Your AI agent works. You stay in control of every cent.

The gap

Put a policy in front of each payment.

Learn how to set an x402 spending allowance, or use Wallie Cloud x402 spending guide to monitor connected agents.

Payment settlement and spending policy solve different problems. Wallie checks your configured limits before authorizing a payment.

How it works

Three moves, then it runs itself.

One-time funding, then fully autonomous fine-grained pay-per-use — every call authorized against policy before money moves.

1

Fund the allowance once

Provision a dedicated agent wallet and load it with a fixed allowance. The agent can never touch more than this — by construction, not by promise.

terminal — human, one timecopy

$ npx wallie init            # provisions agent wallet
$ npx wallie topup 5.00      # loads the $5.00 allowance
$ npx wallie policy perCallMaxUsd 0.50
$ npx wallie policy allowHostSuffixes '["localhost","api.weather.example"]'

2

The agent pays its own way

Swap fetch for payingFetch. Wallie speaks the full x402 wire protocol — 402 challenge, price discovery, signed payment, settlement receipt — and authorizes each price through your policy before signing anything.

Before — raw fetch After — wallie

agent codecopy

const res = await fetch(url);

// ❌ 402 Payment Required — nothing is
//    attached, so the call just fails …
// … or the agent pays with no ceiling,
//    no allowlist and no audit trail.

agent codecopy

import { payingFetch } from "wallie";

const r = await payingFetch(ctx, url);

// ✅ 402 → policy check → sign → pay →
//    retry → receipt → append to ledger
// r.txHash · r.costMicro · r.blockedBy

3

Watch everything. Intervene anytime.

A live dashboard shows balance, spend by destination, and every blocked attempt. Flip the kill switch to block subsequent authorizations. Already signed or settled payments cannot be recalled. Underneath, an append-only ledger records every authorization, payment, and block with rule, reason, and tx hash: your local decision history.

.allowance/ledger.jsonl — append-only audit logLocal decision history

{"t":"payment","at":"2026-08-25T09:41:02Z","url":"…/weather?city=lisbon","amountMicro":"1000","txHash":"0xcddcb9a6…"}
{"t":"payment","at":"2026-08-25T09:43:57Z","url":"…/research?topic=agent-payments","amountMicro":"250000","txHash":"0x4e5bc352…"}
{"t":"blocked","at":"2026-08-25T09:44:31Z","rule":"velocity_circuit_breaker","detail":"rolling 12s spend would exceed $2.00 limit","attemptedMicro":"10000"}

Guardrails

Six rails. All enforced before money moves.

Policies live in a hot-reloaded config file. Change them any time — the next call uses them. Five rules block outright; one escalates to a human.

── PHASE 1 · fine-grained pay-per-use ──
  PAID    weather?city=lisbon        $0.001000  0xcddcb9a6…
  PAID    research?topic=agent-pmts  $0.250000  0x4e5bc352…
 
── PHASE 2 · runaway loop ──
  PAID    loop #1 … #149             $0.010000 each
  BLOCKED loop #150                  velocity_circuit_breaker
 
── PHASE 3 · attack & mispricing ──
  BLOCKED evil-api.example.com       host_not_allowlisted
  BLOCKED report?id=q3-2026          human_approval_required
  BLOCKED feed?key=pro               per_call_cap
 
── RESULT ──
  spent $1.99 across 154 settled payments · 5 blocks enforced
  remaining allowance: $3.007 of $5.00

Protocol

Built on x402. Pluggable settlement.

Wallie includes live USDC payment support on Base and Base Sepolia. The buyer supports x402 v1 and v2 for supported exact-payment offers. Wallie also has a Solana rail with exact payments and upto payment channels, including a recorded public devnet settlement. Start with the practice-money demo, then follow the live-network guide. Seller integrations can use the included Coinbase CDP adapter behind this interface:

interface Facilitator {
  verify(payment: PaymentPayload): Promise<VerifyResult>;
  settle(payment: PaymentPayload): Promise<SettleResult>;
}
// MockChain for practice · Coinbase CDP adapter included for live seller integration

Proof of work

Receipts, not testimonials.

Wallie is a young open-source project, so we do not borrow logos or invent numbers. Instead, here is what you can check yourself: real settlements on public chains, a demo you can run, and source you can read line by line.

Every claim on this page links to its receipt. Practice-money demos are labelled as such; live settlements link to a public explorer.

Stocklana hackathon

The same allowance, now on Solana.

Wallie was built into the Stocklana hackathon — $126,000 in prizes for agents that work with tokenized stocks. Three pieces run on the same six guardrails and the same audit ledger you saw above: a Solana x402 payment rail, a Meteora DBC exit report for the $5,000 Meteora bounty, and a PreStocks premium report with a policy-bounded buyer for the $10,000 PreStocks bounty. Judging closes after 2 October 2026; nothing here claims a prize.

Pricing

Open source core. Hosted when you're ready.

The runtime is open source and self-hostable. Wallie Cloud adds a hosted event feed and heartbeat monitoring that keeps running when your agent's machine is offline.

FAQ

Questions engineers actually ask