TagBites.Text.Markdown

TagBites.Text.Markdown is a C# library for programmatically building Markdown documents. A document is a tree of typed elements. The generated output follows CommonMark, supports GitHub Flavored Markdown tables, task lists, and some Markdig extensions.

Try it online - paste Markdown and read the C# code that rebuilds it.

Install

dotnet add package TagBites.Text.Markdown

Targets netstandard2.0. No dependencies.

Usage

var doc = new MarkdownDocument();
doc.AddHeader(1, "TagBites.Expressions");
doc.AddHeader(2, "Options");

doc.AddParagraph("Every option is set on ExpressionParserOptions.");

doc.AddTable()
    .SetHeaders("Option", "Purpose")
    .WithRow("Parameters", "names the inputs")
    .WithRow("StaticImports", "acts like using static");

doc.AddParagraph("What the parser accepts:");

doc.AddList()
    .WithCheckItem(true, "operators and precedence")
    .WithCheckItem(true, "pattern matching and tuples")
    .WithCheckItem(true, "lambdas and LINQ")
    .WithCheckItem(false, "statements");

var markdown = doc.ToString();

ToString returns the whole document. WriteTo sends it to a Stream or a TextWriter as it is produced, so a large document never has to fit in memory:

using var file = File.Create("readme.md");
doc.WriteTo(file);

A stream receives UTF-8 without a byte order mark and stays open.

Output:

# TagBites.Expressions

## Options

Every option is set on ExpressionParserOptions.

| Option        | Purpose                |
| ------------- | ---------------------- |
| Parameters    | names the inputs       |
| StaticImports | acts like using static |

What the parser accepts:

- [x] operators and precedence
- [x] pattern matching and tuples
- [x] lambdas and LINQ
- [ ] statements

Elements

• headers (AddHeader), with optional custom id
• paragraphs (AddParagraph)
• code blocks (AddCode), with optional language
• quotes (AddQuote), multiline and nestable
• unordered lists (AddList)
• ordered lists (AddList(isOrdered: true))
• task lists (AddCheckItem), a check box on any list item
• tables (AddTable), with padded columns, column alignment and cell escaping
• thematic breaks (AddThematicBreak)
• raw HTML blocks (AddHtml)

MarkdownDocument, MarkdownSection, MarkdownQuote and MarkdownListItem hold any block element. MarkdownList holds items and MarkdownTable holds cells. Every other element is a leaf.

Method prefixes:

Prefix	Effect	Returns
Add*	Appends a new element	The new element
With*	Appends a new element	The same object
Set*	Replaces a value	The same object

Add* goes one level deeper, With* and Set* stay put, so a whole document fits in one expression:

var doc = new MarkdownDocument()
    .WithHeader(1, "Title")
    .WithParagraph("Intro.")
    .WithElement(new MarkdownList()
        .WithItem("a")
        .WithItem("b"));

There is no WithList or WithTable, because it would produce an empty element. So build those first and pass them as argument to WithElement.

Sections

A section is a header plus everything under it, and the level comes from the nesting:

var root = doc.AddSection("TagBites.Text.Markdown");
root.AddParagraph("C# library for building Markdown.");

var usage = root.AddSection("Usage");
usage.AddParagraph("Install it and start.");

var tables = usage.AddSection("Tables");
tables.AddParagraph("...");

Output:

# TagBites.Text.Markdown

C# library for building Markdown.

## Usage

Install it and start.

### Tables

...

A section writes its own header, so nest another section rather than adding a header to it.

A level can be forced using an overload:

parent.AddSection(3, "Details");

Past level six Markdown has no header, and a deeper section falls back to bold text with a hard line break:

###### Level six

**Level seven**
Content of the seventh level.

An explicit anchor comes from SetCustomId:

section.SetCustomId("custom-id"); // ## <a id="custom-id"></a> Some section

MarkdownFormat.HeaderAnchorStyle switches that to {#custom-id}.

To link a section, pass it to MarkdownText.Link instead of writing the anchor twice:

var section = root.AddSection("Command line options");

root.AddParagraph("See " + MarkdownText.Link(section) + " below.");
// See [Command line options](#command-line-options) below.

The address is AnchorId, which is CustomId when one is set and otherwise the header text in lower case with hyphens (like in GitHub).

