v0.7.0 - Enterprise AI Security Platform

🛡️ LightGuard-Agent v0.7.0: Production-Grade Enterprise AI Security Platform

This landmark release transforms LightGuard-Agent into an enterprise-grade AI security architecture designed for autonomous tool-calling agents, Model Context Protocol (MCP) gateways, and high-throughput RAG pipelines.

🚀 Key Capabilities & Security Enhancements

1. Centralized Tool Authorization & RBAC Engine (lightguard.policy):

   • Added ToolCapability enum, ToolMetadata, and ToolPolicyRegistry.
   • Role-Based Access Control (RBAC) via AuthorizationContext(caller_role, caller_id).
   • Human-in-the-loop approval hooks (approval_hook) for critical actions.
   • Enforced strict deny-over-allow precedence with default-deny semantics.

2. Deep Recursive Argument Security & SSRF Defense (lightguard.structured):

   • Recursive inspection of nested dictionaries and arrays with cycle detection (path_ids).
   • Bounded complexity defense with max_depth=10 and max_elements=1000.
   • Complete SSRF defense blocking loopback (127.0.0.1), private networks (RFC 1918), and cloud metadata IP (169.254.169.254).
   • Universal path traversal checks across all string arguments and dangerous command injection prevention.

3. Multi-Provider Streamed Tool Argument Unmarshaling (lightguard.wrapper):

   • Integrated _unmarshal_tool_args across synchronous and asynchronous streaming wrappers.
   • Transparently parses chunked and delta JSON strings into top-level dictionaries before security validation.
   • Verified across OpenAI, Anthropic, Groq, and Ollama multi-tool parallel calls.

4. Hardened RAG Context & Metadata Poisoning Defense (lightguard.rag):

   • Added SourceTrustLevel hierarchy for untrusted vs. trusted retrieval boundaries.
   • Metadata prompt-injection scanning and Markdown exfiltration beacon detection (![beacon](...)).
   • Document length bounds and cryptographic canary provenance tags.

5. Hardened MCP Gateway & Tools Discovery Filtering (lightguard.mcp_gateway):

   • Enforced maximum JSON-RPC payload bounds (max_message_size), rejecting oversized frames with error code -32600.
   • Dynamic tools/list discovery filtering hiding unauthorized tools based on caller capabilities.
   • Server-to-client response inspection blocking secret canary leaks.

6. Structured DLP Redaction & Extended Cloud Secrets (lightguard.privacy):

   • Added redact_structured() and restore_structured() with non-colliding sequential placeholder tokens across nested JSON.
   • Extended secret regex patterns for Google Cloud (AIza...), HuggingFace tokens (hf_...), Stripe keys, Anthropic, and OpenAI.
   • Automatic TTL pruning and capacity eviction in CanaryGuard.

7. Structured Audit Trail & Security Reason Codes (lightguard.audit):

   • Introduced SecurityReasonCode enum providing deterministic, programmatic reason codes for SIEM integration.
   • Structured AuditEvent records and thread-safe AuditLogger with in-memory ring buffer and JSONL file export.
   • Integrated end-to-end into observation processing, action verification, and MCP gateways.

📊 Verification & Test Suite

• Test Results: 162/162 passing tests (100% pass rate) across Python 3.9, 3.10, 3.11, 3.12.
• Coverage: 82% overall statement coverage (>92% across core security modules).
• Dependencies: 0 external runtime dependencies (Pure Python standard library).