diff --git a/CHANGELOG.md b/CHANGELOG.md
index 37be459..131d61a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,6 @@
 # Changelog
 
 ## [Unreleased]
-- Initial multi-module setup with LLM interface and TAK plugin stub.
+- Replaced TAK plugin stub with an offline-first local assistant service that can parse and execute create/edit marker operations.
+- Added local chat UI workflow that binds to the plugin service and returns actionable responses.
+- Added unit tests for operation planning parser.
diff --git a/README.md b/README.md
index dff16bb..1734114 100644
--- a/README.md
+++ b/README.md
@@ -1,17 +1,19 @@
 # Tactical App
 
-Multi-module Android project for an offline-first tactical AI assistant.
+Multi-module Android project for an offline-first tactical AI assistant and ATAK plugin integration.
 
 ## Modules
-- `app`: main Android application with basic home screen.
-- `llm`: common LLM interface, router, and stub implementations.
-- `tak-plugin`: CivTAK plugin stub for future CoT integration.
+- `app`: main Android application with local assistant chat UI.
+- `llm`: common LLM interface, router, and deterministic offline local model.
+- `tak-plugin`: ATAK-facing assistant service that can parse restricted natural-language operations and execute local marker create/edit actions over CoT.
+- `core`: CoT interoperability primitives and beacon support.
 
 ## Building
 Ensure JDK 17 and Android SDK are installed, then run:
 ```
 ./gradlew assembleDebug
 ```
+(If `gradlew` is missing in your clone, use your local Gradle install with `gradle assembleDebug`.)
 
 ## Development
 A simple edge LLM stub server is available:
@@ -19,4 +21,9 @@ A simple edge LLM stub server is available:
 ./scripts/dev/run_edge_stub.sh
 ```
 
+### Local ATAK assistant operation format
+From the local chat UI you can issue:
+- `create marker uid=<id> lat=<x> lon=<y> type=<cot-type>`
+- `edit marker uid=<id> lat=<x?> lon=<y?> type=<cot-type?>`
+
 See `CONTRIBUTING.md` for details.
diff --git a/app/src/main/java/com/example/tacticalapp/LocalChatActivity.kt b/app/src/main/java/com/example/tacticalapp/LocalChatActivity.kt
index a7e1957..a98e844 100644
--- a/app/src/main/java/com/example/tacticalapp/LocalChatActivity.kt
+++ b/app/src/main/java/com/example/tacticalapp/LocalChatActivity.kt
@@ -1,15 +1,63 @@
 package com.example.tacticalapp
 
+import android.content.ComponentName
+import android.content.Context
+import android.content.Intent
+import android.content.ServiceConnection
 import android.os.Bundle
+import android.os.IBinder
 import androidx.appcompat.app.AppCompatActivity
 import com.example.tacticalapp.databinding.ActivityLocalChatBinding
+import com.example.takplugin.TakPluginService
 
 class LocalChatActivity : AppCompatActivity() {
     private lateinit var binding: ActivityLocalChatBinding
+    private var pluginService: TakPluginService? = null
+    private var isBound: Boolean = false
+
+    private val connection = object : ServiceConnection {
+        override fun onServiceConnected(name: ComponentName?, service: IBinder?) {
+            pluginService = (service as? TakPluginService.LocalBinder)?.service()
+            isBound = pluginService != null
+        }
+
+        override fun onServiceDisconnected(name: ComponentName?) {
+            pluginService = null
+            isBound = false
+        }
+    }
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         binding = ActivityLocalChatBinding.inflate(layoutInflater)
         setContentView(binding.root)
+
+        binding.btnSend.setOnClickListener {
+            val prompt = binding.editPrompt.text?.toString().orEmpty()
+            val service = pluginService
+            if (prompt.isBlank() || service == null) {
+                binding.tvResponse.text = "Assistant unavailable. Ensure plugin service is bound."
+                return@setOnClickListener
+            }
+            binding.tvResponse.text = "Working..."
