{
  "schema_version": "1.7.0",
  "id": "x_SHAPI-slack-files-upload-retired",
  "modified": "2026-10-31T01:22:33Z",
  "published": "2025-03-17T00:00:00Z",
  "summary": "files.upload Web API method sunset on 2025-11-12",
  "details": "Slack deprecated files.upload. Apps created on or after 2024-05-16 could not use it, and Slack's reference page says the method stops working and is sunset on 2025-11-12 for existing apps too (the date was moved from 2025-03-11). Code that still uploads through files.upload fails with method_deprecated or deprecated_endpoint errors.\n\nReplace files.upload with the two-step flow: call files.getUploadURLExternal (filename, length) to get an upload_url and file_id, POST the file bytes to upload_url, then call files.completeUploadExternal with the file_id(s) and the channel_id, initial_comment or thread_ts you used to pass to files.upload. The official Slack SDKs wrap this as files_upload_v2 / filesUploadV2 / uploadV2.",
  "affected": [
    {
      "ecosystem_specific": {
        "provider": "slack",
        "endpoint": {
          "method": "POST",
          "path": "/api/files.upload"
        },
        "change_class": "version-sunset",
        "trigger": {
          "any": true
        },
        "effective_date": "2025-11-12"
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://docs.slack.dev/changelog/2025/03/17/files-upload-extension"
    },
    {
      "type": "WEB",
      "url": "https://docs.slack.dev/reference/methods/files.upload"
    },
    {
      "type": "WEB",
      "url": "https://docs.slack.dev/changelog/2024-04-a-better-way-to-upload-files-is-here-to-stay"
    }
  ],
  "database_specific": {
    "severity": "critical",
    "status": "verified",
    "url": "https://shapi.dev/osv/slack-files-upload-retired.json"
  }
}