diff --git a/src/App.jsx b/src/App.jsx
index e09a626..d120fe0 100644
--- a/src/App.jsx
+++ b/src/App.jsx
@@ -3,6 +3,7 @@ import React, { useEffect, useLayoutEffect, useMemo, useRef, useState } from 're
 import { flushSync } from 'react-dom';
 import TextareaAutosize from 'react-textarea-autosize';
 import AssistantMessageContent from './AssistantMessageContent'
+import ChatDatabasePicker from './ChatDatabasePicker'
 import LibraryManager from './LibraryManager'
 import { SettingsPanel, SettingsSidebar } from './SettingsPanels'
 import { applyColorScheme } from './colorSchemes'
@@ -23,7 +24,6 @@ import {
 import {
   AUDIO_RECORDING_TICK_MS,
   BOTTOM_EPSILON,
-  CHAT_LIBRARY_MAP_KEY,
   DEFAULT_BACKEND_API_URL,
   MAX_AUDIO_RECORDING_MS,
   MAX_IMAGE_ATTACHMENT_BYTES,
@@ -52,6 +52,7 @@ import {
   stopMediaStream,
   supportsAudioInputCapture,
 } from './audioInput'
+import { useChatLibrarySelection } from './useChatLibrarySelection'
 
 function appendTranscriptToComposer(currentInput, transcript) {
   const nextTranscript = String(transcript || '').trim()
diff --git a/src/ChatDatabasePicker.jsx b/src/ChatDatabasePicker.jsx
new file mode 100644
index 0000000..f26aedc
--- /dev/null
+++ b/src/ChatDatabasePicker.jsx
@@ -0,0 +1,102 @@
+import { useEffect, useRef, useState } from 'react'
+
+export default function ChatDatabasePicker({
+  activeSessionId,
+  chatLibrary,
+  chatLibrarySlug,
+  chatLibraryStatusSuffix,
+  isLibrarySyncing,
+  libraries,
+  setChatLibraryForSession,
+}) {
+  const dbPickerRef = useRef(null)
+  const [isDbPickerOpen, setIsDbPickerOpen] = useState(false)
+
+  useEffect(() => {
+    if (!isDbPickerOpen) return
+
+    const onPointerDown = (event) => {
+      if (!dbPickerRef.current?.contains(event.target)) {
+        setIsDbPickerOpen(false)
+      }
+    }
+
+    document.addEventListener('mousedown', onPointerDown)
+    return () => document.removeEventListener('mousedown', onPointerDown)
+  }, [isDbPickerOpen])
+
+  useEffect(() => {
+    setIsDbPickerOpen(false)
+  }, [activeSessionId])
+
+  return (
+    <div className="footer-tool-group" ref={dbPickerRef}>
+      <button
+        type="button"
+        className={"db-picker-toggle" + (chatLibrary ? " active" : "")}
+        onClick={() => {
+          if (!activeSessionId) return
+          setIsDbPickerOpen(prev => !prev)
+        }}
+        title={chatLibrary ? `Database: ${chatLibrary.name}${chatLibraryStatusSuffix}` : 'Select database for this chat'}
+        aria-haspopup="menu"
+        aria-expanded={isDbPickerOpen}
+        disabled={!activeSessionId}
+      >
+        <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="none"
+             stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round"
+             aria-hidden="true">
+          <ellipse cx="12" cy="5" rx="8" ry="3"/>
+          <path d="M4 5v6c0 1.7 3.6 3 8 3s8-1.3 8-3V5"/>
+          <path d="M4 11v6c0 1.7 3.6 3 8 3s8-1.3 8-3v-6"/>
+        </svg>
+      </button>
+      {isDbPickerOpen && (
+        <div className="db-picker-menu" role="menu">
+          <button
+            type="button"
+            className={"db-picker-option" + (!chatLibrarySlug ? " selected" : "")}
+            onClick={() => {
+              setChatLibraryForSession(activeSessionId, null)
+              setIsDbPickerOpen(false)
+            }}
+          >
+            <span>No database</span>
+            {!chatLibrarySlug && <span className="db-picker-status">Selected</span>}
+          </button>
+          {libraries.length === 0 ? (
+            <div className="db-picker-empty">No databases yet.</div>
+          ) : (
+            libraries.map(library => {
+              const selected = chatLibrarySlug === library.slug
+              const syncing = isLibrarySyncing(library.slug)
+              const status = !library.files?.length
+                ? 'Empty'
+                : library.states?.is_indexed
+                  ? 'Ready'
+                  : syncing
+                    ? 'Syncing'
+                    : 'Needs sync'
+
+              return (
+                <button
+                  key={library.slug}
+                  type="button"
+                  className={"db-picker-option" + (selected ? " selected" : "")}
+                  disabled={!library.files?.length}
