Grant subscription creation costs slightly more than the amount shown to pay for metatx

[danlipert]

Outstanding Questions

@frankchen07 to set up a discussion with austin + dan + aditya + owocki related to security on this issue. Who is funding the subminer?

User Story

As a grant subscriber, I want to pay the exact amount I'm contributing (continuation of temporary fix for issue #3653)

Why Is this Needed

The metatx relayer requires a small amount of additional tokens to relay the transaction (I think...)

Description

• right now, when it fails, owocki drops 0.1 dai into wallet (line of defense 1)
• right now, owocki made it so that one-time transactions, it bypasses the subminer (superfluous b/c subminer is subscriptions, defense 2)
• solutions
  • subminer fee can be configurable, and the fee is taken out of the subscription
  • the attack vector already exists (charge a small percentage fee on grant contributions)
  • in the subminer, we can make it so that anyone who is not a admin that submits a fee below a threshold or a minute/hour cadence, we just error out
• next course of action for dan is
  • set gas price to 0
  • run a check on cadence
• longer-term fix will be coupled with revenue options
  • fix most likely will solutionize the configurable subminer fee, where the fee is taken out of the subscription

Current Behavior

Example: a 50 DAI subscription costs 50.000001

Expected Behavior

A 50 DAI subscription should cost 50 DAI

Definition of Done

The amount entered by the user is the amount shown in the transaction

Additional Information

I believe we can just configure the metatx relayer to charge 0? @owocki @austintgriffith

[kuhnchris]

alternative: instead of having to pay that fee (which essentially it is), you could ask for 1 DAI or 0.5 DAI when the user funds his first grant, so we have enough 'spare dai' to push those metatx?