Early on at Token, we looked Teller as a possible solution to getting to market quickly. We found two things: 1) the lawyers told us to stay clear (huge greyzone) and 2) the banks themselves didn't want to engage with us using teller even if it sped up development time. We even brought stevie in talk to our lawyers to make his case. He failed to convince them. Finally, we inquired about the price. Stevie was elusive on pricing. I finally asked, "Look, if we paid you $1M, how many banks could we get?" He said one. So at that point, we were so far apart on all issues, so we pulled out. Token will be doing something similar to teller in terms of "one API for all banks" (aggregating banks' PSD2 interface with Token acting as a PISP/AISP). But we are also providing the PSD2 interface for other banks. We have raised plenty of money to do it right ($18.5M Series A to start with), but our pricing to developers will be ridiculously inexpensive. Also, we need to hire developers very quickly, so if you are interested in helping us do it right (no shared secrets, all end-to-end secure protocols, secure central PII storage (where the decryption keys are only available at endpoints), please let us know. We don't have a lot of time left to do this right. We are located in London and San Francisco.