diff --git a/docs/channels/telegram.md b/docs/channels/telegram.md
index 7d3a934f09fc..ef432132c1d9 100644
--- a/docs/channels/telegram.md
+++ b/docs/channels/telegram.md
@@ -369,9 +369,9 @@ curl "https://api.telegram.org/bot<bot_token>/getUpdates"
   </Accordion>
 
   <Accordion title="Rich message formatting">
-    Outbound text uses standard Telegram HTML messages by default, readable across current clients: bold, italic, links, code, spoilers, quotes — not Bot API 10.1 rich-only blocks (native tables, details, rich media, formulas).
+    Outbound text uses standard Telegram HTML messages by default, readable across current clients: bold, italic, links, code, spoilers, quotes — not Bot API 10.2 rich-only blocks (native tables, details, rich media, formulas).
 
-    Opt into Bot API 10.1 rich messages:
+    Opt into Bot API 10.2 rich messages:
 
 ```json5
 {
@@ -383,7 +383,7 @@ curl "https://api.telegram.org/bot<bot_token>/getUpdates"
 }
 ```
 
-    When enabled: the agent is told rich messages are available for this bot/account; Markdown text renders through OpenClaw's Markdown IR as Telegram rich HTML; explicit rich HTML payloads preserve supported Bot API 10.1 tags (headings, tables, details, rich media, formulas); media captions still use Telegram HTML captions (rich messages do not replace captions, and captions cap at 1024 characters).
+    When enabled: the agent is told rich messages are available for this bot/account (with the supported Markdown + HTML-island authoring contract); Markdown text renders through OpenClaw's Markdown IR as typed Bot API 10.2 rich blocks (headings, tables, details, checklists, rich media, formulas, maps, collages); media captions still use Telegram HTML captions (rich messages do not replace captions, and captions cap at 1024 characters).
 
     This keeps model text away from Telegram's rich-Markdown sigils, so currency like `$400-600K` is not parsed as math. Long rich text splits automatically across Telegram's limits. Tables over the 20-column limit fall back to a code block.
 
diff --git a/extensions/telegram/src/channel-actions.contract.test.ts b/extensions/telegram/src/channel-actions.contract.test.ts
index cc884171012e..29504761f3d3 100644
--- a/extensions/telegram/src/channel-actions.contract.test.ts
+++ b/extensions/telegram/src/channel-actions.contract.test.ts
@@ -24,23 +24,64 @@ describe("telegram actions contract", () => {
   });
 
   it.each([
-    { richMessages: undefined, expected: false },
-    { richMessages: false, expected: false },
-    { richMessages: true, expected: true },
-  ])("advertises Telegram rich text only when enabled", ({ richMessages, expected }) => {
+    {
+      richMessages: undefined as boolean | undefined,
+      expectedMarkup: "markdown",
+      expectedOn: false,
+    },
+    {
+      richMessages: false as boolean | undefined,
+      expectedMarkup: "markdown",
+      expectedOn: false,
+    },
+    {
+      richMessages: true as boolean | undefined,
+      expectedMarkup: "markdown_telegram_rich",
+      expectedOn: true,
+    },
+  ])(
+    "returns inbound formatting hints for richMessages=$richMessages",
+    ({ richMessages, expectedMarkup, expectedOn }) => {
+      const hints = telegramPlugin.agentPrompt?.inboundFormattingHints?.({
+        cfg: {
+          channels: {
+            telegram: {
+              botToken: "test-token-placeholder",
+              richMessages,
+            },
+          },
+        } as OpenClawConfig,
+      });
+
+      expect(hints?.text_markup).toBe(expectedMarkup);
+      if (expectedOn) {
+        expect(hints?.rules.join(" ")).toContain("Telegram rich ON");
+        expect(hints?.rules.join(" ")).toContain("Bot API 10.2 blocks");
+        expect(hints?.rules.join(" ")).toContain("<details><summary>");
+        expect(hints?.rules.join(" ")).toContain("Not MarkdownV2/parse_mode");
+        expect(hints?.rules.join(" ")).toContain("Media https URLs only, block-level only");
+      } else {
+        expect(hints?.rules.join(" ")).toContain("Telegram rich OFF");
+        expect(hints?.rules.join(" ")).toContain("richMessages");
+        expect(hints?.rules.join(" ")).not.toContain("Telegram rich ON");
+      }
+    },
+  );
+
+  it("does not advertise a richText message-tool capability", () => {
     const capabilities = telegramPlugin.agentPrompt?.messageToolCapabilities?.({
       cfg: {
         channels: {
           telegram: {
             botToken: "test-token-placeholder",
-            richMessages,
+            richMessages: true,
           },
         },
       } as OpenClawConfig,
     });
 
