Schedules a message to be sent to a channel.

Facts

Method access

HTTP
JavaScript
Python
Java
HTTP
POSThttps://slack.com/api/chat.scheduleMessage
Bolt for Java
app.client().chatScheduleMessage
Powered by Bolt
Bolt for Python
app.client.chat_scheduleMessage
Powered by Bolt
Bolt for JavaScript
app.client.chat.scheduleMessage
Powered by Bolt

Content types

application/x-www-form-urlencodedapplication/json
  • Rate limits

    Tier 3
  • Arguments

    Required arguments

    Authentication token bearing required scopes. Tokens should be passed as an HTTP Authorization header or alternatively, as a POST parameter.

    Example
    xxxx-xxxxxxxxx-xxxx

    Channel, private group, or DM channel to send message to. Can be an encoded ID, or a name. See below for more details.

    Example
    C1234567890

    Unix timestamp representing the future time the message should post to Slack.

    Example
    299876400

    If attachments or blocks are also included, text will be used as fallback text for notifications only.

    A JSON-based array of structured attachments, presented as a URL-encoded string.

    Example
    [{"pretext": "pre-hello", "text": "text-world"}]

    A JSON-based array of structured blocks, presented as a URL-encoded string.

    Example
    [{"type": "section", "text": {"type": "plain_text", "text": "Hello world"}}]

    How this field works and whether it is required depends on other fields you use in your API call. See below for more detail.

    Example
    Hello world
    Optional arguments

    Set to true to post the message as the authed user, instead of as a bot. Defaults to false. Cannot be used by new Slack apps. See chat.postMessage.

    Example
    true

    Find and link user groups. No longer supports linking individual users; use syntax shown in Mentioning Users instead.

    Example
    true

    JSON object with event_type and event_payload fields, presented as a URL-encoded string. Metadata you post to Slack is accessible to any app or user who is a member of that workspace.

    Example
    {"event_type": "task_created", "event_payload": { "id": "11223", "title": "Redesign Homepage"}}

    Change how messages are treated. See chat.postMessage.

    Value should be one ofnonefull
    Example
    full

    Used in conjunction with thread_ts and indicates whether reply should be made visible to everyone in the channel or conversation. Defaults to false.

    Example
    true

    Provide another message's ts value to make this message a reply. Avoid using a reply's ts value; use its parent instead.

    Pass true to enable unfurling of primarily text-based content.

    Example
    true

    Pass false to disable unfurling of media content.

    Example
    false

    Usage info

    Bug alert
    Messages scheduled with chat.scheduleMessage will not post if the metadata parameter is used.

    This method schedules a message for delivery to a public channel, private channel, or direct message (DM, or IM) conversation at a specified time in the future.

    Think of chat.scheduleMessage and chat.postMessage as two siblings in the Slack family. They aren't twins, but they still share many similarities, such as their ability to send messages and include various features like attachments and emojis.

    The text, blocks and attachments fields

    The usage of the text field changes depending on whether you're using blocks. If you're using blocks, this is used as a fallback string to display in notifications. If you aren't, this is the main body text of the message. It can be formatted as plain text, or with mrkdwn.

    Restrictions

    You will only be able to schedule a message up to 120 days into the future. If you specify a post_at timestamp beyond this limit, you’ll receive a time_too_far error response. Additionally, you cannot schedule more than 30 messages to post within a 5-minute window to the same channel. Exceeding this will result in a restricted_too_many error.

    The response includes the scheduled_message_id assigned to your message. Use it with the chat.deleteScheduledMessage method to delete the message before it is sent.

    For details on formatting, usage in threads, and rate limiting, check out chat.postMessage documentation.

    Channels

    You must specify a public channel, private channel, or DM conversation with the channel argument. Each one behaves slightly differently based on the authenticated user's permissions and additional arguments:

    Post to a channel

    You can either pass the channel's name (#general) or encoded ID (C123ABC456), and the message will be posted to that channel. The channel's ID can be retrieved through the channels.list API method.

    Post to a DM

    Pass the DM conversation's channel ID (D123ABC456) or a user's user ID (U123ABC456) as the value of channel to post to that DM conversation.

    The DM conversation's channel ID can be retrieved through the conversations.list API method. Use the types parameters to return only im conversations.

    You might receive a channel_not_found error if your app doesn't have permission to enter into an IM with the intended user.

    Example responses

    Common successful response

    Typical success response

    {
        "ok": true,
        "channel": "C123ABC456",
        "scheduled_message_id": "Q1298393284",
        "post_at": "1562180400",
        "message": {
            "text": "Here's a message for you in the future",
            "username": "ecto1",
            "bot_id": "B123ABC456",
            "attachments": [
                {
                    "text": "This is an attachment",
                    "id": 1,
                    "fallback": "This is an attachment's fallback"
                }
            ],
            "type": "delayed_message",
            "subtype": "bot_message"
        }
    }

    Common error response

    Typical error response if the post_at is invalid (ex. in the past or too far into the future)

    {
        "ok": false,
        "error": "time_in_past"
    }

    Errors

    This table lists the expected errors that this method could return. However, other errors can be returned in the case where the service is down or other unexpected factors affect processing. Callers should always check the value of the ok params in the response.

