--- title: Post a Slack message source: https://docs.newrelic.com/docs/workflow-automation/setup-and-configure/actions-catalog/slack/slack-chat-post-message --- Sends a message to a Slack channel with an optional file attachment. For prerequisites, see [Slack chat actions](https://docs.newrelic.com/docs/workflow-automation/setup-and-configure/actions-catalog/slack/slack-chat#prerequisites). ## Post a message The action identifier is `slack.chat.postMessage`. Sends a message to a Slack channel, with an optional file attachment. ### Inputs The following table describes all available input fields for this action. | Input | Type | Description | Example | | ----------------------- | ------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------- | | **token** | Secret | **Required.** The Slack bot token to use. This should be passed as a secret syntax. Refer to [Add Slack configuration](https://docs.newrelic.com/docs/workflow-automation/setup-and-configure/actions-catalog/slack/slack-chat#slack-configuration) for instructions on setting up a token. | `${{ :secrets:slackToken }}` | | **channel** | String | **Required.** The name of the channel, or a channelID, to send the message. See [Slack API](https://docs.slack.dev/reference/methods/chat.postMessage/#arg_channel) for more information. | `my-slack-channel` | | **text** | String | **Required.** The message to be posted to Slack in the specified `channel`. | `Hello World!` | | **threadTs** | String | **Optional.** Timestamp belonging to parent message, used to create a message reply in a thread. | `.` | | **attachment** | Map | **Optional.** Allows attaching a file with a message onto the specified `channel`. | | | **attachment.filename** | String | **Required** when using `attachment`. Specify the filename for the uploaded file in Slack. | `file.txt` | | **attachment.content** | String | **Required** when using `attachment`. The content of the file to upload as UTF8. | `Hello\nWorld!` | | **selectors** | List | **Optional.** The selectors to get only the specified parameters as output. | `[{\"name\": \"threadTs\", \"expression\": \".threadTs\"}, {\"name\": \"channelID\", \"expression\": \".channelID\"}]` | ### Outputs The following table describes all output fields returned by this action. | Output | Type | Description | | ---------------- | ------- | ------------------------------------------------------------------------------------------------------------------------------------- | | **threadTs** | String | Timestamp of the message thread. May be used in future `postMessage` calls to post a reply in a thread. Example: `.`. | | **channelID** | String | ID of the channel where the message is posted. | | **success** | Boolean | `true` on success, `false` on failure. | | **errorMessage** | String | Failure reason as message. `null` on success. | ### Example **Example 1: Send a Slack message** | Workflow example | | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | ```yaml name: SendMessage steps: - name: send_slack_message type: action action: slack.chat.postMessage version: 1 inputs: token: ${{ :secrets:dn_staging_slack_token }} channel: ${{ .workflowInputs.channel }} text: ${{ .workflowInputs.text }} selectors: - name: threadTs expression: ".threadTs" - name: channelID expression: ".channelID" ``` **Inputs:** ```json { "inputs": [ { "key" : "channel", "value" : "test-channel-workflow" }, { "key" : "text", "value" : "This is my message *with bold text* and `code backticks`" } ] } ``` **Expected output:** ```json [ { "threadTs": "1718897637.400609", "channelID": "C063JK1RHN1", "success": true } ] ``` | **Example 2: Attach a file** | Workflow example | | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | | ```yaml name: SendFileMessage steps: - name: postCsv type: action action: slack.chat.postMessage version: 1 inputs: token: ${{ :secrets:dn_staging_slack_token }} channel: test-channel-workflow text: "Please find the attached file:" attachment: filename: 'file.txt' content: "Hello\nWorld!" ``` **Expected output:** ```json [ { "threadTs": "1718897637.400609", "channelID": "C063JK1RHN1", "success": true } ] ``` |