diff --git a/scripts/hooks/ecc-statusline.js b/scripts/hooks/ecc-statusline.js
new file mode 100644
index 00000000..c4b35f85
--- /dev/null
+++ b/scripts/hooks/ecc-statusline.js
@@ -0,0 +1,160 @@
+#!/usr/bin/env node
+/**
+ * ECC Statusline — statusLine command
+ *
+ * Displays: model | task | $cost Nt Nf Nm | dir ██░░ N%
+ *
+ * Registered in settings.json under "statusLine", not in hooks.json.
+ * Reads bridge file from ecc-metrics-bridge.js and stdin from Claude Code runtime.
+ */
+
+'use strict';
+
+const fs = require('fs');
+const os = require('os');
+const path = require('path');
+const { sanitizeSessionId, readBridge, writeBridgeAtomic } = require('../lib/session-bridge');
+
+const AUTO_COMPACT_BUFFER_PCT = 16.5;
+
+/**
+ * Format duration from ISO timestamp to now.
+ * @param {string} isoTimestamp
+ * @returns {string} e.g. "5s", "12m", "1h23m"
+ */
+function formatDuration(isoTimestamp) {
+  if (!isoTimestamp) return '?';
+  const elapsed = Math.floor((Date.now() - new Date(isoTimestamp).getTime()) / 1000);
+  if (elapsed < 0) return '?';
+  if (elapsed < 60) return `${elapsed}s`;
+  const mins = Math.floor(elapsed / 60);
+  if (mins < 60) return `${mins}m`;
+  const hours = Math.floor(mins / 60);
+  const remMins = mins % 60;
+  return remMins > 0 ? `${hours}h${remMins}m` : `${hours}h`;
+}
+
+/**
+ * Build context progress bar with ANSI colors.
+ * @param {number} remaining - Raw remaining percentage from Claude Code
+ * @returns {string} Colored bar string
+ */
+function buildContextBar(remaining) {
+  if (remaining == null) return '';
+
+  const usableRemaining = Math.max(0, ((remaining - AUTO_COMPACT_BUFFER_PCT) / (100 - AUTO_COMPACT_BUFFER_PCT)) * 100);
+  const used = Math.max(0, Math.min(100, Math.round(100 - usableRemaining)));
+
+  const filled = Math.floor(used / 10);
+  const bar = '\u2588'.repeat(filled) + '\u2591'.repeat(10 - filled);
+
+  if (used < 50) return ` \x1b[32m${bar} ${used}%\x1b[0m`;
+  if (used < 65) return ` \x1b[33m${bar} ${used}%\x1b[0m`;
+  if (used < 80) return ` \x1b[38;5;208m${bar} ${used}%\x1b[0m`;
+  return ` \x1b[5;31m${bar} ${used}%\x1b[0m`;
+}
+
+/**
+ * Read current in-progress task from todos directory.