     expect(capabilities).toContain("inlineButtons");
-    expect(capabilities?.includes("richText")).toBe(expected);
+    expect(capabilities).not.toContain("richText");
   });
 
   it("advertises inline buttons when legacy Telegram capabilities are empty", () => {
@@ -89,8 +130,8 @@ describe("telegram actions contract", () => {
     expect(capabilities).not.toContain("inlineButtons");
   });
 
-  it("uses the selected Telegram account's rich text setting", () => {
-    const capabilities = telegramPlugin.agentPrompt?.messageToolCapabilities?.({
+  it("uses the selected Telegram account's richMessages for inbound formatting hints", () => {
+    const hints = telegramPlugin.agentPrompt?.inboundFormattingHints?.({
       cfg: {
         channels: {
           telegram: {
@@ -107,12 +148,13 @@ describe("telegram actions contract", () => {
       accountId: "ops",
     });
 
-    expect(capabilities).not.toContain("richText");
+    expect(hints?.text_markup).toBe("markdown");
+    expect(hints?.rules.join(" ")).toContain("Telegram rich OFF");
   });
 
-  it("does not resolve Telegram credentials while checking prompt capabilities", () => {
+  it("does not resolve Telegram credentials while checking inbound formatting hints", () => {
     expect(() =>
-      telegramPlugin.agentPrompt?.messageToolCapabilities?.({
+      telegramPlugin.agentPrompt?.inboundFormattingHints?.({
         cfg: {
           channels: {
             telegram: {
@@ -125,8 +167,8 @@ describe("telegram actions contract", () => {
     ).not.toThrow();
   });
 
-  it("uses the configured default Telegram account for prompt capabilities", () => {
-    const capabilities = telegramPlugin.agentPrompt?.messageToolCapabilities?.({
+  it("uses the configured default Telegram account for inbound formatting hints", () => {
+    const hints = telegramPlugin.agentPrompt?.inboundFormattingHints?.({
       cfg: {
         channels: {
           telegram: {
@@ -146,7 +188,8 @@ describe("telegram actions contract", () => {
       } as OpenClawConfig,
     });
 
-    expect(capabilities).toContain("richText");
+    expect(hints?.text_markup).toBe("markdown_telegram_rich");
+    expect(hints?.rules.join(" ")).toContain("Telegram rich ON");
   });
 
