File formats and Agent artifacts
Uploading a file, previewing it in the Portal, and generating it with an Agent are separate capabilities.
Chat attachment formats
Chat Room attachments allow up to 50 MiB per file (shown as 50 MB in the UI).
| Category | Supported extensions | Portal preview |
|---|---|---|
| Images | .jpg, .jpeg, .png, .gif, .webp, .bmp | Image preview; download if the browser cannot display it |
| Documents | .pdf, .docx, .xlsx, .pptx, .hwp, .hwpx | PDF preview up to 10 MiB; download the others |
| Text | .txt, .text, .csv, .md, .markdown, .env, .log, .ini, .conf, .cfg, .properties | Text preview; files over 1 MiB show only the first 256 KiB |
| Data and configuration | .json, .jsonl, .yaml, .yml, .toml | Download |
| HTML | .html, .htm | Download; no execution or HTML attachment preview |
| Video | .mp4 | Download; no in-Portal playback |
| Archives | .zip | Download |
Names such as .env and .env.production are recognized. Format support does not authorize sharing secrets: remove API keys and passwords from configuration files before attaching a copy, and follow the secret guide for actual credentials.
Supported extensions are case-insensitive and normalize the MIME type even when the browser supplies an empty or different type. Other filenames may be accepted through the legacy MIME allowlist. .svg, .svgz, .js, .mjs, .cjs, .exe, .msi, .com, .bat, .cmd, .ps1, and .sh are blocked regardless of their MIME type. Renaming an extension neither converts nor validates a file.
Task and Milestone attachments
Task and Milestone attachments retain their separate legacy MIME allowlist and 50 MiB limit: JPEG, PNG, GIF, WebP, BMP, PDF, DOCX, XLSX, PPTX, TXT, CSV, Markdown, HWP, HWPX, and ZIP. Chat's additional HTML, MP4, JSON, YAML, and other formats do not imply the same expansion for Tasks or Milestones.
Preview boundaries
- Text previews support stored MIME types
text/plain,text/csv, andtext/markdown. Files over 1 MiB show only their first 256 KiB. - PDF previews support files up to 10 MiB.
- Image previews support allowed image formats.
- Download other accepted formats. HTML attachments are separate from HTML artifact previews described below.
A preview is not a security scan or complete file validation. Follow organization security procedures before executing or externally sharing received ZIP files, Office documents, or images.
Generated outputs
| Output | Verified path | Limits |
|---|---|---|
| Chat artifact | Markdown or HTML download UI | Only when the Agent responds with an artifact |
| Meeting result | Text or Markdown download UI | Requires the meeting and artifact generation conditions |
| Workspace file | Ready Agent file/CLI tools | Formats depend on tools, image, and policy; not every extension is guaranteed |
| Generated image | OpenAI key and ready image-generation runtime | Check actual MIME type, storage location, and cost in the result |
You may request PDF, DOCX, XLSX, PPTX, or ZIP, but first verify that the selected image, Skill, or runtime has the necessary generator. Accepting a Chat attachment does not prove the Agent can create that format.
Open and download Chat artifacts
Select an artifact card in a Chat message to open its exact version in the Artifact panel. Choose another version if available. Preview Markdown or HTML, copy Markdown or plain text, or download an HTML artifact as .html and other artifacts as .md.
Unauthorized access shows forbidden; a missing version shows not found. Versioned Chat artifacts do not automatically synchronize with Agent workspace files.
Example request
Create this week's summary as
weekly-summary.mdandweekly-summary.csvin/workspace/reports. First check the tools and path permissions. Do not overwrite existing files or transfer data externally. Report the paths and validation results when finished.
Specify filenames, formats, paths, overwrite rules, and external transfers. See the catalog and browser and CLI guide.