Prove What Your AI Did, Without Exposing the Data
NexArt generates cryptographically verifiable records of AI execution. Watch how a Certified Execution Record is created, verified, and tamper-tested in under two minutes.
NexArt is not a logging or observability tool. It is an AI evidence layer that produces cryptographically verifiable proof of execution.
This demo shows the full lifecycle: execution → certification → verification → tamper detection.
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The four stages of a Certified Execution Record
Every NexArt run follows the same lifecycle. Each stage produces a specific, verifiable artifact.
Step 1: Execute
An AI system runs. A prompt, input, and output are produced by your model, agent, or workflow. NexArt does not change how your system runs; it attaches at the execution boundary.
Step 2: Certify
NexArt generates a Certified Execution Record (CER). Raw data is processed transiently; sensitive fields are replaced with SHA-256 cryptographic commitments. An independent attestation node signs the certificate hash with an Ed25519 key.
Step 3: Verify
Anyone can independently verify the record at verify.nexart.io using standard cryptographic checks. No NexArt account is required. Verification recomputes the hash and checks the signature against the node's published key.
Step 4: Tamper detection
If any protected field of the record is modified after sealing, the certificate hash no longer matches and verification fails immediately. The record is either intact or it is not.
Logs, observability, and the AI evidence layer
NexArt sits in a different category from logging and observability tools. The three complement each other; they solve different problems.
| Dimension | Logs | Observability | NexArt (AI evidence layer) |
|---|---|---|---|
| Primary purpose | Record events the operator's system emits | Trace, debug, and monitor system behavior in real time | Produce cryptographically verifiable proof of AI execution |
| Trust model | Trust the operator's storage and process | Trust the operator's pipeline and vendor | Verify independently against a public Ed25519 key |
| Tamper resistance | None. Editable, deletable, replayable | Retention controls, but operator-mutable | Tamper-evident. Any change breaks the hash |
| Data exposure | Stores raw payloads by default | Stores traces, spans, and prompts by default | Confidential by default. Commitments, not raw data |
| Verifiable by third parties | No | No | Yes. Offline, without a NexArt account |
| Best used for | Operational debugging and forensics | Performance, latency, prompt inspection | Proof, compliance, disputes, client verification |
Debug with logs. Monitor with observability. Prove with NexArt.
When should you use NexArt?
Four decision triggers indicate that verifiable execution, not logging, is what you need.
Logs are no longer sufficient
You need to prove what happened to a third party who does not trust your infrastructure. Application logs can be edited, replayed, or backdated by the operator.
Proof is required
A regulator, auditor, client, or counterparty needs cryptographic evidence, not just a report. NexArt records verify independently with an Ed25519 signature.
Data cannot be shared
Inputs or outputs contain PII, trade secrets, or regulated data. Confidential mode replaces raw values with SHA-256 commitments so the record is verifiable without exposing the underlying data.
An AI decision is likely to be disputed
Lending, hiring, medical triage, insurance, moderation. You want a defensible record of exactly what the model saw and produced, sealed at the moment of execution.
Key properties
- No raw data stored (confidential mode uses cryptographic commitments)
- Independent verification, offline, without a NexArt account
- Tamper-evident under SHA-256 canonicalization
- Works with any AI system: models, agents, workflows, tool calls
- Optional identity binding (email, user ID, organization)
Use cases
Client verification (portable proof)
Hand a signed, portable Certified Execution Record to a client so they can independently verify what your AI produced. No access to your infrastructure required.
Audit and compliance (tamper-evident evidence)
Produce tamper-evident execution evidence for EU AI Act record-keeping, ISO 42001, NIST AI RMF, and SOC 2 audits. Verifiable by third parties.
Dispute resolution (defensible records)
When an AI decision is challenged, a cryptographically signed record proves exactly what the system saw, what it produced, and when. Defensible against later edits.
Agent execution tracking (verifiable workflows)
Attach a Certified Execution Record to every agent step. Chain them into a Project Bundle for a verifiable end-to-end workflow trace.
Category positioning
NexArt is the AI evidence layer. It produces tamper-evident, cryptographically verifiable records of AI execution, sealed at the moment they happen.
NexArt complements observability tools. Systems such as OpenTelemetry, Langfuse, LangSmith, Helicone, and Datadog help operators debug and monitor their own AI systems. NexArt produces a portable proof artifact that any third party can verify without access to the operator's infrastructure. A production AI stack typically uses both.
NexArt replaces logs when proof is required. Traditional application logs can be edited, replayed, or backdated by the operator. A Certified Execution Record is bound to a SHA-256 hash the operator did not choose and countersigned by the NexArt attestation node. Any modification to a protected field breaks verification immediately.
Independent verification is the point. Every record can be verified offline at verify.nexart.io using standard cryptographic checks: recompute the hash, validate the Ed25519 signature against the attestation node's published key. No NexArt account, no operator cooperation, no vendor lock-in.
Try it yourself
Run the interactive demo, or verify a real Certified Execution Record independently.
Related: How it works (detail) · Certified Execution Records · Confidential execution