kcp-harness

Deterministic knowledge governance for any AI agent.

Your agent can read every file in your project. Can it prove why it read what it read?

KCP Harness is an MCP compliance proxy that sits between an AI coding agent and its tools. It intercepts knowledge-related calls, routes them through the kcp-agent deterministic planner (13-gate cascade, no LLM), and produces compliance artifacts — decision traces, audit logs, budget ledgers — as a side effect of normal agent operation.

The agent can't bypass governance because it only talks to the proxy's MCP interface. The proxy decides what knowledge is accessible, tracks spend, and logs every decision. Fail-closed: if the harness can't verify a request, the agent gets nothing.

Agent (Claude Code / Cursor / Copilot / Windsurf / Cline / Crush / OpenClaw / ...)
  │
  │  MCP tool call
  v
┌─────────────────────────────────────────────────────────┐
│  kcp-harness                                            │
│                                                         │
│  classify → govern (13 gates) → execute → audit         │
│                                                         │
│  Side outputs:                                          │
│  · Decision traces     (per-request, deterministic)     │
│  · Audit log           (append-only JSONL)              │
│  · Budget ledger       (itemized, ceiling-enforced)     │
│  · Temporal drift      (plan validity over time)        │
└─────────────────────────────────────────────────────────┘
  │
  v
Knowledge manifests (knowledge.yaml)

Documentation →

Why

Enterprises need agents that are defensible — auditable, reproducible, budget-controlled, temporally pinned. Today's agents can't prove why they read what they read. The harness adds a compliance layer without replacing the agent.

| What you keep | What the harness adds | |---|---| | Your agent (Claude Code, Cursor, Copilot, ...) | Deterministic knowledge selection | | Your workflow (coding, reviewing, shipping) | Decision traces (13 gates per unit) | | Your tools (MCP servers, shell, browser) | Budget enforcement (ceiling, per-currency) | | | Temporal governance (drift detection) | | | Append-only audit log | | | Replay / cross-examination |

You sell the compliance layer. The agents are pluggable.

Install

npm install -g kcp-harness

Or use without installing:

npx kcp-harness --help

Native executables

Pre-built binaries (no Node/Deno required) for Linux x64/arm64, macOS x64/arm64, and Windows x64 — grab them from a release. To build one yourself:

npm ci && npm run build
deno compile --allow-read --allow-env --allow-net --allow-run \
  --node-modules-dir=auto --output kcp-harness dist/cli.js

Quick start

1. Initialize

kcp-harness init          # creates harness.yaml

2. Generate agent integration

kcp-harness integrate claude-code    # or: cursor, copilot, windsurf, cline, continue, crush, openclaw

3. Start coding

Your agent now routes knowledge access through the harness. Every decision is logged.

Supported agents

| Agent | Config | Integration | |---|---|---| | Claude Code | .mcp.json + PreToolUse hooks | kcp-harness integrate claude-code | | Cursor | .cursor/mcp.json + .mdc rules | kcp-harness integrate cursor | | GitHub Copilot | .vscode/mcp.json (uses "servers" key) | kcp-harness integrate copilot | | Windsurf | global config + .windsurfrules | kcp-harness integrate windsurf | | Cline | MCP settings + .clinerules | kcp-harness integrate cline | | Continue | .continue/mcpServers/*.yaml | kcp-harness integrate continue | | Crush | crush.json + PrepareStep | kcp-harness integrate crush | | OpenClaw | openclaw.json + plugin hooks | kcp-harness integrate openclaw |

Each agent has its own MCP config format, rules file, and quirks. The integrate command handles them all — one governance layer, any agent.

How it works

Every tool call flows through a five-stage pipeline:

1. RECEIVE      MCP JSON-RPC request from agent
2. CLASSIFY     Knowledge-navigation or pass-through?
3. GOVERN       13-gate cascade (audience → temporal → budget → ...)
4. EXECUTE      Call downstream tool / return content
5. AUDIT        Log decision to append-only audit log

Classifier

The classifier examines each tool call and determines whether it targets governed knowledge. Read("docs/api.md") where docs/ is governed? Route through the planner. Read("package.json") where package.json isn't governed? Pass through. KCP tools (kcp_plan, kcp_load) are always governed.

