Caapi is another name for Ayahuasca. It is a vine that grows in the amazon. It contains several types of harmala alkaloids which bind with and activate the DMT.
There are several retailers listed in the suppliers section.
Syrian rue is another source for harmala alkaloids. To prepare the seeds, check out The Tao of Rue Extraction link in my signature. You can also make a tea out of the syrian rue seeds, but there are a lot of unwanted alkaloids in it so it has the potential to be hard on your system. That's why it's recommended to extract the alkaloids.
Hope this helps and feel free to shout if you need further clarification.
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