Architecture

SmoothSend uses one public gateway and chain-specific execution backends.

Request flow

High-level flow for both Aptos and AVAX paths.

Terminal

Client / SDK
  -> Cloudflare Gateway (auth, credits, rate-limit, routing)
      -> Aptos Relayer (fee-payer flow)
      -> AVAX Bundler (ERC-4337 JSON-RPC + paymaster signing)
      -> Dashboard APIs / analytics

AVAX (ERC-4337)

EntryPoint v0.7 + VerifyingPaymaster with gateway-authenticated bundler endpoints.

1. SDK calls gateway (`X-Chain: avalanche`, `X-Network: testnet|mainnet`).

2. Gateway authenticates API key and forwards to AVAX bundler with internal secret.

3. Bundler estimates UserOp gas and signs paymaster payload.

4. Bundler submits `handleOps` on EntryPoint and returns `userOpHash`.

Control plane responsibilities

Layer	Responsibilities
Gateway	API key auth, billing checks, chain routing, header forwarding
Bundler / Relayer	Transaction orchestration, nonce ownership, chain submission
Dashboard	Projects, keys, sponsorship rules, usage visibility