    ErrorDescription
    channel_not_found

    Value passed for channel was invalid.

    is_archived

    Channel has been archived.

    invalid_blocks

    Blocks submitted with this message are not valid

    invalid_blocks_format

    The blocks is not a valid JSON object or doesn't match the Block Kit syntax.

    invalid_metadata_format

    Invalid metadata format provided

    invalid_metadata_schema

    Invalid metadata schema provided

    invalid_time

    value passed for post_time was invalid.

    message_limit_exceeded

    Members on this team are sending too many messages. For more details, see https://slack.com/help/articles/115002422943-Usage-limits-for-free-workspaces

    metadata_must_be_sent_from_app

    Message metadata can only be posted or updated using an app-level token

    metadata_too_large

    Metadata exceeds size limit

    msg_too_long

    Message text is too long

    no_text

    No message text provided

    not_in_channel

    Cannot post user messages to a channel they are not in.

    rate_limited

    Application has posted too many messages, read the Rate Limit documentation for more information

    restricted_action

    A workspace preference prevents the authenticated user from posting.

    restricted_action_non_threadable_channel

    Cannot post thread replies into a non_threadable channel.

    restricted_action_read_only_channel

    Cannot post any message into a read-only channel.

    restricted_action_thread_only_channel

    Cannot post top-level messages into a thread-only channel.

    restricted_too_many

    Too many messages were scheduled in the channel for a given period. See usage info for additional details

    slack_connect_file_link_sharing_blocked

    Admin has disabled Slack File sharing in all Slack Connect communications

    time_in_past

    value passed for post_time was in the past.

    time_too_far

    value passed for post_time was too far into the future.

    too_many_attachments

    Too many attachments were provided with this message. A maximum of 100 attachments are allowed on a message.

    access_denied

    Access to a resource specified in the request is denied.

    account_inactive

    Authentication token is for a deleted user or workspace when using a bot token.

    deprecated_endpoint

    The endpoint has been deprecated.

    ekm_access_denied

    Administrators have suspended the ability to post a message.

    enterprise_is_restricted

    The method cannot be called from an Enterprise.

    invalid_auth

    Some aspect of authentication cannot be validated. Either the provided token is invalid or the request originates from an IP address disallowed from making the request.

    method_deprecated

    The method has been deprecated.

    missing_scope

    The token used is not granted the specific scope permissions required to complete this request.

    not_allowed_token_type

    The token type used in this request is not allowed.

    not_authed

    No authentication token provided.

    no_permission

    The workspace token used in this request does not have the permissions necessary to complete the request. Make sure your app is a member of the conversation it's attempting to post a message to.

    org_login_required

    The workspace is undergoing an enterprise migration and will not be available until migration is complete.

    token_expired

    Authentication token has expired

    token_revoked

    Authentication token is for a deleted user or workspace or the app has been removed when using a user token.

    two_factor_setup_required

    Two factor setup is required.

    team_access_not_granted

    The token used is not granted the specific workspace access required to complete this request.

    accesslimited

    Access to this method is limited on the current network

    fatal_error

    The server could not complete your operation(s) without encountering a catastrophic error. It's possible some aspect of the operation succeeded before the error was raised.

    internal_error

    The server could not complete your operation(s) without encountering an error, likely due to a transient issue on our end. It's possible some aspect of the operation succeeded before the error was raised.

    invalid_arg_name

    The method was passed an argument whose name falls outside the bounds of accepted or expected values. This includes very long names and names with non-alphanumeric characters other than _. If you get this error, it is typically an indication that you have made a very malformed API call.

    invalid_arguments

    The method was either called with invalid arguments or some detail about the arguments passed is invalid, which is more likely when using complex arguments like blocks or attachments.

    invalid_array_arg

    The method was passed an array as an argument. Please only input valid strings.

    invalid_charset

    The method was called via a POST request, but the charset specified in the Content-Type header was invalid. Valid charset names are: utf-8 iso-8859-1.

    invalid_form_data

    The method was called via a POST request with Content-Type application/x-www-form-urlencoded or multipart/form-data, but the form data was either missing or syntactically invalid.

    invalid_post_type

    The method was called via a POST request, but the specified Content-Type was invalid. Valid types are: application/json application/x-www-form-urlencoded multipart/form-data text/plain.

    missing_post_type

    The method was called via a POST request and included a data payload, but the request did not include a Content-Type header.

    ratelimited

    The request has been ratelimited. Refer to the Retry-After header for when to retry the request.

    request_timeout

    The method was called via a POST request, but the POST data was either missing or truncated.

    service_unavailable

    The service is temporarily unavailable

    team_added_to_org

    The workspace associated with your request is currently undergoing migration to an Enterprise Organization. Web API and other platform operations will be intermittently unavailable until the transition is complete.

