fix: unify reasoning tags + agent ids (#1613) (thanks @kyleok) (#1629)

CHANGELOG.md

@@ -12,6 +12,7 @@ Docs: https://docs.clawd.bot
 ### Fixes
 - Web UI: hide internal `message_id` hints in chat bubbles.
 - Heartbeat: normalize target identifiers for consistent routing.
+- TUI: unify reasoning tag stripping so `<final>` wrappers stay hidden. (#1613) Thanks @kyleok.
 
 ## 2026.1.23-1
 

src/agents/pi-embedded-utils.test.ts

@@ -460,6 +460,22 @@ File contents here`,
     expect(result).toBe("The actual answer.");
   });
 
+  it("strips final tags while keeping content", () => {
+    const msg: AssistantMessage = {
+      role: "assistant",
+      content: [
+        {
+          type: "text",
+          text: "<final>\nAnswer\n</final>",
+        },
+      ],
+      timestamp: Date.now(),
+    };
+
+    const result = extractAssistantText(msg);
+    expect(result).toBe("Answer");
+  });
+
   it("strips thought tags", () => {
     const msg: AssistantMessage = {
       role: "assistant",

src/agents/pi-embedded-utils.ts

@@ -1,4 +1,5 @@
 import type { AssistantMessage } from "@mariozechner/pi-ai";
+import { stripReasoningTagsFromText } from "../shared/text/reasoning-tags.js";
 import { sanitizeUserFacingText } from "./pi-embedded-helpers.js";
 import { formatToolDetail, resolveToolDisplay } from "./tool-display.js";
 
@@ -166,36 +167,7 @@ export function stripDowngradedToolCallText(text: string): string {
  * that slip through other filtering mechanisms.
  */
 export function stripThinkingTagsFromText(text: string): string {
-  if (!text) return text;
-  // Quick check to avoid regex overhead when no tags present.
-  if (!/(?:think(?:ing)?|thought|antthinking)/i.test(text)) return text;
-
-  const tagRe = /<\s*(\/?)\s*(?:think(?:ing)?|thought|antthinking)\b[^>]*>/gi;
-  let result = "";
-  let lastIndex = 0;
-  let inThinking = false;
-
-  for (const match of text.matchAll(tagRe)) {
-    const idx = match.index ?? 0;
-    const isClose = match[1] === "/";
-
-    if (!inThinking && !isClose) {
-      // Opening tag - save text before it.
-      result += text.slice(lastIndex, idx);
-      inThinking = true;
-    } else if (inThinking && isClose) {
-      // Closing tag - skip content inside.
-      inThinking = false;
-    }
-    lastIndex = idx + match[0].length;
-  }
-
-  // Append remaining text if we're not inside thinking.
-  if (!inThinking) {
-    result += text.slice(lastIndex);
-  }
-
-  return result.trim();
+  return stripReasoningTagsFromText(text, { mode: "strict", trim: "both" });
 }
 
 export function extractAssistantText(msg: AssistantMessage): string {

src/routing/session-key.ts

@@ -67,9 +67,10 @@ 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}$/i.test(trimmed)) return trimmed;
+  if (/^[a-z0-9][a-z0-9_-]{0,63}$/i.test(trimmed)) return trimmed.toLowerCase();
   return (
     trimmed
+      .toLowerCase()
       .replace(/[^a-z0-9_-]+/gi, "-")
       .replace(/^-+/, "")
       .replace(/-+$/, "")

