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files.getUploadURLExternal method

Facts​

DescriptionGets a URL for an edge external file upload
Method Access
POST https://slack.com/api/files.getUploadURLExternal
Scopes
Bot token:
User token:
Content types
application/x-www-form-urlencoded
application/json
Rate LimitsTier 4: 100+ per minute

Arguments​

Required arguments

tokenstringRequired

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

Example: xxxx-xxxxxxxxx-xxxx
lengthintegerRequired

Size in bytes of the file being uploaded.

Example: 53072
filenamestringRequired

Name of the file being uploaded.

Example: laughingoutloudcat.jpg

Optional arguments

snippet_typestringOptional

Syntax type of the snippet being uploaded.

Example: python
alt_txtstringOptional

Description of image for screen-reader.

Example: Aerial view of the Bixby Bridge and coastline of the Big Sur area in California

Usage info​

This method gets a URL that can be used for uploading a file to share within channels. The URL allows clients to send file data to Slack's file upload service.

The workflow is as follows:

  1. Call files.getUploadURLExternal, which returns an upload URL and a file ID.
  2. Upload a file by making a POST request to the upload URL. Include the filename (e.g., -F filename="@text.txt"). Files are processed asynchronously via a job handler.
    • Files can be sent as raw bytes or can be multipart form encoded. Slack will return HTTP 200 if the upload is successful; a non-200 response indicates a failure.
  3. Call files.completeUploadExternal to finalize the upload.
    • There is no need to wait for files to be processed by the job handler; the files.completeUploadExternal method will return with no action until both processes have completed. If files.completeUploadExternal is not called, the upload will be aborted and clients will receive an error.

Response​

Typical success response

{
  "ok": true,
  "upload_url": "https://files.slack.com/upload/v1/ABC123...",
  "file_id": "F123ABC456"
}

Typical error response

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

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 parameter in the response.

Error
Description
access_denied

Access to a resource specified in the request is denied.

accesslimited

Access to this method is limited on the current network

account_inactive

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

alt_txt_too_large

Description for the image is longer than the limit of 1000 character

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.

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.

file_upload_size_restricted

The size of provided file is too large, as the team has restricted uploads of large files.

file_uploads_disabled

Team has disabled all file uploads.

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 called with invalid arguments.

invalid_array_arg

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

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.

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.

method_deprecated

The method has been deprecated.

missing_argument

A required argument was not provided. Typically only occurs when the length provided is 0.

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.

missing_scope

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

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.

not_allowed_token_type

The token type used in this request is not allowed.

not_authed

No authentication token provided.

org_login_required

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

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

snippet_too_large

The provided length is too large to create a snippet, which are limited to 1MB.

storage_limit_reached

File storage limit has been reached. This occurs when free teams have uploaded 5GB of files.

team_access_not_granted

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

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.

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.

unknown_snippet_type

The provided snippet_type is not a supported type.

unknown_subtype

The provided subtype is not a supported type.