Tiny
Measuring only 1ft <> 2ft, these Warfroged were designed for being able to quickly and efficiently climb onto, into and over the much larger Warforged and constructs it serviced.

Base speed of 40, climbing speed of 30, swimming speed of 15
Able to quickly move around, specially designed to be able to climb onto the much large constructs it serviced. 
You are not great in water tho.

Your Constitution score increases by 1, Your strength is reduced by -4, +2 going into Dexterity. Your intelligence is increased by 2.
You're small, but made of a hard metal. You aren't very strong, but quite agile, and with a high intelligence.

You can speak, read, and write Common and 1 other language of your choice.

As a construct made to repair others, you get the Mending cantrip for free.

Once per short rest, you may take an action to cast Mend Wounds (with INT as your spell modifier) to heal yourself, or another Warforged, construct, device or item within touch range.

• A construct you touch regains a number of hit points equal to 1d8 + your INT ability modifier. This spell only effects constructs, Warforged, devices and items.
  For every 3 levels you character is above level 1, add another 1d8. (1d8 at level 1, 2d8 at level 4, 3d8 at level 7, etc)

You may choose 2 tools of you choice.
You are proficient in these tools, and any checked performed using these tools.
These 2 tool are built into your 2 lowers arms (1 each) and so you always carry them around with you.

When you take a long rest, you must spend at least six hours in an inactive, motionless state, rather than sleeping. In this state, you appear inert, but it doesn’t render you unconscious, and you can see and hear as normal.

You were created to have remarkable fortitude, represented by the following benefits:

• You have advantage on saving throws against being poisoned, and you have resistance to poison damage.
• You don’t need to eat, drink, or breathe.
• You are immune to disease.
• You don't need to sleep, and magic can't put you to sleep.

Due to their construct nature, Warforged have natural armor and weapons, and is unable to put on armor. Your unarmored AC is 12+Dexterity, rather than 10. Additionally, a warforged has one "natural weapon" that is installed in their body. This is in the form of 2 forearm blades.

The forearm blades are dual daggers installed in both their upper arms, that can be extended and retracted at will, but not thrown. These daggers count as Light, Finesse and dual-wielding. They are proficient with these weapons.

If you receive daggers with additional benefits (+1, special properties, etc) you may spend 1 hour integrating it into yourself. Base damage may not increase, but you may add the additional affects. It takes 1 hour to remove the dagger again. 2 hours in total if you are swapping. Only dagger variants may be used in this way. A dagger integrated like this only affected the 1 built-in dagger. 2 may be integrated at the same time, 1 per arm.

If you receive armor with additional benefits (+1, special properties, etc) you may spend 1 hour integrating the properties into yourself. Your base AC will not go up, but you may add the additional affects. It takes 1 hour to remove the armor again. 2 hours in total if you are swapping armor. You may only do this with armor you are proficient in.