED (a Chat ownership rule, not broken auth). Updating cards or accessory widgets needs app auth via raw_request. The old text is not recoverable through this server — read it with get_message first if it matters.

Related MCP tools

• Get a message — get_message
• Send a message — send_message
• Delete a message — delete_message

Technical details

• Impact: destructive operation
• Group: Messages
• Description source: update_message registration in src/tools/messages.ts
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