feat(sessions): remove stale-conversation cost notice

packages/core/src/sessions/contextUsage.test.ts

@@ -1,12 +1,6 @@
 import type { AcpMessage } from "@posthog/shared";
 import { describe, expect, it } from "vitest";
-import {
-  createContextUsageTracker,
-  DEFAULT_STALE_COSTLY_THRESHOLD,
-  extractContextUsage,
-  extractLastActivityAt,
-  shouldWarnStaleCostlyConversation,
-} from "./contextUsage";
+import { createContextUsageTracker, extractContextUsage } from "./contextUsage";
 
 function usageUpdateEvent(used: number, size: number): AcpMessage {
   return {
@@ -196,116 +190,3 @@ describe("createContextUsageTracker", () => {
     expect(tracker.update(events)).toEqual(extractContextUsage(events));
   });
 });
-
-describe("shouldWarnStaleCostlyConversation", () => {
-  const now = 1_000_000_000;
-  const threshold = { tokens: 40_000, staleMs: 5 * 60 * 1000 };
-
-  it.each([
-    {
-      name: "large + stale → warn",
-      usedTokens: 50_000,
-      idleMs: 10 * 60 * 1000,
-      expected: true,
-    },
-    {
-      name: "large + fresh → no warn",
-      usedTokens: 50_000,
-      idleMs: 60 * 1000,
-      expected: false,
-    },
-    {
-      name: "small + stale → no warn",
-      usedTokens: 10_000,
-      idleMs: 10 * 60 * 1000,
-      expected: false,
-    },
-    {
-      name: "small + fresh → no warn",
-      usedTokens: 10_000,
-      idleMs: 60 * 1000,
-      expected: false,
-    },
-    {
-      name: "exactly at both thresholds → warn",
-      usedTokens: 40_000,
-      idleMs: 5 * 60 * 1000,
-      expected: true,
-    },
-    {
-      name: "one token below the size threshold → no warn",
-      usedTokens: 39_999,
-      idleMs: 10 * 60 * 1000,
-      expected: false,
-    },
-    {
-      name: "one ms below the stale threshold → no warn",
-      usedTokens: 50_000,
-      idleMs: 5 * 60 * 1000 - 1,
-      expected: false,
-    },
-  ])("$name", ({ usedTokens, idleMs, expected }) => {
-    expect(
-      shouldWarnStaleCostlyConversation({
-        usedTokens,
-        lastActivityAt: now - idleMs,
-        now,
-        threshold,
-      }),
-    ).toBe(expected);
-  });
-
-  it("never warns without a last-activity timestamp", () => {
-    expect(
-      shouldWarnStaleCostlyConversation({
-        usedTokens: 1_000_000,
-        lastActivityAt: null,
-        now,
-        threshold,
-      }),
-    ).toBe(false);
-  });
-
-  it("treats a future timestamp (clock skew) as fresh", () => {
-    expect(
-      shouldWarnStaleCostlyConversation({
-        usedTokens: 50_000,
-        lastActivityAt: now + 60_000,
-        now,
-        threshold,
-      }),
-    ).toBe(false);
-  });
-
-  it("falls back to DEFAULT_STALE_COSTLY_THRESHOLD when none is given", () => {
-    expect(
-      shouldWarnStaleCostlyConversation({
-        usedTokens: DEFAULT_STALE_COSTLY_THRESHOLD.tokens,
-        lastActivityAt: now - DEFAULT_STALE_COSTLY_THRESHOLD.staleMs,
-        now,
-      }),
-    ).toBe(true);
-  });
-});
-
-describe("extractLastActivityAt", () => {
-  it("returns null for an empty event list", () => {
-    expect(extractLastActivityAt([])).toBeNull();
-  });
-
-  it("returns the ts of the most recent event", () => {
-    const events: AcpMessage[] = [
-      { ...agentChunkEvent(), ts: 10 },
-      { ...usageUpdateEvent(50_000, 200_000), ts: 20 },
-    ];
-    expect(extractLastActivityAt(events)).toBe(20);
-  });
-
-  it("returns the maximum ts even when events are out of order", () => {
-    const events: AcpMessage[] = [
-      { ...usageUpdateEvent(50_000, 200_000), ts: 30 },
-      { ...agentChunkEvent(), ts: 10 },
-    ];
-    expect(extractLastActivityAt(events)).toBe(30);
-  });
-});