   it("exposes Telegram thread create CLI remapping through the exported plugin", () => {
diff --git a/extensions/telegram/src/channel.ts b/extensions/telegram/src/channel.ts
index 2c80c1ea3ab3..566e7dbf5263 100644
--- a/extensions/telegram/src/channel.ts
+++ b/extensions/telegram/src/channel.ts
@@ -815,12 +815,34 @@ export const telegramPlugin = createChatChannelPlugin({
           cfg,
           accountId: accountId ?? undefined,
         });
-        const capabilities = inlineButtonsScope === "off" ? [] : ["inlineButtons"];
+        return inlineButtonsScope === "off" ? [] : ["inlineButtons"];
+      },
+      // Authoring contract lives here so every runtime (including native Codex)
+      // sees it via inbound-meta response_format; core system-prompt no longer owns it.
+      inboundFormattingHints: ({ cfg, accountId }) => {
         const selectedAccountId = accountId ?? resolveDefaultTelegramAccountId(cfg);
-        if (mergeTelegramAccountConfig(cfg, selectedAccountId).richMessages === true) {
-          capabilities.push("richText");
+        const richMessages =
+          mergeTelegramAccountConfig(cfg, selectedAccountId).richMessages === true;
+        if (richMessages) {
+          return {
+            text_markup: "markdown_telegram_rich",
+            rules: [
+              "Telegram rich ON (Bot API 10.2 blocks; OpenClaw maps markdown + these HTML islands to typed blocks).",
+              'Supported: headings, tables (markdown, or `<table>` HTML for caption/colspan/rowspan/align), block/pull quotes (`<aside>` + `<cite>`), `<details><summary>` (+`open`), dividers `<hr/>`, sup/sub/mark/spoilers, `<ul>`/`<ol>` + `<input type="checkbox" checked/>` tasks, code, anchors `<a name="x"></a>` + `<a href="#x">label</a>`, custom emoji `<tg-emoji emoji-id="...">`, maps `<tg-map lat="" long="" zoom=""/>`, collages/slideshows `<tg-collage>`/`<tg-slideshow>`, block media e.g. `<img src="https://..."/>` (+`<figure>`/`<figcaption>`).',
+              "Math: `<tg-math>` inline, `<tg-math-block>` block; never `$...$`/`\\(...\\)`.",
+              "Not MarkdownV2/parse_mode.",
+              "Collapse=`<details>` (not expandable blockquote); structured bullets=`<ul><li>` (not literal bullets).",
+              "Media https URLs only, block-level only, captions/credits when useful; buttons plain text; normal files via attachments.",
+            ],
+          };
         }
-        return capabilities;
+        return {
+          text_markup: "markdown",
+          rules: [
+            "Telegram rich OFF. Standard Telegram formatting only; no rich tables/details/block media/formulas.",
+            "Owner can enable `richMessages` for this Telegram account.",
+          ],
+        };
       },
       reactionGuidance: ({ cfg, accountId }) => {
         const level = resolveTelegramReactionLevel({
diff --git a/extensions/telegram/src/rich-blocks-html.ts b/extensions/telegram/src/rich-blocks-html.ts
index 5f4fed42bcb8..99b3d750fd71 100644
--- a/extensions/telegram/src/rich-blocks-html.ts
+++ b/extensions/telegram/src/rich-blocks-html.ts
@@ -1,6 +1,6 @@
 // HTML-fragment parsing and inline-island conversion for the Telegram rich
 // blocks emitter. Agents author rich content as markdown plus a documented set
-// of HTML islands (see the core system prompt's "Telegram rich ON" contract);
+// of HTML islands (see agentPrompt.inboundFormattingHints "markdown_telegram_rich");
 // this module owns the tolerant parser and inline (RichText-level) mapping,
 // while rich-blocks-html-map.ts owns block-level island mapping.
 import { tokenizeHtmlTags } from "openclaw/plugin-sdk/text-chunking";
diff --git a/src/agents/cli-runner/helpers.system-prompt.test.ts b/src/agents/cli-runner/helpers.system-prompt.test.ts
index 70d7b7e930d2..e63871ac97bb 100644
--- a/src/agents/cli-runner/helpers.system-prompt.test.ts
+++ b/src/agents/cli-runner/helpers.system-prompt.test.ts
@@ -162,21 +162,18 @@ describe("buildCliAgentSystemPrompt", () => {
     expect(prompt).toContain("sessionId=session-123");
   });
 
-  it("includes Telegram rich text guidance for CLI final replies", () => {
+  it("includes Telegram channel context for CLI final replies without core rich guidance", () => {
     const prompt = buildCliAgentSystemPrompt({
       workspaceDir: "/tmp/openclaw",
       tools: [],
       modelDisplay: "anthropic/claude-opus-4-8",
       runtimeChannel: "telegram",
       runtimeChatType: "direct",
-      runtimeCapabilities: ["richText"],
     });
 
-    expect(prompt).toContain("Telegram rich ON");
-    expect(prompt).toContain("headings, tables");
-    expect(prompt).toContain("media https URLs only, block-level only");
-    expect(prompt).toContain("Not MarkdownV2/parse_mode");
     expect(prompt).toContain("channel=telegram");
+    expect(prompt).not.toContain("Telegram rich ON");
+    expect(prompt).not.toContain("Telegram rich OFF");
     expect(prompt).not.toContain("### message tool");
   });
 
diff --git a/src/agents/cli-runner/prepare.test.ts b/src/agents/cli-runner/prepare.test.ts
index a6d6bc9cb112..c40183512615 100644
--- a/src/agents/cli-runner/prepare.test.ts
+++ b/src/agents/cli-runner/prepare.test.ts
@@ -2372,7 +2372,7 @@ describe("shouldSkipLocalCliCredentialEpoch", () => {
     }
   });
 
