diff --git a/packages/coding-agent/CHANGELOG.md b/packages/coding-agent/CHANGELOG.md
index db40072b8..1634a9501 100644
--- a/packages/coding-agent/CHANGELOG.md
+++ b/packages/coding-agent/CHANGELOG.md
@@ -12,6 +12,10 @@
 - Token counting is now scoped to the model being billed rather than to a process-global tokenizer: session maintenance, stats, advisors, `/context`, snapcompact inline imaging, and `compress` each count through the owning agent's `Tokenizer` (`agent.tokenizer`). Message counting is `Tokenizer.countMessage`/`countMessages` (replacing the free `estimateTokens(message, tokenizer)` helper; the legacy shim keeps a compat `estimateTokens` export for legacy pi extensions). `estimateToolSchemaTokens`, `estimateSkillsTokens`, `computeNonMessageTokens`, and `computeNonMessageBreakdown` take an explicit tokenizer; `scripts/measure-prompt-tokens.ts` accepts an optional model id (argv) so its numbers match what that model is charged.
 - The advisor runtime's `maintainContext` hook now receives the pending update as a message instead of a pre-computed token count — sizing it needs the advisor model's tokenizer, which the host owns.
 
+### Fixed
+
+- Fixed a prompt cancelled during turn setup (Esc while the pre-stream spinner is up, after dispatch had started) vanishing entirely: it was never persisted to the session — so the `/tree` and `/branch` selectors had nothing to rewind to — and was not returned to the editor either, while its optimistic transcript row kept lingering. A prompt dropped before reaching the agent (abort or usage-preflight denial racing setup) is now handed back: the stale transcript row is removed and the typed text and image attachments are restored to the editor for editing.
+
 ## [17.3.8] - 2026-08-19
 
 ### Added
diff --git a/packages/coding-agent/src/modes/interactive-mode.ts b/packages/coding-agent/src/modes/interactive-mode.ts
index a114559a2..5c2545181 100644
--- a/packages/coding-agent/src/modes/interactive-mode.ts
+++ b/packages/coding-agent/src/modes/interactive-mode.ts
@@ -103,6 +103,7 @@ import { type AgentRegistry, MAIN_AGENT_ID } from "../registry/agent-registry";
 import {
 	type AgentSession,
 	type AgentSessionEvent,
+	type DroppedPrompt,
 	type ResolvedRoleModel,
 	SHUTDOWN_CONSOLIDATE_BUDGET_MS,
 } from "../session/agent-session";
@@ -912,6 +913,7 @@ export class InteractiveMode implements InteractiveModeContext {
 		this.session.setTitleGenerationStart?.(() => {
 			this.#inputController.notifyTitleGenerationStart();
 		});
+		this.session.setPromptDropped?.(prompt => this.#restoreDroppedPrompt(prompt));
 		this.#observerRegistry = new SessionObserverRegistry();
 	}
 
@@ -1821,6 +1823,30 @@ export class InteractiveMode implements InteractiveModeContext {
 		return true;
 	}
 
+	/**
+	 * Hands back a prompt the session dropped before dispatch (an Esc abort or
+	 * usage preflight denial raced turn setup). The message was never persisted,
+	 * so the tree/branch selectors cannot offer it — remove the optimistic
+	 * transcript row and put the typed text back in the editor for editing.
+	 */
+	#restoreDroppedPrompt(prompt: DroppedPrompt): void {
+		this.clearOptimisticUserMessage();
+		this.#pendingWorkingMessage = undefined;
+		if (this.loadingAnimation) {
+			this.#stopLoadingAnimation(true);
+		}
+		this.rebuildChatFromMessages();
+		// The drop arrives asynchronously (after the abort settles); never clobber
+		// a draft the user has already started typing in the meantime.
+		if (!this.editor.getText().trim()) {
+			this.editor.pendingImages = prompt.images ? [...prompt.images] : [];
+			this.editor.pendingImageLinks = prompt.images ? prompt.images.map(() => undefined) : [];
+			this.editor.imageLinks = this.editor.pendingImageLinks;
+			this.editor.setText(prompt.text);
+		}
+		this.ui.requestRender();
+	}
+
 	markPendingSubmissionStarted(input: SubmittedUserInput): boolean {
 		if (this.#pendingSubmittedInput !== input || input.cancelled) {
 			return false;
diff --git a/packages/coding-agent/src/session/agent-session-types.ts b/packages/coding-agent/src/session/agent-session-types.ts
index 50f3be5b8..2d3ffb019 100644
--- a/packages/coding-agent/src/session/agent-session-types.ts
+++ b/packages/coding-agent/src/session/agent-session-types.ts
@@ -306,6 +306,16 @@ export interface PromptOptions {
 	skipCompactionCheck?: boolean;
 }
 
