# Adding Default Keymaps to QMK Configurator :id=adding-default-keymaps
This page covers how to add a default keymap for a keyboard to QMK Configurator.
## Technical Information :id=technical-information
QMK Configurator uses JSON as its native file format for keymaps. As much as possible, these should be kept such that they behave the same as running `make <keyboard>:default` from `qmk_firmware`.
Keymaps in this directory require four key-value pairs:
*`keyboard` (string)
* This is the name of the keyboard, the same as would be used when running a compile job through `make` (e.g. `make 1upkeyboards/1up60rgb:default`).
*`keymap` (string)
* Should be set to `default`.
*`layout` (string)
* This is the layout macro used by the default keymap.
*`layers` (array)
* The keymap itself. This key should contain one array per layer, which themselves should contain the keycodes that make up that layer.
Additionally, most keymaps contain a `commit` key. This key is not consumed by the API that back-stops QMK Configurator, but is used by Configurator's maintainers to tell which version of a keymap was used to create the JSON keymap in this repository. The value is the SHA of the last commit to modify a board's default `keymap.c` in the `qmk_firmware` repository. The SHA is found by checking out [the `master` branch of the `qmk/qmk_firmware` repository](https://github.com/qmk/qmk_firmware/tree/master/) and running `git log -1 --pretty=oneline -- keyboards/<keyboard>/keymaps/default/keymap.c` (use `keymap.json` if the keyboard in question has this file instead), which should return something similar to:
f14629ed1cd7c7ec9089604d64f29a99981558e8 Remove/migrate action_get_macro()s from default keymaps (#5625)
```
In this example, `f14629ed1cd7c7ec9089604d64f29a99981558e8` is the value that should be used for `commit`.
## Example :id=example
If one wished to add a default keymap for the H87a by Hineybush, one would run the `git log` command above against the H87a's default keymap in `qmk_firmware`:
The default keymap uses the `LAYOUT_all` macro, so that will be the value of the `layout` key. Compiled to a QMK Configurator JSON keymap, our resulting file should be:
The white space in the `layers` arrays have no effect on the functionality of the keymap, but are used to make these files easier for humans to read.
## Caveats :id=caveats
### Layers can only be referenced by number :id=layer-references
A common QMK convention is to name layers using a series of `#define`s, or an `enum` statement:
```c
enum layer_names {
_BASE,
_MEDIA,
_FN
};
```
This works in C, but for Configurator, you *must* use the layer's numeric index –`MO(_FN)` would need to be `MO(2)` in the above example.
### No support for custom code of any kind :id=custom-code
Features that require adding functions to the keymap.c file, such as Tap Dance or Unicode, can not be compiled in Configurator **at all**. Even setting `TAP_DANCE_ENABLE = yes` in the `qmk_firmware` repository at the keyboard level will prevent Configurator from compiling **any** firmware for that keyboard. This is limited both by the API and the current spec of our JSON keymap format.
### Limited Support for Custom keycodes :id=custom-keycodes
There is a way to support custom keycodes: if the logic for a custom keycode is implemented at the keyboard level instead of the keymap level in qmk_firmware, that keycode *can* be used in Configurator and it *will* compile and work. Instead of using the following in your `keymap.c`:
For QMK Configurator to support your keyboard, your keyboard must be present in the `master` branch of the `qmk_firmware` repository. For instructions on this, please see [Supporting Your Keyboard in QMK Configurator](reference_configurator_support.md).