+ * @param {string} sessionId
+ * @returns {string} Task activeForm text or empty string
+ */
+function readCurrentTask(sessionId) {
+  try {
+    const claudeDir = process.env.CLAUDE_CONFIG_DIR || path.join(os.homedir(), '.claude');
+    const todosDir = path.join(claudeDir, 'todos');
+    if (!fs.existsSync(todosDir)) return '';
+
+    const files = fs
+      .readdirSync(todosDir)
+      .filter(f => f.startsWith(sessionId) && f.includes('-agent-') && f.endsWith('.json'))
+      .map(f => ({ name: f, mtime: fs.statSync(path.join(todosDir, f)).mtime }))
+      .sort((a, b) => b.mtime - a.mtime);
+
+    if (files.length === 0) return '';
+
+    const todos = JSON.parse(fs.readFileSync(path.join(todosDir, files[0].name), 'utf8'));
+    const inProgress = todos.find(t => t.status === 'in_progress');
+    return inProgress?.activeForm || '';
+  } catch {
+    return '';
+  }
+}
+
+function runStatusline() {
+  let input = '';
+  const stdinTimeout = setTimeout(() => process.exit(0), 3000);
+  process.stdin.setEncoding('utf8');
+  process.stdin.on('data', chunk => (input += chunk));
+  process.stdin.on('end', () => {
+    clearTimeout(stdinTimeout);
+    try {
+      const data = JSON.parse(input);
+      const model = data.model?.display_name || 'Claude';
+      const dir = data.workspace?.current_dir || process.cwd();
+      const session = data.session_id || '';
+      const remaining = data.context_window?.remaining_percentage;
+
+      const sessionId = sanitizeSessionId(session);
+      const bridge = sessionId ? readBridge(sessionId) : null;
+
+      // Write context % back to bridge for context-monitor
+      if (sessionId && bridge && remaining != null) {
+        bridge.context_remaining_pct = remaining;
+        try {
+          writeBridgeAtomic(sessionId, bridge);
+        } catch {
+          /* best effort */
+        }
+      }
+
+      // Current task
+      const task = session ? readCurrentTask(session) : '';
+
+      // Metrics from bridge
+      let metricsStr = '';
+      if (bridge) {
+        const parts = [];
+        if (bridge.total_cost_usd > 0) {
+          parts.push(`$${bridge.total_cost_usd.toFixed(2)}`);
+        }
+        if (bridge.tool_count > 0) {
+          parts.push(`${bridge.tool_count}t`);
+        }
+        if (bridge.files_modified_count > 0) {
+          parts.push(`${bridge.files_modified_count}f`);
+        }
+        const dur = formatDuration(bridge.first_timestamp);
+        if (dur !== '?') {
+          parts.push(dur);
+        }
+        if (parts.length > 0) {
+          metricsStr = `\x1b[36m${parts.join(' ')}\x1b[0m`;
+        }
+      }
+
+      // Context bar
+      const ctx = buildContextBar(remaining);
+
+      // Build output
+      const dirname = path.basename(dir);
+      const segments = [`\x1b[2m${model}\x1b[0m`];
+
+      if (task) {
+        segments.push(`\x1b[1m${task}\x1b[0m`);
+      }
+      if (metricsStr) {
+        segments.push(metricsStr);
+      }
+      segments.push(`\x1b[2m${dirname}\x1b[0m`);
+
+      process.stdout.write(segments.join(' \x1b[2m\u2502\x1b[0m ') + ctx);
+    } catch {
+      // Silent fail
+    }
+  });
+}
+
+module.exports = { formatDuration, buildContextBar, readCurrentTask };
+
+if (require.main === module) runStatusline();
diff --git a/tests/hooks/ecc-statusline.test.js b/tests/hooks/ecc-statusline.test.js
new file mode 100644
index 00000000..fee5a4a3
--- /dev/null
+++ b/tests/hooks/ecc-statusline.test.js
@@ -0,0 +1,180 @@
+/**
+ * Tests for scripts/hooks/ecc-statusline.js
+ *
+ * Run with: node tests/hooks/ecc-statusline.test.js
+ */
+
+const assert = require('assert');
+
+const { formatDuration, buildContextBar, readCurrentTask } = require('../../scripts/hooks/ecc-statusline');
+
+// Test helper
+function test(name, fn) {
+  try {
+    fn();
+    console.log(`  \u2713 ${name}`);
+    return true;
+  } catch (err) {
+    console.log(`  \u2717 ${name}`);
+    console.log(`    Error: ${err.message}`);
+    return false;
