Code

Use fenced code blocks with a language identifier for syntax highlighting:

```rust
fn main() {
    println!("Hello!");
}
```

Renders as:

rust

fn main() {
    println!("Hello!");
}

Supported Languages

Syntax highlighting is powered by PrismJS. We're still expanding the set of supported languages — if yours isn't highlighted yet, it will be soon.

Ping us on Discord if the language you need is missing!

Meta Attributes

You can add attributes after the language identifier to control how the block looks. Use key=value syntax, separated by spaces:

Attribute	Description	Example
`file`	Display a filename badge	`file=parser.rs`
`highlight`	Highlight specific lines	`highlight=3,5-8,12`
`caption`	Add a description below the block	`caption="Error handling logic"`

Filename

Shows a filename badge in the code block header:

```rust file=src/main.rs
fn main() {
    let config = Config::load();
    run(config);
}
```

Renders as:

src/main.rs

rust

fn main() {
    let config = Config::load();
    run(config);
}

Line Highlighting

Highlight specific lines to draw attention to important parts:

```python highlight=3-4
def greet(name):
    """Say hello."""
    message = f"Hello, {name}!"
    print(message)
```

Renders as:

python

def greet(name):
    """Say hello."""
    message = f"Hello, {name}!"
    print(message)

Format	Example	Description
Single line	`highlight=5`	Highlights line 5
Range	`highlight=10-15`	Highlights lines 10 through 15
Mixed	`highlight=2,5-8,12`	Combines singles and ranges

Caption

Captions show up below the code block:

```javascript file=api.js highlight=4 caption="User fetching and parsing"
async function fetchUser(id) {
    const response = await fetch("/api/users/" + id);
    const data = await response.json();
    return User.parse(data);
}
```

Renders as:

api.js

javascript

async function fetchUser(id) {
    const response = await fetch("/api/users/" + id);
    const data = await response.json();
    return User.parse(data);
}

User fetching and parsing

UI Features

Every code block comes with a copy button and a language badge. If the block has a block ID, there's also a link button so readers can grab a direct link to it.