`MerchantRpc.requestHandler`

Creates a Fetch API-compatible request handler for merchant RPC operations. This allows merchants to sponsor transaction fees for users and handle Porto RPC requests in various server environments.

Imports

Named

import { MerchantRpc } from 'porto/server'

Usage

MerchantRpc.requestHandler is compatible with any server framework that supports the Fetch API, including:

import { MerchantRpc } from 'porto/server'
 
const handler = MerchantRpc.requestHandler({
  address: process.env.MERCHANT_ADDRESS,
  key: process.env.MERCHANT_PRIVATE_KEY,
})

Next.js

The MerchantRpc module exports GET, OPTIONS, and POST helpers over the requestHandler function for Next.js.

import { MerchantRpc } from 'porto/server'
 
export const GET = MerchantRpc.GET
 
export const OPTIONS = MerchantRpc.OPTIONS
 
export const POST = MerchantRpc.POST({
  address: process.env.NEXT_PUBLIC_MERCHANT_ADDRESS,
  key: process.env.NEXT_PUBLIC_MERCHANT_PRIVATE_KEY,
})

Cloudflare Workers

Use the MerchantRpc.requestHandler function directly in your Cloudflare Worker.

import { env } from 'cloudflare:workers'
import { MerchantRpc } from 'porto/server'
 
export default {
  fetch: MerchantRpc.requestHandler({
    address: env.MERCHANT_ADDRESS,
    base: '/rpc',
    key: env.MERCHANT_PRIVATE_KEY,
  }),
} satisfies ExportedHandler<Env>

Hono

Use the MerchantRpc.requestHandler function directly in your Hono server.

import { Hono } from 'hono'
import { MerchantRpc } from 'porto/server'
 
const app = new Hono()
 
app.all('/rpc', (c) => MerchantRpc.requestHandler({
  address: c.env.MERCHANT_ADDRESS,
  key: c.env.MERCHANT_PRIVATE_KEY,
})(c.req.raw))
 
export default app

Express

If you are using a server framework that supports the Node.js http API (e.g. Express) instead of the Fetch API, you can use the MerchantRpc.requestListener function instead:

import express from 'express'
import { MerchantRpc } from 'porto/server'
 
const app = express()
 
app.all('/rpc', MerchantRpc.requestListener({
  address: process.env.MERCHANT_ADDRESS,
  key: process.env.MERCHANT_PRIVATE_KEY,
}))
 
app.listen(3000)

Other Frameworks

Using MerchantRpc.requestHandler (for Fetch API frameworks) or MerchantRpc.requestListener (for Node.js API frameworks) should get you far enough.

If you would like to see an example of your framework here, please open a discussion and we'll add it.

Conditional Sponsoring

The sponsor option can be used to conditionally sponsor calls. When a function is provided to sponsor, the first parameter is a request object and the return value is a boolean indicating whether to sponsor the call.

In the following example, the call will only be sponsored if the to address is the same as the target address.

import { MerchantRpc } from 'porto/server'
 
const target = '0x...'
 
const handler = MerchantRpc.requestHandler({
  address: process.env.MERCHANT_ADDRESS,
  key: process.env.MERCHANT_PRIVATE_KEY,
  sponsor(request) {
    return request.calls.every((call) => call.to === target)
  },
})

You can also pass an async function to sponsor if you wish to call out to an external service to determine whether to sponsor the call.

import { MerchantRpc } from 'porto/server'
import { myAsyncFunction } from './myAsyncFunction'
 
const handler = MerchantRpc.requestHandler({
  address: process.env.MERCHANT_ADDRESS,
  key: process.env.MERCHANT_PRIVATE_KEY,
  async sponsor(request) { 
    return await myAsyncFunction(request) 
  }, 
})

Parameters

type Parameters = {
  /** Address of the Merchant Account. */
  address: Address.Address
  /** Base path of the request handler. */
  base?: string | undefined
  /** Supported chains. */
  chains?: Porto.Config<chains>['chains'] | undefined
  /** An Admin Key of the Merchant Account to use for signing. */
  key:
    | Hex.Hex
    | (Pick<OneOf<Key.Secp256k1Key | Key.P256Key>, 'type'> & {
        privateKey: Hex.Hex
      })
  /** Whether to sponsor calls or not, and the condition to do so. */
  sponsor?:
    | boolean
    | ((
        request: RpcSchema.wallet_prepareCalls.Parameters,
      ) => Promise<boolean>)
      | undefined
  /** Supported transports. */
  transports?: Porto.Config<chains>['transports'] | undefined
}

Returns

type ReturnType = (request: Request) => Promise<Response>

A function that accepts a Fetch API Request and returns a Fetch API Response.