generate-file

Generate File Skill

Produce a downloadable file artifact from chat. The agent picks the format (Markdown for portable text, HTML for styled / print-ready output), drafts the content, then calls the create_file tool. The file appears in chat as an inline download card and can be previewed via the Peek panel.

Phase: 87.1 (foundation — MD + HTML only). DOCX / XLSX land in 87.2; PDF in 87.3.

Quick Start

Use this skill when the user asks for any of:

• A file, an export, a download
• A "report", "summary", "doc", "spec", "README"
• A styled / printable / formatted document
• "Save this as a file" / "give me a downloadable version"
• A standalone deliverable (resume, proposal, meeting notes, retro doc)

Format Choice

Strict decision rule — pick exactly one based on intent:

Use md when…	Use html when…
Content is editable / portable plain text	Output needs visual styling or layout
User will paste into another markdown surface (notes, GitHub, Slack)	User wants a print-ready or shareable rendered doc
Headings, bullet lists, code blocks are enough	Tables need cell styling, page breaks, color, custom fonts
Examples: specs, READMEs, summaries, meeting notes, brain-dump exports	Examples: status report, formatted retrospective, styled receipt, dashboard snapshot

When uncertain, prefer md — it is portable and the user can always export to HTML later. Do not invent other formats; this phase only supports md and html.

Tool Reference

create_file(
  filename: string,    # suggested name; sanitised server-side
  content: string,     # UTF-8 body, must be non-empty and ≤ 10 MB encoded
  format: "md" | "html"
)

Returns: { artifact_id, filename, mime_type, size_bytes, format }.

Constraints

• Max 10 MB per file. Content over the limit is rejected with FILE_TOO_LARGE before any storage I/O.
• Filename is sanitised server-side. Path components (../etc/...), control characters, and unsafe characters are stripped. The extension is forced to match format, so the agent cannot smuggle e.g. report.exe.md.
• Empty content is rejected with EMPTY_FILE.
• MIME map is server-controlled. format='md' maps to text/markdown, format='html' to text/html. The model cannot override the MIME type.
• Auto-executes without approval prompt. This is an intentional UX deviation from create_note / create_issue (which require approval). Rationale: file generation is non-destructive content creation the user explicitly requested in conversation; the file is private to the requester until they share it. Document this when explaining the action to the user ("I generated the file — here's the download").
• HTML rendered in a sandboxed iframe on preview. Do NOT include <script> tags, external script references, or javascript: URLs in HTML content — the preview iframe explicitly does not allow scripts.