fix(profile): resolve no-scheme URLs and ignore placeholder URN drift

docs/MEMORY.md

@@ -1,8 +1,13 @@
 # Memory Log
-Last Updated: 2026-02-25
+Last Updated: 2026-02-27
 
 Append-only log. Add entries; do not rewrite historical entries except typo fixes.
 
+## 2026-02-27
+- Correction: `profile` treated no-scheme LinkedIn URLs (for example `linkedin.com/in/<handle>`) as plain usernames, so recipient resolution requested invalid member identities and returned `Invalid request`.
+- Fix: updated URL parsing to normalize no-scheme LinkedIn URLs before route parsing, and added tests for no-scheme supported/unsupported paths.
+- Guardrail: recipient cache warnings now ignore synthetic/non-canonical URNs (for example fixture-style placeholders) and tests use isolated cache paths to prevent cross-run cache contamination.
+
 ## 2026-02-25
 - Correction: process guidance was fragmented across root markdown files and drifted over time.
 - Fix: consolidated process rules into `AGENTS.md`, moved specification to `docs/SPEC.md`, and started managed freshness checks.

src/lib/recipient.ts

@@ -18,13 +18,15 @@ import { parseLinkedInUrl } from "./url-parser.js";
 
 const DEBUG_RECIPIENT =
 	process.env.LI_DEBUG_RECIPIENT === "1" || process.env.LI_DEBUG_RECIPIENT === "true";
-const RECIPIENT_CACHE_PATH =
-	process.env.LI_RECIPIENT_CACHE_PATH ?? path.join(os.tmpdir(), "li-recipient-cache.json");
 
 function isProfileViewEnabled(): boolean {
 	return process.env.LI_ENABLE_PROFILEVIEW === "1" || process.env.LI_ENABLE_PROFILEVIEW === "true";
 }
 
+function getRecipientCachePath(): string {
+	return process.env.LI_RECIPIENT_CACHE_PATH ?? path.join(os.tmpdir(), "li-recipient-cache.json");
+}
+
 function debugRecipient(message: string): void {
 	if (!DEBUG_RECIPIENT) {
 		return;
@@ -35,8 +37,9 @@ function debugRecipient(message: string): void {
 type RecipientCache = Record<string, { urn: string; updatedAt: number }>;
 
 function loadRecipientCache(): RecipientCache {
+	const cachePath = getRecipientCachePath();
 	try {
-		const raw = readFileSync(RECIPIENT_CACHE_PATH, "utf8");
+		const raw = readFileSync(cachePath, "utf8");
 		const parsed = JSON.parse(raw) as RecipientCache;
 		if (!parsed || typeof parsed !== "object") {
 			return {};
@@ -48,21 +51,35 @@ function loadRecipientCache(): RecipientCache {
 }
 
 function saveRecipientCache(cache: RecipientCache): void {
+	const cachePath = getRecipientCachePath();
 	try {
-		mkdirSync(path.dirname(RECIPIENT_CACHE_PATH), { recursive: true });
-		writeFileSync(RECIPIENT_CACHE_PATH, JSON.stringify(cache), "utf8");
+		mkdirSync(path.dirname(cachePath), { recursive: true });
+		writeFileSync(cachePath, JSON.stringify(cache), "utf8");
 	} catch {
 		// Best-effort cache; ignore failures.
 	}
 }
 
+function isCacheableRecipientUrn(urn: string): boolean {
+	if (!urn.startsWith("urn:li:")) {
+		return false;
+	}
+	if (urn.startsWith("urn:li:member:")) {
+		return /^urn:li:member:\d+$/.test(urn);
+	}
+	if (urn.startsWith("urn:li:fsd_profile:")) {
+		return /^urn:li:fsd_profile:ACo[A-Za-z0-9_-]+$/.test(urn);
+	}
+	return false;
+}
+
 function warnIfRecipientChanged(key: string, currentUrn: string): void {
-	if (!key || !currentUrn) {
+	if (!key || !currentUrn || !isCacheableRecipientUrn(currentUrn)) {
 		return;
 	}
 	const cache = loadRecipientCache();
 	const previous = cache[key]?.urn ?? "";
-	if (previous && previous !== currentUrn) {
+	if (isCacheableRecipientUrn(previous) && previous !== currentUrn) {
 		process.stderr.write(
 			`[li][recipient] warning=profile_urn_changed key=${key} prev=${previous} next=${currentUrn}\n`,
 		);

src/lib/url-parser.ts

@@ -47,6 +47,11 @@ export function parseLinkedInUrl(input: string): ParsedLinkedInUrl | null {
 		return parseUrl(trimmed);
 	}
 
