AI Decision Logging for Auditability and Traceability
Every AI decision, cryptographically recorded. Append-only logs signed with Ed25519 — independently verifiable, tamper-evident, and audit-ready.
AI decision logging is the foundation of AI governance. Without verifiable records of how decisions were made, compliance cannot be proven, errors cannot be investigated, and systems cannot be trusted.
What is AI decision logging?
AI decision logging is the process of recording every significant action taken by an AI system as a structured, verifiable record. Each log entry includes the decision label, input context, selected outcome, model or policy version, timestamp, and a cryptographic signature.
Unlike general application logs — which are mutable and lack integrity guarantees — AI decision logs in CertifiedData are append-only, Ed25519-signed, and chain-linked via SHA-256 hashes. Any modification to a prior entry breaks the chain, making tampering immediately detectable without access to the original system.
Decision log record structure
Every decision entry in CertifiedData records:
{
"decision_id": "dec_01j9k2m...",
"timestamp": "2025-11-14T09:23:41Z",
"decision_label": "loan_approved",
"input_context": { "applicant_risk_tier": "low" },
"outcome": "approved",
"model_version": "credit-model-v2.1",
"dataset_certificate_id": "cert_01j9k...",
"chain_hash": "sha256:a3f9b2e1...",
"signature": "ed25519:MEYCIQDx..."
}The chain_hash links this entry to the prior record. The signature is verified using CertifiedData's public key. The dataset_certificate_id ties the decision to the certified dataset used.
Why AI decision logging matters
Auditability
Every decision becomes independently auditable. Regulators, auditors, and enterprise buyers can verify system behavior without requiring access to internal systems.
Traceability
Each log entry is linked to the dataset, model version, and policy that produced it — enabling full reconstruction of the decision path from input to outcome.
Tamper detection
Chain-linked SHA-256 hashes mean any modification, deletion, or insertion of a log entry is immediately detectable. The chain breaks — proving tampering occurred.
Compliance evidence
Structured, cryptographically signed records satisfy EU AI Act Articles 12 and 19 documentation requirements without additional manual documentation work.
Dataset linkage
Each decision references a certified dataset certificate ID, creating a direct link between the data used and the outcome produced — essential for AI supply chain governance.
Independent verification
Any party with the log entry and CertifiedData's public key can verify the signature. No issuer access, no account, no API call required.
AI decision traceability
AI decision traceability is the ability to reconstruct the full path from input data to decision outcome. Traceability is built on top of logging — every entry in the decision log creates a link in the traceability chain.
CertifiedData enables end-to-end traceability by linking each decision to its certified dataset (via dataset_certificate_id), its model version, and the prior decision record (via chain_hash). Any party can follow the chain from a specific decision backwards to the data that produced it.
Decision logs vs audit logs
| Feature | Standard audit logs | CertifiedData decision logs |
|---|---|---|
| Mutable | Often yes | Never — append-only |
| Cryptographic proof | No | Ed25519 signature per entry |
| Dataset linkage | No | Certificate ID reference |
| Chain integrity | No | SHA-256 chain hash |
| Independent verification | No | Public key verification |
| Regulatory grade | Partial | EU AI Act Article 12 + 19 |
EU AI Act logging requirements
The EU AI Act introduces binding logging obligations for high-risk AI systems. CertifiedData decision logging directly addresses these requirements:
Article 12 — Record-keeping
Requires logging of system inputs, outputs, and decision context. CertifiedData records all three per entry, with timestamps and model version.
Article 19 — Technical documentation
Requires documentation sufficient for external audit. Cryptographically signed, chain-linked decision logs provide machine-verifiable evidence without manual documentation.
Article 10 — Data governance
Requires traceability of training data. Each decision log entry references a certified dataset ID, linking the decision to the specific data used.
Live decision log
All publicly available AI decisions on CertifiedData are recorded in a live, append-only, cryptographically verifiable log.
View the decision log →Frequently asked questions
What is AI decision logging?
AI decision logging is the process of recording every significant action taken by an AI system — including the decision label, input context, selected outcome, policy version, timestamp, and a cryptographic signature. Unlike traditional system logs, AI decision logs are append-only, hash-linked, and Ed25519-signed, making them tamper-evident and independently verifiable.
How does AI decision logging support EU AI Act compliance?
EU AI Act Article 12 requires high-risk AI systems to maintain logs of system behavior that enable traceability. Article 19 requires technical documentation sufficient for audit. CertifiedData decision logs provide structured, timestamped, cryptographically signed records for every AI action — satisfying both articles with machine-verifiable evidence rather than manual documentation.
What is the difference between AI decision logging and AI audit trails?
Decision logging is the process of recording individual events. An audit trail is the structured, chronological history built from those records. CertifiedData decision logs are both: each entry is signed and chain-linked so the sequence cannot be altered, creating a complete audit trail from the moment logging starts.
Can AI decision logs be independently verified?
Yes. Each decision record includes an Ed25519 signature verifiable using CertifiedData's public key at /.well-known/signing-keys.json. The chain hash links each entry to the prior record, so any attempt to insert, delete, or modify a log entry breaks the chain — detectable without access to the original logging system.
How is AI decision logging different from general application logging?
General application logs are mutable, lack cryptographic integrity, and are not linked to AI artifacts. AI decision logs in CertifiedData are append-only, each entry is Ed25519-signed, entries are SHA-256 chain-linked to prior records, and each decision is associated with a certified dataset reference. This creates a governance-grade audit record, not a debugging log.
Start logging AI decisions today.
If your AI system makes decisions, you will need an audit log that holds up in front of a regulator. CertifiedData gives you a cryptographically signed, hash-chained record. Free tier includes 1,000 records/month — no credit card.
- 1Create a free accountNo credit card. Two minutes.
- 2Get your API keyOne key. Scoped, revocable, rotateable.
- 3Send your first decisionOne curl. Appears in the public ledger within seconds.
Related Evidence
Decision Ledger
Cryptographically verifiable AI decision records with auditability and live proof.
Compliance Logging
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Decision Logging
Append-only, signed decision logs linked to certified artifacts.
Decision Traceability
Trace decisions from outcomes back to certified data sources.
Synthetic Data Certification
Dataset provenance, certification, and machine-verifiable artifact records.
Verify
Public verification for records, certificates, hashes, and signatures.