correctover-mcp-server

CCS-native MCP Server — 6-dimension runtime verification with fail-closed guarantee

---

What is this?

correctover-mcp-server is an MCP (Model Context Protocol) server that embeds CCS (Correctover Conformance Standard) runtime verification directly into the protocol layer. Every tool call is verified across 6 dimensions before execution — if verification fails, the action is never executed (fail-closed).

This is not an observer-pattern governance hook. It is a protocol-level guarantee.

Architecture

┌─────────────────────────────────────────────────────┐
│                    MCP Client                         │
│   (any MCP 2026-07-28 compliant client)              │
├─────────────────────────────────────────────────────┤
│              Streamable HTTP Transport                │
│   (POST /mcp, _meta version negotiation)             │
─────────────────────────────────────────────────────┤
│           CCS Runtime Verification                    │
│   ┌──────────┬──────────┬──────────┬──────────┐     │
│   │ Structure│  Schema  │  Latency │   Cost   │     │
│   │ Verifier │ Validator│  Monitor │  Monitor │     │
│   ├──────────┼──────────┼──────────┼──────────┤     │
│   │ Identity │ Integrity│  Policy  │ Failover │     │
│   │ Tracker  │  Checker │  Engine  │  Engine  │     │
│   └──────────┴──────────┴──────────┴──────────┘     │
│   ANY dimension fails → Action BLOCKED (never runs)  │
├─────────────────────────────────────────────────────┤
│                  Tool Execution                       │
│   (only reached if ALL 6 dimensions pass)            │
└─────────────────────────────────────────────────────┘

6-Dimension Verification

Dimension	Verifies	Failure Mode
Structure	Request has valid structure, protocol version, method	Malformed request rejected
Schema	Input matches expected tool schema	Invalid input rejected
Latency	Verification within budget (P50<10μs, P99<25μs)	Timeout → Fail-Closed
Cost	Resource usage within limits	Budget exceeded → blocked
Identity	Client is traceable (clientInfo present)	Untraceable → rejected
Integrity	Request is complete and non-empty	Corrupted → rejected

Quick Start

Install

git clone https://github.com/Correctover/correctover-mcp-server.git
cd correctover-mcp-server
npm install

Run

# Development
npm run dev

# Production
npm run build
npm start

Configure

# Environment variables
export MCP_PORT=3000          # Default: 3000
export MCP_HOST=127.0.0.1     # Default: 127.0.0.1
export CCS_AUDIT=true         # Enable audit logging

MCP Protocol Compliance

This server implements MCP 2026-07-28 (modern-only):

• ✅ server/discover — broadcasts protocol versions, capabilities, CCS identity
• ✅ Streamable HTTP transport (POST /mcp)
• ✅ _meta per-request version negotiation (no initialize handshake)
• ✅ resultType on all responses (complete / input_required)
• ✅ MRTR pattern for human-in-the-loop (InputRequiredResult)
• ✅ subscriptions/listen for change notifications
• ✅ CacheableResult with ttlMs + cacheScope
• ✅ Standard headers (Mcp-Method, Mcp-Name, MCP-Protocol-Version)
• ❌ No initialize handshake (modern-only, no dual-era)
• ❌ No HTTP+SSE transport (deprecated)

Available Tools

ccs_verify

Run 6-dimension runtime verification on an agent action.

{
  "agent_id": "agent-123",
  "action_type": "tool_call",
  "tool_name": "search_web",
  "tool_input": { "query": "test" }
}

ccs_evidence_hash

Generate integrity evidence hash for audit chain sealing.

{
  "action_id": "action-456",
  "result": { "output": "verified" },
  "verifier_id": "ccs"
}

ccs_status

Get CCS runtime status and performance statistics.

Available Resources

• ccs://policy/default — Default verification policy configuration
• ccs://status/runtime — Real-time runtime statistics
• ccs://config/verifier — Verifier configuration (latency budget, cost limits)

CCS Extension

This server advertises the CCS extension via server/discover:

{
  "extensions": {
    "io.modelcontextprotocol/ccs": {
      "version": "1.0.0",
      "dimensions": ["structure", "schema", "latency", "cost", "identity", "integrity"],
      "failClosed": true,
      "maxOverheadUs": 25
    }
  }
}

Integration with Halo

The ccs_evidence_hash tool generates hashes compatible with Halo's verification block (v0.2.30+), enabling sealed audit chains:

{
  "verification": {
    "status": "verified",
    "verifier": "ccs",
    "policy_ref": "default",
    "checked_at": "2026-08-03T12:00:00Z",
    "evidence_hash": "0x..."
  }
}

Performance

• P50 verification latency: < 10μs
• P99 verification latency: < 25μs
• Fail-closed guarantee: Action blocked if ANY dimension fails

Development

# Build
npm run build

# Test
npm test

# Lint
npm run lint

# Format
npm run format

License

MIT

References

• CCS Standard (DOI: 10.5281/zenodo.21271910)
• MCP 2026-07-28 Specification
• Halo Record