Study 5 — code402 LEI Check Independent Assurance

Status

Phase 1 complete — paid fulfilment pending

Current classification: payment_contract_observed

Atinamos is independently testing the code402 lei-check paid machine service.

DRJ invited Atinamos to perform the test and explicitly welcomed publication of successes or failures. That invitation is recorded as provenance only. It did not alter the test method or result and should not be read as endorsement.

This page currently records a pre-payment contract observation. It does not claim that paid fulfilment has been verified.

Service under test

POST https://code402.dev/v1/tools/lei-check/call

The live service describes its useful scope as validation of a Legal Entity Identifier using structure plus ISO 7064 MOD-97-10 check digits.

A successful free-tier response explicitly stated:

scope: structure+checksum only

Atinamos observed no claim in that result that the LEI exists in an external registry.

Live request shape

An initial unwrapped request returned:

HTTP 400
INPUT_SCHEMA_INVALID
expected { "input": { … } }

The live REST request therefore required:

{
  "input": {
    "lei": "5493001KJTIIGC8Y1R12"
  }
}

The correctly formed request returned HTTP 200 through the free tier.

Free-tier observation

Observed at 2026-09-03 08:33:48 UTC:

{
  "valid": true,
  "normalized": "5493001KJTIIGC8Y1R12",
  "reason": "checksum valid",
  "scope": "structure+checksum only"
}

The response reported:

tier: free
settled: false

It also contained an XDR-1 receipt. Receipt signature verification is still pending, so the presence of that receipt is not being presented as independently verified cryptographic proof.

The checksum result itself will also be checked independently in the deterministic-test phase before a paid fulfilment conclusion is reached.

Published payment metadata

The live health and x402 discovery surfaces advertised:

The health surface reported dynamic pricing. The test therefore treats live values as timestamped observations rather than permanent price claims.

Authoritative HTTP 402 challenge

After the free-tier allowance was exhausted, an ordinary unsigned request returned HTTP 402 at 2026-09-03 08:50:49 UTC.

The payment-required header decoded to:

x402Version: 2
scheme: exact
network: eip155:8453
amount: 999
payTo: 0xc59c85e661d34084a7769f955d17fd38254a6235
maxTimeoutSeconds: 300
asset: 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913

This is the canonical Phase-1 preflight contract retained by Atinamos.

Dual x402 representation observed

The same response also carried a compatibility JSON body reporting:

x402Version: 1
network: base
scheme: eip3009
chain_id: 8453

while the payment header used x402 v2 and eip155:8453.

Atinamos records this as a dual representation observed, not as a defect. Later payment/interoperability testing may show whether the distinction is operationally significant.

What has been established

Phase 1 independently establishes that, at the observation time:

• the endpoint was reachable;
• the live request envelope could be determined;
• the service exposed a narrow structure+checksum only scope;
• the free tier returned a structured result and XDR-1 receipt;
• the current price and payment destination were machine readable;
• malformed payment material was rejected;
• the service produced a genuine unsigned HTTP 402 payment challenge;
• the authoritative header challenge represented x402 v2 on Base.

What has not yet been established

Atinamos has not yet:

• signed a valid payment authorisation;
• spent USDC on this test;
• observed paid settlement;
• observed paid fulfilment;
• independently recomputed the LEI checksum expectation;
• verified the XDR-1 receipt signature;
• established that the LEI exists in any registry.

Those later stages will be added to this same study.

Machine-readable buyer evidence

A buyer can query the exact service route:

GET /v1/trust?endpoint=https://code402.dev/v1/tools/lei-check/call

The current record deliberately tells a buyer that the payment contract has been observed but paid fulfilment remains pending.

That distinction lets the buying agent apply its own policy rather than receiving a universal Atinamos BUY/NO-BUY verdict.

Public technical evidence

The sanitised technical Phase-1 record is published in the Atinamos evidence repository:

• code402 LEI Check experiment
• Machine-readable evidence

Current conclusion

Atinamos independently observed a coherent live payment contract for code402 LEI Check and a narrowly stated structure/checksum scope. Paid fulfilment and XDR-1 signature verification remain untested at this stage.

A successful contract observation is evidence. It is not a permanent trust rating.

You can pay to be tested. You cannot pay to be trusted.