/harness-mcp-scan

name: harness-mcp-scan
description: Static security scan of a harness's declared MCP surface via `harness mcp-scan {path}`. Reads `.mcp/servers.json` + `.harness/claims.json`. Pure-read, no dispatch. Exits 1 on findings at or above `--fail-on` severity.
argument-hint: "[--path .] [--fail-on low|medium|high] [--format table|json]"
allowed-tools: Bash

Calls `harness mcp-scan` to enumerate every declared MCP server + tool and flag policy / permission / dependency issues. Never executes any tool; pure static analysis.

Algorithm

Implementation: [`scripts/mcp-scan.mjs`](../../scripts/mcp-scan.mjs).

1. Invoke the pinned `harness` binary (`metaharness@~0.4.1`, resolved from a local install or the one-time `~/.ruflo/metaharness-cache-<pin>` cache — never `@latest`): `harness mcp-scan <path> --json`. 2. Parse `findings[]` with `{ severity, id, server, tool, message }`. 3. `--fail-on <severity>`: exit 1 when any finding is at or above that level. Default `high`. 4. Output JSON (default) or markdown table.

Severity rank

| Severity | Rank | |---|---:| | low | 1 | | medium | 2 | | high | 3 |

`--fail-on high` (default) only fails on HIGH; `--fail-on medium` also fails on MEDIUM; `--fail-on low` fails on any finding.

CI integration

- name: MCP static scan
  run: node plugins/ruflo-metaharness/scripts/mcp-scan.mjs --fail-on high

The exit code is the only thing CI watches; the JSON output goes to artifacts for human review.

Graceful degradation

When `harness` binary is unavailable (no network, blocked registry), emits structured `{ degraded: true, reason: 'metaharness-not-available' }` and exits 0. Ruflo continues — ADR-150 architectural constraint.