| slack_token | Slack token, must has files:write permission | yes | — |
| slack_api_url | Custom slack api url | — | — |
| channel_id | Slack channel id. | — | — |
| content | File contents via a POST variable. If omitting this parameter, you must provide a file. | — | — |
| file_path | File contents via multipart/form-data. If omitting this parameter, you must submit content. | — | — |
| file_path_follow_symbolic_links | Indicates whether to follow symbolic links | — | true |
| file_name | Filename of file. | — | — |
| file_type | A file type identifier. | — | — |
| if_no_files_found | file not founding options: warn, error or ignore. alike actions/upload-artifact | — | — |
| initial_comment | The message text introducing the file in specified channels. | — | — |
| thread_ts | Provide another message`s ts value to upload this file as a reply. Never use a reply`s ts value; use its parent instead. | — | — |
| title | Title of file. | — | — |
| retries | max API retry count. default retries is 3 | — | — |
| delete_file_ids_before_upload | file deletion before upload. comma separeted file ids. this argument is purpose for previous uploaded file replacement. | — | — |