allow402
Coming soon
Built for the agentic web

AI agents call paid APIs. No crypto required.

allow402 sits between your agent and any x402-protected API. Your agent makes a normal HTTP request. We handle the 402, the wallet, the EIP-3009 signature. It just works.

allow402 — Key activity
Live
Keys
4
Calls
1,281
Spent
1.34M
research-agentx402_a1b…active
847 calls892k214ms avg
892k / 2.0M credits (45%)
data-pipelinex402_c3d…active
312 calls328k183ms avg
328k / 1.0M credits (33%)
prod-appx402_e5f…idle
98 calls103k891ms avg
103k / 0.5M credits (21%)
claude tool-usex402_g7h…idle
24 calls25k156ms avg
25k / 0.2M credits (13%)
Live demo

Try it right now.

Enter any x402-protected URL — see the 402 → payment → 200 flow live.

Try a real x402 API call
4,976
API calls
49,760
Credits used
Replace aave.eth with any ENS name, then hit Run — both outcomes appear side by side, right here. No signup.
The problem

Why developers struggle with API payments

Every option available today forces you to make a painful tradeoff.

01
x402 APIs need a wallet
Your agent has no wallet. x402-protected APIs respond with 402 Payment Required and expect an on-chain USDC authorization — your agent can't produce one.
✗No wallet = no access
✗Can't store private keys in agent memory
✗Every new API needs its own setup
02
EIP-3009 signing is complex
The protocol requires EIP-712 typed signatures, nonce management, and precise deadline handling. One mistake and calls fail silently with no useful error.
✗EIP-712 domain hashing pitfalls
✗Nonces must be unique per transfer
✗Silent failures with no debug info
03
Reimplementing 402 every time
Every agent project that touches a paid API needs the same 402→sign→retry loop. Weeks of plumbing before your agent makes its first useful call.
✗No reusable abstraction
✗Hard to test, harder to monitor
✗Zero visibility into spend per agent
allow402 solves all three.
No wallet to manage. No billing to build. The full x402 stack, abstracted into one API key.
Coming soon
Architecture

How it works

allow402 sits as a transparent proxy. You never touch a wallet.

01
You call the API
SDK or HTTP with your API key. No wallet, no private keys needed.
02
We intercept the 402
We parse the payment requirements and sign an EIP-3009 USDC authorization.
03
You get the 200
Facilitator verifies on Base. API returns 200. Credits auto-deducted.
AI Agent
→
allow402
→
x402 API
Waiting…
Built for everyone

One platform, three use cases.

For AI Agents

Autonomous payments for autonomous agents.

Give your LLM agent an allow402 key and a credit budget. It calls any paid API — no approval loop, no gas management.

✓Pre-funded credit budgets
✓Per-key spend limits
✓Full audit trail
For Developers

Ship in minutes, not weeks.

Two lines of SDK code and you're calling any paid API. No wallet, no blockchain knowledge. Focus on what you're building.

✓JS & TS SDK
✓Works in any environment
✓Full event logging
For Teams

Distribute budgets, not credentials.

Issue one key per teammate or agent with its own credit cap. When it's gone, it's gone. One account, full visibility.

✓Per-key spend caps
✓Real-time usage per member
✓Revoke any key instantly
Features

Everything handled for you.

API key auth
Generate keys in the dashboard. Scoped, revocable, tracked. No OAuth dance.
EIP-3009 signing
We sign transferWithAuthorization on your behalf via a secure proxy wallet.
Credit system
1 credit = 1 micro-USDC (10⁻⁶). Top up with card or crypto. View your balance in $ or €.
Credits Available
98.72M ≈ $98.72
Live dashboard
Balance, transactions, and call logs in real time.
coinbase-pricesLIVE
weather-api
openai-proxy
maps-api
Any x402 service
Register any x402-compatible API. Base mainnet and Sepolia supported.
← 402 Payment Required
⚡ signing EIP-3009...
→ PAYMENT-SIGNATURE: eyJ...
← 200 OK ✓
Transparent retry
402 → sign → retry is invisible. Your code always gets a clean 200.
Your data stays yours.
✓API requests are never stored
✓API responses are never stored
✓Only billing metadata is retained
✓Payment proofs kept for auditability
SDK

Two lines. Payment handled.

Give your agent an API key. The 402 flow, the wallet, the EIP-3009 signature — none of it reaches your code.

✓ No wallet setup
✓ No USDC management
✓ No on-chain transactions
$ npm install @allow402/sdk
SDK Live Demo — x402 flow
$|
index.ts
import { Allow402Client } from '@allow402/sdk'

const client = new Allow402Client({
  apiKey: process.env.ALLOW402_KEY,
  logLevel: 'verbose',  // see every payment event
})

// Proxy any x402-protected URL
const result = await client.proxy(
  'https://api.weather.com/v1/forecast'
)

console.log(result.data)
// → { temp: 22, condition: 'sunny' }

console.log(result.payment.amountUsd)
// → "$0.000025"
Key budgets

Your keys,
your budget.

Create API keys with a fixed credit allocation. Each key spends freely — but only within the budget you set.

01
Create a key with a credit budget
Allocate a fixed amount of credits to an API key. Those credits are reserved — set aside specifically for that key.
02
Hand it to any program or client
Share the key with a backend, a script, an AI agent, or a third-party service. No wallet, no top-up, no crypto knowledge needed.
03
It only spends what you gave it
The key is hard-capped at its budget. Calls beyond the limit are rejected automatically. You stay in full control.
allow402
ACTIVE
prod-app
x402_abc••••••••••••
CREDIT BUDGET
0 / 500k
≈ $0.00 / $0.50
RECENT CALLS
weather-api/forecast
−1k
price-feed/BTC
−2k
weather-api/forecast
−1k
maps-api/geocode
−3k
Building a x402 API?
Generate a key with a small credit budget — enough for a few test calls — and share it with your customers. They test your API immediately, no wallet, no USDC, no friction.
Coming soon
Comparison

Infrastructure you don't build anymore.

Everything that used to take weeks of crypto infra work — handled.

Feature
✕ Without allow402
✓ With allow402
HTTP 402 handling
No native support
Built-in payment layer
Wallet management
Private keys + signing infra
Fully abstracted
Settlement
Blockchain tx complexity
Instant finality layer
Access control
Manual request gating
Automatic API proxy
Billing
Reconcile usage manually
Real-time credit metering
Abuse protection
Rate limits + fraud logic
Handled automatically
Time to launch (traditional)Weeks
Time to launch (allow402)Minutes
FAQ

Frequently asked questions.

Ready to call your first x402 API?

Create an account, get an API key, and make your first call in under 5 minutes.

allow402

payment proxy · agentic web