TL;DR

Exploring whether we can do direct per‑request or per‑epoch on‑chain transfers to service providers (SPs) on a chain that’s extremely cheap, highly scalable, and offers a privacy path. A brief summary of the options:

• MVP fastest (EVM & USDC‑native): Deploy the minimal contracts on an existing OP Stack L2 (OP Mainnet/Base) or Arbitrum Nova and pay SPs directly on‑chain. Later, move to an app‑specific OP Chain (Alt‑DA) or Arbitrum Orbit L3 if we need sovereign cost control.
• ZK/app‑chain path: If we prefer validity proofs/ZK, use Polygon CDK Validium or ZKsync ZK Stack to spin up a low‑fee app‑chain. Great for gaming‑style volumes.
• Privacy‑first: Research viability of Aztec (privacy L2) for private transfer semantics; or bridge to Namada/Penumbra shielded pools for redemptions.

Bottom line: We can do an MVP on OP/Arbitrum with native USDC, then move to an app‑chain with privacy at that level, while exploring a separate native-privacy track.

Goal

We need a way for users / clients to pay Waku service providers directly on‑chain. The chain must support:

• Tiny payments at scale: low fees (sub‑cent), quick finality.
• Good developer ergonomics: EVM preferred, composable tooling.
• Stablecoin liquidity: native USDC strongly preferred.
• Privacy runway: not necessarily at MVP, but a credible track for future private payments.
• Operational reliability: credible neutrality (sequencer), clear DA story, robust bridges.

Considerations: Censorship Resistance, Fee floor & volatility, DA/security model, USDC availability, EVM equivalence, Maturity (RaaS, tooling), Privacy roadmap, Migration/sovereignty path.

Direct‑pay mechanic: user submits payment tx (or batched stream) on‑chain to the SP’s address. Waku messages carry the tx reference/receipt. More-Scalable Alternative: per‑epoch streaming/escrow contracts that net‑out tiny per‑msg fees into periodic on‑chain transfers (see Appendix for details)

Overview

Existing L2s (for streaming/escrow contracts)

• OP Stack L2 (OP Mainnet/Base): EVM native, USDC, cheap EIP-4844 blobs, mature infra.