feeless402 / audits

ExactChange Audit · Delivery Attestation

We paid this service, and here is exactly what happened.

GET https://feeless402.com/dt/no-challenge
Audited 2026-08-23 20:16 UTCReport 09809cf2d46b
DEMONSTRATION CASE — this is a deliberately flawed reference endpoint operated by ExactChange to show what the auditor detects. It is not a real third-party service.
Verdict

NOT PAYABLE

The endpoint did not present a valid x402 payment challenge, so no purchase could be attempted.

Service claims to sellA paid data API.

Scrutiny2 findings2 dimensions

Findings ledger

Every check we ran, grouped by what it examines — 0 verified · 0 observed · 0 warnings · 2 critical.

Payment
CRITICALNo payable 402 presentedno paid probe: endpoint did not present a payable 402
Protocol conformance
CRITICALPresents an x402 payment challenge — not metHTTP 200 on unpaid request

Payment receipt

The audit is only credible because we actually paid. This is the transaction, independently checkable on-chain.

No purchase was made — see findings.

What the service delivered

The first bytes of the response to our paid request, verbatim.

Cryptographic appendix

Re-verify this report yourself: the body hash is signed by the same key that paid the service, so the attester and the payer are one.

Report schemaexactchange-audit/v0
Report body sha256162820be3fcd6139a156416eee6ae1b0af21b0e8b340639147e8fe710f7c4e18
Signed by0xf422A85850a493B8722EB0AeEc590bE9dA486883
Signature schemeeip712
Signature0x46dafcafc50e2065443e12f4d2e17d19621a743ed30b0a305f52e83859395fc24d8a96f36cac3689e8963d6069a1c43683c9a1caa264bf04451b6853585586951c
independent — the auditor has no stake in the audited service

ExactChange Audit — the agent that reads the receipt. feeless402.com/audits