packages/core/src/sessions/contextUsage.ts

@@ -138,76 +138,3 @@ function extractBreakdown(msg: AcpMessage["message"]): ContextBreakdown | null {
   const params = msg.params as { breakdown?: ContextBreakdown } | undefined;
   return params?.breakdown ?? null;
 }
-
-/**
- * Threshold controlling when {@link shouldWarnStaleCostlyConversation} fires.
- */
-export interface StaleCostlyThreshold {
-  /** Minimum context tokens for a conversation to count as "large". */
-  tokens: number;
-  /**
-   * Minimum idle time (ms) before a conversation counts as "stale". See
-   * {@link DEFAULT_STALE_COSTLY_THRESHOLD} for how this bound is chosen.
-   */
-  staleMs: number;
-}
-
-/**
- * Defaults for the stale-costly conversation warning.
- *
- * `tokens` (100k): only conversations big enough that a cold prefix rebuild is
- * a real cost — roughly 10% of the 1M context window — trip the warning.
- *
- * `staleMs` (60 min): Anthropic ephemeral caches default to a 5-minute TTL and
- * can opt into a 1-hour one; the effective value depends on what the Agent SDK
- * requests, which we don't control or observe. We deliberately use the longer
- * 1-hour bound so the cache is almost certainly cold before we warn — warning
- * while it is still warm would nag about a continuation that is in fact cheap,
- * the worse failure. Erring long only means we occasionally skip a warning,
- * never that we nag needlessly.
- */
-export const DEFAULT_STALE_COSTLY_THRESHOLD: StaleCostlyThreshold = {
-  tokens: 100_000,
-  staleMs: 60 * 60 * 1000,
-};
-
-/**
- * Decide whether to warn that continuing a conversation will be costly: true
- * when it is both large (>= `threshold.tokens`) and stale (idle >=
- * `threshold.staleMs`). See {@link DEFAULT_STALE_COSTLY_THRESHOLD} for the
- * pricing rationale behind the defaults.
- *
- * Pure and time-injected (no `Date.now()`). A `null` `lastActivityAt` never
- * warns, and a future timestamp (clock skew) reads as fresh.
- */
-export function shouldWarnStaleCostlyConversation(args: {
-  usedTokens: number;
-  lastActivityAt: number | null;
-  now: number;
-  threshold?: StaleCostlyThreshold;
-}): boolean {
-  const { usedTokens, lastActivityAt, now } = args;
-  const threshold = args.threshold ?? DEFAULT_STALE_COSTLY_THRESHOLD;
-  if (lastActivityAt === null) return false;
-  if (usedTokens < threshold.tokens) return false;
-  return now - lastActivityAt >= threshold.staleMs;
-}
-
-/**
- * Best-effort "time of last activity" for a session: the most recent (maximum)
- * `ts` among events, or null for an empty list. Scans for the max rather than
- * trusting positional order, so an out-of-order append can't report a staler
- * time than reality. (Uses a loop, not the spread form of `Math.max`, which can
- * overflow the stack on long event lists.) Heuristic proxy for prompt-cache
- * freshness — `ts` is stamped on *any* AcpMessage (agent chunks, tool calls,
- * client-side events), not only turns sent to the model. Good enough for a soft
- * cost warning; not a billing signal.
- */
-export function extractLastActivityAt(events: AcpMessage[]): number | null {
-  if (events.length === 0) return null;
-  let latest = events[0].ts;
-  for (let i = 1; i < events.length; i++) {
-    if (events[i].ts > latest) latest = events[i].ts;
-  }
-  return latest;
-}

packages/shared/src/analytics-events.ts

@@ -135,12 +135,6 @@ export interface PromptSentProperties {
   prompt_length_chars: number;
 }
 
-export interface StaleConversationGateChoiceProperties {
-  choice: "compact" | "continue" | "new_session";
-  used_tokens: number;
-  cost_usd: number | null;
-}
-
 // Git operations
 export interface GitActionExecutedProperties {
   action_type: GitActionType;
@@ -1012,7 +1006,6 @@ export const ANALYTICS_EVENTS = {
   TASK_RUN_COMPLETED: "Task run completed",
   TASK_RUN_CANCELLED: "Task run cancelled",
   PROMPT_SENT: "Prompt sent",
-  STALE_CONVERSATION_GATE_CHOICE: "Stale conversation gate choice",
 
   // Claude Code session import
   CLAUDE_SESSIONS_SHOWN: "Claude Code sessions shown",
@@ -1167,7 +1160,6 @@ export type EventPropertyMap = {
   [ANALYTICS_EVENTS.TASK_RUN_COMPLETED]: TaskRunCompletedProperties;
   [ANALYTICS_EVENTS.TASK_RUN_CANCELLED]: TaskRunCancelledProperties;
   [ANALYTICS_EVENTS.PROMPT_SENT]: PromptSentProperties;
-  [ANALYTICS_EVENTS.STALE_CONVERSATION_GATE_CHOICE]: StaleConversationGateChoiceProperties;
 
