Pre-Alpha

Spending controls
for AI agents

Open-source financial governance for autonomous agents making x402 payments. Policy engine, audit trail, and circuit breakers — so your agents spend smart.

Everything a CFO would want.
Built for machines.

Paybound sits between your AI agents and the payment facilitator, enforcing policies before money moves.

🛡

Policy Engine

Per-agent budgets, per-transaction limits, time-windowed spending caps, and allowlists. Define rules in YAML, enforce them at the proxy.

📊

Transaction Ledger

Full audit trail with cost attribution. Every payment attempt is logged — approved or denied — with the policy decision and reasoning.

🔄

Proxy Facilitator

Transparent interception of x402 payment flows. Drop-in replacement that agents use without code changes. Forwards to any upstream facilitator.

Circuit Breakers

Automatic spend freezes when anomalies are detected. Rolling windows catch runaway agents before they drain your budget.

Simple by design

A pass-through proxy with a policy engine and a SQLite ledger. Paybound never touches, holds, or redirects funds.

🤖 AI Agent
@paybound/sdk
——→
x402 request
⛨ Paybound Proxy
policy · ledger · breakers
——→
if approved
🏦 Facilitator
settlement + compliance
——→
payment settled
🌐 Resource
API / content

Up and running in minutes

Drop in the SDK, point your agents at the proxy, define policies in YAML. That's it.

example.ts
import { PayboundClient } from '@paybound/sdk';

// Point your agent at the Paybound proxy
const client = new PayboundClient({
  proxyUrl: 'http://localhost:4020',
  agentId:  'research-bot-1',
});

// Make x402 payments — Paybound enforces your policies
const response = await client.fetch(
  'https://api.example.com/data',
  { method: 'GET' }
);

// ✅ Approved: under budget, within limits
// ❌ Denied:  over budget → logged + blocked

What Paybound doesn't do

These aren't just design choices — they're hard constraints.

🚫

Never custodies funds

Paybound never holds, escrows, or controls money. All settlement flows through the upstream facilitator.

🚫

Never redirects payments

Payment destinations are pass-through. Paybound can block a payment, but never change where it goes.

🚫

Never issues tokens

No token, no coin, no points. Paybound is governance infrastructure, not a financial product.

Fully open source

MIT licensed. Read every line. Self-host it. Fork it. The code is the trust layer.

Your agents are spending money.
Shouldn't someone be watching?

Paybound is pre-alpha. We're looking for feedback from builders working with x402 and autonomous agents.