Yes, it is possible.
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Yes. The value of the exchange would be the fair market value of the services provided. They would disregard the tokens and look at the form of the transaction. The tokens might play into whether income was recognized when received under the accrual method, but either way, it will be recognized when services are performed. Consideration can take all different forms and it is almost impossible to make transactions between unrelated parties non-taxable by changing the "currency."