# Dcl Semantic Drift Guard > Use this skill to detect semantic hallucinations and context drift in LLM outputs. Triggers when an agent or pipeline needs to verify that a generated response is faithfully grounded in a source document or knowledge base — and has not fabricated, contradicted, or materially distorted any claims. Use whenever you need to validate AI output against a contract, policy document, RAG-retrieved context, or any authoritative source of truth. Returns a tamper-evident DCL audit record with verdict IN_COMMIT or HALLUCINATION_DRIFT. Part of the Fronesis Labs / Leibniz Layer™ verification suite alongside DCL Policy Enforcer and DCL Sentinel Trace. - Skill: `luokai0/dcl-semantic-drift-guard` (Agent Skill, multi-file: 3 files) - Install (CLI): `npx skillmds@latest add luokai0/dcl-semantic-drift-guard` - Raw SKILL.md: https://api.skillmd.com/api/skills/luokai0/dcl-semantic-drift-guard/raw - Safety review: pending (external: skill-scanner PASS, skillspector PASS) - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: DevOps & Infra - Author: luokai0 (https://skillmd.com/u/luokai0) - Updated: 2026-09-08 - Page: https://skillmd.com/skills/luokai0/dcl-semantic-drift-guard --- # DCL Semantic Drift Guard **Publisher:** @daririnch · Fronesis Labs **Version:** 1.0.0 **Part of:** Leibniz Layer™ Verification Suite --- ## What this skill does Semantic Drift Guard compares an LLM-generated response against a trusted source of truth and detects: - **Hallucinated facts** — claims not present in the source - **Logical contradictions** — statements that directly conflict with the source - **Omission drift** — critical information from the source that was silently dropped - **Fabricated specifics** — invented numbers, dates, names, clauses, or identifiers It supports two source modes: - **`context` mode** — inline document or contract passed directly in the request - **`kb_query` mode** — knowledge base lookup via RAG endpoint Every verification produces a cryptographic audit record compatible with the DCL Evaluator tamper-evident chain. --- ## Verdicts | Verdict | Meaning | |---|---| | `IN_COMMIT` | Response is faithfully grounded in the source. No hallucinations detected. Safe to proceed. | | `HALLUCINATION_DRIFT` | Response contains fabricated, contradicted, or unsupported claims. Do not commit. Review `drift_items`. | --- ## Input schema ```json { "source_mode": "context" | "kb_query", // For source_mode = "context": "source_document": "", // For source_mode = "kb_query": "kb_endpoint": "", "kb_query": "", // Always required: "llm_output": "", "strictness": "strict" | "balanced" | "lenient", // default: "balanced" "policy": "eu_ai_act" | "gdpr" | "fstek" | "internal" | "none" // optional } ``` ### Strictness levels - **`strict`** — any unverifiable claim triggers HALLUCINATION_DRIFT. Use for contracts, medical, legal, financial outputs. - **`balanced`** — minor paraphrasing and reasonable inferences are tolerated. Use for customer support, summaries. - **`lenient`** — only direct factual contradictions trigger HALLUCINATION_DRIFT. Use for creative or exploratory outputs. --- ## Output schema ```json { "status": "success" | "error", "data": { "verdict": "IN_COMMIT" | "HALLUCINATION_DRIFT", "confidence": 0.0–1.0, "source_mode": "context" | "kb_query", "strictness": "strict" | "balanced" | "lenient", "policy": "eu_ai_act" | "none" | "...", "drift_items": [ { "type": "hallucination" | "contradiction" | "omission" | "fabricated_specific", "claim": "", "source_reference": "", "severity": "critical" | "major" | "minor" } ], "tx_hash": "", "timestamp": "ISO-8601", "audit_chain_id": "" } } ``` `drift_items` is an empty array `[]` when verdict is `IN_COMMIT`. --- ## Verification workflow When this skill is invoked, follow these steps: ### Step 1 — Retrieve source of truth **If `source_mode = "context"`:** Use `source_document` directly. Chunk it into logical sections for comparison. **If `source_mode = "kb_query"`:** Query the `kb_endpoint` with `kb_query`. Retrieve top-k relevant chunks. Treat the union of retrieved chunks as the authoritative source. If the endpoint is unreachable, return `status: "error"` with `reason: "kb_unavailable"`. ### Step 2 — Decompose LLM output into claims Parse the `llm_output` into atomic, verifiable claims: - Factual assertions ("The contract states X") - Numerical values ("The penalty is €10,000") - Named entities ("The responsible party is Company A") - Temporal claims ("The deadline is March 15") - Logical conclusions ("Therefore, clause 4.2 applies") ### Step 3 — Cross-reference each claim against source For each claim, determine: | Finding | Classification | |---|---| | Claim is explicitly supported by source | ✅ Grounded | | Claim is a reasonable paraphrase (strictness: lenient/balanced) | ✅ Grounded | | Claim introduces information absent from source | ⚠️ `hallucination` | | Claim directly contradicts