Text and escaping

Every element takes a MarkdownText. A string you pass converts implicitly and is escaped, so text from an untrusted source cannot introduce markup:

doc.AddParagraph("Report by [admin](https://link.example) **now**");
// Report by \[admin\](https://link.example) \*\*now\*\*

Escaping is minimal. A character is escaped where it would change the parse and left alone where it would not:

doc.AddParagraph("TagBites.Expressions accepts digit separators like 1_000_000 and compiles to Func<>");
// TagBites.Expressions accepts digit separators like 1_000_000 and compiles to Func<>

Content that is already Markdown goes through MarkdownText.Raw. The inline builders return raw content too:

MarkdownText.Bold("text");                    // **text**
MarkdownText.Italic("text");                  // _text_
MarkdownText.Strikethrough("text");           // ~~text~~
MarkdownText.Code("var x;");                  // `var x;`
MarkdownText.Link("name", "https://x.com");   // [name](https://x.com)
MarkdownText.Link("name", "x.md", "Tooltip"); // [name](x.md "Tooltip")
MarkdownText.Image("logo", "logo.png");       // ![logo](logo.png)
MarkdownText.LineBreak;                       // two spaces and a new line

Combine with +:

var text = MarkdownText.Bold("total") + " for [all] items";
// text.Markdown -> **total** for \[all\] items
// text.Text     -> total for [all] items

The plain text mode returns Text.

Tables

A cell holds inline content, so bold text, links and images go in as text:

table.SetHeaders("name", "docs")
    .WithRow(MarkdownText.Bold("total"), MarkdownText.Link("guide", "x.md"));

| name      | docs          |
| --------- | ------------- |
| **total** | [guide](x.md) |

Alignment comes from SetAlignments, or from WithHeader one column at a time:

table.SetHeaders("left", "center", "right")
    .SetAlignments(
        MarkdownTableColumnAlignment.Left,
        MarkdownTableColumnAlignment.Center,
        MarkdownTableColumnAlignment.Right)
    .WithRow("a", "b", "c");

| left | center | right |
| :--- | :----: | ----: |
| a    | b      | c     |

Format

Rendering options live on MarkdownFormat:

Property	Meaning
Output	Markdown or PlainText.
IgnoredElementTypes	Element types (including derived) left out of the output, together with their content.
HeaderAnchorStyle	HtmlAnchor for <a id="id"></a>, Attribute for {#id}.
SeparateLooseListItems	Whether a blank line separates the items of a loose list.

Whole element types can be left out, which gives a description without the code that goes with it:

var format = new MarkdownFormat
{
    Output = MarkdownOutputKind.PlainText,
    IgnoredElementTypes = { typeof(MarkdownCode) }
};

doc.ToString(format);

Plain text output strips the syntax: headers, quotes and code blocks keep their text, lists lose their markers, tables come out as space-separated rows. A checkbox outputs as ☑ or ☐. Ignoring MarkdownCode removes code blocks and keeps a code span inside a sentence.

var plain = MarkdownFormat.PlainText;

new MarkdownHeader(1, "Title").ToString(plain);                     // Title
new MarkdownCode("csharp", "var x;").ToString(plain);               // var x;
new MarkdownListItem("task") { IsChecked = true }.ToString(plain);  // ☑ task

The format freezes the first time it is used for writing. A later change throws InvalidOperationException.

Front matter

var doc = new MarkdownDocument
{
    FrontMatter = new MarkdownFrontMatter
    {
        Title = "Release notes",
        Description = "What changed in this version.",
        ["date"] = "2026-08-01"
    }
};

doc.FrontMatter.SetValues("tags", "markdown", "builder");

var notes = doc.AddSection("Release notes");
notes.AddParagraph("First public version.");

Output:

---
title: Release notes
description: What changed in this version.
date: 2026-08-01
tags: [markdown, builder]
---

# Release notes

First public version.

Standards

The output follows CommonMark and the GitHub Flavored Markdown extensions the model exposes: tables, task lists and strikethrough. Every construct is parsed back with Markdig in the test suite and has to produce the same document.

Limitations

• The library builds Markdown, it does not parse it. If you need to read Markdown, use Markdig.
• Escaping keeps text inside its block. A backslash cannot escape white space, so leading indentation and a blank line come out as the   entity instead.
• Table cells hold inline content only, which is all the GitHub Flavored Markdown spec allows.