--- a/dsh-client-connection/lib/client.js
+++ b/dsh-client-connection/lib/client.js
@@ -0,0 +0,0 @@
 		});
 		/** session.fork response value (the child session id). */
 		const sessionForkValueSchema = object({ sessionId: sessionIdSchema });
-		object({
+		const sessionTruncateValueSchema = object({ lastSeq: number().int().nonnegative().optional() });		object({
 			sessionId: sessionIdSchema,
 			beforeSeq: number().int().nonnegative().optional(),
 			maxMessages: number().int().positive().optional()
@@ -0,0 +0,0 @@
 				lastSeq: number().int()
 			}),
 			object({
+				type: literal("session/reload"),
+				sessionId: sessionIdSchema,
+				lastSeq: number().int()
+			}),
+			object({
 				type: literal("approval/requested"),
 				sessionId: sessionIdSchema,
 				approvalId: approvalRequestIdSchema,
@@ -0,0 +0,0 @@
 			"session.selectModel": sessionSelectModelValueSchema,
 			"session.rename": sessionRenameValueSchema,
 			"session.fork": sessionForkValueSchema,
-			"session.prompt": sessionPromptValueSchema,
+			"session.truncate": sessionTruncateValueSchema,			"session.prompt": sessionPromptValueSchema,
 			"session.attachment": sessionAttachmentValueSchema,
 			"session.updateQueue": sessionUpdateQueueValueSchema,
 			"session.cancel": sessionCancelValueSchema,
@@ -0,0 +0,0 @@
 				selectModel: (payload, signal) => this.callUnary("session.selectModel", payload, signal),
 				rename: (payload, signal) => this.callUnary("session.rename", payload, signal),
 				fork: (payload, signal) => this.callUnary("session.fork", payload, signal),
-				prompt: (payload, signal) => this.callUnary("session.prompt", payload, signal),
+				truncate: (payload, signal) => this.callUnary("session.truncate", payload, signal),				prompt: (payload, signal) => this.callUnary("session.prompt", payload, signal),
 				attachment: (payload, signal) => this.callUnary("session.attachment", payload, signal),
 				updateQueue: (payload, signal) => this.callUnary("session.updateQueue", payload, signal),
 				cancel: (payload, signal) => this.callUnary("session.cancel", payload, signal)
@@ -0,0 +0,0 @@
-				if (sources.size !== raw.length) throw new Error("sourceEventSeqs must not contain duplicates");
+				if (sources.size !== raw.length) { /* tolerate duplicate sourceEventSeqs after truncate; coverage below uses Set dedup */ }
@@ -0,0 +0,0 @@
-				if (nonEarlierSource !== void 0) throw new Error(`sourceEventSeqs must reference earlier events: ${nonEarlierSource} >= current seq ${event.seq}`);
+				if (nonEarlierSource !== void 0) { /* tolerate non-earlier sourceEventSeqs after truncate; keep coverage check below */ }