nexus-mcp/documentation/project-history/SESSION_SNAPSHOT_2026-04-13.md

Session snapshot - 2026-04-13

Session goals

• Migrate existing Identity and Workday MCP servers into unified Nexus-MCP sharded architecture
• Establish foundation for scaling to 53 tools across 9 system categories
• Implement atomic, piece-at-a-time shard deployment capability
• Maintain all existing functionality while enabling future expansion

Accomplishments

Architecture transformation completed

✅ Created nexus-mcp sharded architecture following Gemini conversation design decisions

• Plugin-based model with 6 shards: identity, workday, audit, itsm, assets, logistics
• Orchestrator pattern with feature flag control (src/main.py)
• Clean separation: orchestrator → shards → lib/adapters
• Mock mode support across all shards via USE_MOCK flag

✅ Migrated 31 working tools from legacy servers into sharded model

• Identity shard: 15 tools (8 AD + 7 Entra ID) from Identity/identity_mcp_server.py
• Workday shard: 7 worker/org tools from Workday/workday-mcp/server.py
• Audit shard: 9 cross-system drift detectors extracted from both legacy servers
• Added 2 audit query tools (nexus_audit_recent, nexus_audit_stats)
• Total: 33 tools registered

✅ Implemented SOC 2 audit logging with automatic PII redaction

• Every tool invocation logged to JSONL (CC7.2 / CC6.1 compliance)
• Automatic redaction of passwords, tokens, secrets, PII
• Per-tool metadata: event_id, shard, action_category, latency_ms, mock_mode flag

✅ Created comprehensive mock data library (lib/mock_data.py)

• Deliberate drift scenarios built in (Bob Martinez title mismatch, Carol Chen department drift, etc.)
• Enables full 53-tool testing without credentials
• Supports realistic audit tool validation

✅ Established Red/Yellow/Green status stub shards

• Red shards (itsm, assets, logistics) created as placeholder modules
• Stub client adapters for 6 future systems (entra_client, helix_client, intune_client, lansweeper_client, fedex_client, workday_client)
• Feature flags default to false — load only when credentials available

✅ Documentation and operational readiness

• Created nexus-mcp/README.md with full tool reference and shard status board
• Created nexus-mcp/Local-Setup.md with installation, configuration, feature flag guide
• Updated repository README.md to position Nexus-MCP as primary server
• Preserved legacy Identity and Workday folders for reference (not yet archived)

Verification completed

✅ Smoke test passed — server imports and loads without errors

• Expected output confirmed: 3 shards loaded (identity, workday, audit), 3 disabled, 33 tools registered
• SOC 2 audit middleware active
• Pylance validation pending full codebase scan

✅ Structure validated against ProjectNexus-main reference implementation

• Folder layout matches: src/, src/shards/, lib/, tests/, logs/
• All framework files present: main.py, config.py, audit_log.py, .env.example, pyproject.toml
• Test suites migrated from Identity and Workday (pytest run pending virtual env setup)

Technical decisions

1. nexus-mcp lives at repository root as primary deliverable (not in servers/ subfolder)
2. Legacy folders preserved until full pytest validation passes (Identity/, Workday/ to be archived in future commit)
3. ProjectNexus patterns followed exactly for consistency with Replit prototyping
4. Feature flags default to true for Green shards (identity, workday, audit), false for Red shards
5. Mock mode is primary development workflow until API credentials approved (aligns with WIS-008 "Holding Pattern")
6. SOC 2 audit logging mandatory in all environments (AUDIT_LOGGING_ENABLED=true enforced)
7. Dedicated virtual environment created at nexus-mcp/.venv for clean dependency isolation

Technical debt and pending

• Pytest validation incomplete — test suites migrated but not yet executed with updated import paths
• Markdown linting warnings in Local-Setup.md (15 style issues — non-blocking, cosmetic only)
• Live API credential integration still pending (Workday API, Entra Graph API)
• Legacy folder archival deferred until user verification of nexus-mcp functionality
• Claude Desktop config not yet updated to use nexus-mcp (users still on legacy servers)

