diff --git a/dashboard/components/SimpleInput.js b/dashboard/components/SimpleInput.js
index 9f817fa..9acf746 100644
--- a/dashboard/components/SimpleInput.js
+++ b/dashboard/components/SimpleInput.js
@@ -1,5 +1,6 @@
 import { html, useState, useRef, useCallback, useMemo, useEffect } from '../lib/preact.js';
 import { getStatusMeta } from '../utils/status.js';
+import { getTriggerInfo as _getTriggerInfo, filteredSkills as _filteredSkills } from '../utils/autocomplete.js';
 
 export function SimpleInput({ sessionId, status, onRespond, autocompleteConfig = null }) {
   const [text, setText] = useState('');
@@ -13,48 +14,12 @@ export function SimpleInput({ sessionId, status, onRespond, autocompleteConfig =
   const autocompleteRef = useRef(null);
   const meta = getStatusMeta(status);
 
-  // Detect if cursor is at a trigger position for autocomplete
   const getTriggerInfo = useCallback((value, cursorPos) => {
-    // No config means no autocomplete
-    if (!autocompleteConfig) return null;
-
-    const { trigger } = autocompleteConfig;
-
-    // Find the start of the current "word" (after last whitespace before cursor)
-    let wordStart = cursorPos;
-    while (wordStart > 0 && !/\s/.test(value[wordStart - 1])) {
-      wordStart--;
-    }
-
-    // Check if word starts with this agent's trigger character
-    if (value[wordStart] === trigger) {
-      return {
-        trigger,
-        filterText: value.slice(wordStart + 1, cursorPos).toLowerCase(),
-        replaceStart: wordStart,
-        replaceEnd: cursorPos,
-      };
-    }
-
-    return null;
+    return _getTriggerInfo(value, cursorPos, autocompleteConfig);
   }, [autocompleteConfig]);
 
-  // Filter skills based on user input after trigger
   const filteredSkills = useMemo(() => {
-    if (!autocompleteConfig || !triggerInfo) return [];
-
-    const { skills } = autocompleteConfig;
-    const { filterText } = triggerInfo;
-
-    let filtered = skills;
-    if (filterText) {
-      filtered = skills.filter(s =>
-        s.name.toLowerCase().includes(filterText)
-      );
-    }
-
-    // Server pre-sorts, but re-sort after filtering for stability
-    return filtered.sort((a, b) => a.name.localeCompare(b.name));
+    return _filteredSkills(autocompleteConfig, triggerInfo);
   }, [autocompleteConfig, triggerInfo]);
 
