Mix all ingredients in a mixing bowl EXCEPT for the water. Knead well.
If the dough seems crumbly add water, 1 tsp. at a time, kneading well between additions.
If you end up adding too much water, simply stir in a tiny bit more tapioca flour (about 1/2 tsp. at a time.)
Roll the dough out between two pieces of parchment paper until the dough is about an 1/8 inch in thickness.
Cut into squares and transfer the squares to a baking sheet using a spatula. Poking the crackers with a fork is optional and a tiny bit time-consuming, but I did find that they were crunchier when I did this.
Bake at 325 F. for approximately 20-30 minutes. They will be hard to the touch (don't burn yourself!) and have a slightly golden tint to them when they are done.
Allow to cool completely before eating, or they won't be crunchy.
Please note that the nutrition data below is a ballpark figure. Exact data is not possible. Note that you can certainly eat more than 2 crackers for one serving. I just had to pick a number in order to roughly calculate the data here.