+	// Handle LinkedIn URLs pasted without a scheme (e.g. linkedin.com/in/user)
+	if (isLikelyLinkedInUrlWithoutScheme(trimmed)) {
+		return parseUrl(`https://${trimmed}`);
+	}
+
 	// Treat as plain username (for profile lookups)
 	return {
 		type: "profile",
@@ -104,7 +109,7 @@ function parseUrl(urlString: string): ParsedLinkedInUrl | null {
 
 	// Validate it's a LinkedIn domain
 	const hostname = url.hostname.toLowerCase();
-	if (!hostname.endsWith("linkedin.com") && hostname !== "linkedin.com") {
+	if (hostname !== "linkedin.com" && !hostname.endsWith(".linkedin.com")) {
 		return null;
 	}
 
@@ -146,6 +151,10 @@ function parseUrl(urlString: string): ParsedLinkedInUrl | null {
 	return null;
 }
 
+function isLikelyLinkedInUrlWithoutScheme(input: string): boolean {
+	return /^(?:[a-z0-9-]+\.)*linkedin\.com(?:\/|$)/i.test(input);
+}
+
 /**
  * Extract the ID portion from a LinkedIn URN.
  *

tests/unit/recipient.test.ts

@@ -7,6 +7,9 @@
  * - Profile URNs (e.g., "urn:li:fsd_profile:ACoAABcd1234")
  */
 
+import { rmSync, writeFileSync } from "node:fs";
+import os from "node:os";
+import path from "node:path";
 import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
 import { LinkedInClient } from "../../src/lib/client.js";
 import { resolveRecipient } from "../../src/lib/recipient.js";
@@ -28,10 +31,19 @@ describe("recipient", () => {
 		getCredentials: ReturnType<typeof vi.fn>;
 	};
 	let previousProfileViewEnv: string | undefined;
+	let previousRecipientCachePathEnv: string | undefined;
+	let recipientCachePath: string;
 
 	beforeEach(() => {
 		previousProfileViewEnv = process.env.LI_ENABLE_PROFILEVIEW;
+		previousRecipientCachePathEnv = process.env.LI_RECIPIENT_CACHE_PATH;
 		process.env.LI_ENABLE_PROFILEVIEW = "0";
+		recipientCachePath = path.join(
+			os.tmpdir(),
+			`li-recipient-test-cache-${process.pid}-${Date.now()}.json`,
+		);
+		process.env.LI_RECIPIENT_CACHE_PATH = recipientCachePath;
+		rmSync(recipientCachePath, { force: true });
 		mockClient = {
 			request: vi.fn(),
 			requestAbsolute: vi.fn(),
@@ -53,6 +65,12 @@ describe("recipient", () => {
 		} else {
 			process.env.LI_ENABLE_PROFILEVIEW = previousProfileViewEnv;
 		}
+		if (previousRecipientCachePathEnv === undefined) {
+			delete process.env.LI_RECIPIENT_CACHE_PATH;
+		} else {
+			process.env.LI_RECIPIENT_CACHE_PATH = previousRecipientCachePathEnv;
+		}
+		rmSync(recipientCachePath, { force: true });
 	});
 
 	describe("resolveRecipient", () => {
@@ -338,6 +356,30 @@ describe("recipient", () => {
 				});
 			});
 
+			it("resolves a profile URL without scheme", async () => {
+				mockClient.request.mockResolvedValueOnce({
+					json: () =>
+						Promise.resolve({
+							elements: [
+								{
+									entityUrn: "urn:li:fsd_profile:ACoAABcd1234",
+									publicIdentifier: "peggyrayzis",
+								},
+							],
+						}),
+				});
+
+				const result = await resolveRecipient(
+					mockClient as unknown as LinkedInClient,
+					"linkedin.com/in/peggyrayzis",
+				);
+
+				expect(result).toEqual({
+					username: "peggyrayzis",
+					urn: "urn:li:fsd_profile:ACoAABcd1234",
+				});
+			});
+
 			it("resolves a profile URL with trailing slash", async () => {
 				mockClient.request.mockResolvedValueOnce({
 					json: () =>
@@ -503,6 +545,76 @@ describe("recipient", () => {
 			});
 		});
 
