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Attorney-Client Privilege • ABA Model Rule 1.6 Aligned • GDPR-Ready • CCPA

API Security for Law Firms
Protect Client Confidentiality

The AI Security Layer for legal: append-only audit log for privilege defensibility, contained subprocess execution for AI legal research, privileged-data scrubbing before LLM calls, and matter-level access enforcement. All 4 platforms from $2,000/mo, billed annually.

ABA Model Rule 1.6 aligned
Append-only audit log
GDPR-Ready (Articles 5/17/32)
94,000+
training samples (24 categories)
12
assessment frameworks (+8 reference)
Append-only
audit log (auth events hash-chained)
7-year
default audit-log retention
Matter-level
access control + ethical walls
AES-256
encryption + TLS 1.3 transit
Target: Sub-5ms
gateway proxy overhead (cached)
99.9%
Uptime target · 1-hr P1 (Enterprise)

Legal API Threats We Prevent

Proactive protection against threats targeting privileged client data

Privilege Breach

Unauthorized access to attorney-client privileged documents via case management APIs. Matter-level RBAC, ethical-wall enforcement, and Zero Trust risk scoring on every request.

Prevention: Role-based access, privilege tagging, audit logging

Client Data Exfiltration

Bulk scraping of client matter data, billing records, and case files. Sliding-window rate limits + behavioral baselines flag enumeration attacks at the gateway.

Prevention: Rate limiting, pattern detection, data masking

eDiscovery Tampering

Attackers manipulate eDiscovery APIs to alter document metadata or access restricted productions. Every access is written to the append-only audit log for chain-of-custody review.

Prevention: Append-only audit log, access logging

Four Platforms for Legal

API Security + MCP Security + AI Gateway + Verification Engine — unified on one finding bus for law firm workloads

API Security

Privilege Protection

Secure case management, document management, and billing APIs. Matter-level access control and ethical-wall enforcement at the gateway, with conflict-check API hooks.

  • Matter-level access control
  • Ethical wall enforcement
  • Client conflict checking

MCP Security

AI Legal Research

Secure AI agents that assist with legal research and document drafting. Every tools/call passes 7 sequential checks — permission, MFA, rate limit, rug-pull (SHA-256), threat detect, forwarding, response scan — before touching client matters.

  • Legal research agent security
  • Contract drafting audit trails
  • AI hallucination detection

AI Gateway

Document Review

Route LLM calls for document review and legal analysis. Privileged-data scrubbing before LLM processing; adaptive Z-score circuit breaker for failover.

  • Privilege-aware LLM routing
  • Client data redaction
  • eDiscovery AI security

Verification Engine

4 Validation Layers

Validate every AI-drafted clause and research summary before it leaves your firm. Real-time checks on AI gateway traffic; a response carrying a critical PII or secret finding is blocked before delivery, streaming or not.

  • Privilege / PII masking + forbidden-phrase constraints
  • Source grounding (citation verification on AI-drafted briefs)
  • Structural validation (UTBMS/LEDES, JSON schema, regex)

Every Tool Call Passes 7 Sequential Checks

Zero code changes to your case management system or AI research stack. Target: Sub-5ms gateway proxy overhead on cached, single-region paths.

1
Permission check
Matter-level RBAC: does this attorney have privilege to this matter?
2
MFA verification
TOTP required for sensitive matters (M&A, litigation holds)
3
Rate limiting
Sliding-window check, Redis-backed with in-memory fallback
4
Rug-pull verification
SHA-256 of tool definition vs. registered hash — block on drift
5
Threat detection
Scan tool arguments for injection patterns + privilege markers
6
Server forwarding
Execute via stdio subprocess, HTTP, or WebSocket transport
7
Response scanning
IndirectInjectionScanner blocks LLM-directed instructions in output
✓
Audit log written
Audit record: arguments, response, decision, correlation ID
Fail-closed quota state on Redis error • Per-key asyncio lock prevents TOCTOU races • 10 dedicated Prometheus metrics

5 Capabilities You Won't Find Anywhere Else

Not in Anthropic's MCP spec. Not in API gateways. Not in WAFs. Platform-level additions built for privileged-data workloads.

