FilCDN M2 Payment Setup

Motivation

We want a simple payment setup that rewards both CDN and SP for serving retrievals, but serves more as a placeholder for future iterations than trying to be a fully specced out system. It has two goals: There are payments, but they are not hindering product development. It’s not too expensive, and not too complex.

Payment Rails

For each PDP proof set withCDN=true, there will be 3 payment rails:

1. PDP
   1. Cashflow: Client ➡️ SP
   2. Expectation: SP fulfills PDP proofs
   3. Verifier: PDPVerifier ✅
   4. Pricing scheme: $2/TiB/mo (see https://github.com/FilOzone/filecoin-services/blob/1b99d8b39bf7f35608884b0bd7bd768810ee2372/service_contracts/src/PandoraService.sol#L38C39-L38C49)
   5. Settlement: Validated by PDP verifier
   6. Example: Client pays SP 2$ for storing 1TB of data for 1 month.
   7. Notes
      1. This is already in place and owned by the FilOz team

2. SP serves cache misses to CDN
   1. Cashflow: Client ➡️ SP
   2. Expectation: SP serves PDP data to FilCDN (on cache miss) only if `addCDN` is purchased
   3. Verifier: CDNVerifier ⌛
   4. Pricing scheme: .50$/m
   5. Settlement:
      1. validated by CDNVerifier, which tracks SP availability. For now, FilCDN only cares whether the SP was able to serve the file on cache-miss or not.
      2. We would like to deploy an initial version without the verifier, in which case the SP can withdraw independently of their performance - for the sake of an iterative approach. Question: Is it acceptable to ship without a verifier to early users? Or does there have to be a verifier, guiding the relationship between user and SP?
   6. Example: Client pays SP .50$ per month for reliably serving cache-miss egress to the CDN.
   7. Notes:
      1. From a legal perspective it’s safer when the Client rewards the SP for FilCDN services, and not FilCDN
      2. FilCDN can still ensure through a verifier contract that SP only gets rewarded if they perform well. For this, FilCDN doesn’t need to be the one paying the SP - thanks to the verifier concept.
      3. This flat fee can be adjusted later on, once we have learned more. It represents half of what’s defined in https://github.com/FilOzone/filecoin-services/blob/1b99d8b39bf7f35608884b0bd7bd768810ee2372/service_contracts/src/PandoraService.sol#L39

3. FilCDN serves retrievals
   1. Cashflow: Client ➡️ FilCDN
   2. Expectation: FilCDN serves retrievals
   3. Verifier: ❌ (Trusted)
   4. Pricing scheme: .50$/m
   5. Settlement:
      1. No requirements, FilCDN is a trusted party
   6. Example: Client pays FilCDN .50$ for accelerating PDP content for one month.
   7. Notes:
      1. For now, FilCDN will have to be trusted (lack of proof of retrieval). Potential future solution: Marketplace of different CDNs
      2. This flat fee can be adjusted later on, once we have learned more. It represents half of what’s defined in https://github.com/FilOzone/filecoin-services/blob/1b99d8b39bf7f35608884b0bd7bd768810ee2372/service_contracts/src/PandoraService.sol#L39

References

• Payment Rail struct

Notes

• When reading, replace every mention of $ with USDFC