feat: add Stop button to halt agent without destroying context

agent.py

@@ -240,6 +240,14 @@ def nudge(self):
         self.task = self.communicate(UserMessage(self.agent0.read_prompt("fw.msg_nudge.md")))
         return self.task
 
+    @extension.extensible
+    def stop(self):
+        """Stop the running agent immediately, preserving conversation history."""
+        self.kill_process()
+        self.paused = False
+        self.streaming_agent = None
+        self.log.log(type="info", content="Agent stopped by user.")
+
     @extension.extensible
     def get_agent(self):
         return self.streaming_agent or self.agent0

api/stop.py

@@ -0,0 +1,14 @@
+from helpers.api import ApiHandler, Request, Response
+
+
+class Stop(ApiHandler):
+    async def process(self, input: dict, request: Request) -> dict | Response:
+        ctxid = input.get("context", "")
+        if not ctxid:
+            raise Exception("No context id provided")
+        context = self.use_context(ctxid)
+        context.stop()
+        return {
+            "message": "Agent stopped.",
+            "context": context.id,
+        }

tests/test_stop_agent.py

@@ -0,0 +1,125 @@
+import sys
+import threading
+from pathlib import Path
+from unittest.mock import MagicMock, patch
+
+import pytest
+from flask import Flask
+
+PROJECT_ROOT = Path(__file__).resolve().parents[1]
+if str(PROJECT_ROOT) not in sys.path:
+    sys.path.insert(0, str(PROJECT_ROOT))
+
+from agent import AgentContext
+from initialize import initialize_agent
+from api.stop import Stop
+
+
+@pytest.fixture
+def ctx():
+    ctxid = "ctx-stop-test"
+    context = AgentContext(config=initialize_agent(), id=ctxid, set_current=False)
+    yield context
+    AgentContext.remove(ctxid)
+
+
+class TestAgentContextStop:
+    """Unit tests for AgentContext.stop() method."""
+
+    def test_stop_clears_paused_state(self, ctx):
+        ctx.paused = True
+        ctx.stop()
+        assert ctx.paused is False
+
+    def test_stop_clears_streaming_agent(self, ctx):
+        ctx.streaming_agent = MagicMock()
+        ctx.stop()
+        assert ctx.streaming_agent is None
+
+    def test_stop_calls_kill_process(self, ctx):
+        with patch.object(ctx, "kill_process") as mock_kill:
+            ctx.stop()
+            mock_kill.assert_called_once()
+
+    def test_stop_logs_info_message(self, ctx):
+        initial_log_count = len(ctx.log.logs)
+        ctx.stop()
+        assert len(ctx.log.logs) > initial_log_count
+        last_log = ctx.log.logs[-1]
+        assert last_log.type == "info"
+        assert "stopped" in last_log.content.lower()
+
+    def test_stop_preserves_conversation_history(self, ctx):
+        ctx.log.log(type="user", heading="test", content="hello world")
+        log_count_before = len(ctx.log.logs)
+        ctx.stop()
+        # Should have original logs + the "stopped" info log
+        assert len(ctx.log.logs) == log_count_before + 1
+
+    def test_stop_does_not_reset_agent(self, ctx):
+        original_agent = ctx.agent0
+        ctx.stop()
+        assert ctx.agent0 is original_agent
+
+    def test_stop_when_not_running_is_safe(self, ctx):
+        """Calling stop when nothing is running should not raise."""
+        ctx.task = None
+        ctx.paused = False
+        ctx.streaming_agent = None
+        ctx.stop()  # should not raise
+        assert ctx.paused is False
+
+    def test_stop_differs_from_nudge(self, ctx):
+        """Stop should NOT restart the agent (unlike nudge)."""
+        ctx.stop()
+        # After stop, task should be None (no new task started)
+        # nudge() would set self.task to a new communicate() call
+        assert ctx.task is None
+
+    def test_stop_differs_from_reset(self, ctx):
+        """Stop should NOT clear the log (unlike reset)."""
+        ctx.log.log(type="user", heading="test", content="preserved")
+        ctx.stop()
+        # reset() calls log.reset() which clears everything
+        assert len(ctx.log.logs) >= 2  # original + stopped message
+
+
+class TestStopApiHandler:
+    """Tests for the api/stop.py endpoint."""
+
+    @pytest.mark.asyncio
+    async def test_stop_api_returns_success(self, ctx):
+        app = Flask("stop-api-test")
+        app.secret_key = "test-secret"
+        lock = threading.RLock()
+
+        handler = Stop(app, lock)
+        result = await handler.process({"context": ctx.id}, None)
+
+        assert result["message"] == "Agent stopped."
+        assert result["context"] == ctx.id
+
+    @pytest.mark.asyncio
+    async def test_stop_api_raises_without_context_id(self):
+        app = Flask("stop-api-test")
+        app.secret_key = "test-secret"
+        lock = threading.RLock()
+
+        handler = Stop(app, lock)
+        with pytest.raises(Exception, match="No context id provided"):
+            await handler.process({"context": ""}, None)
+
+    @pytest.mark.asyncio
+    async def test_stop_api_actually_stops_agent(self, ctx):
+        ctx.paused = True
+        ctx.streaming_agent = MagicMock()
+
+        app = Flask("stop-api-test")
+        app.secret_key = "test-secret"
+        lock = threading.RLock()
+
+        handler = Stop(app, lock)
+        await handler.process({"context": ctx.id}, None)
+
+        assert ctx.paused is False
+        assert ctx.streaming_agent is None

