diff --git a/lib/utils/health.js b/lib/utils/health.js
new file mode 100644
index 0000000..acafa28
--- /dev/null
+++ b/lib/utils/health.js
@@ -0,0 +1,26 @@
+'use strict';
+
+function num(x) { return typeof x === 'number' && Number.isFinite(x) ? x : 0; }
+
+/**
+ * Compute health scores based on violation density per 1K executable LOC.
+ * Expects a summary with fields: lines.executable (or physical) and counts per category.
+ * Returns integers 0..100 for overall, structural, semantic.
+ */
+function computeHealth(summary) {
+  const exec = Math.max(1, num(summary && summary.lines && summary.lines.executable) || num(summary && summary.lines && summary.lines.physical) || 1000);
+  const total = num(summary && summary.magicNumbers) + num(summary && summary.complexity) + num(summary && summary.domainTerms) + num(summary && summary.architecture);
+  const structuralTotal = num(summary && summary.complexity) + num(summary && summary.architecture);
+  const semanticTotal = num(summary && summary.domainTerms) + num(summary && summary.magicNumbers);
+  const perK = total / (exec / 1000);
+  const perKStructural = structuralTotal / (exec / 1000);
+  const perKSemantic = semanticTotal / (exec / 1000);
+  const toScore = (d) => Math.max(0, Math.min(100, 100 - d * 10));
+  return {
+    overall: Math.round(toScore(perK)),
+    structural: Math.round(toScore(perKStructural)),
+    semantic: Math.round(toScore(perKSemantic))
+  };
+}
+
+module.exports = { computeHealth };
\ No newline at end of file
diff --git a/scripts/ratchet.js b/scripts/ratchet.js
index e24e373..ee41558 100755
--- a/scripts/ratchet.js
+++ b/scripts/ratchet.js
@@ -85,22 +85,8 @@ function summarize(payload) {
   };
 }
 
-// Rough health scoring using violation density (per K executable LOC if available)
-function computeHealth(summary) {
-  const exec = Math.max(1, num(summary.lines && summary.lines.executable) || num(summary.lines && summary.lines.physical) || 1000);
-  const total = num(summary.magicNumbers) + num(summary.complexity) + num(summary.domainTerms) + num(summary.architecture);
-  const structuralTotal = num(summary.complexity) + num(summary.architecture);
-  const semanticTotal = num(summary.domainTerms) + num(summary.magicNumbers);
-  const perK = total / (exec / 1000);
-  const perKStructural = structuralTotal / (exec / 1000);
-  const perKSemantic = semanticTotal / (exec / 1000);
-  const toScore = (d) => Math.max(0, Math.min(100, 100 - d * 10));
-  return {
-    overall: Math.round(toScore(perK)),
-    structural: Math.round(toScore(perKStructural)),
-    semantic: Math.round(toScore(perKSemantic))
-  };
-}
+// Health scoring moved to utility for testability
+const { computeHealth } = require(path.join(__dirname, '..', 'lib', 'utils', 'health.js'));
 
 function detectIntent(args) {
   if (args && (args.refactoring || args.intent === 'refactoring')) return 'refactoring';
diff --git a/tests/integration/health-gating.test.js b/tests/integration/health-gating.test.js
index c3e86fc..3d4b7cf 100644
--- a/tests/integration/health-gating.test.js
+++ b/tests/integration/health-gating.test.js
@@ -49,6 +49,56 @@ describe('health gating', function () {
     assert.ok(res.out.includes('HEALTH-GATE FAIL'));
   });
 
