diff --git a/packages/app/src/pages/session/composer/session-composer-region.tsx b/packages/app/src/pages/session/composer/session-composer-region.tsx
index e89f7f1cd..b9ede3fa4 100644
--- a/packages/app/src/pages/session/composer/session-composer-region.tsx
+++ b/packages/app/src/pages/session/composer/session-composer-region.tsx
@@ -2,6 +2,7 @@ import { Show, createEffect, createMemo, onCleanup } from "solid-js"
 import { createStore } from "solid-js/store"
 import { useNavigate } from "@solidjs/router"
 import { useSpring } from "@codeplane-ai/ui/motion-spring"
+import { Button } from "@codeplane-ai/ui/button"
 import { Icon } from "@codeplane-ai/ui/icon"
 import { PromptInput } from "@/components/prompt-input"
 import { useLanguage } from "@/context/language"
@@ -323,12 +324,23 @@ export function SessionComposerRegion(props: {
         >
           <div
             ref={props.inputRef}
-            class="flex w-full items-center gap-2 rounded-[12px] border border-border-weak-base bg-background-base px-4 py-3 text-14-regular text-text-weak"
+            class="flex w-full flex-wrap items-center gap-2 rounded-[12px] border border-border-weak-base bg-background-base px-4 py-3 text-14-regular text-text-weak"
           >
             <Icon name={isCronSession() ? "bell" : "archive"} size="small" class="shrink-0" />
-            <span>
+            <span class="min-w-0 flex-1">
               {isCronSession() ? language.t("session.cron.readonly") : language.t("session.archived.readOnly")}
             </span>
+            <Show when={isCronSession() && props.state.working()}>
+              <Button
+                type="button"
+                variant="secondary"
+                size="small"
+                disabled={props.state.aborting()}
+                onClick={() => props.state.abort()}
+              >
+                {language.t("prompt.action.stop")}
+              </Button>
+            </Show>
           </div>
         </Show>
       </div>
diff --git a/packages/app/src/pages/session/composer/session-composer-state.ts b/packages/app/src/pages/session/composer/session-composer-state.ts
index bd3a05184..968174cb0 100644
--- a/packages/app/src/pages/session/composer/session-composer-state.ts
+++ b/packages/app/src/pages/session/composer/session-composer-state.ts
@@ -1,4 +1,4 @@
-import { createEffect, createMemo, on, onCleanup } from "solid-js"
+import { batch, createEffect, createMemo, on, onCleanup } from "solid-js"
 import { createStore } from "solid-js/store"
 import type { PermissionRequest, QuestionRequest, Todo } from "@codeplane-ai/sdk/v2"
 import { useParams } from "@solidjs/router"
@@ -77,6 +77,7 @@ export function createSessionComposerState(options?: { closeMs?: number | (() =>
     dock: todos().length > 0 && live(),
     closing: false,
     opening: false,
+    aborting: false,
   })
 
   const permissionResponding = createMemo(() => {
@@ -102,6 +103,26 @@ export function createSessionComposerState(options?: { closeMs?: number | (() =>
       })
   }
 
+  const abort = () => {
+    const id = params.id
+    if (!id || store.aborting) return
+
+    batch(() => {
+      globalSync.todo.set(id, [])
+      sync.set("todo", id, [])
+      sync.set("session_status", id, idle)
+      setStore("aborting", true)
+    })
+
+    sdk.client.session
+      .abort({ sessionID: id })
+      .catch((err: unknown) => {
+        const description = err instanceof Error ? err.message : String(err)
+        showToast({ title: language.t("common.requestFailed"), description })
+      })
+      .finally(() => setStore("aborting", false))
+  }
+
   let timer: number | undefined
   let raf: number | undefined
 
@@ -194,7 +215,10 @@ export function createSessionComposerState(options?: { closeMs?: number | (() =>
     permissionRequest,
     permissionResponding,
     decide,
+    abort,
+    aborting: () => store.aborting,
     todos,
+    working: busy,
     dock: () => store.dock,
     closing: () => store.closing,
     opening: () => store.opening,
diff --git a/packages/codeplane/src/server/routes/instance/session.ts b/packages/codeplane/src/server/routes/instance/session.ts
index 6d89cf95a..e4e5e9133 100644
--- a/packages/codeplane/src/server/routes/instance/session.ts
+++ b/packages/codeplane/src/server/routes/instance/session.ts
@@ -30,8 +30,11 @@ import { Bus } from "@/bus"
 import { NamedError } from "@codeplane-ai/shared/util/error"
 import { jsonRequest, runRequest } from "./trace"
 import { queryBoolean } from "@/server/query"
+import { CronScheduler } from "@/cron"
+import { makeRuntime } from "@/effect/run-service"
 
 const log = Log.create({ service: "server" })
+const cronSchedulerRuntime = makeRuntime(CronScheduler.Service, CronScheduler.defaultLayer)
 
 export const SessionRoutes = lazy(() =>
   new Hono()
@@ -439,6 +442,16 @@ export const SessionRoutes = lazy(() =>
       async (c) =>
         jsonRequest("SessionRoutes.abort", c, function* () {
           const sessionID = c.req.valid("param").sessionID
+          const session = yield* Session.Service
+          const info = yield* session.get(sessionID).pipe(
+            Effect.catch(() => Effect.succeed(undefined as Session.Info | undefined)),
+          )
+          const cronRunID = info?.cronRunID
+          if (cronRunID) {
+            yield* Effect.tryPromise(() => cronSchedulerRuntime.runPromise((svc) => svc.cancelRun(cronRunID))).pipe(
+              Effect.catch(() => Effect.void),
+            )
+          }
           const svc = yield* SessionPrompt.Service
           const aborted = new DOMException("Aborted", "AbortError")
           // Mark all pending+running queue rows cancelled BEFORE cancelling