webui/components/chat/input/bottom-actions-bar.html

@@ -2,6 +2,7 @@
 <head>
   <script type="module">
     import { store } from "/components/chat/input/input-store.js";
+    import { store as chatsStore } from "/components/sidebar/chats/chats-store.js";
   </script>
 </head>
 <body>
@@ -22,6 +23,16 @@
         <span x-text="$store.chatInput.paused ? 'Resume Agent' : 'Pause Agent'"></span>
       </button>
 
+      <button type="button" class="text-button stop-button"
+              @click="$store.chatInput.stopAgent()"
+              x-show="$store.chats?.selectedContext?.running"
+              title="Stop the agent immediately">
+        <svg xmlns="http://www.w3.org/2000/svg" fill="currentColor" viewBox="0 0 24 24" width="14" height="14" aria-hidden="true">
+          <path d="M6 6h12v12H6z"></path>
+        </svg>
+        <span>Stop Agent</span>
+      </button>
+
       <button type="button" class="text-button" id="nudges_window" @click="$store.chatInput.nudge()">
         <svg id="Layer_1" data-name="Layer 1" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 49 58" fill="currentColor" width="14" height="14" aria-hidden="true">
           <path d="m11.97,16.32c-.46,0-.91-.25-1.15-.68-.9-1.63-1.36-3.34-1.36-5.1C9.45,4.73,14.18,0,20,0s10.55,4.73,10.55,10.55c0,.87-.13,1.75-.41,2.76-.19.7-.9,1.13-1.62.93-.7-.19-1.12-.92-.93-1.62.21-.79.31-1.44.31-2.07,0-4.36-3.55-7.91-7.91-7.91s-7.91,3.55-7.91,7.91c0,1.3.35,2.59,1.03,3.82.36.64.13,1.44-.51,1.79-.21.11-.42.17-.64.17Z" stroke-width="0.5" stroke="currentColor"/>
@@ -77,6 +88,10 @@
       flex-shrink: 0;
     }
     .text-button p { margin-block: 0; }
+    .stop-button { color: var(--color-error, #e74c3c) !important; }
+    .stop-button:hover:not(:disabled) {
+      background-color: rgba(231, 76, 60, 0.1) !important;
+    }
 
     @media (max-width: 768px) {
       .text-buttons-row {

webui/components/chat/input/input-store.js

@@ -115,6 +115,18 @@ const model = {
     }
   },
 
+  async stopAgent() {
+    try {
+      const context = globalThis.getContext();
+      if (!globalThis.sendJsonData) throw new Error("sendJsonData not available");
+      await globalThis.sendJsonData("/stop", { context });
+    } catch (e) {
+      if (globalThis.toastFetchError) {
+        globalThis.toastFetchError("Error stopping agent", e);
+      }
+    }
+  },
+
   async loadKnowledge() {
     try {
       const resp = await shortcuts.callJsonApi(

webui/index.js

@@ -524,6 +524,20 @@ globalThis.pauseAgent = async function (paused) {
   await inputStore.pauseAgent(paused);
 };
 
+globalThis.stopAgent = async function () {
+  await inputStore.stopAgent();
+};
+
+// Escape key to stop running agent (only when not typing in an input/textarea)
+document.addEventListener("keydown", (e) => {
+  if (e.key === "Escape" && chatsStore.selectedContext?.running) {
+    const tag = document.activeElement?.tagName;
+    if (tag === "TEXTAREA" || tag === "INPUT") return;
+    e.preventDefault();
+    globalThis.stopAgent();
+  }
+});
+
 function generateShortId() {
   const chars =
     "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";