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Read-Only Assurance and Zero Network Egress (P8-10)

This document details the read-only assurance model and empirical network egress controls enforced by vhecfsck.

1. Engine Invariants

  • LanceDB / Lance: File hashes and modification times (mtime) on disk are snapshotted before and after execution. Audit operations use read-only dataset snapshots (--dataset-version N) and verify zero bytes written or modified.
  • Qdrant: Read-only gRPC/HTTP API client sessions. Points, collections, and segment telemetry are introspected without invoking write or compaction endpoints.
  • PostgreSQL / pgvector: Connections enforce SET SESSION CHARACTERISTICS AS TRANSACTION READ ONLY and default_transaction_read_only=on. pg_stat_database and pg_stat_user_tables write counters are verified to remain zero. Minimum-privilege audits run against SELECT-only roles.

2. Zero Network Egress Control

vhecfsck is designed for air-gapped, zero-egress production environments: - No Telemetry: No analytics, usage tracking, or pingbacks. - No External Dependencies: Zero CDN requests, external web fonts, or remote script tags. - Empirical Verification: tests/integration/test_readonly_all.py monkeypatches Python's socket.socket.connect interface to verify that 0 socket connections are attempted outside the designated local target URI.

3. Re-running Verification

Run the full read-only assurance test suite:

uv run pytest tests/integration/test_readonly_all.py -v