fix: generate session and thread titles in sentence case (#123389)

Generated titles came back in Title Case because none of the title prompts stated a capitalization style; asked for a "title" with no case rule, models default to Title Case and nothing downstream corrects it. The tool-call purpose titles already ask for sentence case, so session titles, Discord auto-thread titles, and Telegram DM topic labels were the outliers.

Sets sentence case in each title prompt rather than post-processing: the titles follow the user's language, and sentence-case rules are language-specific, so a mechanical normalizer would mangle German nouns and proper nouns like OpenClaw or GitHub.

extensions/discord/src/monitor/thread-title.generate.test.ts

@@ -72,7 +72,7 @@ describe("generateThreadTitle", () => {
       userMessage:
         "Channel: release-status\n\nChannel description: Deploy updates and incident notes\n\nMessage:\nSummarize deployment blockers and owner follow-ups.",
       prompt:
-        "Generate a concise Discord thread title (3-6 words). Return only the title. Use channel context when provided and avoid redundant channel-name words unless needed for clarity.",
+        "Generate a concise Discord thread title (3-6 words) in sentence case: capitalize only the first word and words that are always capitalized. Return only the title. Use channel context when provided and avoid redundant channel-name words unless needed for clarity.",
       modelRef: "openai/gpt-4.1-mini@local",
       timeoutMs: 60_000,
       maxLength: 600,

extensions/discord/src/monitor/thread-title.ts

@@ -9,7 +9,7 @@ const MAX_THREAD_TITLE_SOURCE_CHARS = 600;
 const MAX_THREAD_TITLE_CHANNEL_NAME_CHARS = 120;
 const MAX_THREAD_TITLE_CHANNEL_DESCRIPTION_CHARS = 320;
 const DISCORD_THREAD_TITLE_SYSTEM_PROMPT =
-  "Generate a concise Discord thread title (3-6 words). Return only the title. Use channel context when provided and avoid redundant channel-name words unless needed for clarity.";
+  "Generate a concise Discord thread title (3-6 words) in sentence case: capitalize only the first word and words that are always capitalized. Return only the title. Use channel context when provided and avoid redundant channel-name words unless needed for clarity.";
 
 export async function generateThreadTitle(params: {
   cfg: OpenClawConfig;

extensions/telegram/src/auto-topic-label-config.ts

@@ -5,7 +5,7 @@ import type {
 } from "openclaw/plugin-sdk/config-contracts";
 
 const AUTO_TOPIC_LABEL_DEFAULT_PROMPT =
-  "Generate a very short topic label (2-4 words, max 25 chars) for a chat conversation based on the user's first message below. No emoji. Use the same language as the message. Be concise and descriptive. Return ONLY the topic name, nothing else.";
+  "Generate a very short topic label (2-4 words, max 25 chars) for a chat conversation based on the user's first message below. No emoji. Use the same language as the message, in sentence case: capitalize only the first word and words that language always capitalizes. Be concise and descriptive. Return ONLY the topic name, nothing else.";
 
 export function resolveAutoTopicLabelConfig(
   directConfig?: TelegramDirectConfig["autoTopicLabel"],

extensions/telegram/src/auto-topic-label.test.ts

@@ -11,7 +11,7 @@ import { resolveAutoTopicLabelConfig } from "./auto-topic-label-config.js";
 import { generateTelegramTopicLabel } from "./auto-topic-label.js";
 
 const EXPECTED_DEFAULT_PROMPT =
-  "Generate a very short topic label (2-4 words, max 25 chars) for a chat conversation based on the user's first message below. No emoji. Use the same language as the message. Be concise and descriptive. Return ONLY the topic name, nothing else.";
+  "Generate a very short topic label (2-4 words, max 25 chars) for a chat conversation based on the user's first message below. No emoji. Use the same language as the message, in sentence case: capitalize only the first word and words that language always capitalizes. Be concise and descriptive. Return ONLY the topic name, nothing else.";
 
 describe("resolveAutoTopicLabelConfig", () => {
   it("returns enabled with default prompt when configs are undefined", () => {

src/gateway/dashboard-session-title.test.ts

@@ -75,7 +75,7 @@ describe("maybeGenerateDashboardSessionTitle", () => {
     expect(generateConversationLabelWithFallback).toHaveBeenCalledWith({
       userMessage: "Help me plan the release",
       prompt:
-        "Generate a concise session title (3-6 words, max 60 characters) from the user's first message. Use the same language as the message. No emoji. Return only the title.",
+        "Generate a concise session title (3-6 words, max 60 characters) from the user's first message. Use the same language as the message, in sentence case: capitalize only the first word and words that language always capitalizes. No emoji. Return only the title.",
       cfg,
       agentId: "main",
       utilityModelRef: "openai/gpt-5.6-luna",

src/gateway/dashboard-session-title.ts

@@ -30,7 +30,7 @@ type DashboardSessionTitleModelEntry = Pick<
 const DASHBOARD_SESSION_TITLE_MAX_CHARS = 60;
 const DASHBOARD_SESSION_TITLE_SOURCE_MAX_CHARS = 1_000;
 const DASHBOARD_SESSION_TITLE_PROMPT =
-  "Generate a concise session title (3-6 words, max 60 characters) from the user's first message. Use the same language as the message. No emoji. Return only the title.";
+  "Generate a concise session title (3-6 words, max 60 characters) from the user's first message. Use the same language as the message, in sentence case: capitalize only the first word and words that language always capitalizes. No emoji. Return only the title.";
 
 // One title request per session generation. Concurrent triggers cannot race duplicate model
 // calls or metadata writes; late callers receive the in-flight promise so they