Structured Contextual Distillation (SCD v3.1): A Deterministic, Vendor-Independent Protocol for Persistent, Verifiable Agent State

Structured Contextual Distillation (SCD v3.1): A deterministic external state protocol that relocates agent memory from volatile model internals to cryptographically protected filesystem artifacts. v3.1.1 updates (February 2026): Erratum incorporated: Section 6.1 hardware specification corrected — deployment hardware is Mac mini M4 with 24 GB unified memory (not 16 GB as stated in the original PDF). This does not affect any results or conclusions. Cross-reference: The MirrorGraph paper (doi:10.5281/zenodo.18540444) provides empirical validation of the knowledge mesh architecture that SCD was designed to support, demonstrating small-world navigability and greedy routing on the power-of-two difference graph Dn. Affiliation update: Author affiliation is N1 Intelligence (OPC) Pvt Ltd. Key contributions: RFC 8785 JSON canonicalization for byte-identical serialization SHA-256 integrity chains for tamper-evident state history Constitutional governance layer resistant to indirect prompt injection 100% determinism over 1005 sequential state transitions Cross-vendor continuity (Gemini ↔ Claude handoffs) Trojan horse defense: governance blocks malicious file payloads 22 pages. Code: github.com/MirrorDNA-Reflection-Protocol/MirrorDNA