+/** Payload for {@link AgentSession.setPromptDropped}: a user prompt cancelled
+ *  before it reached the agent (an abort or usage preflight denial raced turn
+ *  setup), so it was never persisted to the session. */
+export interface DroppedPrompt {
+	/** The prompt exactly as typed, before template/command expansion. */
+	text: string;
+	/** Image attachments submitted with the prompt. */
+	images?: ImageContent[];
+}
+
 /** Options for AgentSession.followUp(). */
 export interface FollowUpOptions {
 	/** Enqueue as a hidden developer message instead of a user follow-up. */
diff --git a/packages/coding-agent/src/session/agent-session.ts b/packages/coding-agent/src/session/agent-session.ts
index aa13bb6be..26ad0a36d 100644
--- a/packages/coding-agent/src/session/agent-session.ts
+++ b/packages/coding-agent/src/session/agent-session.ts
@@ -219,6 +219,7 @@ import type {
 	AsyncJobSnapshot,
 	CommandMetadataChangedListener,
 	ContextUsageBreakdown,
+	DroppedPrompt,
 	FollowUpOptions,
 	FreshSessionResult,
 	HandoffResult,
@@ -535,6 +536,9 @@ export class AgentSession {
 	#titleSystemPrompt: string | undefined;
 	#titleGenerationStart: (() => void) | undefined;
 	#titleGenerationInFlightFor: string | undefined;
+	/** Host hook invoked when a typed user prompt is dropped before dispatch;
+	 *  see {@link setPromptDropped}. */
+	#promptDropped: ((prompt: DroppedPrompt) => void) | undefined;
 	#titleGenerationAbortController = new AbortController();
 	#toolChoiceQueue = new ToolChoiceQueue();
 
@@ -5326,6 +5330,9 @@ export class AgentSession {
 	 */
 	async prompt(text: string, options?: PromptOptions): Promise<boolean> {
 		const expandPromptTemplates = options?.expandPromptTemplates ?? true;
+		// Slash/custom-command handling below rewrites `text`; keep the original
+		// so a dropped prompt is handed back exactly as the user typed it.
+		const typedText = text;
 
 		// Handle extension commands first (execute immediately, even during streaming)
 		if (expandPromptTemplates && text.startsWith("/")) {
@@ -5439,8 +5446,9 @@ export class AgentSession {
 			preludeMessages.push(eagerTaskPrelude);
 		}
 
+		let dispatched = false;
 		try {
-			await this.#promptWithMessage(message, expandedText, {
+			dispatched = await this.#promptWithMessage(message, expandedText, {
 				...options,
 				images: normalizedImages,
 				prependMessages:
@@ -5454,6 +5462,13 @@ export class AgentSession {
 			this.#toolChoiceQueue.removeByLabel("eager-todo");
 			this.#toolChoiceQueue.removeByLabel("external-thinking");
 		}
+		if (!dispatched && message.role === "user") {
+			// An abort (Esc) or preflight denial raced turn setup: the prompt never
+			// reached the agent or the session file. Hand it back to the host so the
+			// user can edit/resubmit instead of losing it (tree/branch can't offer
+			// a message that was never persisted).
+			this.#promptDropped?.({ text: typedText, images: options?.images });
+		}
 		return true;
 	}
 
