We can't find a single x402/L402 security test outside this repo. Prove us wrong.

[msaleme]

x402 is processing 1B+ HTTP 402 responses/day through Cloudflare. L402 is growing on Lightning. Agent-to-agent payments are becoming real.

But who's actually testing the security of these flows?

We built 39 dedicated tests for agent payment protocols — unauthorized execution, budget overflow, replay attacks, facilitator trust, cross-chain confusion, autonomy risk scoring. As far as we can tell, no other tool covers this.

Questions for the community:

• Are you integrating x402 or L402 into agent workflows? What's your security testing look like today?
• What payment-specific attack scenarios worry you most?
• Would a CI gate that scores "should this agent spend money unsupervised?" be useful?

We're especially interested in hearing from teams at fintechs, neobanks, or payment platforms building on these rails.

Context:

• x402 test suite (25 tests)
• L402 test suite (14 tests)
• Agent Autonomy Risk Score

[msaleme]

Update: this question aged well.

AI trading agents just lost $45M because no one tested what happens when an agent can approve its own payments. Step Finance's treasury was drained of 261,854 SOL — not through a smart contract exploit, but because the agents had the same wallet permissions as the compromised executives. No spending ceiling, no multi-sig gate, no rate limit on autonomous payment decisions.

Our x402/L402 harness (X4-055, X4-038, X4-014) tests for cascading payment chains, double-spend, and fake facilitator injection. Full writeup with code snippets and gap analysis here: #177

Still haven't found another x402/L402 security test suite. The offer stands.