Governor

Two modes:

• Plan-first (fast path) — the agent calls kcp_plan first. The harness caches the approved plan. Subsequent reads are checked against the cached plan — no re-planning.
• Auto-plan (fallback) — the agent reads a governed path without planning. The harness runs the planner automatically. Slower, but governance is enforced even for agents that don't know about kcp_plan.

The 13-gate cascade

Every knowledge unit is evaluated through 13 deterministic gates, in order:

audience → not_for → temporal → deprecated → supersession → relevance →
attestation → payment → access → strict → max_units → money_budget → context_budget

A unit must pass all gates. The gate that blocks it is recorded in the decision trace. Same inputs → same plan. No model involved.

MCP tools

Once connected, agents can use these governance tools:

| Tool | Description | |---|---| | kcp_plan | Deterministic load plan — which units, in what order, which skipped and why | | kcp_load | Plan + load eligible unit content | | kcp_trace | Full 13-gate decision trace | | kcp_validate | Lint a knowledge.yaml | | harness_status | Current governance state | | harness_budget | Itemized spend tracking | | harness_temporal_check | Plan drift detection |

Compliance artifacts

Audit log

Append-only JSONL. Every decision — governed or pass-through — is logged with sequence number, timestamp, tool, targets, and governance decision:

cat .kcp-harness/audit.jsonl | jq 'select(.governed == true)'

Budget ledger

Append-only itemized spend tracking. Per-currency running totals. Ceiling enforcement — a load that would exceed the budget is rejected atomically (no partial loads).

Temporal governance

Plans are registered with a temporal watcher. On subsequent calls, the watcher re-evaluates against the current time. If units have drifted (expired, newly valid), the harness emits a drift event. Long-running sessions stay honest.

Configuration

# harness.yaml
version: "1.0"

governance:
  domains:
    - manifest: "./knowledge.yaml"
      paths: ["docs/", "src/"]

  policy:
    fail_closed: true
    audit_all: true
    max_units: 5
    budget:
      amount: 1.00
      currency: USDC

audit:
  path: ".kcp-harness/audit.jsonl"

CLI

kcp-harness serve  [--config harness.yaml]   Start the MCP proxy
kcp-harness init                             Create a harness.yaml template
kcp-harness check  [--config harness.yaml]   Validate configuration
kcp-harness integrate <agent> [options]       Generate agent integration files
kcp-harness integrate --list                  List supported agents

Library

import { classify, govern, BudgetLedger, TemporalWatch } from "kcp-harness";
import { generate, listAgents } from "kcp-harness";

// Classify a tool call
const result = classify("Read", { file_path: "docs/api.md" }, governedDomains);

// Generate integration files
const output = generate("claude-code", { manifest: "./knowledge.yaml", paths: ["docs/"] });

Architecture

┌──────────────────────────────────────────────┐
│  Layer 3: Integration Packages               │
│  Agent-specific configs + rules files        │
│  (claude-code, cursor, copilot, ...)         │
├──────────────────────────────────────────────┤
│  Layer 2: KCP Compliance Harness             │  ← THIS
│  MCP proxy — deterministic governance        │
├──────────────────────────────────────────────┤
│  Layer 1: kcp-agent (planner core)           │
│  13-gate cascade, decision traces            │
└──────────────────────────────────────────────┘

Forking agents puts you in competition. A harness puts you in composition.

Tests

npm test     # 123 tests across 9 test files

Covers: classifier (28), audit (14), session (9), governor (5), proxy (10), integration (9), budget-ledger (14), temporal-watch (6), integrations (28).

License

Apache-2.0 · By eXOReaction AS, hosted under Cantara.