channels.history

Fetches history of messages and events from a channel.

Facts

Method URL: https://slack.com/api/channels.history

Preferred HTTP method: GET

Accepted content types: application/x-www-form-urlencoded

Rate limiting: Tier 3

Works with:

Token type	Required scope(s)
bot	`bot`
user	`channels:history`

This method returns a portion of message events from the specified public channel.

To read the entire history for a channel, call the method with no latest or oldest arguments, and then continue paging using the instructions below.

To retrieve a single message, set latest to the message’s ts value, inclusive to true, and dial your count down to 1.

Arguments

Argument	Example	Required	Description
`token`	`xxxx-xxxxxxxxx-xxxx`	Required	Authentication token bearing required scopes.
`channel`	`C1234567890`	Required	Channel to fetch history for.
`count`	`100`	Optional, default=100	Number of messages to return, between 1 and 1000.
`inclusive`	`true`	Optional, default=0	Include messages with latest or oldest timestamp in results.
`latest`	`1234567890.123456`	Optional, default=now	End of time range of messages to include in results.
`oldest`	`1234567890.123456`	Optional, default=0	Start of time range of messages to include in results.
`unreads`	`true`	Optional, default=0	Include `unread_count_display` in the output?

Present arguments as parameters in application/x-www-form-urlencoded querystring or POST body. This method does not currently accept application/json.

Response

Typical success response containing the channel's history

{
    "ok": true,
    "latest": "1358547726.000003",
    "messages": [
        {
            "type": "message",
            "ts": "1358546515.000008",
            "user": "U2147483896",
            "text": "Hello"
        },
        {
            "type": "message",
            "ts": "1358546515.000007",
            "user": "U2147483896",
            "text": "World",
            "is_starred": true,
            "reactions": [
                {
                    "name": "space_invader",
                    "count": 3,
                    "users": [
                        "U1",
                        "U2",
                        "U3"
                    ]
                },
                {
                    "name": "sweet_potato",
                    "count": 5,
                    "users": [
                        "U1",
                        "U2",
                        "U3",
                        "U4",
                        "U5"
                    ]
                }
            ]
        },
        {
            "type": "something_else",
            "ts": "1358546515.000007"
        },
        {
            "text": "Containment unit is 98% full",
            "username": "ecto1138",
            "bot_id": "B19LU7CSY",
            "attachments": [
                {
                    "text": "Don't get too attached",
                    "id": 1,
                    "fallback": "This is an attachment fallback"
                }
            ],
            "type": "message",
            "subtype": "bot_message",
            "ts": "1503435956.000247"
        }
    ],
    "has_more": false
}

Error response when the specified channel cannot be found

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

Navigating through collections of messages

The messages array contains up to 100 messages between latest and oldest. If there were more than 100 messages between those two points, then has_more will be true.

Provide timestamps in latest and oldest to specify the period in channel’s history you want to cover. If a message has the same timestamp as latest or oldest it will not be included in the list, unless inclusive is true. The inclusive parameter is ignored when latest or oldest is not specified.

If the response includes has_more then the client can make another call, using the ts value of the final messages as the latest param to get the next page of messages.

If there are more than 100 messages between the two timestamps then the messages returned are the ones closest to latest. In most cases an application will want the most recent messages and will page backward from there. If oldest is provided but not latest then the messages returned are those closest to oldest, allowing you to page forward through history if desired.

Retrieving a single message

channels.history can also be used to pluck a single message from the archive.

You'll need a message's ts value, uniquely identifying it within a channel. You'll also need that channel's ID.

Provide another message's ts value as the latest parameter. Specify true for the inclusive parameter and set the count to 1. If it exists, you'll receive the queried message in return.

GET /api/channels.history?token=TOKEN_WITH_CHANNELS_HISTORY_SCOPE&channel=C2EB2QT8A&latest=1476909142.000007&inclusive=true&count=1

Easily generate a permalink URL for any specific message using chat.getPermalink.

Message types

Messages of type "message" are user-entered text messages sent to the channel, while other types are events that happened within the channel. All messages have both a type and a sortable ts, but the other fields depend on the type. For a list of all possible events, see the channel messages documentation.

Messages that have been reacted to by team members will have a reactions array delightfully included.

If a message has been starred by the calling user, the is_starred property will be present and true. This property is only added for starred items, so is not present in the majority of messages.

The is_limited boolean property is only included for free teams that have reached the free message limit. If true, there are messages before the current result set, but they are beyond the message limit.

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.

Error	Description
`channel_not_found`	Value passed for `channel` was invalid.
`invalid_ts_latest`	Value passed for `latest` was invalid
`invalid_ts_oldest`	Value passed for `oldest` was invalid
`not_authed`	No authentication token provided.
`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.
`account_inactive`	Authentication token is for a deleted user or workspace.
`token_revoked`	Authentication token is for a deleted user or workspace or the app has been removed.
`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.
`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_array_arg`	The method was passed a PHP-style array argument (e.g. with a name like `foo[7]`). These are never valid with the Slack API.
`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/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.
`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.
`request_timeout`	The method was called via a `POST` request, but the `POST` data was either missing or truncated.
`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.

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.

Warning	Description
`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.