src/shared/text/reasoning-tags.ts

@@ -0,0 +1,61 @@
+export type ReasoningTagMode = "strict" | "preserve";
+export type ReasoningTagTrim = "none" | "start" | "both";
+
+const QUICK_TAG_RE = /<\s*\/?\s*(?:think(?:ing)?|thought|antthinking|final)\b/i;
+const FINAL_TAG_RE = /<\s*\/?\s*final\b[^>]*>/gi;
+const THINKING_TAG_RE = /<\s*(\/?)\s*(?:think(?:ing)?|thought|antthinking)\b[^>]*>/gi;
+
+function applyTrim(value: string, mode: ReasoningTagTrim): string {
+  if (mode === "none") return value;
+  if (mode === "start") return value.trimStart();
+  return value.trim();
+}
+
+export function stripReasoningTagsFromText(
+  text: string,
+  options?: {
+    mode?: ReasoningTagMode;
+    trim?: ReasoningTagTrim;
+  },
+): string {
+  if (!text) return text;
+  if (!QUICK_TAG_RE.test(text)) return text;
+
+  const mode = options?.mode ?? "strict";
+  const trimMode = options?.trim ?? "both";
+
+  let cleaned = text;
+  if (FINAL_TAG_RE.test(cleaned)) {
+    FINAL_TAG_RE.lastIndex = 0;
+    cleaned = cleaned.replace(FINAL_TAG_RE, "");
+  } else {
+    FINAL_TAG_RE.lastIndex = 0;
+  }
+
+  THINKING_TAG_RE.lastIndex = 0;
+  let result = "";
+  let lastIndex = 0;
+  let inThinking = false;
+
+  for (const match of cleaned.matchAll(THINKING_TAG_RE)) {
+    const idx = match.index ?? 0;
+    const isClose = match[1] === "/";
+
+    if (!inThinking) {
+      result += cleaned.slice(lastIndex, idx);
+      if (!isClose) {
+        inThinking = true;
+      }
+    } else if (isClose) {
+      inThinking = false;
+    }
+
+    lastIndex = idx + match[0].length;
+  }
+
+  if (!inThinking || mode === "preserve") {
+    result += cleaned.slice(lastIndex);
+  }
+
+  return applyTrim(result, trimMode);
+}

ui/src/ui/format.ts

@@ -1,3 +1,5 @@
+import { stripReasoningTagsFromText } from "../../../src/shared/text/reasoning-tags.js";
+
 export function formatMs(ms?: number | null): string {
   if (!ms && ms !== 0) return "n/a";
   return new Date(ms).toLocaleString();
@@ -67,38 +69,6 @@ export function parseList(input: string): string[] {
     .filter((v) => v.length > 0);
 }
 
-const THINKING_TAG_RE = /<\s*\/?\s*(?:think(?:ing)?|final)\s*>/gi;
-const THINKING_OPEN_RE = /<\s*(?:think(?:ing)?|final)\s*>/i;
-const THINKING_CLOSE_RE = /<\s*\/\s*(?:think(?:ing)?|final)\s*>/i;
-
 export function stripThinkingTags(value: string): string {
-  if (!value) return value;
-  const hasOpen = THINKING_OPEN_RE.test(value);
-  const hasClose = THINKING_CLOSE_RE.test(value);
-  if (!hasOpen && !hasClose) return value;
-  // If we don't have a balanced pair, avoid dropping trailing content.
-  if (hasOpen !== hasClose) {
-    if (!hasOpen) return value.replace(THINKING_CLOSE_RE, "").trimStart();
-    return value.replace(THINKING_OPEN_RE, "").trimStart();
-  }
-
-  if (!THINKING_TAG_RE.test(value)) return value;
-  THINKING_TAG_RE.lastIndex = 0;
-
-  let result = "";
-  let lastIndex = 0;
-  let inThinking = false;
-  for (const match of value.matchAll(THINKING_TAG_RE)) {
-    const idx = match.index ?? 0;
-    if (!inThinking) {
-      result += value.slice(lastIndex, idx);
-    }
-    const tag = match[0].toLowerCase();
-    inThinking = !tag.includes("/");
-    lastIndex = idx + match[0].length;
-  }
-  if (!inThinking) {
-    result += value.slice(lastIndex);
-  }
-  return result.trimStart();
+  return stripReasoningTagsFromText(value, { mode: "preserve", trim: "start" });
 }