-  it("passes Telegram rich text capabilities into CLI system prompts", async () => {
+  it("passes Telegram channel context into CLI system prompts without core rich guidance", async () => {
     const { dir, sessionFile } = createSessionFile();
     setActivePluginRegistry(
       createTestRegistry([
@@ -2382,7 +2382,7 @@ describe("shouldSkipLocalCliCredentialEpoch", () => {
           plugin: {
             ...createChannelTestPluginBase({ id: "telegram", label: "Telegram" }),
             agentPrompt: {
-              messageToolCapabilities: () => ["richText"],
+              messageToolCapabilities: () => ["inlineButtons"],
             },
           } satisfies ChannelPlugin,
         },
@@ -2398,14 +2398,14 @@ describe("shouldSkipLocalCliCredentialEpoch", () => {
         provider: "test-cli",
         model: "test-model",
         timeoutMs: 1_000,
-        runId: "run-test-telegram-rich-text",
+        runId: "run-test-telegram-channel",
         messageChannel: "telegram",
         config: createCliBackendConfig(),
       });
 
       expect(context.systemPrompt).toContain("channel=telegram");
-      expect(context.systemPrompt).toContain("Telegram rich ON");
-      expect(context.systemPrompt).toContain("Not MarkdownV2/parse_mode");
+      expect(context.systemPrompt).not.toContain("Telegram rich ON");
+      expect(context.systemPrompt).not.toContain("Telegram rich OFF");
     } finally {
       fs.rmSync(dir, { recursive: true, force: true });
     }
diff --git a/src/agents/system-prompt.test.ts b/src/agents/system-prompt.test.ts
index 2059f19d6446..a168459fb891 100644
--- a/src/agents/system-prompt.test.ts
+++ b/src/agents/system-prompt.test.ts
@@ -1085,7 +1085,7 @@ describe("buildAgentSystemPrompt", () => {
     expect(prompt).toContain("style primary|success|danger");
   });
 
-  it("describes Telegram rich text only for rich Telegram runtimes", () => {
+  it("does not embed Telegram rich-text authoring guidance in core messaging", () => {
     const telegramPrompt = buildAgentSystemPrompt({
       workspaceDir: "/tmp/openclaw",
       toolNames: ["message"],
@@ -1094,14 +1094,6 @@ describe("buildAgentSystemPrompt", () => {
         capabilities: ["richText"],
       },
     });
-    const discordPrompt = buildAgentSystemPrompt({
-      workspaceDir: "/tmp/openclaw",
-      toolNames: ["message"],
-      runtimeInfo: {
-        channel: "discord",
-        capabilities: ["richText"],
-      },
-    });
     const plainTelegramPrompt = buildAgentSystemPrompt({
       workspaceDir: "/tmp/openclaw",
       toolNames: ["message"],
@@ -1110,49 +1102,23 @@ describe("buildAgentSystemPrompt", () => {
       },
     });
 
-    expect(telegramPrompt).toContain("Telegram rich ON");
-    expect(telegramPrompt).toContain("Bot API 10.2 blocks");
-    expect(telegramPrompt).toContain("<details><summary>");
-    expect(telegramPrompt).toContain("caption/colspan/rowspan/align");
-    expect(telegramPrompt).toContain("block/pull quotes");
-    expect(telegramPrompt).toContain('<input type="checkbox" checked/>');
-    expect(telegramPrompt).toContain('anchors `<a name="x"></a>` + `<a href="#x">label</a>`');
-    expect(telegramPrompt).toContain(
-      "Math: `<tg-math>` inline, `<tg-math-block>` block; never `$...$`/`\\(...\\)`",
-    );
-    expect(telegramPrompt).toContain("collages/slideshows");
-    expect(telegramPrompt).toContain('<tg-map lat="" long="" zoom=""/>');
-    expect(telegramPrompt).toContain("Collapse=`<details>` (not expandable blockquote)");
-    expect(telegramPrompt).toContain("structured bullets=`<ul><li>` (not literal bullets)");
-    expect(telegramPrompt).toContain('block media e.g. `<img src="https://..."/>`');
-    expect(telegramPrompt).toContain("captions/credits when useful");
-    expect(telegramPrompt).toContain("media https URLs only, block-level only");
-    expect(telegramPrompt).toContain("Not MarkdownV2/parse_mode");
-    expect(telegramPrompt).toContain("OpenClaw maps markdown + these HTML islands to typed blocks");
-    expect(telegramPrompt).toContain("buttons plain text");
-    expect(telegramPrompt.indexOf("Telegram rich ON")).toBeGreaterThan(
-      telegramPrompt.indexOf(SYSTEM_PROMPT_CACHE_BOUNDARY),
-    );
-    expect(discordPrompt).not.toContain("Telegram rich ON");
+    expect(telegramPrompt).not.toContain("Telegram rich ON");
+    expect(telegramPrompt).not.toContain("Telegram rich OFF");
     expect(plainTelegramPrompt).not.toContain("Telegram rich ON");
-    expect(plainTelegramPrompt).toContain("Telegram rich OFF");
-    expect(plainTelegramPrompt).toContain("no rich tables");
-    expect(plainTelegramPrompt).toContain("enable rich messages for this account/channel");
+    expect(plainTelegramPrompt).not.toContain("Telegram rich OFF");
+    expect(telegramPrompt).toContain("final text normally routes to source");
   });
 