+		describe("recipient cache warnings", () => {
+			it("skips warning when cached previous URN is a synthetic placeholder", async () => {
+				writeFileSync(
+					recipientCachePath,
+					JSON.stringify({
+						peggyrayzis: {
+							urn: "urn:li:fsd_profile:ABC123",
+							updatedAt: Date.now(),
+						},
+					}),
+					"utf8",
+				);
+				mockClient.request.mockResolvedValueOnce({
+					json: () =>
+						Promise.resolve({
+							elements: [
+								{
+									entityUrn: "urn:li:fsd_profile:ACoAABcd1234",
+									publicIdentifier: "peggyrayzis",
+								},
+							],
+						}),
+				});
+				const stderrSpy = vi.spyOn(process.stderr, "write").mockReturnValue(true);
+
+				await resolveRecipient(mockClient as unknown as LinkedInClient, "peggyrayzis");
+
+				expect(
+					stderrSpy.mock.calls.some((call) =>
+						String(call[0]).includes("warning=profile_urn_changed"),
+					),
+				).toBe(false);
+				stderrSpy.mockRestore();
+			});
+
+			it("emits warning when cached previous URN is valid and changes", async () => {
+				writeFileSync(
+					recipientCachePath,
+					JSON.stringify({
+						peggyrayzis: {
+							urn: "urn:li:fsd_profile:ACoAABcd1111",
+							updatedAt: Date.now(),
+						},
+					}),
+					"utf8",
+				);
+				mockClient.request.mockResolvedValueOnce({
+					json: () =>
+						Promise.resolve({
+							elements: [
+								{
+									entityUrn: "urn:li:fsd_profile:ACoAABcd2222",
+									publicIdentifier: "peggyrayzis",
+								},
+							],
+						}),
+				});
+				const stderrSpy = vi.spyOn(process.stderr, "write").mockReturnValue(true);
+
+				await resolveRecipient(mockClient as unknown as LinkedInClient, "peggyrayzis");
+
+				expect(
+					stderrSpy.mock.calls.some((call) =>
+						String(call[0]).includes("warning=profile_urn_changed"),
+					),
+				).toBe(true);
+				stderrSpy.mockRestore();
+			});
+		});
+
 		describe("edge cases", () => {
 			it("handles response without publicIdentifier", async () => {
 				mockClient.request.mockResolvedValueOnce({

tests/unit/url-parser.test.ts

@@ -55,6 +55,15 @@ describe("url-parser", () => {
 				});
 			});
 
+			it("handles linkedin.com profile URLs without scheme", () => {
+				const result = parseLinkedInUrl("linkedin.com/in/peggyrayzis");
+
+				expect(result).toEqual({
+					type: "profile",
+					identifier: "peggyrayzis",
+				});
+			});
+
 			it("handles mobile linkedin URLs (m.linkedin.com)", () => {
 				const result = parseLinkedInUrl("https://m.linkedin.com/in/peggyrayzis");
 
@@ -337,12 +346,23 @@ describe("url-parser", () => {
 				expect(result).toBeNull();
 			});
 
+			it("returns null for domains that only suffix-match linkedin.com", () => {
+				expect(parseLinkedInUrl("https://notlinkedin.com/in/peggyrayzis")).toBeNull();
+				expect(parseLinkedInUrl("https://evil-linkedin.com/in/peggyrayzis")).toBeNull();
+			});
+
 			it("returns null for LinkedIn URL with unsupported path", () => {
 				const result = parseLinkedInUrl("https://www.linkedin.com/learning");
 
 				expect(result).toBeNull();
 			});
 
+			it("returns null for no-scheme LinkedIn URL with unsupported path", () => {
+				const result = parseLinkedInUrl("linkedin.com/learning");
+
+				expect(result).toBeNull();
+			});
+
 			it("returns null for malformed URN", () => {
 				const result = parseLinkedInUrl("urn:li:");
 

vitest.config.ts

@@ -1,10 +1,15 @@
+import os from 'node:os'
+import path from 'node:path'
 import { defineConfig } from 'vitest/config'
 
 export default defineConfig({
   test: {
     globals: true,
     environment: 'node',
-    env: { NO_COLOR: '1' },
+    env: {
+      NO_COLOR: '1',
+      LI_RECIPIENT_CACHE_PATH: path.join(os.tmpdir(), `li-recipient-cache-vitest-${process.pid}.json`),
+    },
     include: ['tests/**/*.test.ts'],
     coverage: {
       provider: 'v8',