Axis 3: Components

Overview

The GCBoK defines six core components of the GitCover stack:

graph TD GCAL["GCAL - Advisory Lock"] GCEP["GCEP - Exchange Protocol"] GCSYNC["GCSYNC - Sync (Outbound)"] GCUCB["GCUCB - Communication Bus"] GCPN["GCPN - PrimaNota"] GCDMS["GCDMS"] GCAL -->|"Lock-Koordination"| GCEP GCEP -.->|"OSCAL/OPA Hooks"| OPA["OPA Policy Engine"] GCSYNC -->|"Outbound"| RAG["RAG / MCP"] GCUCB -->|"Guardrails"| OPA

GCDMS - GitCover Document Management System

Evidence and document management system based on .v7g.md containers and metadata. Toolchain: v7g-pack, v7g-verify, v7g-sign, v7g-export.

GCPN - GitCover PrimaNota

Metadata mechanism for creating tamper-proof evidence chains (predecessor/successor) for business documents. The historical term PrimaNota denotes an ordering key that assigns a unique key for association to a business transaction - e.g., a journal entry of double-entry bookkeeping or a multi-part posting process (receivable, VAT, cost center/cost object allocation). GCPN transfers this principle to a UUIDv7 basis: Each document receives a time-ordered identifier (RFC 9562) and is chained to its predecessor and successor documents via Predecessor/Successor references.

The chaining is non-chronological: A document recorded later can be inserted as a predecessor (Predecessor-Insert) into an existing chain - crucial for GoBD Rz. 80 (progressive and retrograde examination). Match-key fields (order number, debtor, gross amount, etc.) enable automatic chain association without manual assignment.

The .v7g.md container format combines human-readable metadata (YAML + Markdown) with machine-processable business data (embedded JSON) and is stored in Git repositories whose commit hash serves as a cryptographic integrity proof.

Application areas beyond accounting: GDPR records of processing activities (Art. 30), NIS2 incident chains, MADR architecture decisions, OIDC/OAuth token lifecycle, OSCAL assessment results.

Utility model protection: File no. 20 2026 000 272.7 - in force. Protected subject matter: Container data structure for UUIDv7-based, tamper-proof business document management with dynamic Predecessor/Successor chaining. Patent application filed (47 claims).

GCUCB - GitCover Unified Communication Bus

Shared-memory-based context bus with deterministic V7GUID addressing. Central data hub between AI agents, OPA validators, and audit systems.

The Overhead Problem

Source Finding
RMMAP (EuroSys 2024) Serialization = 17-72% of workflow time
AgentTaxo (ICLR 2025) 20-60% of tokens = coordination overhead
AgentDiet (arXiv 2025) 39.9-59.7% of input tokens are useless

The Solution

GCUCB eliminates repeated serialization/deserialization through typed direct access to memory-mapped file regions. AI agents receive typed, V7GUID-referenced structs directly from the bus - without huge system prompts.

OPA/Rego acts as a VPRM (Verifiable Process Reward Model): Guardrails are created by a deterministic rule set, not by prompt engineering.

Distinction

Component Layer Distinction from GCUCB
GCEP Persistence (Git-to-Git) Instance-to-instance; GCUCB = runtime memory bus
GCSYNC Outbound (Git -> RAG) External channel; GCUCB = internal bus
GCPN Chaining logic Evidence chains (predecessor/successor); GCUCB = transport/access

GCEP - GitCover Exchange Protocol

Instance-to-instance exchange protocol between Git repos on different media. Semantically determined by OSCAL catalogs and OPA-defined hooks/callbacks.

IETF track planned (I-D, short name: gcep). Patent application: 10 2025 003 359.1.

Protocol Layers: ACP, MCP and GCEP

GCEP must not be confused with the AI agent protocols. All three solve different problems at different layers:

graph TD A["Präsentations-Ebene / UI
(z. B. VS Code)"] -->|"Agent Client Protocol (ACP)"| B["Logik-Ebene / KI-Agent"] B -->|"Model Context Protocol (MCP)"| C["Infrastruktur- & Daten-Ebene"] C -->|"GitCover Exchange Protocol (GCEP)
mit Advisory Locks"| D["Verteilte Git-Server / VCS"] style A fill:#bbdefb style B fill:#c8e6c9 style C fill:#ffe0b2 style D fill:#f8bbd0
Layer Protocol Direction Purpose
UI bridge ACP (Agent Client Protocol) UI ↔ Agent Connects the user interface (e.g., VS Code) with the agent logic
AI context bridge MCP (Model Context Protocol) Agent ↔ Data Structured agent access to data sources (documents, tools)
Repository layer GCEP Server ↔ Server Replication, synchronization, and securing of state between physical Git instances

The combination is highly relevant for management: The agent works at high speed via ACP/MCP; GCEP ensures at the underlying repository layer that commit and synchronization paths remain consistent.

Advisory Locks in the AI Era

Autonomous AI agents generate write accesses at high frequency. Without a locking protocol at the Git level, two agents acting in parallel - or an agent and a human clerk - can modify the same repositories simultaneously and produce inconsistent states (Race Conditions).

Aspect Advisory Lock Mandatory Lock
Mechanism Processes check the lock status voluntarily before writing The operating system enforces the lock forcibly
Behavior on timeout Agent can react strategically: postpone a subgoal, issue a UI notification Often dead system states (deadlocks)
Suitability for AI agents High - agent queries the lock status in advance (e.g., via an MCP Git server) Low - blocks the agent pipeline

An AI agent can query the GCEP lock status in advance ("Is this repository locked for another place of business?") and adjust its planning accordingly - instead of blocking hard.

GCAL - GitCover Advisory Lock

Distributed lock mechanism between Git repos - analogous to the PostgreSQL advisory lock, but at the repo level. Prerequisite for GCEP: Before two instances exchange data, a lock must ensure atomic handover.

GCSYNC - GitCover Sync

Outbound channel from GitCover into other data storage systems. Provides data for RAG systems, MCP servers, and Nextcloud Shares.

See also: Property rights and patent status in Property Rights. Research recognition in Research Project.