+                  onClick={() => {
+                    setChatLibraryForSession(activeSessionId, library.slug)
+                    setIsDbPickerOpen(false)
+                  }}
+                >
+                  <span>{library.name}</span>
+                  <span className="db-picker-status">{selected ? 'Selected' : status}</span>
+                </button>
+              )
+            })
+          )}
+        </div>
+      )}
+    </div>
+  )
+}
diff --git a/src/useChatLibrarySelection.js b/src/useChatLibrarySelection.js
new file mode 100644
index 0000000..6f023bf
--- /dev/null
+++ b/src/useChatLibrarySelection.js
@@ -0,0 +1,124 @@
+import { useEffect, useMemo, useState } from 'react'
+import { CHAT_LIBRARY_MAP_KEY } from './appConfig'
+
+function libraryJobIsActive(job) {
+  return job?.status === 'queued' || job?.status === 'running'
+}
+
+function getLibraryStatusSuffix(library, hasActiveJob) {
+  if (!library) return ''
+  if (!library.files?.length) return ' (empty)'
+  if (library.states?.is_indexed) return ''
+  return hasActiveJob ? ' (syncing)' : ' (needs sync)'
+}
+
+function loadChatLibraryMap() {
+  try {
+    const raw = localStorage.getItem(CHAT_LIBRARY_MAP_KEY)
+    return raw ? JSON.parse(raw) : {}
+  } catch {
+    return {}
+  }
+}
+
+export function useChatLibrarySelection({ activeSessionId, libraries, libraryJobs }) {
+  const [chatLibraryBySession, setChatLibraryBySession] = useState(loadChatLibraryMap)
+
+  useEffect(() => {
+    try {
+      localStorage.setItem(CHAT_LIBRARY_MAP_KEY, JSON.stringify(chatLibraryBySession || {}))
+    } catch {}
+  }, [chatLibraryBySession])
+
+  useEffect(() => {
+    const validSlugs = new Set(libraries.map(library => library.slug))
+    setChatLibraryBySession(prev => {
+      let changed = false
+      const next = {}
+      for (const [sessionId, slug] of Object.entries(prev || {})) {
+        if (validSlugs.has(slug)) {
+          next[sessionId] = slug
+        } else {
+          changed = true
+        }
+      }
+      return changed ? next : prev
+    })
+  }, [libraries])
+
+  const chatLibrarySlug = activeSessionId ? (chatLibraryBySession[activeSessionId] || null) : null
+
+  const chatLibrary = useMemo(() => {
+    return libraries.find(lib => lib.slug === chatLibrarySlug) || null
+  }, [chatLibrarySlug, libraries])
+
+  const chatLibraryHasActiveJob = useMemo(() => {
+    if (!chatLibrarySlug) return false
+    return libraryJobs.some(job => job.slug === chatLibrarySlug && libraryJobIsActive(job))
+  }, [chatLibrarySlug, libraryJobs])
+
+  const chatLibraryStatusSuffix = useMemo(() => {
+    return getLibraryStatusSuffix(chatLibrary, chatLibraryHasActiveJob)
+  }, [chatLibrary, chatLibraryHasActiveJob])
+
+  function getChatLibrarySlugForSession(sessionId) {
+    if (!sessionId) return null
+    return chatLibraryBySession[sessionId] || null
+  }
+
+  function getChatLibraryForSession(sessionId) {
+    const slug = getChatLibrarySlugForSession(sessionId)
+    if (!slug) return null
+    return libraries.find(lib => lib.slug === slug) || null
+  }
+
+  function isLibrarySyncing(slug) {
+    if (!slug) return false
+    return libraryJobs.some(job => job.slug === slug && libraryJobIsActive(job))
+  }
+
+  function setChatLibraryForSession(sessionId, slug) {
+    if (!sessionId) return
+    setChatLibraryBySession(prev => {
+      const next = { ...(prev || {}) }
+      if (slug) {
+        next[sessionId] = slug
+      } else {
+        delete next[sessionId]
+      }
+      return next
+    })
+  }
+
+  function removeLibraryFromChatSelections(slug) {
+    if (!slug) return
+    setChatLibraryBySession(prev => {
+      let changed = false
+      const next = {}
+      for (const [sessionId, librarySlug] of Object.entries(prev || {})) {
+        if (librarySlug === slug) {
+          changed = true
+          continue
+        }
+        next[sessionId] = librarySlug
+      }
+      return changed ? next : prev
+    })
+  }
+
+  function clearChatLibrarySelections() {
+    setChatLibraryBySession({})
+  }
+
+  return {
+    chatLibrary,
+    chatLibraryBySession,
+    chatLibrarySlug,
+    chatLibraryStatusSuffix,
+    clearChatLibrarySelections,
+    getChatLibraryForSession,
+    isLibrarySyncing,
+    removeLibraryFromChatSelections,
+    setChatLibraryForSession,
+  }
+}