-  it("describes Telegram rich text for source replies without the message tool", () => {
+  it("describes source replies without the message tool", () => {
     const prompt = buildAgentSystemPrompt({
       workspaceDir: "/tmp/openclaw",
       runtimeInfo: {
         channel: "telegram",
-        capabilities: ["richText"],
       },
     });
 
     expect(prompt).toContain("final text normally routes to source");
     expect(prompt).toContain("If turn says final private");
-    expect(prompt).toContain("Telegram rich ON");
-    expect(prompt).toContain("headings, tables");
     expect(prompt).not.toContain("### message tool");
   });
 
diff --git a/src/agents/system-prompt.ts b/src/agents/system-prompt.ts
index 56d78e541c4a..9854b3e2d4b3 100644
--- a/src/agents/system-prompt.ts
+++ b/src/agents/system-prompt.ts
@@ -500,7 +500,6 @@ function buildMessagingSection(params: {
   isMinimal: boolean;
   availableTools: Set<string>;
   inlineButtonsEnabled: boolean;
-  richTextEnabled: boolean;
   runtimeChannel?: string;
   runtimeChatType?: ChatType;
   messageChannelOptions?: string;
@@ -516,8 +515,6 @@ function buildMessagingSection(params: {
   const showGenericInlineButtonHint = params.runtimeChannel !== "slack";
   const groupMessageToolOnly =
     messageToolOnly && (params.runtimeChatType === "group" || params.runtimeChatType === "channel");
-  const telegramRuntime = params.runtimeChannel === "telegram";
-  const telegramRichTextEnabled = telegramRuntime && params.richTextEnabled;
   const hasSessionsSpawn = params.availableTools.has("sessions_spawn");
   const hasSubagents = params.availableTools.has("subagents");
   const hasSessionsYield = params.availableTools.has("sessions_yield");
@@ -537,11 +534,6 @@ function buildMessagingSection(params: {
     messageToolOnly
       ? "- Current source visible reply MUST use `message(action=send)`; final text is private. Skip tool = user gets nothing. Brief tool-call progress is visible; no hidden instructions/private data/reasoning."
       : "- Current-session final text normally routes to source. If turn says final private, visible output uses `message(action=send)`.",
-    telegramRuntime
-      ? telegramRichTextEnabled
-        ? '- Telegram rich ON (Bot API 10.2 blocks; OpenClaw maps markdown + these HTML islands to typed blocks): headings, tables (markdown, or `<table>` HTML for caption/colspan/rowspan/align), block/pull quotes (`<aside>` + `<cite>`), `<details><summary>` (+`open`), dividers `<hr/>`, sup/sub/mark/spoilers, `<ul>`/`<ol>` + `<input type="checkbox" checked/>` tasks, code, anchors `<a name="x"></a>` + `<a href="#x">label</a>`, custom emoji `<tg-emoji emoji-id="...">`, maps `<tg-map lat="" long="" zoom=""/>`, collages/slideshows `<tg-collage>`/`<tg-slideshow>`, block media e.g. `<img src="https://..."/>` (+`<figure>`/`<figcaption>`). Math: `<tg-math>` inline, `<tg-math-block>` block; never `$...$`/`\\(...\\)`. Not MarkdownV2/parse_mode. Collapse=`<details>` (not expandable blockquote); structured bullets=`<ul><li>` (not literal bullets); media https URLs only, block-level only, captions/credits when useful; buttons plain text; normal files via attachments.'
-        : "- Telegram rich OFF. Standard Telegram HTML only; no rich tables/details/media/formulas. Ask owner to enable rich messages for this account/channel."
-      : "",
     "- Cross-session: `sessions_send(sessionKey, message)`.",
     subagentOrchestrationGuidance,
     completionEventGuidance,
@@ -1316,7 +1308,6 @@ export function buildAgentSystemPrompt(params: {
       isMinimal,
       availableTools,
       inlineButtonsEnabled,
-      richTextEnabled: runtimeCapabilitiesLower.has("richtext"),
       runtimeChannel,
       runtimeChatType,
       messageChannelOptions,
diff --git a/src/auto-reply/reply/get-reply-run.ts b/src/auto-reply/reply/get-reply-run.ts
index 6092acd33343..961621540d2c 100644
--- a/src/auto-reply/reply/get-reply-run.ts
+++ b/src/auto-reply/reply/get-reply-run.ts
@@ -656,7 +656,10 @@ export async function runPreparedReply(
   const groupSystemPrompt = normalizeOptionalString(promptSessionCtx.GroupSystemPrompt) ?? "";
   const inboundMetaPrompt = buildInboundMetaSystemPrompt(
     isNewSession ? sessionCtx : { ...sessionCtx, ThreadStarterBody: undefined },
-    { includeFormattingHints: !useFastReplyRuntime },
+    cfg,
+    // promptSessionCtx restores the persisted channel/account for system-event
+    // turns, so reply formatting hints resolve against the delivery channel.
+    { includeFormattingHints: !useFastReplyRuntime, formattingHintsCtx: promptSessionCtx },
   );
   const execOverridePromptHint = buildExecOverridePromptHint({
     execOverrides,
diff --git a/src/auto-reply/reply/inbound-meta.test.ts b/src/auto-reply/reply/inbound-meta.test.ts
index e5ae040f0b64..2133b78b0e45 100644
--- a/src/auto-reply/reply/inbound-meta.test.ts
+++ b/src/auto-reply/reply/inbound-meta.test.ts
@@ -1,6 +1,7 @@
 // Tests inbound metadata normalization before prompt injection.
 import { describe, expect, it, vi } from "vitest";
 import type { SessionEntry, SessionGoalStatus } from "../../config/sessions/types.js";
+import type { OpenClawConfig } from "../../config/types.openclaw.js";
 import { resetPluginRuntimeStateForTest, setActivePluginRegistry } from "../../plugins/runtime.js";
 import { createTestRegistry } from "../../test-utils/channel-plugins.js";
 import { withEnv } from "../../test-utils/env.js";
@@ -11,21 +12,33 @@ import {
   refreshActiveGoalContext,
 } from "./inbound-meta.js";
 
