--- title: "Knap Template Renderer" description: "Write a Knap template, paste JSON data, and get Markdown. Knap is the Liquid-style template language behind Obsidian Web Clipper and Importer, with 70 Markdown-aware filters for headings, tables, wikilinks and YAML frontmatter. The engine runs in your browser with no eval, and the same renderer is available over the FindUtils API and MCP server." url: https://findutils.com/developers/knap-template-renderer/ category: developers --- # Knap Template Renderer Write a Knap template, paste JSON data, and get Markdown. Knap is the Liquid-style template language behind Obsidian Web Clipper and Importer, with 70 Markdown-aware filters for headings, tables, wikilinks and YAML frontmatter. The engine runs in your browser with no eval, and the same renderer is available over the FindUtils API and MCP server. **Use this tool:** [Knap Template Renderer](https://findutils.com/developers/knap-template-renderer/) ## Programmatic access - Browser-only: this tool works on a file, the DOM, or a browser API and has no REST or MCP id. ## Why Render Knap Templates Here? Knap is the template language that Obsidian Web Clipper and Obsidian Importer use to turn a web page or an imported record into a Markdown note: variables in double braces, filters after a pipe, if and for blocks, and a set of filters that know Markdown, so a list of names becomes a table, a tag becomes a wikilink, and a field becomes a YAML frontmatter line. Writing a template inside the Clipper's settings is slow, because every change means clipping a page again. This page is the loop you actually want: template on the left, data in the middle, Markdown on the right, rendered as you type, with each error reported at its line and column. The engine is the MIT knap package, an AST interpreter with no eval, and it runs entirely in your browser. ## Frequently Asked Questions ### What is Knap? Knap is a template language for producing Markdown, published by the Obsidian team under the MIT licence at knap.md. It is the engine behind the templates in Obsidian Web Clipper and Obsidian Importer. A template mixes literal Markdown with {{ variables }}, filters after a pipe, {% if %} and {% for %} blocks, and comments in {# #}. Its filters know Markdown: they can write headings, tables, wikilinks, callouts and YAML frontmatter lines from plain data. ### How do I write a variable, a filter and a loop? A variable is {{ title }}; a nested value is {{ book.author }}. A filter follows a pipe, with colon-separated quoted arguments: {{ published | date:"YYYY-MM-DD" }} or {{ tags | join:", " }}, and filters chain left to right. A loop is {% for item in items %} ... {% endfor %}, with loop.index, loop.index0, loop.first and loop.last available inside. A condition is {% if author %} ... {% elseif site %} ... {% else %} ... {% endif %}, with ==, !=, and, or, not, contains and parentheses. ### Which filters are available? The standard set of the knap package, which the page lists under the editors from the running engine so the list is always exact. It covers Markdown formatting (bold, italic, code, code_block, h1 to h6, blockquote, callout, list, table, link, image, wikilink, footnote, yaml, yaml_property), text (trim, upper, lower, capitalize, title, kebab, snake, camel, replace, truncate, indent), dates (date, date_modify, duration), numbers (calc, number_format, round), collections (join, split, sort, unique, where, map, first, last, slice, compact, sum) and HTML cleanup (strip_tags, remove_tags, html_to_json). The DOM-dependent filters from knap/html are not loaded. ### What does the data panel expect? One JSON object. Each top-level key becomes a variable, so {"title": "Deep Work", "tags": ["books"]} makes {{ title }} and {{ tags }} available, and nested objects and arrays are reached with dots and loops. A JSON syntax error is shown under the data panel with the parser's message. An empty panel renders the template with no variables, which is a quick way to see which placeholders it uses. ### Is the template run as code? No. Knap is an AST interpreter: the template is parsed into a tree and evaluated node by node. No JavaScript is generated or evaluated, and this page creates the engine with native regular expressions disabled. The link and image filters escape their labels and drop javascript:, vbscript: and data: destinations. The Preview tab renders inside a sandboxed frame that may not load scripts, images from the network, or fonts. ### How do I write YAML frontmatter? Put the three dashes in the template and use yaml_property for the lines. {{ tags | wikilink | yaml_property:"tags" }} writes tags: followed by one quoted [[wikilink]] per item, which is what Obsidian expects in a note's properties. A plain string works too: {{ year | yaml_property:"year" }}. The sample template on this page starts that way. ### Can I use this to test an Obsidian Web Clipper template? Yes, for the template logic. Paste the template and a JSON object with the variables the Clipper would provide, such as title, author, published, description, content and tags, and iterate here instead of clipping a page after each change. The Clipper's own variable extraction, such as selectors and schema lookups, happens in the extension and is not simulated on this page. ### Is my template or data uploaded? No. The knap package is fetched once as a script, and after that the template, the data and the rendered Markdown stay in your browser; no request carries them. You can confirm that in the browser's network panel while editing. ### Can I render Knap templates from a script or an AI agent? Yes. The same code runs on the FindUtils API and MCP server as the knap_render tool. Send the template text and a JSON object of variables, optionally trim_output, and read the Markdown from the markdown field along with any warnings. A syntax error comes back with its line and column. Templates are capped at 200,000 characters and output at 1,000,000. ### How is this different from a Liquid or Handlebars template? The shape is the same as Liquid: double braces, pipes, if and for tags. The differences are the filter set, which is written for Markdown rather than HTML, the colon-and-quotes argument syntax (date:"YYYY-MM-DD" rather than date: "%Y-%m-%d"), elseif rather than elsif, loop.* rather than forloop.*, and the ?? fallback operator. The JSON to Liquid tool on this site can convert a Knap template into Shopify Liquid and lists the constructs that do not map. ## Related Tools - [JSON to Liquid](https://findutils.com/developers/json-to-liquid/) - [Markdown Previewer](https://findutils.com/developers/markdown-previewer/) - [JSON to Markdown Table](https://findutils.com/convert/json-to-markdown-table/) - [JSON Formatter](https://findutils.com/developers/json-formatter/) - [JSON to TypeScript](https://findutils.com/developers/json-to-typescript/) - [JSON YAML Converter](https://findutils.com/developers/json-yaml-converter/)