+  }
+}
+
+function runTests() {
+  console.log('\n=== Testing ecc-statusline.js ===\n');
+
+  let passed = 0;
+  let failed = 0;
+
+  // formatDuration tests
+  console.log('formatDuration:');
+
+  if (
+    test('null returns "?"', () => {
+      assert.strictEqual(formatDuration(null), '?');
+    })
+  )
+    passed++;
+  else failed++;
+
+  if (
+    test('undefined returns "?"', () => {
+      assert.strictEqual(formatDuration(undefined), '?');
+    })
+  )
+    passed++;
+  else failed++;
+
+  if (
+    test('timestamp 30 seconds ago ends with "s"', () => {
+      const ts = new Date(Date.now() - 30 * 1000).toISOString();
+      const result = formatDuration(ts);
+      assert.ok(result.endsWith('s'), `Expected ending in "s", got: ${result}`);
+    })
+  )
+    passed++;
+  else failed++;
+
+  if (
+    test('timestamp 5 minutes ago ends with "m"', () => {
+      const ts = new Date(Date.now() - 5 * 60 * 1000).toISOString();
+      const result = formatDuration(ts);
+      assert.ok(result.endsWith('m'), `Expected ending in "m", got: ${result}`);
+    })
+  )
+    passed++;
+  else failed++;
+
+  if (
+    test('timestamp 90 minutes ago contains "h"', () => {
+      const ts = new Date(Date.now() - 90 * 60 * 1000).toISOString();
+      const result = formatDuration(ts);
+      assert.ok(result.includes('h'), `Expected "h" in result, got: ${result}`);
+    })
+  )
+    passed++;
+  else failed++;
+
+  if (
+    test('future timestamp returns "?"', () => {
+      const ts = new Date(Date.now() + 60 * 1000).toISOString();
+      const result = formatDuration(ts);
+      assert.strictEqual(result, '?');
+    })
+  )
+    passed++;
+  else failed++;
+
+  // buildContextBar tests
+  console.log('\nbuildContextBar:');
+
+  if (
+    test('null returns empty string', () => {
+      assert.strictEqual(buildContextBar(null), '');
+    })
+  )
+    passed++;
+  else failed++;
+
+  if (
+    test('undefined returns empty string', () => {
+      assert.strictEqual(buildContextBar(undefined), '');
+    })
+  )
+    passed++;
+  else failed++;
+
+  if (
+    test('80% remaining contains green ANSI code', () => {
+      const bar = buildContextBar(80);
+      assert.ok(bar.includes('\x1b[32m'), `Expected green ANSI in: ${JSON.stringify(bar)}`);
+    })
+  )
+    passed++;
+  else failed++;
+
+  if (
+    test('50% remaining contains yellow ANSI code', () => {
+      const bar = buildContextBar(50);
+      assert.ok(bar.includes('\x1b[33m'), `Expected yellow ANSI in: ${JSON.stringify(bar)}`);
+    })
+  )
+    passed++;
+  else failed++;
+
+  if (
+    test('20% remaining contains red blink ANSI code', () => {
+      const bar = buildContextBar(20);
+      assert.ok(bar.includes('\x1b[5;31m'), `Expected red blink ANSI in: ${JSON.stringify(bar)}`);
+    })
+  )
+    passed++;
+  else failed++;
+
+  if (
+    test('context bar contains block characters', () => {
+      const bar = buildContextBar(60);
+      assert.ok(bar.includes('\u2588') || bar.includes('\u2591'), 'Expected block characters in bar');
+    })
+  )
+    passed++;
+  else failed++;
+
+  if (
+    test('context bar contains percentage', () => {
+      const bar = buildContextBar(70);
+      assert.ok(bar.includes('%'), 'Expected percentage in bar');
+    })
+  )
+    passed++;
+  else failed++;
+
+  // readCurrentTask tests
+  console.log('\nreadCurrentTask:');
+
+  if (
+    test('nonexistent session returns empty string', () => {
+      const result = readCurrentTask('nonexistent-session-xyz-999');
+      assert.strictEqual(result, '');
+    })
+  )
+    passed++;
+  else failed++;
+
+  if (
+    test('empty string session returns empty string', () => {
+      const result = readCurrentTask('');
+      assert.strictEqual(result, '');
+    })
+  )
+    passed++;
+  else failed++;
+
+  // Summary
+  console.log(`\nResults: ${passed} passed, ${failed} failed\n`);
+  return { passed, failed };
+}
+
+const { failed } = runTests();
+process.exit(failed > 0 ? 1 : 0);