01

Hardened Local MCP Servers

MCP servers the proxy launches locally (stdio, off unless the operator sets MCP_STDIO_SERVERS_ENABLED) run in their own session (setsid), drop to nobody if started as root, and get no-new-privs, ambient capabilities cleared and RLIMIT_AS/FSIZE/NOFILE/NPROC ceilings. Remote (HTTP) servers are proxied and inspected, not sandboxed, and network egress is not filtered.

modules/mcp/interceptor_transport.py — _proxy_preexec
02

Tool Definition Hash Registry

SHA-256 hash of every research tool definition pinned at tools/list. On every tools/call, the cached definition is re-hashed and compared. Drift raises MCPRugPullDetectedError, blocks execution, and publishes a CRITICAL event.

modules/mcp/tool_registry.py • Redis-backed
03

Adaptive Z-Score Circuit Breaker

Statistical, not threshold-based. Z-score > 3.0 against per-hour time-of-day baselines. 4 overlapping sliding windows (1m/5m/15m/1h). Progressive recovery (10→25→50→100%).

gateway/ — 2,208 LOC combined
04

Cross-Pillar Correlation

Findings from all four pillars land on one threat-event bus. A compound correlator groups them in 5-minute windows by correlation ID and by organization + client IP, and raises one incident when they match a known multi-stage pattern: a prompt injection at the gateway plus an SSRF probe and a path traversal at the API from the same client become a single critical Lethal Trifecta finding.

modules/compound_correlator • findings.mcp_security.compound
05

Append-Only Audit Log

HMAC-SHA256 hash chain on authentication and domain events (since 2026-09-13), each entry signing the previous. Three verification levels (full chain / single entry / last-N). Control mapping (not an attestation) for privilege defensibility, eDiscovery chain-of-custody, and SOC 2 CC7.2.

modules/compliance/audit_chain.py
+

MCP Correlation Analyzer

Cross-session attack detection: 6-dimension risk score (max 110) across tool sensitivity, data volume, burst, denials, prior detections, and tool diversity. Catches coordinated multi-user attacks and 24h slow-and-low patterns.

MCPCorrelationAnalyzer — alert at score > 50

One Finding Bus. All Four Pillars.

Every pillar publishes its findings to one threat event bus. The compound correlator joins findings on the same request by correlation ID, and separate requests from one client by organization + client IP.

Attorney
Matter Session
Prompt
Research Agent
Tool Call
Case API
Response
Verification
Every tool call is written to mcp_tool_calls with its correlation ID • Compound findings link every contributing finding • Hash-chain entries are tamper-evident for privilege defense

Legal Use Cases

Built for every type of legal organization

Am Law 200 Firms

Enterprise-grade security for large law firms. Protect multi-office deployments with global compliance requirements.

APIs secured: /matters, /documents, /billing

Corporate Legal

Secure in-house legal department APIs. Protect contract management, entity management, and outside counsel collaboration.

APIs secured: /contracts, /entities, /counsel

Legal Tech Companies

API security for LegalTech SaaS platforms. Protect multi-tenant data and ensure client isolation at the gateway.

APIs secured: /tenants, /workflows, /integrations

Audit Evidence, Built In From Day One

Every privileged-data access written to the append-only audit log. Control crosswalk: each SOC 2 control is mapped to its overlapping ISO 27001 controls.

ABA Model Rule 1.6
aligned
SOC 2 Type II
observation in progress
GDPR-Ready
Articles 5 / 17 / 32
CCPA
consumer rights workflow
ISO 27001
93 Annex A · aligned
NIST CSF 2.0
106 subcategories mapped

"-Ready" / "aligned" reflect capability posture. ABA Model Rules are an ethics framework, not a third-party certification; SOC 2 Type II observation in progress with external audit H2 2026.

Protect Client Privilege

Join law firms and legal tech companies using G8KEPR to protect privileged communications, secure AI legal research, and maintain client confidentiality with documented evidence.

30-day free trial (extend to 90 days free)
12 frameworks mapped
ABA Model Rule 1.6 aligned