Signed AI decision logging

Append-only, Ed25519-signed AI decision records with SHA-256 chain links. Every record is independently verifiable — hash + signature — without calling CertifiedData. EU AI Act Article 12-aligned.

Sign a decision →Browse public feed Product overview

Chain architecture

Internal full-fidelity chain

All fields including PII-sensitive content. SHA-256 chain-linked across every record. Ed25519-signed per record. Retained per plan (7y for Build+). Not publicly accessible — only accessible to authenticated account owner.

→All payload fields
→Chain-linked SHA-256
→Ed25519 per record
→Audit vault access (Trust+)
→Export-ready (Trust+)

Public sterilized chain

Available when publicMode: true. Strips PII-sensitive fields (entity identifiers, explanation detail). Preserves: actor type, decision, model identifier, policy, timestamp, cert reference, signature. Published to /decision-log.

→PII stripped
→actor type + decision + model retained
→Signed chain-link preserved
→Publicly crawlable
→EU AI Act Article 50-compatible

Decision record payload

Field	Required	Description
actor	required	System or agent identity — model ID, agent name, service identifier
decision	required	The action taken — approval, rejection, classification, routing, etc.
artifactReference	optional	cert_id of the certified dataset or artifact that influenced this decision
model	optional	Model identifier and version — e.g. gpt-4o-2024-05-13, internal-classifier-v3
policy	optional	Policy or ruleset applied — e.g. spend-limit-v2, eu-ai-act-article-12
explanation	optional	Human-readable explanation of why this decision was made
review	optional	Manual review status: pending, approved, rejected, escalated
entity	optional	Subject of the decision — patient ID, loan applicant, transaction, etc.
publicMode	optional	true: sterilized version published to public feed. false: internal only (default)

The canonicalized payload (RFC 8785 JSON Canonicalization Scheme) is what gets hashed and signed. The signature covers the full normalized record, not a summary.

Capability matrix

Action	Anonymous	Authenticated	Production	Public Proof
Log decision (demo)	✓ 30/min/IP	✓ 1k/mo	✓ unlimited	✓ demo verify
Log decision (production)	✗ auth required	✓ free+	✓	✓ opt-in public
Verify decision record	✓ no limit	✓	✓	✓ public endpoint
Browse public decision feed	✓ public	✓	✓	✓ /decision-log
Inspect checkpoints	✓ public	✓	✓	✓ chain verify
Search decision log	✗ auth required	✓	✓	—
Export audit records	✗	✓ Trust+	✓ Trust+	—
Artifact provenance link	✗	✓ Build+	✓ Build+	✓ on record

API examples

Demo endpoint — no account

# Demo decision (no account, 30/min/IP)
curl -X POST https://certifieddata.io/api/demo/decision \
  -H "Content-Type: application/json" \
  -d '{
    "actor": "my-agent",
    "decision": "approve",
    "explanation": "Testing the demo endpoint"
  }'

Production decision log (authenticated)

curl -X POST https://certifieddata.io/v1/decisions \
  -H "Authorization: Bearer $CERTIFIEDDATA_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "actor": "loan-underwriting-model-v3",
    "decision": "approve",
    "model": "internal-credit-model-v3.2",
    "entity": "applicant:anon-7f2a",
    "policy": "credit-risk-policy-v2",
    "explanation": "Credit score 720, DTI 28%, employment verified 4 years",
    "artifactReference": "cert_abc123",
    "publicMode": false
  }'

Verify · public feed · signing keys

# Verify a decision record by ID
curl "https://certifieddata.io/api/decision-log/verify?id=drec_xxxx"

# Public decision feed
curl "https://certifieddata.io/api/decision-log/latest?limit=20"

# Signing key discovery
curl "https://certifieddata.io/.well-known/decision-signing-keys.json"

Independent verification

Verify any decision record without contacting CertifiedData:

1Fetch the record from GET /api/decision-log/verify?id=drec_xxxx
2Compute SHA-256 over the RFC 8785-canonicalized payload
3Compare against the record's stored hash
4Fetch the signing public key from /.well-known/decision-signing-keys.json
5Verify the Ed25519 signature using the public key

signing-keys.json Public decision feed Unified verify surface

Decision Ledger overview Public decision feed Interactive demo EU AI Act Article 12 Transparency center Verify surface