Verifiable Settlement Layer

Don't just format your data.
Prove it.

A non-custodial API that validates a payload against its bound schema, recovers what it can, signs the result, and hands it straight back. Receiving parties verify the signature themselves, offline, against published public keys.

Start with SDCStudio Test locally, free
sdcvalidator — reject, then recover
Real output, not a mockup. A malformed xdcount-value is kept and tagged INV, an ISO 21090 exceptional value carrying the reason, so the record stays valid and stays signable. Reproduce it with sdcvalidator 4.5.0.
sdcvalidator on PyPI Apache-2.0 source SDCRM specification ISO 21090 exceptional values

What it does

Three properties, each one checkable

Non-custodial

We sign your data. We do not store it.

The payload is validated, signed, and returned. Nothing is retained. You keep control of where sensitive healthcare, financial or supply-chain data travels and who receives it.

Recoverable

Semantic errors do not have to break the pipeline.

A standard validator rejects bad data and stops. Tier 2 validation quarantines the unresolvable part and injects an ISO 21090 Exceptional Value in its place, so the record stays valid, stays signed, and keeps moving with the gap recorded rather than hidden.

Independently verifiable

Verification needs nothing from us.

Signatures are checked against openly published keys. No call to our servers, no account, no rate limit, and no dependency on us continuing to exist. That last property is the point of the whole design.

How you adopt it

Build locally. Verify anywhere.

1

Test for free

Run sdcvalidator locally against your own models. Apache-2.0, no account.

2

Sign through the API

Send a validated payload to VSL. It comes back signed, with the validation metadata bound into the record.

3

Recipients verify offline

They check the signature against the published key. You are not in the loop, which is what makes it scale.

The shape of it

Payload in, signed payload out

Axius sits in the middle of the exchange for exactly one round trip. Nothing is retained, and the recipient never has to come back to us.

The VSL round trip An originator submits a payload; VSL validates it against its bound schema, injects an ISO 21090 exceptional value for any recoverable semantic gap, signs the result and returns it; the recipient verifies the signature offline against the published public key. ORIGINATOR AXIUS · VSL RECIPIENT Model and rules bound Payload generated Signed payload held Validate against schema Recoverable gap: inject ISO 21090 EV Sign · ECDSA P-256 Signed payload received Verify offline, published key Process, or reject as tampered submit return signed copy back

Structural failures are rejected outright with an error report. Only recoverable semantic gaps take the exceptional-value path, and the gap is recorded in the record rather than papered over.

Prove it, don't assert it.

Start with the open-source validator. Move to signed validation when you need a third party to check your work without trusting you.

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