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Agent Spend Protocol

Designed for Agent Commerce · Authorize First, Settle Later

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Authorize First

Payee receives a signed payment mandate from the payer, completing the transaction instantly. No need to wait for on-chain confirmation, ideal for high-frequency micropayment scenarios

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Settle Later

Payee submits mandates to settlement processor within the settlement window to batch debit from payer's on-chain wallet, with fund security guaranteed by smart contract

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Embedded Payment

Payment mandates can be directly embedded in x402, MCP, A2A and other protocol calls, enabling programmable embedded payments

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Trust-minimized

Users retain fund custody, settlement processors can only debit within authorized limits, all logic enforced by smart contract

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High-Frequency Transactions

Supports API pay-per-call billing, streaming data transmission, automated agent interactions and other high-frequency, low-latency scenarios

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Extensible Architecture

All components including debit wallets, settlement processors, identity authentication, and dispute resolution are extensible and replaceable

Quick Understanding ​

What is ASP? ​

Agent Spend Protocol (ASP) is an embedded payment protocol designed for agent commerce, powered by stablecoin-based settlement. It enables AI agents to embed one-time payment mandates directly in protocol calls, achieving instant payment confirmation and deferred settlement.

Core Philosophy ​

ASP is built on the principle of "Authorize First, Settle Later":

  1. Authorization Phase: Payee receives a signed payment mandate from payer, transaction completes instantly
  2. Settlement Phase: Payee submits mandates to settlement processor within settlement window to batch debit from payer's on-chain wallet

This design enables ASP to support high-frequency, low-latency micropayment scenarios while maintaining transaction security.

Key Features ​

Two Transaction Modes ​

Intent Mode (Payer-Initiated)

  • One-round interaction, low latency
  • Suitable for micropayments, automated calls

Order Mode (Payee-Initiated)

  • Two-round interaction, flexible pricing
  • Suitable for task settlement, subscription services

Protocol Integration ​

  • x402: HTTP protocol extension for agents
  • MCP: Model Context Protocol
  • A2A: Agent-to-Agent communication
  • AP2: Agent user authorization protocol

Why Choose ASP? ​

FeatureTraditional PaymentASP
Transaction SpeedSlow (wait for on-chain confirmation)Fast (authorization completes immediately)
Transaction CostHigh (every transaction on-chain)Low (batch settlement)
Minimum AmountLimited (affected by gas fees)Very low (supports micropayments)
Trust ModelPay first, service laterAuthorize first, settle later
ProgrammabilityLowHigh (embedded payments)
ComplianceLimitedComplete (KYA/Dispute)

Start Exploring ​

📖 Understanding the Protocol ​

  • Overview - Understand ASP's design philosophy and core features
  • Core Concepts - Deep dive into payment mandates, debit wallets and other key components
  • Transaction Modes - Learn about Intent Mode and Order Mode

🏗️ Architecture ​

  • Architecture - Explore system components, roles and extensibility

Agent Spend Protocol · Making AI Agent Payments as Natural as Breathing

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Released under the MIT License.

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