--- a/dsh-session-persistence/lib/index.js
+++ b/dsh-session-persistence/lib/index.js
@@ -0,0 +0,0 @@
 		this.preparations.invalidate(id);
 	}
 	/**
-	* Prepare and reserve the exact unpublished Session used by resume.
+	 * Discard `atSeq` and everything after (truncate). Flushes the live
+	 * write-behind FIRST, then rewrites the artifact keeping only seq < atSeq
+	 * and resets the durable cursor.
+	 */
+	async truncate(id, atSeq) {
+		if (!Number.isSafeInteger(atSeq) || atSeq < 0) throw new TypeError(`truncate atSeq must be a non-negative safe integer, got ${String(atSeq)}`);
+		const session = this.ctx.sessions.get(id);
+		if (session !== void 0 && this.live.has(session)) await this.flush(session);
+		return this.serialize(id, () => this.truncateCore(id, atSeq));
+	}
+
+	async truncateCore(id, atSeq) {
+		const stored = await this.backend.loadStored(id);
+		if (stored === void 0) throw new Error(`session "${id}" not found`);
+		const kept = stored.events.filter((event) => event.seq < atSeq);
+		if (this.backend.rewriteStored === void 0) throw new Error(`${this.backend.name} does not support durable truncate`);
+		await this.backend.rewriteStored(stored.meta, kept);
+		const session = this.ctx.sessions.get(id);
+		const live = session !== void 0 ? this.live.get(session) : void 0;
+		if (live !== void 0 && live.writes) {
+			live.writes.cancelAutomaticWait();
+			live.writes.pending = live.writes.pending.filter((event) => event.seq < atSeq);
+			if (live.writes.pending.length > 0) live.writes.armTimer();
+		}
+		const state = this.states.get(id) ?? { meta: stored.meta, cursor: 0, materialized: true };
+		state.meta = structuredClone(stored.meta);
+		state.cursor = atSeq;
+		state.materialized = true;
+		this.states.set(id, state);
+		this.preparations.invalidate(id);
+	}
+/**
+ * Prepare and reserve the exact unpublished Session used by resume.
 	* Revision retries converge once the durable log remains unchanged for one
 	* read/check round trip; continuous external writers may delay completion.
 	* @param id - persisted session to prepare.