# Modifiers
Modifiers transform tag values inline: `{tag|modifier}` or `{tag|modifier:argument}`.
All modifiers work with both strings and lists.
## Summary Table
| `ast` | `{tag\|ast}` | Parse source file to JSON AST, brief by default (auto-detects language) |
| `ast` | `{tag\|ast:brief}` | Parse source file, brief output (signatures only, no bodies) |
| `ast` | `{tag\|ast:full}` | Parse source file, full output with bodies and imports |
| `ast` | `{tag\|ast:rs}` | Parse source code with explicit language (14 languages) |
| `clipboard` | `{tag\|clipboard}` | Copy value to system clipboard (pass-through) |
| `contains` | `{tag\|contains:X}` | Check if contains substring (predicate, supports `:not`) |
| `empty` | `{tag\|empty}` | Check if string or list is empty (predicate, supports `:not`) |
| `equals` | `{tag\|equals:X}` | Check if equals value (predicate, supports `:not`) |
| `format` | `{tag\|format:json}` | Convert between json, json5, yaml, toml formats |
| `is_dir` | `{tag\|is_dir}` | Check if path is a directory (predicate, supports `:not`) |
| `is_file` | `{tag\|is_file}` | Check if path is a file (predicate, supports `:not`) |
| `join` | `{tag\|join}` | Join list with `\n` |
| `join` | `{tag\|join:X}` | Join list with custom separator |
| `load` | `{tag\|load}` | Fetch URL to temp file, resolve local path, or pass through base64 |
| `lower` | `{tag\|lower}` | Transform to lowercase |
| `resolve` | `{tag\|resolve}` | Resolve path to absolute form (`~`, `.`, `..`) |
| `reverse` | `{tag\|reverse}` | Reverse string or list order |
| `scan` | `{tag\|scan}` | Scan directory and return list of file paths (via vibe-fs) |
| `size` | `{tag\|size}` | Length of string or element count of list |
| `sort` | `{tag\|sort}` | Sort ascending (default) |
| `sort` | `{tag\|sort:asc}` | Sort ascending |
| `sort` | `{tag\|sort:desc}` | Sort descending |
| `split` | `{tag\|split}` | Split string to list by `\n` |
| `split` | `{tag\|split:X}` | Split string to list by separator X |
| `take` | `{tag\|take:N}` | Take first N characters or elements |
| `text` | `{tag\|text}` | Extract text from HTML/PDF or convert image to base64 |
| `trim` | `{tag\|trim}` | Strip whitespace, drop empty list elements |
| `trim` | `{tag\|trim:chars}` | Strip custom characters, drop matching list elements |
| `uniq` | `{tag\|uniq}` | Remove duplicate characters (string) or elements (list) |
| `upper` | `{tag\|upper}` | Transform to UPPERCASE |
## Escape Mnemonics
Use these codes in modifier arguments to bypass YAML whitespace trimming:
| `\n` | Newline |
| `\t` | Tab |
| `\s` | Space |
Example: `{tag|join:,\s}` → `", "` (comma-space).
## Predicate Modifiers
Return `"true"`/`"false"` as strings for `when` conditions. Invert with `:not`:
```yaml
{tag|is_file:not}
```
## Chaining
```yaml
{tag|empty:not}
```
## Escaping Literals
Use `{{...}}` to include literal braces:
```yaml
# Literal, not a tag:
{{name}}