File inventory

Created files

nexus-mcp/
├── src/
│   ├── main.py                          # Orchestrator (copied from ProjectNexus)
│   ├── __init__.py                      # Package marker
│   └── shards/
│       ├── __init__.py                  # Shard registry
│       ├── identity.py                  # 🟢 15 tools (AD + Entra)
│       ├── workday.py                   # 🟢 7 tools (Worker + Org)
│       ├── audit.py                     # 🟡 9 tools (Cross-system drift)
│       ├── itsm.py                      # 🔴 Stub (BMC Helix)
│       ├── assets.py                    # 🔴 Stub (Lansweeper + Intune)
│       └── logistics.py                 # 🔴 Stub (FedEx)
├── lib/
│   ├── __init__.py                      # Package marker
│   ├── config.py                        # Environment config (copied from ProjectNexus)
│   ├── audit_log.py                     # SOC 2 logger (copied from ProjectNexus)
│   ├── ad_adapter.py                    # Migrated from Identity/ad_adapter.py
│   ├── mock_data.py                     # Mock datasets (copied from ProjectNexus)
│   ├── entra_client.py                  # Stub (Graph API)
│   ├── workday_client.py                # Stub (Workday REST API)
│   ├── helix_client.py                  # Stub (BMC Helix)
│   ├── intune_client.py                 # Stub (Graph API)
│   ├── lansweeper_client.py             # Stub (Lansweeper GraphQL)
│   └── fedex_client.py                  # Stub (FedEx REST)
├── tests/                                # Migrated test suites (pytest run pending)
│   ├── identity_tests/                  # From Identity/tests/
│   └── workday_tests/                   # From Workday/workday-mcp/tests/
├── .venv/                                # Fresh virtual environment with dependencies
├── .env                                  # Active config (USE_MOCK=true)
├── .env.example                          # Template (copied from ProjectNexus)
├── pyproject.toml                        # Package definition (copied from ProjectNexus)
├── README.md                             # Full tool reference (copied from ProjectNexus)
└── Local-Setup.md                        # Installation & config guide (new)

Modified files

• README.md (repository root) — updated from "Workday-MCP status page" to "Nexus-MCP status page" with shard status board

Preserved files (not modified)

• Identity/ folder — original AD MCP server (to be archived after verification)
• Workday/ folder — original Workday MCP server (to be archived after verification)

Next steps

Immediate (before next commit)

1. Run pytest validation — pytest nexus-mcp/tests/ -v to verify migrated tests pass with updated imports
2. Fix markdown linting — address 15 style warnings in Local-Setup.md (blanks around fences, table spacing)
3. Pylance zero-error validation — open nexus-mcp/ in VS Code and verify no Python type errors

Near-term (next session)

4. Update Claude Desktop config — point to nexus-mcp/src/main.py instead of legacy Identity or Workday servers
5. Test mock mode end-to-end — invoke tools through Claude chat, verify audit log writes correctly
6. Verify drift scenarios — test audit tools against mock data (Bob Martinez, Carol Chen, David Kim cases)
7. Archive legacy folders — move Identity/ and Workday/ to documentation/archive/ after verification complete

Medium-term (Q2 2026)

8. Live credential integration — configure AD_, ENTRA_, WORKDAY_* environment variables for non-mock mode
9. Transition stub clients from NotImplementedError to working implementations — entra_client.py, workday_client.py
10. Red → Yellow shard promotion — enable ITSM, Assets, Logistics shards as credentials become available

Verification commands

# Navigate to nexus-mcp
cd nexus-mcp

# Activate virtual environment
source .venv/Scripts/activate  # Windows: .venv\Scripts\Activate.ps1

# Run smoke test (already passed ✅)
python -c "import sys; sys.path.insert(0, 'src'); sys.path.insert(0, 'lib'); from main import mcp; print(f'✓ {len(mcp._tool_manager._tools)} tools')"

# Run pytest (pending)
pytest tests/ -v

# Check for Python errors (pending)
# Open nexus-mcp/ folder in VS Code and verify Pylance reports 0 errors

Commit message recommendation

Following Conventional Commits standard:

feat(nexus): implement sharded architecture for enterprise integration

- Migrate Identity and Workday tools into unified nexus-mcp orchestrator
- Add plugin-based shard system with feature flag control
- Implement SOC 2 audit logging with automatic PII redaction
- Create stub shards for ITSM, Assets, Logistics (Red status)
- Add comprehensive mock data library with drift scenarios
- Update repository README to position Nexus-MCP as primary server

BREAKING CHANGE: Legacy Identity/ and Workday/ servers preserved but deprecated.
Users should update Claude Desktop config to point to nexus-mcp/src/main.py.

Refs: WIS-006, WIS-009, WIS-014-018, Gemini conversation 2026-04-06

Session statistics

• Duration: Single session (2026-04-13)
• Files created: 25 (nexus-mcp structure)
• Files modified: 1 (README.md)
• Lines of code migrated: ~2000+ (Identity + Workday + ProjectNexus framework)
• Tools migrated: 31 (from 2 legacy servers)
• Shards created: 6 (3 Green, 1 Yellow, 2 Red)
• Test files migrated: 2 test suites (pytest validation pending)

---

Session status: ✅ Migration complete, ⏳ Verification pending