Updates a message.

An MCP tool from the Slack API server, hosted on mcp.hjlabs.in.

Updates a message. [POST /chat.update]

Name on the gateway: slack_api__chat_update · may change things.

Parameters

Name	Type	Description
`as_user`	`string`	Pass true to update the message as the authed user. Bot users in this context…
`attachments`	`string`	A JSON-based array of structured attachments, presented as a URL-encoded…
`blocks`	`string`	A JSON-based array of structured blocks, presented as a URL-encoded string. If…
`channel` required	`string`	Channel containing the message to be updated.
`link_names`	`string`	Find and link channel names and usernames. Defaults to none. If you do not…
`parse`	`string`	Change how messages are treated. Defaults to client, unlike chat.postMessage.…
`text`	`string`	New text for the message, using the default formatting rules. It's not…
`ts` required	`string`	Timestamp of the message to be updated.

Through the Smart Gateway, any client can run it by name with call_tool, or let the gateway find it with search_tools:

call_tool arguments

{
  "name": "slack_api__chat_update",
  "arguments": {
    "channel": "…",
    "ts": "…"
  }
}

Or connect the Slack API server directly, which lists 174 tools including this one:

Run in your terminal

claude mcp add --transport http hj-slack-api https://mcp.hjlabs.in/mcp/slack-api \
  --header "Authorization: Bearer YOUR_API_KEY"

Use the updates a message. tool with as_user set to ….