+            service.ask(prompt) { reply ->
+                runOnUiThread {
+                    binding.tvResponse.text = reply.answer
+                }
+            }
+        }
+    }
+
+    override fun onStart() {
+        super.onStart()
+        isBound = bindService(Intent(this, TakPluginService::class.java), connection, Context.BIND_AUTO_CREATE)
+    }
+
+    override fun onStop() {
+        if (isBound) {
+            unbindService(connection)
+            isBound = false
+        }
+        super.onStop()
     }
 }
diff --git a/app/src/main/res/layout/activity_local_chat.xml b/app/src/main/res/layout/activity_local_chat.xml
index 8d9c0ab..1ab7ac3 100644
--- a/app/src/main/res/layout/activity_local_chat.xml
+++ b/app/src/main/res/layout/activity_local_chat.xml
@@ -5,9 +5,24 @@
     android:orientation="vertical"
     android:padding="16dp">
 
+    <EditText
+        android:id="@+id/editPrompt"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:hint="Ask local ATAK assistant or run: create marker uid=... lat=... lon=..."
+        android:inputType="textMultiLine" />
+
+    <Button
+        android:id="@+id/btnSend"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:layout_marginTop="8dp"
+        android:text="Send" />
+
     <TextView
-        android:id="@+id/tvPlaceholder"
+        android:id="@+id/tvResponse"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
-        android:text="@string/local_chat_placeholder" />
+        android:layout_marginTop="16dp"
+        android:text="Response appears here" />
 </LinearLayout>
diff --git a/llm/src/main/java/com/example/llm/LocalLlm.kt b/llm/src/main/java/com/example/llm/LocalLlm.kt
index c7ff8c0..4a07d9a 100644
--- a/llm/src/main/java/com/example/llm/LocalLlm.kt
+++ b/llm/src/main/java/com/example/llm/LocalLlm.kt
@@ -4,10 +4,21 @@ import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.flow
 
 /**
- * Placeholder local LLM implementation.
+ * Offline deterministic local assistant intended for constrained tactical nodes.
  */
 class LocalLlm : Llm {
     override suspend fun chat(messages: List<Llm.Message>): Flow<Llm.TokenChunk> = flow {
-        emit(Llm.TokenChunk(text = "local-response", done = true))
+        val prompt = messages.lastOrNull()?.content?.trim().orEmpty()
+        val guidance = buildString {
+            append("Local ATAK assistant (offline mode). ")
+            append("I can answer planning questions and run local actions with the formats: ")
+            append("'create marker uid=<id> lat=<x> lon=<y> type=<cot-type>' or ")
+            append("'edit marker uid=<id> lat=<x?> lon=<y?> type=<cot-type?>'. ")
+            if (prompt.isNotBlank()) {
+                append("Received: ")
+                append(prompt)
+            }
+        }
+        emit(Llm.TokenChunk(text = guidance, done = true))
     }
 }
diff --git a/tak-plugin/build.gradle.kts b/tak-plugin/build.gradle.kts
index ff78f48..f07fe44 100644
--- a/tak-plugin/build.gradle.kts
+++ b/tak-plugin/build.gradle.kts
@@ -27,6 +27,9 @@ android {
 
 dependencies {
     implementation(project(":llm"))
+    implementation(project(":core"))
     implementation("org.jetbrains.kotlinx:kotlinx-coroutines-android:1.9.0")
     // CivTAK SDK placeholder
+
+    testImplementation("junit:junit:4.13.2")
 }
diff --git a/tak-plugin/src/main/java/com/example/takplugin/TakOperationExecutor.kt b/tak-plugin/src/main/java/com/example/takplugin/TakOperationExecutor.kt
new file mode 100644
index 0000000..30b14e0
--- /dev/null
+++ b/tak-plugin/src/main/java/com/example/takplugin/TakOperationExecutor.kt
@@ -0,0 +1,44 @@
+package com.example.takplugin
+
+import android.content.Context
+import com.example.core.interop.Interop
+import com.example.core.interop.MarkerEntity
+import java.util.concurrent.ConcurrentHashMap
+
+/** Executes restricted local operations against ATAK/CoT interop. */
+class TakOperationExecutor(context: Context) {
+    private val markerCache = ConcurrentHashMap<String, MarkerEntity>()
+
+    init {
+        // default local target for ATAK server running on same device/network.