@@ -5536,12 +5551,16 @@ export class AgentSession {
 			skipPostPromptRecoveryWait?: boolean;
 			acceptTerminalEmptyStop?: boolean;
 		},
-	): Promise<void> {
+	): Promise<boolean> {
+		// Returns false when the prompt was dropped before reaching the agent —
+		// every pre-dispatch bail (generation bump from abort, disposal, usage
+		// preflight denial) exits silently, and prompt() uses the outcome to hand
+		// the typed text back to the host instead of losing it.
 		this.#beginInFlight();
 		const generation = this.#promptGeneration;
 		try {
 			await this.#recovery.maybeRestoreRetryFallbackPrimary();
-			if (!(await this.#runUsageAwarePreflightForNextModelCall())) return;
+			if (!(await this.#runUsageAwarePreflightForNextModelCall())) return false;
 			// Flush any pending bash messages before the new prompt
 			await this.#bash.flushPending();
 			this.#eval.flushPending();
@@ -5609,7 +5628,7 @@ export class AgentSession {
 			// Early bail-out: if a newer abort/prompt cycle started during setup,
 			// return before mutating shared state (nextTurn messages, system prompt).
 			if (this.#promptGeneration !== generation) {
-				return;
+				return false;
 			}
 
 			// A pending xd:// delta accompanies the next user-authored prompt,
@@ -5644,7 +5663,7 @@ export class AgentSession {
 			// resuming would start a turn on a torn-down session.
 			const disposingBeforeTransition = this.#isDisposed;
 			await this.#memory.transition;
-			if ((this.#isDisposed && !disposingBeforeTransition) || this.#promptGeneration !== generation) return;
+			if ((this.#isDisposed && !disposingBeforeTransition) || this.#promptGeneration !== generation) return false;
 			const beforeAgentStartSystemPrompt = await this.#buildSystemPromptForAgentStart(expandedText);
 
 			let baseXdevCatalogDelivered = true;
@@ -5695,7 +5714,7 @@ export class AgentSession {
 
 			// Bail out if a newer abort/prompt cycle has started since we began setup
 			if (this.#promptGeneration !== generation) {
-				return;
+				return false;
 			}
 
 			// Auto thinking: classify this real user turn and set the effective level
@@ -5709,7 +5728,7 @@ export class AgentSession {
 			if (this.isAutoThinking && isUserTurn) {
 				await this.#models.applyAutoThinkingLevel(expandedText, generation);
 				if (this.#promptGeneration !== generation) {
-					return;
+					return false;
 				}
 			}
 			const xdevMountNotice = isUserQueuedMessage(message)
@@ -5721,7 +5740,7 @@ export class AgentSession {
 
 			await this.#maintenance.runPrePromptCompactionIfNeeded(messages);
 			if (this.#promptGeneration !== generation) {
-				return;
+				return false;
 			}
 
 			const agentPromptOptions = options?.toolChoice ? { toolChoice: options.toolChoice } : undefined;
@@ -5757,6 +5776,7 @@ export class AgentSession {
 			if (!options?.skipPostPromptRecoveryWait) {
 				await this.#waitForPostPromptRecovery(generation);
 			}
+			return true;
 		} finally {
 			// The per-turn before_agent_start override lives only for this turn.
 			this.#tools.clearTurnSystemPromptOverride();
@@ -6648,6 +6668,14 @@ export class AgentSession {
 		this.#titleGenerationStart = handler;
 	}
 
+	/** Install the host hook that receives a typed user prompt dropped before
+	 *  dispatch (an Esc abort or usage preflight denial raced turn setup). The
+	 *  prompt never reached the agent or the session file, so without this hook
+	 *  it would vanish; interactive mode restores it to the editor for editing. */
+	setPromptDropped(handler: ((prompt: DroppedPrompt) => void) | undefined): void {
+		this.#promptDropped = handler;
+	}
+
 	/**
 	 * Abort current operation and wait for agent to become idle.
 	 *