Payment proxy for x402 APIs

Turn any x402 API into a simple fetch call.

We handle payments, signatures, and retries automatically.

No walletsNo gasNo payment logic
Read the docs
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%)
< 200ms
Median latency
ERC-3009
Gasless USDC auth
Base + Solana
Settlement
1 line
SDK integration
Try it right now

See the 402 flow, live.

Enter any x402-protected URL — watch the 402 → payment → 200 flow happen in real time.

Try a real x402 API call
4,976
API calls
49,760
Credits used
Try
Free end-to-end test on Base Sepolia — allow402 signs and settles a real on-chain USDC payment, but on testnet so it costs nothing.
Pick an example or paste any x402 URL. Quote previews the exact price (no call, no charge); Send runs the full flow. 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.

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…
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
Built for everyone

One platform, three use cases.

Everything included

Spend controls, out of the box.

Every key you issue comes with the full toolkit — no extra configuration.

agent-claudex402_a1b2…c3d4active
credits49,760 / 500,000
max/call 5,000expires neverrevocable
Configurable API keys
One key per agent — name it, fund it with a credit budget, cap per-call spend (maxCostPerCall). Scoped, revocable, hard-enforced in the database.
Credits Available
98.72M ≈ $98.72
Live dashboard
Balance, transactions, and call logs in real time.
0
1
2
3
4
5
Cache strategy 0–5
Pick how stale you'll accept — off to 24h. The more you tolerate, the cheaper: full price down to ×0.1.
← 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.
weather-api/forecast−1,000 · 2s ago
price-feed/BTC−2,000 · 14s ago
maps-api/geocode−3,000 · 41s ago
Full audit trail
Every call logged: endpoint, cost, latency, cache status. Per key, per service, in real time.
transferWithAuthorization(
  …signed by proxy wallet
)
EIP-3009 signing
We sign on your behalf via a secure proxy wallet. Keys never leave our infra.
$USDC$ € Fiat
1 = 1 µUSDC
Credit system
Pay with USDC or fiat. Balance in $ or €.
coinbase-pricesLIVE
weather-api
openai-proxy
Any x402 service
Base mainnet & Sepolia, plus Solana (SPL / Token-2022 USDC).
GET /v1/quote
?url=x402.goldrush.dev/…/aave.eth
→ { cost: 1050, costUsd: "$0.00105" }
Price preflight
Know the exact cost before you commit to a call.
Your data stays yours.
No API responses stored
Only billing metadata retained
Payment proofs for auditability
Scoped, revocable API keys
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
SDK playground

Run it yourself.

SDK Live Demo — x402 flow
$|
Why it matters

The internet is becoming machine-operated.

Agents will not "click APIs". They will call and pay for them autonomously. But today, no infrastructure exists for that.

allow402 is the missing payment layer.

Let your agents
pay their way.

One key. One budget. Every x402 API.

FAQ

Frequently asked questions.