+        if (Interop.host.isBlank()) {
+            Interop.host = "127.0.0.1"
+        }
+        Interop.enabled = true
+        Interop.startSelfBeacon(context)
+    }
+
+    fun execute(op: TakOperation): String = when (op) {
+        is TakOperation.CreateMarker -> create(op)
+        is TakOperation.EditMarker -> edit(op)
+    }
+
+    private fun create(op: TakOperation.CreateMarker): String {
+        val marker = MarkerEntity(uid = op.uid, lat = op.lat, lon = op.lon, type = op.type)
+        markerCache[op.uid] = marker
+        Interop.publishMarker(marker)
+        return "Created marker ${op.uid} at ${op.lat},${op.lon} type=${op.type}."
+    }
+
+    private fun edit(op: TakOperation.EditMarker): String {
+        val existing = markerCache[op.uid] ?: return "Cannot edit marker ${op.uid}: marker not found in local cache."
+        val updated = existing.copy(
+            lat = op.lat ?: existing.lat,
+            lon = op.lon ?: existing.lon,
+            type = op.type ?: existing.type,
+        )
+        markerCache[op.uid] = updated
+        Interop.publishMarker(updated)
+        return "Updated marker ${op.uid} to ${updated.lat},${updated.lon} type=${updated.type}."
+    }
+}
diff --git a/tak-plugin/src/main/java/com/example/takplugin/TakOperationPlanner.kt b/tak-plugin/src/main/java/com/example/takplugin/TakOperationPlanner.kt
new file mode 100644
index 0000000..96ccd15
--- /dev/null
+++ b/tak-plugin/src/main/java/com/example/takplugin/TakOperationPlanner.kt
@@ -0,0 +1,53 @@
+package com.example.takplugin
+
+import java.util.Locale
+
+/** Converts free text into constrained local ATAK server operations. */
+class TakOperationPlanner {
+    fun plan(prompt: String): TakOperation? {
+        val line = prompt.lowercase(Locale.US).trim()
+        return when {
+            line.startsWith("create marker") -> parseCreate(prompt)
+            line.startsWith("edit marker") -> parseEdit(prompt)
+            else -> null
+        }
+    }
+
+    private fun parseCreate(prompt: String): TakOperation? {
+        val uid = value(prompt, "uid") ?: return null
+        val lat = value(prompt, "lat")?.toDoubleOrNull() ?: return null
+        val lon = value(prompt, "lon")?.toDoubleOrNull() ?: return null
+        val type = value(prompt, "type") ?: "b-m-p"
+        return TakOperation.CreateMarker(uid = uid, lat = lat, lon = lon, type = type)
+    }
+
+    private fun parseEdit(prompt: String): TakOperation? {
+        val uid = value(prompt, "uid") ?: return null
+        val lat = value(prompt, "lat")?.toDoubleOrNull()
+        val lon = value(prompt, "lon")?.toDoubleOrNull()
+        val type = value(prompt, "type")
+        if (lat == null && lon == null && type == null) return null
+        return TakOperation.EditMarker(uid = uid, lat = lat, lon = lon, type = type)
+    }
+
+    private fun value(prompt: String, key: String): String? {
+        val regex = Regex("""\b$key\s*=\s*([^\s,;]+)""", RegexOption.IGNORE_CASE)
+        return regex.find(prompt)?.groupValues?.getOrNull(1)
+    }
+}
+
+sealed class TakOperation {
+    data class CreateMarker(
+        val uid: String,
+        val lat: Double,
+        val lon: Double,
+        val type: String,
+    ) : TakOperation()
+
+    data class EditMarker(
+        val uid: String,
+        val lat: Double?,
+        val lon: Double?,
+        val type: String?,
+    ) : TakOperation()
+}
diff --git a/tak-plugin/src/main/java/com/example/takplugin/TakPluginService.kt b/tak-plugin/src/main/java/com/example/takplugin/TakPluginService.kt
index 5f1f9f1..defb25c 100644
--- a/tak-plugin/src/main/java/com/example/takplugin/TakPluginService.kt
+++ b/tak-plugin/src/main/java/com/example/takplugin/TakPluginService.kt
@@ -2,11 +2,65 @@ package com.example.takplugin
 
 import android.app.Service
 import android.content.Intent
+import android.os.Binder
 import android.os.IBinder
+import com.example.llm.Llm
+import com.example.llm.LocalLlm
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.cancel
+import kotlinx.coroutines.flow.toList
+import kotlinx.coroutines.launch
 
 /**
- * Placeholder TAK plugin service.
