x402
HTTP 402 Payment Required — the native web standard for machine payments.
- Native HTTP integration
- Facilitator-agnostic
- Works with any EVM chain
Agent Commerce Control Layer
Stop Agent spend before it becomes an incident.
Harpd puts every Agent payment behind policy, budget and approval — then turns the result into a finance-ready reconciliation and audit trail. Start with a no-code paid pilot; keep your wallets and facilitators.
Non-custodial — never touches funds Pre-payment policy enforcement Signed intent receipts Live in minutes, not weeks
app.harpd.com/overview
Today SpendLive USDC volume
Today CallsEvery agent call
Active AgentsYour AI agents
AnomaliesFlagged instantly
Budget Alert
Per-agent budget alerts
Per-agent budget alerts
New Endpoint
List endpoints in the Marketplace
List endpoints in the Marketplace
Reconciled
Reconciled on-chain
Reconciled on-chain
Paid pilot · 14 days · no code changes
From runaway spend to an evidence pack your finance team can sign off.
We connect a Collector or gateway in front of your existing payment path, configure guardrails, and leave you with measured savings — not another dashboard to maintain.
See the pilot plan → Best for teams with live Agent spend or a security review blocking launch.
About this page
How to use this page
- Skim the hero to understand what Harpd does in one line.
- Use Start Free to create an account, or Read Docs to self-serve.
- Explore the product sections — Protocols, Features, Marketplace — and open the FAQ for common questions.
What you'll find here
- A capability overview, a live dashboard preview, supported protocols and facilitators, feature breakdown, marketplace samples, and a FAQ.
One Platform, Every Protocol
x402, MPP, AP2 — unified observability above any facilitator. No vendor lock-in.
MPP
Machine Payments Protocol — an HTTP-native payment flow for agents paying for API and tool calls.
- Session-based budgets
- Mandate management
- Reservation & settlement
AP2
Agent Payments Protocol — signed mandates and verifiable authorization for agent-initiated payments.
- Signed mandates
- Verifiable user intent
- Configurable guardrails
Works across payment and infrastructure integrations
We sit above the facilitator layer — aggregating, reconciling, and scoring across payment rails and the infrastructure around them.
Don't see yours? Request a facilitator integration — we add new ones weekly.
The controls that unlock production
Move from “we hope the agent behaves” to a payment path that is denied by default, reviewable and provable.
Payment Firewall
Every settlement is checked before money moves. Deny risky requests, reserve budget and escalate high-impact payments to a human.
- Sub-second event ingestion
- Per-agent & per-endpoint breakdown
- Settlement status tracking
- Anomaly detection (spikes, dead endpoints, concentration)
Proof, not just logs
Give security, finance and customers a complete answer for every automated payment: who acted, why it was allowed and what settled.
- eth_getTransactionReceipt verification
- Mismatch detection & alerting
- Confirmation latency tracking
- Sweep API for bulk reconciliation
Budget Engine & Approvals
Hard limits per agent, session, or mandate. Human-in-the-loop approval for large payments — before they settle.
- Daily/monthly budgets per agent
- 80%/100% alert thresholds
- Approval queue for large payments
- Session budgets and AP2 mandate guardrails
Marketplace: Monetize Your Endpoints
List your x402/MPP/AP2 endpoints in the neutral directory. Buyers discover by quality score — you get paid automatically.
- Cross-tenant discovery
- Quality scores from real usage
- 10% revenue share, Stripe Connect payouts
- Featured slots for visibility
Enterprise Compliance
VAT calculation, fiat invoicing, expense categorization, audit-ready exports — built for finance teams.
- Multi-jurisdiction VAT rates
- Automated invoice generation
- Expense categories & GL codes
- Tamper-evident audit exports
White-Label & OEM
Resell Harpd as your own observability layer. Custom domain, branding, partner revenue share — your customers never know we exist.
- Full white-label (logo, colors, domain)
- Sub-tenant provisioning via API
- Configurable revenue share (default 20%)
- Partner dashboard & analytics
The Neutral Endpoint Directory
Discover, compare, and monetize agent-payable endpoints. Quality scored on real usage across all Harpd tenants.
x402 data Featured
Weather API Pro
Real-time weather data for any coordinate — sample listing.
Calls2.3M
Spend$4,821
Reliability99.8%
Latency187ms
MPP compute Verified
LLM Inference Cluster
Distributed LLM inference with session-based billing. Supports Llama-3, Mixtral, custom models.
Calls847K
Spend$12,450
Reliability99.2%
Latency1.2s
AP2 finance
KYC Verification
Automated KYC/AML checks for agent onboarding. Mandate-based recurring verification.
Calls156K
Spend$7,890
Reliability100%
Latency2.1s
Ready to Ship Production Agent Payments?
Join 100+ teams building on Harpd. Free tier includes 10K events/month — no credit card required.
Questions? Talk to our team or join Discord
Frequently asked questions
What is Harpd?
Harpd is the Agent Commerce Control Layer — a non-custodial payment firewall for AI agents. It decides what an agent may spend, who it may pay, and when a human must approve, then creates verifiable evidence for every decision.
How does Harpd work?
Route settlements through the Harpd Gateway or instrument your agents with
@harpd/observe. Harpd checks identity, vendor policy, budget, approval and idempotency before settlement, then reconciles the result and signs a traceable payment receipt.Does Harpd hold my money or private keys?
No. Harpd is strictly non-custodial. It observes and reconciles payments but never custodies funds, signs transactions, or stores private keys. Settlement happens on-chain between your agents and the facilitator.
Which payment protocols does Harpd support?
x402 (HTTP 402 Payment Required), MPP (Machine Payments Protocol), and AP2 (Agent Payments Protocol). Harpd unifies observability across all three.
Which blockchains and integrations are supported?
Harpd is designed for Ethereum, Base, Arbitrum, Polygon, and other EVM chains. Integrations vary by protocol and can include Coinbase, Stripe, Circle, infrastructure providers, and your own self-hosted facilitator.
Can I monetize my own endpoints?
Yes, via the Harpd Marketplace. List your x402/MPP/AP2 endpoints, get discovered by quality score, and receive payouts through Stripe Connect with a 10% revenue share.
Is the Harpd observer SDK open source?
The
@harpd/observe observer SDK is open source. The dashboard and collector are commercial with a free tier of 10,000 events/month.How much does Harpd cost?
There is a free tier with 10,000 events/month and no credit card required. Paid plans scale by event volume — see Pricing.