# `jadpo help`

Show commands, flags and examples.

Show every command grouped by job, or one command's arguments, flags and examples, a rule's page by the id on an error's rule: line, or a standard type's page by its name, offline. `jadpo help types` lists every standard type. With --json, print the whole command reference and the rule catalogue as data, or one type's shape.

```text
jadpo help [command]
```

## Arguments

- `command` (optional): The command, rule or standard type to explain

## On every command

- `--json`: Print data for tools instead of text
- `--full`: Show everything a report shortens
- `--help`: Show every flag, with examples
- `--color <when>`: Choose when to use colour

`jadpo help --json` writes one JSON document to standard output instead of text, with the same exit code. The document has `schemaVersion`, `command` (`"help"`), `ok`, `data` (what the command produced, `null` when it failed) and `diagnostics` (each error with its `rule`, `reason`, `next` and `help`). A command that needs a terminal refuses `--json` and names the flags that do the same job.

## Examples

```text
# Show every command
jadpo help
# Show one command's arguments, flags and examples
jadpo help completions
# Read a rule's page, from an error's rule: line
jadpo help import.unused
# Read a standard type's page: its shape and an example
jadpo help PersonName
# List every standard type from A to Z
jadpo help types
# Print the command reference and rule catalogue for tools
jadpo help --json
```

## Errors

- [`cli.help_arguments`](/docs/errors/cli.help_arguments.md): A `jadpo help` command names more than one command or rule