+ * ATAK-facing local assistant service.
+ *
+ * This service is intentionally offline-first and can execute restricted,
+ * local server operations such as marker create/edit from natural language.
  */
 class TakPluginService : Service() {
-    override fun onBind(intent: Intent?): IBinder? = null
+    private val serviceScope = CoroutineScope(SupervisorJob() + Dispatchers.IO)
+    private val llm: Llm = LocalLlm()
+    private val planner = TakOperationPlanner()
+    private val executor by lazy { TakOperationExecutor(applicationContext) }
+
+    inner class LocalBinder : Binder() {
+        fun service(): TakPluginService = this@TakPluginService
+    }
+
+    private val binder = LocalBinder()
+
+    override fun onBind(intent: Intent?): IBinder = binder
+
+    fun ask(prompt: String, onResult: (TakAssistantReply) -> Unit) {
+        serviceScope.launch {
+            val baseReply = llm.chat(listOf(Llm.Message("user", prompt))).toList().joinToString("") { it.text }
+            val operation = planner.plan(prompt)
+            val operationMessage = operation?.let { executor.execute(it) }
+            onResult(
+                TakAssistantReply(
+                    answer = buildString {
+                        append(baseReply)
+                        if (!operationMessage.isNullOrBlank()) {
+                            append("\n\n")
+                            append(operationMessage)
+                        }
+                    },
+                    operationExecuted = operation != null,
+                )
+            )
+        }
+    }
+
+    override fun onDestroy() {
+        serviceScope.cancel()
+        super.onDestroy()
+    }
 }
+
+
+data class TakAssistantReply(
+    val answer: String,
+    val operationExecuted: Boolean,
+)
diff --git a/tak-plugin/src/test/java/com/example/takplugin/TakOperationPlannerTest.kt b/tak-plugin/src/test/java/com/example/takplugin/TakOperationPlannerTest.kt
new file mode 100644
index 0000000..924d0ba
--- /dev/null
+++ b/tak-plugin/src/test/java/com/example/takplugin/TakOperationPlannerTest.kt
@@ -0,0 +1,26 @@
+package com.example.takplugin
+
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+class TakOperationPlannerTest {
+    private val planner = TakOperationPlanner()
+
+    @Test
+    fun parsesCreateMarker() {
+        val op = planner.plan("create marker uid=alpha lat=10.5 lon=-20.25 type=a-f-G-U-C-I")
+        assertTrue(op is TakOperation.CreateMarker)
+        op as TakOperation.CreateMarker
+        assertEquals("alpha", op.uid)
+        assertEquals(10.5, op.lat, 0.0)
+        assertEquals(-20.25, op.lon, 0.0)
+        assertEquals("a-f-G-U-C-I", op.type)
+    }
+
+    @Test
+    fun ignoresNonActionPrompt() {
+        val op = planner.plan("what can you do?")
+        assertEquals(null, op)
+    }
+}