Wire normalizeMcpCommand into mcp_command_mismatch detector

dist/mesh/engine.js

@@ -50,16 +50,23 @@ function detectMcpCommandMismatch(policies) {
     const findings = [];
     const byName = groupMcpServersByName(policies);
     for (const [name, servers] of byName) {
-        const commands = new Map();
+        // Group by canonical identity, not raw command string, so neutral
+        // differences (npx -y vs npx, .cmd/.exe suffix, flag reordering)
+        // don't produce false-positive mcp_command_mismatch findings.
+        const byIdentity = new Map();
         for (const server of servers) {
-            const existing = commands.get(server.command) ?? [];
+            const existing = byIdentity.get(server.canonicalIdentity) ?? [];
             existing.push(server);
-            commands.set(server.command, existing);
+            byIdentity.set(server.canonicalIdentity, existing);
         }
-        if (commands.size <= 1) {
+        if (byIdentity.size <= 1) {
             continue;
         }
-        const commandList = [...commands.keys()].map((cmd) => `"${cmd}"`).join(' vs ');
+        // Message still shows the user-visible commands so the finding is
+        // actionable — even though grouping was on canonical identity.
+        const commandList = [...new Set(servers.map((s) => s.command))]
+            .map((cmd) => `"${cmd}"`)
+            .join(' vs ');
         const primary = servers[0];
         findings.push({
             kind: 'mcp_command_mismatch',

dist/parsers/codex.js

@@ -1,4 +1,5 @@
 import { readFile } from 'node:fs/promises';
+import { normalizeMcpCommand } from 'agent-gov-core';
 import { configPath } from '../discovery.js';
 import { isUnpinnedCommand, serverCommand } from './mcp.js';
 import { configParseFinding } from './errors.js';
@@ -289,6 +290,11 @@
         servers.push({
             name,
             command,
+            canonicalIdentity: normalizeMcpCommand({
+                command: draft.command,
+                args: draft.args,
+                url: draft.url ?? draft.serverUrl,
+            }),
             enabled: draft.enabled !== false,
             env: draft.env,
             headers: draft.headers,

dist/parsers/mcp.js

@@ -1,3 +1,4 @@
+import { normalizeMcpCommand } from 'agent-gov-core';
 import { configPath, isRecord, lineOfJsonKey, readJsonObjectWithSource } from '../discovery.js';
 import { configParseFinding } from './errors.js';
 const MCP_CONFIGS = [
@@ -65,6 +66,11 @@
         servers.push({
             name,
             command,
+            canonicalIdentity: normalizeMcpCommand({
+                command: raw.command,
+                args: raw.args,
+                url: raw.url ?? raw.serverUrl,
+            }),
             enabled: serverEnabled(raw),
             env: raw.env ?? {},
             headers: raw.headers ?? {},

package.json

@@ -1,3 +1,3 @@
 {
   "name": "policymesh",
   "version": "0.1.18",
@@ -31,7 +31,7 @@
     "test": "node --test"
   },
   "dependencies": {
-    "agent-gov-core": "github:Conalh/agent-gov-core#v0.1.1"
+    "agent-gov-core": "github:Conalh/agent-gov-core#v0.1.2"
   },
   "devDependencies": {
     "@types/node": "^24.0.0",

src/mesh/engine.ts

@@ -62,18 +62,25 @@ function detectMcpCommandMismatch(policies: RepoPolicies): Finding[] {
   const byName = groupMcpServersByName(policies);
 
   for (const [name, servers] of byName) {
-    const commands = new Map<string, McpServer[]>();
+    // Group by canonical identity, not raw command string, so neutral
+    // differences (npx -y vs npx, .cmd/.exe suffix, flag reordering)
+    // don't produce false-positive mcp_command_mismatch findings.
+    const byIdentity = new Map<string, McpServer[]>();
     for (const server of servers) {
-      const existing = commands.get(server.command) ?? [];
+      const existing = byIdentity.get(server.canonicalIdentity) ?? [];
       existing.push(server);
-      commands.set(server.command, existing);
+      byIdentity.set(server.canonicalIdentity, existing);
     }
 
-    if (commands.size <= 1) {
+    if (byIdentity.size <= 1) {
       continue;
     }
 
