diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8d5412dcd..e39c291d2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -18,6 +18,7 @@ Status: unreleased.
 - Telegram: allow caption param for media sends. (#1888) Thanks @mguellsegarra.
 - Telegram: avoid block replies when streaming is disabled. (#1885) Thanks @ivancasco.
 - Auth: show copyable Google auth URL after ASCII prompt. (#1787) Thanks @robbyczgw-cla.
+- Routing: precompile session key regexes. (#1697) Thanks @Ray0907.
 
 ## 2026.1.24-3
 
diff --git a/src/routing/session-key.ts b/src/routing/session-key.ts
index 028e657cb..7f9f209ed 100644
--- a/src/routing/session-key.ts
+++ b/src/routing/session-key.ts
@@ -11,6 +11,12 @@ export const DEFAULT_AGENT_ID = "main";
 export const DEFAULT_MAIN_KEY = "main";
 export const DEFAULT_ACCOUNT_ID = "default";
 
+// Pre-compiled regex
+const VALID_ID_RE = /^[a-z0-9][a-z0-9_-]{0,63}$/i;
+const INVALID_CHARS_RE = /[^a-z0-9_-]+/g;
+const LEADING_DASH_RE = /^-+/;
+const TRAILING_DASH_RE = /-+$/;
+
 function normalizeToken(value: string | undefined | null): string {
   return (value ?? "").trim().toLowerCase();
 }
@@ -52,14 +58,14 @@ export function normalizeAgentId(value: string | undefined | null): string {
   const trimmed = (value ?? "").trim();
   if (!trimmed) return DEFAULT_AGENT_ID;
   // Keep it path-safe + shell-friendly.
-  if (/^[a-z0-9][a-z0-9_-]{0,63}$/i.test(trimmed)) return trimmed.toLowerCase();
+  if (VALID_ID_RE.test(trimmed)) return trimmed.toLowerCase();
   // Best-effort fallback: collapse invalid characters to "-"
   return (
     trimmed
       .toLowerCase()
-      .replace(/[^a-z0-9_-]+/g, "-")
-      .replace(/^-+/, "")
-      .replace(/-+$/, "")
+      .replace(INVALID_CHARS_RE, "-")
+      .replace(LEADING_DASH_RE, "")
+      .replace(TRAILING_DASH_RE, "")
       .slice(0, 64) || DEFAULT_AGENT_ID
   );
 }
@@ -67,13 +73,13 @@ export function normalizeAgentId(value: string | undefined | null): string {
 export function sanitizeAgentId(value: string | undefined | null): string {
   const trimmed = (value ?? "").trim();
   if (!trimmed) return DEFAULT_AGENT_ID;
-  if (/^[a-z0-9][a-z0-9_-]{0,63}$/i.test(trimmed)) return trimmed.toLowerCase();
+  if (VALID_ID_RE.test(trimmed)) return trimmed.toLowerCase();
   return (
     trimmed
       .toLowerCase()
-      .replace(/[^a-z0-9_-]+/gi, "-")
-      .replace(/^-+/, "")
-      .replace(/-+$/, "")
+      .replace(INVALID_CHARS_RE, "-")
+      .replace(LEADING_DASH_RE, "")
+      .replace(TRAILING_DASH_RE, "")
       .slice(0, 64) || DEFAULT_AGENT_ID
   );
 }
@@ -81,13 +87,13 @@ export function sanitizeAgentId(value: string | undefined | null): string {
 export function normalizeAccountId(value: string | undefined | null): string {
   const trimmed = (value ?? "").trim();
   if (!trimmed) return DEFAULT_ACCOUNT_ID;
-  if (/^[a-z0-9][a-z0-9_-]{0,63}$/i.test(trimmed)) return trimmed.toLowerCase();
+  if (VALID_ID_RE.test(trimmed)) return trimmed.toLowerCase();
   return (
     trimmed
       .toLowerCase()
-      .replace(/[^a-z0-9_-]+/g, "-")
-      .replace(/^-+/, "")
-      .replace(/-+$/, "")
+      .replace(INVALID_CHARS_RE, "-")
+      .replace(LEADING_DASH_RE, "")
+      .replace(TRAILING_DASH_RE, "")
       .slice(0, 64) || DEFAULT_ACCOUNT_ID
   );
 }