   // Show/hide autocomplete based on trigger detection
@@ -229,7 +194,7 @@ export function SimpleInput({ sessionId, status, onRespond, autocompleteConfig =
             <div class="px-3 py-2 text-sm text-dim">No matching skills</div>
           ` : filteredSkills.map((skill, i) => html`
             <div
-              key=${i}
+              key=${skill.name}
               class="px-3 py-2 cursor-pointer text-sm transition-colors ${
                 i === selectedIndex
                   ? 'bg-selection/50 text-bright'
diff --git a/dashboard/tests/autocomplete.test.js b/dashboard/tests/autocomplete.test.js
new file mode 100644
index 0000000..8c21118
--- /dev/null
+++ b/dashboard/tests/autocomplete.test.js
@@ -0,0 +1,162 @@
+import { describe, it } from 'node:test';
+import assert from 'node:assert/strict';
+import { getTriggerInfo, filteredSkills } from '../utils/autocomplete.js';
+
+const mockConfig = {
+  trigger: '/',
+  skills: [
+    { name: 'commit', description: 'Create a git commit' },
+    { name: 'review-pr', description: 'Review a pull request' },
+    { name: 'comment', description: 'Add a comment' },
+  ],
+};
+
+describe('getTriggerInfo', () => {
+  it('returns null when no autocompleteConfig', () => {
+    const result = getTriggerInfo('/hello', 1, null);
+    assert.equal(result, null);
+  });
+
+  it('returns null when autocompleteConfig is undefined', () => {
+    const result = getTriggerInfo('/hello', 1, undefined);
+    assert.equal(result, null);
+  });
+
+  it('detects trigger at position 0', () => {
+    const result = getTriggerInfo('/', 1, mockConfig);
+    assert.deepEqual(result, {
+      trigger: '/',
+      filterText: '',
+      replaceStart: 0,
+      replaceEnd: 1,
+    });
+  });
+
+  it('detects trigger after space', () => {
+    const result = getTriggerInfo('hello /co', 9, mockConfig);
+    assert.deepEqual(result, {
+      trigger: '/',
+      filterText: 'co',
+      replaceStart: 6,
+      replaceEnd: 9,
+    });
+  });
+
+  it('detects trigger after newline', () => {
+    const result = getTriggerInfo('line1\n/rev', 10, mockConfig);
+    assert.deepEqual(result, {
+      trigger: '/',
+      filterText: 'rev',
+      replaceStart: 6,
+      replaceEnd: 10,
+    });
+  });
+
+  it('returns null for non-trigger character', () => {
+    const result = getTriggerInfo('hello world', 5, mockConfig);
+    assert.equal(result, null);
+  });
+
+  it('returns null for wrong trigger (! when config expects /)', () => {
+    const result = getTriggerInfo('!commit', 7, mockConfig);
+    assert.equal(result, null);
+  });
+
+  it('returns null for trigger embedded in a word', () => {
+    const result = getTriggerInfo('path/to/file', 5, mockConfig);
+    assert.equal(result, null);
+  });
+
+  it('extracts filterText correctly', () => {
+    const result = getTriggerInfo('/commit', 7, mockConfig);
+    assert.equal(result.filterText, 'commit');
+    assert.equal(result.replaceStart, 0);
+    assert.equal(result.replaceEnd, 7);
+  });
+
+  it('filterText is lowercase', () => {
+    const result = getTriggerInfo('/CoMmIt', 7, mockConfig);
+    assert.equal(result.filterText, 'commit');
+  });
+
+  it('replaceStart and replaceEnd are correct for mid-input trigger', () => {
+    const result = getTriggerInfo('foo /bar', 8, mockConfig);
+    assert.equal(result.replaceStart, 4);
+    assert.equal(result.replaceEnd, 8);
+  });
+
+  it('works with a different trigger character', () => {
+    const codexConfig = { trigger: '!', skills: [] };
+    const result = getTriggerInfo('!test', 5, codexConfig);
+    assert.deepEqual(result, {
+      trigger: '!',
+      filterText: 'test',
+      replaceStart: 0,
+      replaceEnd: 5,
+    });
+  });
+});
+
+describe('filteredSkills', () => {
+  it('returns empty array without config', () => {
+    const info = { filterText: '' };
+    assert.deepEqual(filteredSkills(null, info), []);
+  });
+
+  it('returns empty array without triggerInfo', () => {
+    assert.deepEqual(filteredSkills(mockConfig, null), []);
+  });
+
+  it('returns empty array when both are null', () => {
+    assert.deepEqual(filteredSkills(null, null), []);
+  });
+
+  it('returns all skills with empty filter', () => {
+    const info = { filterText: '' };
+    const result = filteredSkills(mockConfig, info);
+    assert.equal(result.length, 3);
+  });
+
+  it('filters case-insensitively', () => {
+    const info = { filterText: 'com' };
+    const result = filteredSkills(mockConfig, info);
+    const names = result.map(s => s.name);
+    assert.ok(names.includes('commit'));
+    assert.ok(names.includes('comment'));
+    assert.ok(!names.includes('review-pr'));
+  });
+
+  it('matches anywhere in name', () => {
+    const info = { filterText: 'view' };
+    const result = filteredSkills(mockConfig, info);
+    assert.equal(result.length, 1);
+    assert.equal(result[0].name, 'review-pr');
+  });
+
+  it('sorts alphabetically', () => {
+    const info = { filterText: '' };
+    const result = filteredSkills(mockConfig, info);
+    const names = result.map(s => s.name);
+    assert.deepEqual(names, ['comment', 'commit', 'review-pr']);
+  });
+
+  it('returns empty array when no matches', () => {
+    const info = { filterText: 'zzz' };
+    const result = filteredSkills(mockConfig, info);
+    assert.deepEqual(result, []);
+  });
+
+  it('does not mutate the original skills array', () => {
+    const config = {
+      trigger: '/',
+      skills: [
+        { name: 'zebra', description: 'z' },
+        { name: 'alpha', description: 'a' },
+      ],
+    };
+    const info = { filterText: '' };
+    filteredSkills(config, info);
+    assert.equal(config.skills[0].name, 'zebra');
+    assert.equal(config.skills[1].name, 'alpha');
+  });
+});
diff --git a/dashboard/utils/autocomplete.js b/dashboard/utils/autocomplete.js
new file mode 100644
index 0000000..3b34289
--- /dev/null
+++ b/dashboard/utils/autocomplete.js
@@ -0,0 +1,48 @@
+// Pure logic for autocomplete trigger detection and skill filtering.
+// Extracted from SimpleInput.js for testability.
+
+/**
+ * Detect if cursor is at a trigger position for autocomplete.
+ * Returns trigger info object or null.
+ */
+export function getTriggerInfo(value, cursorPos, autocompleteConfig) {
+  if (!autocompleteConfig) return null;
+
+  const { trigger } = autocompleteConfig;
+
+  // Find the start of the current "word" (after last whitespace before cursor)
+  let wordStart = cursorPos;
+  while (wordStart > 0 && !/\s/.test(value[wordStart - 1])) {
+    wordStart--;
+  }
+
+  // Check if word starts with this agent's trigger character
+  if (value[wordStart] === trigger) {
+    return {
+      trigger,
+      filterText: value.slice(wordStart + 1, cursorPos).toLowerCase(),
+      replaceStart: wordStart,
+      replaceEnd: cursorPos,
+    };
+  }
+
+  return null;
+}
+
+/**
+ * Filter and sort skills based on trigger info.
+ * Returns sorted array of matching skills.
+ */
+export function filteredSkills(autocompleteConfig, triggerInfo) {
+  if (!autocompleteConfig || !triggerInfo) return [];
+
+  const { skills } = autocompleteConfig;
+  const { filterText } = triggerInfo;
+
+  let filtered = filterText
+    ? skills.filter(s => s.name.toLowerCase().includes(filterText))
+    : skills.slice();
+
+  // Server pre-sorts, but re-sort after filtering for stability
+  return filtered.sort((a, b) => a.name.localeCompare(b.name));
+}