+  it('passes gate when score equals threshold (>= semantics)', function () {
+    const cwd = mkTmp();
+    // exec=1000, structural=3 → overall=70
+    const cats = { magicNumbers: [], complexity: Array.from({length:3},()=>({})), domainTerms: [], architecture: [], counts: {} };
+    const base = { categories: cats, effort: { byCategory: {} }, lines: { physical: 1000, executable: 1000 }, meta: {} };
+    const curr = { categories: cats, effort: { byCategory: {} }, lines: { physical: 1000, executable: 1000 }, meta: {} };
+    const cfg = { ratchet: { health: { enabled: true, gateOn: 'overall', minOverall: 70 } } };
+    const res = runRatchet(cwd, base, curr, { AI_SNIFFTEST_CONFIG_JSON: JSON.stringify(cfg) });
+    assert.strictEqual(res.code, 0);
+  });
+
+  it('respects gateOn: passes with structural gate, fails with semantic gate', function () {
+    const cwd = mkTmp();
+    // structural=1 (score=90), semantic=5 (score=50), overall=6 (score=40)
+    const cats = { magicNumbers: Array.from({length:5},()=>({})), complexity: Array.from({length:1},()=>({})), domainTerms: [], architecture: [], counts: {} };
+    const base = { categories: cats, effort: { byCategory: {} }, lines: { physical: 1000, executable: 1000 }, meta: {} };
+    const curr = { categories: cats, effort: { byCategory: {} }, lines: { physical: 1000, executable: 1000 }, meta: {} };
+    const cfgStruct = { ratchet: { health: { enabled: true, gateOn: 'structural', minOverall: 90 } } };
+    const cfgSem = { ratchet: { health: { enabled: true, gateOn: 'semantic', minOverall: 90 } } };
+    const resStruct = runRatchet(cwd, base, curr, { AI_SNIFFTEST_CONFIG_JSON: JSON.stringify(cfgStruct) });
+    const resSem = runRatchet(cwd, base, curr, { AI_SNIFFTEST_CONFIG_JSON: JSON.stringify(cfgSem) });
+    assert.strictEqual(resStruct.code, 0);
+    assert.ok(resSem.out.includes('HEALTH-GATE FAIL'));
+  });
+
+  it('applies intentOverrides when intent=refactoring', function () {
+    const cwd = mkTmp();
+    const cats = { magicNumbers: [], complexity: Array.from({length:3},()=>({})), domainTerms: [], architecture: [], counts: {} }; // overall=70
+    const base = { categories: cats, effort: { byCategory: {} }, lines: { physical: 1000, executable: 1000 }, meta: {} };
+    const curr = { categories: cats, effort: { byCategory: {} }, lines: { physical: 1000, executable: 1000 }, meta: {} };
+    const cfg = { ratchet: { health: { enabled: true, gateOn: 'overall', minOverall: 80, intentOverrides: { refactoring: { minOverall: 60 } } } } };
+    // Without intent override → fail
+    const res1 = runRatchet(cwd, base, curr, { AI_SNIFFTEST_CONFIG_JSON: JSON.stringify(cfg) });
+    assert.ok(res1.out.includes('HEALTH-GATE FAIL'));
+    // With intent=refactoring → pass
+    const env2 = { AI_SNIFFTEST_CONFIG_JSON: JSON.stringify(cfg) };
+    // pass extra arg via environment by setting AI_SNIFFTEST_ARGS? Not supported; append to argv instead
+    // We call node directly including --intent=refactoring by modifying runRatchet here
+    const b = path.join(cwd, 'baseline.json');
+    const c = path.join(cwd, 'current.json');
+    writeJson(b, base);
+    writeJson(c, curr);
+    try {
+      const out = cp.execFileSync(process.execPath, [path.join(process.cwd(), 'scripts/ratchet.js'), `--baseline=${b}`, `--current=${c}`, '--intent=refactoring'], { cwd, env: { ...process.env, ...env2 }, stdio: 'pipe' });
+      assert.strictEqual(String(out).includes('HEALTH-GATE FAIL'), false);
+    } catch (e) {
+      assert.fail('expected pass with intent override');
+    }
+  });
+
   it('bypasses gate when HEALTH_BYPASS=true', function () {
     const cwd = mkTmp();
     // Make baseline and current have same category counts so deltas=0 (avoid traditional ratchet failure)
@@ -60,4 +110,20 @@ describe('health gating', function () {
     // Bypass active: gating not enforced; exit should be success since there are no deltas
     assert.strictEqual(res.code, 0);
   });
+
+  it('bypasses gate via commit token in latest commit message', function () {
+    const cwd = mkTmp();
+    // Keep deltas=0
+    const cats = { magicNumbers: Array.from({length:20},()=>({})), complexity: [], domainTerms: [], architecture: [], counts: {} }; // semantic heavy → low score
+    const base = { categories: cats, effort: { byCategory: {} }, lines: { physical: 1000, executable: 1000 }, meta: {} };
+    const curr = { categories: cats, effort: { byCategory: {} }, lines: { physical: 1000, executable: 1000 }, meta: {} };
+    // Initialize a git repo and commit with bypass token
+    cp.execSync('git init', { cwd });
+    fs.writeFileSync(path.join(cwd, 'tmp.txt'), 'x');
+    cp.execSync('git add .', { cwd });
+    cp.execSync("git -c user.email=test@example.com -c user.name='Test' commit -m '[health-bypass] demo'", { cwd });
+    const cfg = { ratchet: { health: { enabled: true, gateOn: 'semantic', minOverall: 90, bypass: { commitToken: '[health-bypass]' } } } };
+    const res = runRatchet(cwd, base, curr, { AI_SNIFFTEST_CONFIG_JSON: JSON.stringify(cfg) });
+    assert.strictEqual(res.code, 0);
+  });
 });
diff --git a/tests/lib/utils/health.test.js b/tests/lib/utils/health.test.js
new file mode 100644
index 0000000..12d6082
--- /dev/null
+++ b/tests/lib/utils/health.test.js
@@ -0,0 +1,43 @@
+/* eslint-env mocha */
+/* global describe, it */
+'use strict';
+
+const assert = require('assert');
+const { computeHealth } = require('../../../lib/utils/health');
+
+function summary({ exec = 1000, magicNumbers = 0, complexity = 0, domainTerms = 0, architecture = 0 } = {}) {
+  return {
+    magicNumbers,
+    complexity,
+    domainTerms,
+    architecture,
+    lines: { executable: exec }
+  };
+}
+
+describe('utils/health.computeHealth', function () {
+  it('returns 100s when there are no violations', function () {
+    const s = summary({ exec: 1000 });
+    const h = computeHealth(s);
+    assert.deepStrictEqual(h, { overall: 100, structural: 100, semantic: 100 });
+  });
+
+  it('drops to 0 when perK density is 10 (1000 exec, 10 total)', function () {
+    const s = summary({ exec: 1000, complexity: 5, architecture: 5 });
+    const h = computeHealth(s);
+    assert.strictEqual(h.overall, 0);
+    assert.strictEqual(h.structural, 0);
+    assert.strictEqual(h.semantic, 100);
+  });
+
+  it('computes expected rounding at partial densities', function () {
+    // 2000 exec LOC, total=5 → perK=2.5 → score=100 - 25 = 75
+    const s = summary({ exec: 2000, magicNumbers: 2, complexity: 3 });
+    const h = computeHealth(s);
+    assert.strictEqual(h.overall, 75);
+    // structural=3, perK=1.5 → 85
+    assert.strictEqual(h.structural, 85);
+    // semantic=2, perK=1.0 → 90
+    assert.strictEqual(h.semantic, 90);
+  });
+});
\ No newline at end of file