What's the most cost-effective way to serve wallet requests using a JSON-RPC gateway?

The most cost-effective approach is usually:

Use a lightweight, stateless JSON-RPC gateway that proxies only the methods you need, with aggressive caching and batching, and route most requests to low-cost/self-hosted backend nodes or a shared provider tier.

A practical cost-optimized setup looks like this:

1. Put a thin gateway in front of your wallet backend

   • Handle auth, rate limiting, request normalization, and method routing.
   • Keep it stateless so you can autoscale cheaply.

2. Batch and deduplicate requests

   • Wallets often ask for balances, nonce, chain info, token metadata, etc.
   • Group identical requests across users where possible.
   • Use JSON-RPC batch requests for clients that support it.

3. Cache aggressively for read-heavy calls

   • Short TTL cache for:
     • eth_chainId
     • token metadata
     • gas estimates
     • recent block data
     • balances/allowances when acceptable
   • Use in-memory cache for hot data and Redis for shared cache.

4. Serve “cheap reads” from your own nodes, outsource “expensive edge cases”

   • Run your own full nodes for common chains and frequent methods.
   • Fall back to a provider only for rare, archival, or bursty traffic.
   • This hybrid model is usually cheaper than sending everything to a premium RPC provider.

5. Split traffic by method

   • Read-only / high-frequency: your own nodes + cache
   • State-changing / signed: direct to wallet flow, minimal gateway logic
   • Archive / historical / tracing: external provider or separate expensive tier

6. Use request shaping

   • Enforce per-wallet/user quotas.
   • Reject or slow obviously abusive polling.
   • Prefer push/subscriptions where supported instead of polling.

7. Minimize compute per request

   • Avoid heavy middleware, deep logging, and synchronous DB calls in the hot path.
   • Log asynchronously and sample non-critical telemetry.

If you want the absolute lowest unit cost

A good rule of thumb is:

• Self-host the gateway + common RPC nodes
• Cache the top 80–90% of read traffic
• Use a third-party RPC provider only as overflow/fallback

That tends to beat “all requests to a managed gateway” on cost once volume gets meaningful.

If you’re choosing an architecture

• Lowest ops burden: managed RPC provider + gateway
• Lowest ongoing cost at scale: self-hosted nodes + gateway + cache
• Best balance: hybrid routing with caching and fallback

If you want, I can sketch a reference architecture for a wallet JSON-RPC gateway optimized for cost, or help estimate costs for your expected request volume.