-    const commandList = [...commands.keys()].map((cmd) => `"${cmd}"`).join(' vs ');
+    // Message still shows the user-visible commands so the finding is
+    // actionable — even though grouping was on canonical identity.
+    const commandList = [...new Set(servers.map((s) => s.command))]
+      .map((cmd) => `"${cmd}"`)
+      .join(' vs ');
     const primary = servers[0];
     findings.push({
       kind: 'mcp_command_mismatch',

src/parsers/codex.ts

@@ -1,4 +1,5 @@
 import { readFile } from 'node:fs/promises';
+import { normalizeMcpCommand } from 'agent-gov-core';
 import { configPath } from '../discovery.js';
 import { isUnpinnedCommand, serverCommand } from './mcp.js';
 import { configParseFinding } from './errors.js';
@@ -362,6 +363,11 @@
     servers.push({
       name,
       command,
+      canonicalIdentity: normalizeMcpCommand({
+        command: draft.command,
+        args: draft.args,
+        url: draft.url ?? draft.serverUrl,
+      }),
       enabled: draft.enabled !== false,
       env: draft.env,
       headers: draft.headers,

src/parsers/mcp.ts

@@ -1,3 +1,4 @@
+import { normalizeMcpCommand } from 'agent-gov-core';
 import { configPath, isRecord, lineOfJsonKey, readJsonObjectWithSource } from '../discovery.js';
 import { configParseFinding } from './errors.js';
 import type { Finding, McpServer, McpSurface, SurfaceId } from '../types.js';
@@ -104,6 +105,11 @@
     servers.push({
       name,
       command,
+      canonicalIdentity: normalizeMcpCommand({
+        command: raw.command,
+        args: raw.args,
+        url: raw.url ?? raw.serverUrl,
+      }),
       enabled: serverEnabled(raw),
       env: raw.env ?? {},
       headers: raw.headers ?? {},

src/types.ts

@@ -1,3 +1,3 @@
 export type Severity = 'low' | 'medium' | 'high' | 'critical';
 
 export type SurfaceId =
@@ -29,7 +29,18 @@
 
 export interface McpServer {
   name: string;
+  /** Human-readable launch string. Used in messages/matrix rows only. */
   command: string;
+  /**
+   * Canonical identity of the launch command from agent-gov-core's
+   * normalizeMcpCommand, computed *without* env. Two servers with the same
+   * canonicalIdentity launch the same workload, even if their raw command
+   * strings differ in neutral ways (flag reordering, `-y`/`--yes`,
+   * `.cmd`/`.exe` suffix). The mismatch detector groups by this field,
+   * not by `command`. Env differences are reported separately by
+   * mcp_env_mismatch and intentionally excluded here.
+   */
+  canonicalIdentity: string;
   enabled: boolean;
   env: Record<string, string>;
   headers: Record<string, string>;

test/cli-output.test.mjs

@@ -1,3 +1,3 @@
 import test from 'node:test';
 import assert from 'node:assert/strict';
 import { execFile } from 'node:child_process';
@@ -337,6 +337,30 @@
   assert.ok(report.matrix.some((row) => row.capability === 'MCP: github' && row.values.codex?.includes('@modelcontextprotocol/server-github@2.0.0')));
 });
 
+test('CLI does not flag mcp_command_mismatch on neutral -y flag drift between surfaces', async () => {
+  // Regression for the PolicyMesh audit's false-positive class:
+  // root MCP uses `npx -y <pkg>`, Cursor uses `npx <pkg>`. `-y` only
+  // suppresses npx's install prompt — it doesn't change what runs.
+  // Pre-fix, this fixture produced a high-severity mcp_command_mismatch
+  // because the detector grouped by the raw joined command string.
+  // Post-fix, the detector groups by normalizeMcpCommand canonical
+  // identity, which drops `-y`/`--yes`, so the surfaces are equivalent.
+  const repo = join(testDir, 'fixtures', 'mcp-command-neutral-flag-equivalence');
+
+  const { stdout } = await execFileAsync(
+    process.execPath,
+    ['dist/index.js', 'audit', '--repo', repo, '--format', 'json'],
+    { cwd: packageRoot }
+  );
+  const report = JSON.parse(stdout);
+
+  const mismatchFindings = report.findings.filter(
+    (finding) => finding.kind === 'mcp_command_mismatch'
+  );
+  assert.deepEqual(mismatchFindings, [], 'expected no mcp_command_mismatch findings');
+  assert.equal(report.surfaceCount, 2);
+});
+
 test('CLI reports Codeium plugin MCP command drift against root MCP config', async () => {
   const repo = join(testDir, 'fixtures', 'codeium-plugin-mcp-config');
 

test/fixtures/mcp-command-neutral-flag-equivalence/.cursor/mcp.json

@@ -0,0 +1,8 @@
+{
+  "mcpServers": {
+    "github": {
+      "command": "npx",
+      "args": ["@modelcontextprotocol/server-github@1.2.3"]
+    }
+  }
+}

test/fixtures/mcp-command-neutral-flag-equivalence/.mcp.json

@@ -0,0 +1,8 @@
+{
+  "mcpServers": {
+    "github": {
+      "command": "npx",
+      "args": ["-y", "@modelcontextprotocol/server-github@1.2.3"]
+    }
+  }
+}