tempo.Attribution

Encode and inspect the 32-byte attribution memos used by Tempo charge payments.

Usage

import { Attribution } from 'mppx/tempo'
 
const memo = Attribution.encode({
  challengeId: 'challenge-123',
  clientId: 'my-app',
  serverId: 'api.example.com',
})
 
console.log(Attribution.isMppMemo(memo))
true
console.log(Attribution.verifyServer(memo, 'api.example.com'))
true
console.log(Attribution.verifyChallengeBinding(memo, 'challenge-123'))
true

The charge client uses the Challenge realm as serverId. Pass that realm to verifyServer when matching an on-chain transfer to your server. decode returns the version, server and client fingerprints, and Challenge-bound nonce; it returns null for a memo without the MPP tag and version. Fingerprints are hashes, not the original identities.

Return type

type Memo = `0x${string}` // Attribution.encode
type Decoded = {
  clientFingerprint: `0x${string}` | null
  nonce: `0x${string}`
  serverFingerprint: `0x${string}`
  version: number
} | null // Attribution.decode

isMppMemo, verifyChallengeBinding, and verifyServer return boolean. Attribution.tag is the four-byte MPP tag; Attribution.anonymous is the all-zero client fingerprint.

Parameters

challengeId

• Type: string

Challenge ID used to derive the memo nonce for encode or checked by verifyChallengeBinding.

clientId (optional)

• Type: string

Client identity used to derive a fingerprint in encode. Omit it for an anonymous client fingerprint.

memo

• Type: `0x${string}`

32-byte memo inspected by decode, isMppMemo, verifyChallengeBinding, or verifyServer.

serverId

• Type: string

Server identity used to derive a fingerprint in encode or checked by verifyServer.