# Argument resolution
To make argument input easier and less error-prone, Starkli supports _argument resolution_, the process of expanding simple, human-readable input into actual field element arguments expected by the network.
By default, arguments are only parsed as raw field elements, accepting both decimal and hexadecimal representations.
To make arguments expandable, and thus trigger the resolution process, use the format `scheme:content`, where `scheme` is one of the supported [schemes](#schemes), and `content` is the scheme-specific content.
## Schemes
### `addr`
The `addr` scheme resolves the address name provided as `content` into a full address using an _address book_ under the current network ID. As of this writing, the actual address book feature hasn't been implemented, and a hard-coded address book is used instead, which contains only one entry `eth` for the `ETH` token address.
### `u256`
The `u256` scheme interprets `content` as an unsigned 256-bit integer and resolves into _2_ field element arguments for the low and high 128 bits, respectively. This scheme is useful for working with contracts expecting `u256` arguments, such as the standard ERC20 contract.
### `str`
The `str` scheme encodes `content` as [Cairo short string](https://book.starknet.io/chapter_2/strings.html#working_with_short_strings).
### `const`
The `const` scheme uses `content` as the key to look up a hard-coded table to commonly used constant values. The current list of constants are:
| `u256_max` | `0xffffffffffffffffffffffffffffffff, 0xffffffffffffffffffffffffffffffff` |
| `felt_max` | `0x0800000000000011000000000000000000000000000000000000000000000000` |
## Scheme omission
Normally, the `scheme:` prefix is required for opting in to argument resolution. However, there's one exception: the `addr:` prefix can be omitted when an address is expected.
As an example, consider the `starkli invoke` command. To use the `addr` scheme, one would run:
```console
starkli invoke addr:eth ...
```
However, since the first positional argument for the `starkli invoke` is always expected to be an address, this command can be simplified into:
```console
starkli invoke eth ...
```