   // Claude Code session import
   [ANALYTICS_EVENTS.CLAUDE_SESSIONS_SHOWN]: ClaudeSessionsShownProperties;

packages/ui/src/features/sessions/components/SessionView.tsx

@@ -5,11 +5,7 @@ import {
   type SessionService,
 } from "@posthog/core/sessions/sessionService";
 import { useService } from "@posthog/di/react";
-import {
-  type AcpMessage,
-  ANALYTICS_EVENTS,
-  type StaleConversationGateChoiceProperties,
-} from "@posthog/shared";
+import type { AcpMessage } from "@posthog/shared";
 import type { Task, TaskRunStatus } from "@posthog/shared/domain-types";
 import { showOfflineToast } from "@posthog/ui/features/connectivity/connectivityToast";
 import {
@@ -33,7 +29,6 @@ import { QueuedMessagesDock } from "@posthog/ui/features/sessions/components/Que
 import { ReasoningLevelSelector } from "@posthog/ui/features/sessions/components/ReasoningLevelSelector";
 import { RawLogsView } from "@posthog/ui/features/sessions/components/raw-logs/RawLogsView";
 import { SessionResourcesBar } from "@posthog/ui/features/sessions/components/SessionResourcesBar";
-import { StaleConversationCostNotice } from "@posthog/ui/features/sessions/components/StaleConversationCostNotice";
 import { SteerQueueToggle } from "@posthog/ui/features/sessions/components/SteerQueueToggle";
 import { ThreadView } from "@posthog/ui/features/sessions/components/ThreadView";
 import { CHAT_CONTENT_MAX_WIDTH } from "@posthog/ui/features/sessions/constants";
@@ -51,12 +46,10 @@ import {
 } from "@posthog/ui/features/sessions/sessionViewStore";
 import type { Plan } from "@posthog/ui/features/sessions/types";
 import { useSessionHandoffInProgress } from "@posthog/ui/features/sessions/useSession";
-import { useStaleConversationGate } from "@posthog/ui/features/sessions/useStaleConversationGate";
 import { useSettingsStore } from "@posthog/ui/features/settings/settingsStore";
 import { useIsWorkspaceCloudRun } from "@posthog/ui/features/workspace/useWorkspace";
 import { useConnectivity } from "@posthog/ui/hooks/useConnectivity";
 import { toast } from "@posthog/ui/primitives/toast";
-import { track } from "@posthog/ui/shell/analytics";
 import {
   pendingTaskPromptStoreApi,
   usePendingTaskPrompt,
@@ -328,43 +321,6 @@ export function SessionView({
     [isOnline, onBeforeSubmit],
   );
 
-  // Warn PostHog staff before continuing a large, idle conversation whose
-  // prompt cache has likely expired (see useStaleConversationGate).
-  const staleGate = useStaleConversationGate(sessionId, events);
-
-  // Plain functions, not useCallbacks: the notice isn't memoized, and the
-  // values they close over (usage, cost) change with every streamed event.
-  const trackStaleGateChoice = (
-    choice: StaleConversationGateChoiceProperties["choice"],
-  ) =>
-    track(ANALYTICS_EVENTS.STALE_CONVERSATION_GATE_CHOICE, {
-      choice,
-      used_tokens: staleGate.usedTokens,
-      cost_usd: staleGate.costUsd,
-    });
-
-  const handleStaleCompact = () => {
-    if (!isOnline) {
-      showOfflineToast();
-      return;
-    }
-    trackStaleGateChoice("compact");
-    staleGate.onContinue();
-    onSendPrompt("/compact");
-  };
-
-  const handleStaleContinue = () => {
-    trackStaleGateChoice("continue");
-    staleGate.onContinue();
-  };
-
-  const handleStaleNewSession = onNewSession
-    ? () => {
-        trackStaleGateChoice("new_session");
-        onNewSession();
-      }
-    : undefined;
-
   const [isDraggingFile, setIsDraggingFile] = useState(false);
   const editorRef = useRef<PromptInputHandle>(null);
   const dragCounterRef = useRef(0);
@@ -666,38 +622,7 @@ export function SessionView({
                       )}
                     </Flex>
                   </Flex>
-                ) : hideInput ? null : staleGate.active ? (
-                  // Replaces the composer (and any pending permission — answering
-                  // one also resumes the costly turn) until the user chooses.
-                  isRunning ? (
-                    <ComposerSlot compact={compact}>
-                      <StaleConversationCostNotice
-                        usedTokens={staleGate.usedTokens}
-                        lastActivityAt={staleGate.lastActivityAt}
-                        costUsd={staleGate.costUsd}
-                        onContinue={handleStaleContinue}
-                        onCompact={
-                          firstPendingPermission
-                            ? undefined
-                            : handleStaleCompact
-                        }
-                        onNewSession={handleStaleNewSession}
-                      />
-                    </ComposerSlot>
-                  ) : (
-                    // While reconnecting the gate still covers the composer
-                    // slot: handoff can leave pendingPermissions set, and the
-                    // choices must not fire into a half-connected session.
-                    <Flex
-                      align="center"
-                      justify="center"
-                      gap="2"
-                      className="min-h-[66px]"
-                    >
-                      <ConnectingToAgent />
-                    </Flex>
-                  )
-                ) : firstPendingPermission ? (
+                ) : hideInput ? null : firstPendingPermission ? (
                   <ComposerSlot compact={compact}>
                     <PermissionSelector
                       toolCall={firstPendingPermission.toolCall}