fix(agent): correct uuidv7 sequence handling

packages/agent/src/harness/session/uuid.ts

@@ -8,10 +8,10 @@ export function uuidv7(): string {
 	const timestamp = Date.now();
 
 	if (timestamp > lastTimestamp) {
-		sequence = (random[6] << 23) | (random[7] << 16) | (random[8] << 8) | random[9];
+		sequence = random[6] * 0x1000000 + random[7] * 0x10000 + random[8] * 0x100 + random[9];
 		lastTimestamp = timestamp;
 	} else {
-		sequence = (sequence + 1) | 0;
+		sequence = (sequence + 1) >>> 0;
 		if (sequence === 0) {
 			lastTimestamp++;
 		}
@@ -28,7 +28,7 @@ export function uuidv7(): string {
 	bytes[7] = (sequence >>> 20) & 0xff;
 	bytes[8] = 0x80 | ((sequence >>> 14) & 0x3f);
 	bytes[9] = (sequence >>> 6) & 0xff;
-	bytes[10] = ((sequence << 2) & 0xff) | (random[10] & 0x03);
+	bytes[10] = ((sequence & 0x3f) << 2) | (random[10] & 0x03);
 	bytes[11] = random[11];
 	bytes[12] = random[12];
 	bytes[13] = random[13];

packages/agent/src/index.ts

@@ -29,6 +29,7 @@ export * from "./harness/session/repo/jsonl.js";
 export * from "./harness/session/repo/memory.js";
 export * from "./harness/session/repo/shared.js";
 export * from "./harness/session/session.js";
+export { uuidv7 } from "./harness/session/uuid.js";
 export * from "./harness/skills.js";
 export * from "./harness/system-prompt.js";
 // Harness

packages/agent/test/harness/session-uuid.test.ts

@@ -0,0 +1,50 @@
+import { describe, expect, it, vi } from "vitest";
+
+const randomBytesMock = vi.hoisted(() => vi.fn<(size: number) => Buffer>());
+
+vi.mock("node:crypto", () => ({
+	randomBytes: randomBytesMock,
+}));
+
+import { uuidv7 } from "../../src/harness/session/uuid.js";
+
+const UUID_V7_RE = /^[0-9a-f]{8}-[0-9a-f]{4}-7[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/;
+const TIMESTAMP = 0x0123456789ab;
+
+function parseTimestamp(uuid: string): number {
+	return Number.parseInt(uuid.replaceAll("-", "").slice(0, 12), 16);
+}
+
+describe("uuidv7", () => {
+	it("uses the RFC 9562 layout and preserves monotonic order", () => {
+		randomBytesMock
+			.mockReturnValueOnce(
+				Buffer.from([0, 0, 0, 0, 0, 0, 0xff, 0xff, 0xff, 0xfe, 0x01, 0x11, 0x22, 0x33, 0x44, 0x55]),
+			)
+			.mockReturnValueOnce(Buffer.alloc(16))
+			.mockReturnValueOnce(Buffer.alloc(16));
+		const dateNow = vi.spyOn(Date, "now").mockReturnValue(TIMESTAMP);
+
+		try {
+			const first = uuidv7();
+			const second = uuidv7();
+			const third = uuidv7();
+
+			expect(first).toBe("01234567-89ab-7fff-bfff-f91122334455");
+			expect(second).toBe("01234567-89ab-7fff-bfff-fc0000000000");
+			expect(third).toBe("01234567-89ac-7000-8000-000000000000");
+			expect(first).toMatch(UUID_V7_RE);
+			expect(second).toMatch(UUID_V7_RE);
+			expect(third).toMatch(UUID_V7_RE);
+			expect(parseTimestamp(first)).toBe(TIMESTAMP);
+			expect(parseTimestamp(second)).toBe(TIMESTAMP);
+			expect(parseTimestamp(third)).toBe(TIMESTAMP + 1);
+			expect(first < second).toBe(true);
+			expect(second < third).toBe(true);
+			expect(randomBytesMock).toHaveBeenCalledTimes(3);
+			expect(randomBytesMock).toHaveBeenCalledWith(16);
+		} finally {
+			dateNow.mockRestore();
+		}
+	});
+});

packages/coding-agent/src/core/session-manager.ts

@@ -1,4 +1,4 @@
-import type { AgentMessage } from "@earendil-works/pi-agent-core";
+import { type AgentMessage, uuidv7 } from "@earendil-works/pi-agent-core";
 import type { ImageContent, Message, TextContent } from "@earendil-works/pi-ai";
 import { randomUUID } from "crypto";
 import {
@@ -16,7 +16,6 @@ import {
 import { readdir, readFile, stat } from "fs/promises";
 import { join, resolve } from "path";
 import { getAgentDir as getDefaultAgentDir, getSessionsDir } from "../config.js";
-import { uuidv7 } from "../utils/uuid.js";
 import {
 	type BashExecutionMessage,
 	type CustomMessage,

packages/coding-agent/src/utils/uuid.ts

@@ -1,44 +0,0 @@
-import { randomBytes } from "node:crypto";
-
-let lastTimestamp = -Infinity;
-let sequence = 0;
-
-export function uuidv7(): string {
-	const random = randomBytes(16);
-	const timestamp = Date.now();
-
-	if (timestamp > lastTimestamp) {
-		sequence = (random[6] << 23) | (random[7] << 16) | (random[8] << 8) | random[9];
-		lastTimestamp = timestamp;
-	} else {
-		sequence = (sequence + 1) | 0;
-		if (sequence === 0) {
-			lastTimestamp++;
-		}
-	}
-
-	const bytes = new Uint8Array(16);
-	bytes[0] = (lastTimestamp / 0x10000000000) & 0xff;
-	bytes[1] = (lastTimestamp / 0x100000000) & 0xff;
-	bytes[2] = (lastTimestamp / 0x1000000) & 0xff;
-	bytes[3] = (lastTimestamp / 0x10000) & 0xff;
-	bytes[4] = (lastTimestamp / 0x100) & 0xff;
-	bytes[5] = lastTimestamp & 0xff;
-	bytes[6] = 0x70 | ((sequence >>> 28) & 0x0f);
-	bytes[7] = (sequence >>> 20) & 0xff;
-	bytes[8] = 0x80 | ((sequence >>> 14) & 0x3f);
-	bytes[9] = (sequence >>> 6) & 0xff;
-	bytes[10] = ((sequence << 2) & 0xff) | (random[10] & 0x03);
-	bytes[11] = random[11];
-	bytes[12] = random[12];
-	bytes[13] = random[13];
-	bytes[14] = random[14];
-	bytes[15] = random[15];
-
-	return formatUuid(bytes);
-}
-
-function formatUuid(bytes: Uint8Array): string {
-	const hex = Array.from(bytes, (byte) => byte.toString(16).padStart(2, "0"));
-	return `${hex.slice(0, 4).join("")}-${hex.slice(4, 6).join("")}-${hex.slice(6, 8).join("")}-${hex.slice(8, 10).join("")}-${hex.slice(10, 16).join("")}`;
-}