The reason to use this over asking a model for raw HTML is the edit path: a line-range replacement sends only the replacement, and reading a page back in text mode returns roughly a thousandth-scale summary of a 106KB file rather than the file. That is what makes a build-inspect-refine loop affordable enough to run several times.
An MCP server that builds and edits HTML files, so an agent's output arrives as a page you can scan and share rather than a wall of markdown. Pages are assembled from named components against a template shell, and every later change is surgical: patch by CSS selector, set an attribute, replace a line range, or swap one rendered section. It works on strings and an AST — no headless browser is involved.
- A page assembled from structured components and a template shell, previewed before it is written to disk — `render_page`, `preview_html`
- The available templates and components listed, with their variables, defaults and props — `list_templates`, `list_components`, `get_template_schema`, `get_component_schema`
- Element content replaced by CSS selector and attributes set the same way — `patch_html`, `set_attribute`
- A line range replaced outright, which is the cheapest edit because only the new content is sent — `edit_html_range`
- Rendered sections listed, replaced and inserted by index, since pages built this way carry their section boundaries — `list_sections`, `edit_section`, `insert_section`
- Existing HTML read back in several modes, including a plain-text mode with offsets for token-minimal inspection — `read_html`
- Raw HTML written straight to a file, and an existing file beautified — `write_raw_html`, `write_html_file`, `format_html`
- An entity edit propagated through the dependency graph to every section that references it, and the document audited for stale cross-references — `propagate_edit`, `check_consistency`
- Your own template registered at run time and usable immediately — `register_template`
No account and no key; files are written to your own disk. Node.js 20 or newer, launched with `npx -y @aimino/fast-html-mcp-server` over stdio; the MCP registry entry for the same server points at `@aimino/opentalk2html-notmd` 0.1.2. 22 components and the template shells ship with the package, so there is nothing to fetch at render time. Output passes through DOMPurify and files are written tmp-then-rename, so an interrupted write does not corrupt the page. Licensed under the GNU General Public License v3.0.
One command — npx -y @aimino/fast-html-mcp-server