The Authorization Problem Nobody's Solving

This week, the AI payments space moved fast.

Cloudflare gave AI agents identity and wallets. MetaMask announced agent wallets with "mistake recovery" features. Catena Labs raised $30M from a16z to build an AI-native bank with a national trust charter.

One question went unanswered across all announcements:

Can you prove the agent was authorized to spend that?

The Liability Gap

Giving agents payment access is straightforward. Connect a wallet. Sign transactions. Done.

The hard part isn't the payment mechanism. It's proving intent.

When an agent books a $4,800 flight instead of a $480 one, finance will ask: "Who authorized this?" Without cryptographic proof of policy bounds, you're stuck reconstructing intent from logs.

That's not an audit trail. That's a liability exposure.

Two Architectural Models

The industry is splitting into two camps:

Reactive authorization: Give agents broad wallet access. Monitor transactions. Recover from mistakes after they happen.

Proactive authorization: Constrain what agents can do before money moves. Make unauthorized transactions cryptographically impossible.

MetaMask's "mistake recovery" is reactive. You already lost the money. Now you're recovering it. That's damage control, not authorization.

The problem: enterprises don't want recovery. They want prevention.

What Pre-Authorization Actually Means

Real authorization is architectural, not procedural.

At AgentWallex, we built it with three layers:

1. MPC 2-of-3 Threshold Signing

No single party holds a complete private key. The agent holds one share. The policy engine holds another. A backup share sits in secure storage.

Transactions require 2-of-3 signatures. The agent can initiate. But the policy engine must co-sign.

This isn't multisig with human approvers. It's automated cryptographic verification against pre-set rules.

2. Policy Constraints as Code

Before any transaction executes, it's verified against policy:

const policy = {
  dailyLimit: 5000, // USDC
  allowlist: ["vendor-a.eth", "vendor-b.eth"],
  rateCap: 10, // transactions per hour
  timeWindow: { start: "09:00", end: "17:00", timezone: "UTC" }
};

The policy engine evaluates every transaction:

Does it exceed daily spend?
Is the recipient on the allowlist?
Is it within rate limits?
Is it during allowed hours?

If any check fails, the co-signature doesn't happen. The transaction is rejected before it reaches the blockchain.

3. On-Chain Proof of Intent

Every approved transaction includes policy metadata:

{
  "txHash": "0x7f3e...",
  "agent": "agent-id-42",
  "amount": 480,
  "recipient": "vendor-a.eth",
  "policyVersion": "v2.3",
  "constraints": {
    "dailyLimit": 5000,
    "allowlist": ["vendor-a.eth"],
    "timestamp": "2025-04-23T14:32:01Z"
  },
  "signatures": ["agent-share", "policy-share"]
}

This isn't an audit log you generate later. It's cryptographic evidence generated at authorization time.

If the agent tried to send $4,800, the policy engine wouldn't co-sign. The transaction wouldn't exist on-chain. No recovery needed.

The CFO Scenario

An autonomous procurement agent runs for three months. Finance asks: "Can we verify every transaction was authorized?"

Without policy bounds:
You pull agent logs. Cross-reference transaction history. Hope the agent didn't delete or modify records. Reconstruct intent manually.

With policy bounds:
You export on-chain transactions. Every payment includes the policy version and constraints that authorized it. Auditable, verifiable, tamper-proof.

The difference isn't UX. It's legal exposure.

Why This Matters Now

Catena Labs is building an AI-native bank. That's the custody layer.

We're building the payment gateway. That's the authorization and settlement layer.

Both are necessary. But neither solves liability unless authorization is cryptographically provable.

The question isn't "can agents pay?" It's "can you prove what you let them pay for?"

Pre-Auth vs. Post-Recovery

MetaMask's approach: agents act freely, mistakes get recovered.

Our approach: agents act within cryptographic bounds, certain mistakes can't happen.

It's the difference between a correction mechanism and a prevention architecture.

One assumes you'll need to undo transactions. The other makes unauthorized transactions impossible to sign.

The Missing Piece

The AI payments infrastructure is coming together:

Catena Labs is building the bank
x402 protocol is standardizing micropayments
Cloudflare and MetaMask are giving agents wallets

What's missing is provable pre-authorization.

Who decides what the agent can spend? How do you prove those limits were enforced? What happens when the agent tries to exceed them?

Those aren't product features. They're architectural requirements.

What We Built

AgentWallex is live in sandbox at app.agentwallex.com. 3,600+ teams on the waitlist.

The architecture:

MPC wallets via our Paratro infrastructure (2-of-3 threshold, no exposed keys)
Policy Engine with per-agent limits, allowlists, rate caps, time rules
x402 native for sub-150ms micropayment authorization
Unified payment engine for both task payments and API billing

It's not bolted-on compliance. It's authorization as infrastructure.

Every payment carries cryptographic proof of the policy that allowed it. Not post-hoc. Pre-authorized.

The Real Question

The industry is solving "how do agents pay?"

The harder question is "how do you prove you authorized it?"

That's not a wallet feature. It's an architecture.

We built ours on MPC + policy constraints. Provable pre-authorization, not mistake recovery.

Because if you need an undo button, your authorization already failed.

AgentWallex — The Payment Gateway for AI Agents

Sandbox live: app.agentwallex.com

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