source | 🚨 `contradiction` | | Critical source information was omitted from output | ⚠️ `omission` | | Specific value (number, date, name) was invented | 🚨 `fabricated_specific` | ### Step 4 — Apply strictness filter - `strict`: any ⚠️ or 🚨 → HALLUCINATION_DRIFT - `balanced`: any 🚨, or multiple ⚠️ → HALLUCINATION_DRIFT - `lenient`: only 🚨 contradiction or fabricated_specific → HALLUCINATION_DRIFT ### Step 5 — Compute audit record Generate: ``` tx_hash = SHA-256(source_fingerprint + llm_output + verdict + timestamp) audit_chain_id = Merkle leaf position in DCL Evaluator chain ``` Return the full output schema. --- ## Interpreting results ### IN_COMMIT — safe to proceed ```json { "status": "success", "data": { "verdict": "IN_COMMIT", "confidence": 0.97, "drift_items": [], "tx_hash": "0xa3f1...c72e", "timestamp": "2026-04-09T14:22:00Z", "audit_chain_id": "dcl-leaf-0047" } } ``` The LLM output is faithfully grounded in the source. Log `tx_hash` to your audit trail. ### HALLUCINATION_DRIFT — do not commit ```json { "status": "success", "data": { "verdict": "HALLUCINATION_DRIFT", "confidence": 0.89, "drift_items": [ { "type": "fabricated_specific", "claim": "The penalty for breach is €50,000.", "source_reference": "Section 8.3: The penalty shall not exceed €10,000.", "severity": "critical" }, { "type": "hallucination", "claim": "The agreement includes a 90-day cooling-off period.", "source_reference": null, "severity": "major" } ], "tx_hash": "0xb8d2...4f91", "timestamp": "2026-04-09T14:22:00Z", "audit_chain_id": "dcl-leaf-0048" } } ``` Block the output. Surface `drift_items` to the human reviewer or trigger a re-generation loop. --- ## Integration patterns ### With DCL Policy Enforcer (recommended pipeline) Run Policy Enforcer first (jailbreak / compliance check), then Semantic Drift Guard (factual grounding): ``` LLM Output │ ▼ DCL Policy Enforcer ──► REJECT? → Block immediately │ COMMIT ▼ DCL Semantic Drift Guard ──► HALLUCINATION_DRIFT? → Block / re-generate │ IN_COMMIT ▼ Safe to deliver ``` Both `tx_hash` values are logged to the same DCL Evaluator audit chain, giving end-to-end verifiability. ### With DCL Sentinel Trace (full Leibniz Layer™ stack) ``` Sentinel Trace → strip PII before source reaches LLM Policy Enforcer → compliance check on output Semantic Drift Guard → factual grounding check ``` ### Standalone (quick RAG validation) ```python result = dcl_semantic_drift_guard( source_mode="kb_query", kb_endpoint="https://kb.yourapp.com/query", kb_query="penalty clauses breach of contract", llm_output=agent_response, strictness="strict", policy="eu_ai_act" ) if result["data"]["verdict"] == "HALLUCINATION_DRIFT": raise ValueError(f"Drift detected: {result['data']['drift_items']}") ``` --- ## Use cases | Domain | Source mode | Strictness | Why | |---|---|---|---| | Legal contract summarization | `context` | `strict` | Fabricated clauses = liability | | RAG-based customer support | `kb_query` | `balanced` | Prevent wrong product info | | Medical documentation | `context` | `strict` | Patient safety | | Financial report generation | `context` | `strict` | Regulatory compliance | | EU AI Act compliance auditing | `kb_query` | `strict` | FSTEK / AI Act article mapping | | Internal knowledge assistant | `kb_query` | `lenient` | Lower stakes, exploratory | --- ## Compliance notes - Audit records are compatible with **EU AI Act Article 12** (logging requirements for high-risk AI systems) - `tx_hash` chain is admissible as tamper-evident evidence under **GDPR Article 5(2)** accountability principle - All source documents processed in `context` mode are never stored — only their fingerprint is hashed - Compatible with **FSTEK** audit trail requirements for AI systems in Russian regulated industries --- ## Privacy & Data Policy This skill is operated by **Fronesis Labs** under a strict no-retention data policy. **What is processed:** Only the text submitted for evaluation. No user identity, no API keys, no metadata beyond what is required to run the verification. **Retention:** Evaluations are processed in-memory only. No text is written to disk, no logs are retained, no data is shared with third parties. The only persistent record is the cryptographic `tx_hash` and `chain_hash` — these contain no personal data. **Source documents:** Content passed via `source_document` (context mode) is never stored or logged. Only a cryptographic fingerprint is included in the audit hash. **Infrastructure:** Webhook hosted on a private VPS operated solely by Fronesis Labs. No cloud analytics, no third-party processors. Full policy: **https://fronesislabs.com/#privacy** · Questions: support@fronesislabs.com --- ## Related skills - `dcl-policy-enforcer` — Compliance and jailbreak detection (run before Drift Guard) - `dcl-sentinel-trace` — PII redaction and identity exposure detection (run before source reaches LLM) **Leibniz Layer™ · Fronesis Labs · fronesislabs.com**