    Warnings

    This table lists the expected warnings that this method will return. However, other warnings can be returned in the case where the service is experiencing unexpected trouble.

    WarningDescription
    message_truncated

    The text field of a message should have no more than 40,000 characters. We truncate really long messages.

    missing_charset

    The method was called via a POST request, and recommended practice for the specified Content-Type is to include a charset parameter. However, no charset was present. Specifically, non-form-data content types (e.g. text/plain) are the ones for which charset is recommended.

    superfluous_charset

    The method was called via a POST request, and the specified Content-Type is not defined to understand the charset parameter. However, charset was in fact present. Specifically, form-data content types (e.g. multipart/form-data) are the ones for which charset is superfluous.

    Arguments

    Need a token? Create and install a Slack app to begin.
    This will make a real API request. Beware of using it with live workspaces.

    API response


    Submit your arguments to see the API response
    Scheduling a message
    Java
    JavaScript
    Python
    HTTP
    Java
    import com.slack.api.bolt.App; import com.slack.api.bolt.AppConfig; import com.slack.api.bolt.jetty.SlackAppServer; import com.slack.api.methods.SlackApiException; import java.io.IOException; import java.time.ZonedDateTime; import java.time.temporal.ChronoUnit; public class ChatScheduleMessage { public static void main(String[] args) throws Exception { var config = new AppConfig(); config.setSingleTeamBotToken(System.getenv("SLACK_BOT_TOKEN")); config.setSigningSecret(System.getenv("SLACK_SIGNING_SECRET")); var app = new App(config); // `new App()` does the same app.command("/schedule", (req, ctx) -> { var logger = ctx.logger; var tomorrow = ZonedDateTime.now().truncatedTo(ChronoUnit.DAYS).plusDays(1).withHour(9); try { var payload = req.getPayload(); // Call the chat.scheduleMessage method using the built-in WebClient var result = ctx.client().chatScheduleMessage(r -> r // The token you used to initialize your app .token(ctx.getBotToken()) .channel(payload.getChannelId()) .text(payload.getText()) // Time to post message, in Unix Epoch timestamp format .postAt((int) tomorrow.toInstant().getEpochSecond()) ); // Print result logger.info("result: {}", result); } catch (IOException | SlackApiException e) { logger.error("error: {}", e.getMessage(), e); } // Acknowledge incoming command event return ctx.ack(); }); var server = new SlackAppServer(app); server.start(); } }
    JavaScript
    Code to initialize Bolt app
    // Require the Node Slack SDK package (github.com/slackapi/node-slack-sdk) const { WebClient, LogLevel } = require("@slack/web-api"); // WebClient instantiates a client that can call API methods // When using Bolt, you can use either `app.client` or the `client` passed to listeners. const client = new WebClient("xoxb-your-token", { // LogLevel can be imported and used to make debugging simpler logLevel: LogLevel.DEBUG });
    // Unix timestamp for tomorrow morning at 9AM const tomorrow = new Date(); tomorrow.setDate(tomorrow.getDate() + 1); tomorrow.setHours(9, 0, 0); // Channel you want to post the message to const channelId = "C12345"; try { // Call the chat.scheduleMessage method using the WebClient const result = await client.chat.scheduleMessage({ channel: channelId, text: "Looking towards the future", // Time to post message, in Unix Epoch timestamp format post_at: tomorrow.getTime() / 1000 }); console.log(result); } catch (error) { console.error(error); }
    Python
    Code to initialize Bolt app
    import datetime import logging import os # Import WebClient from Python SDK (github.com/slackapi/python-slack-sdk) from slack_sdk import WebClient from slack_sdk.errors import SlackApiError # WebClient instantiates a client that can call API methods # When using Bolt, you can use either `app.client` or the `client` passed to listeners. client = WebClient(token=os.environ.get("SLACK_BOT_TOKEN")) logger = logging.getLogger(__name__)
    # Create a timestamp for tomorrow at 9AM tomorrow = datetime.date.today() + datetime.timedelta(days=1) scheduled_time = datetime.time(hour=9, minute=30) schedule_timestamp = datetime.datetime.combine(tomorrow, scheduled_time).strftime('%s') # Channel you want to post message to channel_id = "C12345" try: # Call the chat.scheduleMessage method using the WebClient result = client.chat_scheduleMessage( channel=channel_id, text="Looking towards the future", post_at=schedule_timestamp ) # Log the result logger.info(result) except SlackApiError as e: logger.error("Error scheduling message: {}".format(e))
    HTTP
    POST https://slack.com/api/chat.scheduleMessage Content-type: application/json Authorization: Bearer xoxb-your-token { "channel": "YOUR_CHANNEL_ID", "text": "Hey, team. Don't forget about breakfast catered by John Hughes Bistro today.", "post_at": 1551891428, }