Data Flow Diagrams

For the complete data flow documentation covering all 8 operations (Transform, Rehydrate, RAG, Proxy, Streaming, File Processing, Image/OCR, Batch), see the canonical reference:

Architecture: Data Flow Diagrams

Security-Relevant Summary

All data flows follow the same trust boundary model:

• Trusted Zone (OGuardAI runtime, plus the Python NER sidecar when deployed): Raw PII exists here in memory during request processing, and never crosses to the untrusted zone
• Untrusted Zone (LLMs, tools, logs, vector stores): Only semantic tokens {{type:id:cap}} and safe metadata cross the boundary, plus any value an operator explicitly lists in a policy whitelist (the shipped strict policies have an empty whitelist)
• Session state: Encrypted with AES-256-GCM, client-held (sealed mode), in-process (memory mode), or encrypted at rest in a shared Redis (redis mode).
• Revocation table: Stores HMAC-SHA-256 hashes only, no raw PII
• Audit events: Entity types and counts only, no raw values logged

For detailed trust boundary analysis, see the Security Whitepaper.