+const EMPTY_CFG = {} as OpenClawConfig;
+
+const { formattingHintCalls } = vi.hoisted(() => ({
+  formattingHintCalls: [] as Array<{ cfg: OpenClawConfig; accountId?: string | null }>,
+}));
+
 vi.mock("../../channels/plugins/registry-loaded.js", () => ({
   getLoadedChannelPluginById: (channelId: string) =>
     channelId === "slack"
       ? {
           agentPrompt: {
-            inboundFormattingHints: () => ({
-              text_markup: "slack_mrkdwn",
-              rules: [
-                "Use Slack mrkdwn, not standard Markdown.",
-                "Bold uses *single asterisks*.",
-                "Links use <url|label>.",
-                "Code blocks use triple backticks without a language identifier.",
-                "Do not use markdown headings or pipe tables.",
-              ],
-            }),
+            inboundFormattingHints: (params: {
+              cfg: OpenClawConfig;
+              accountId?: string | null;
+            }) => {
+              formattingHintCalls.push(params);
+              return {
+                text_markup: "slack_mrkdwn",
+                rules: [
+                  "Use Slack mrkdwn, not standard Markdown.",
+                  "Bold uses *single asterisks*.",
+                  "Links use <url|label>.",
+                  "Code blocks use triple backticks without a language identifier.",
+                  "Do not use markdown headings or pipe tables.",
+                ],
+              };
+            },
           },
         }
       : undefined,
@@ -112,17 +125,20 @@ function createGoalSessionEntry(
 
 describe("buildInboundMetaSystemPrompt", () => {
   it("includes stable routing fields and omits chat ids", () => {
-    const prompt = buildInboundMetaSystemPrompt({
-      MessageSid: "123",
-      MessageSidFull: "123",
-      ReplyToId: "99",
-      OriginatingTo: "telegram:5494292670",
-      AccountId: " work ",
-      OriginatingChannel: "telegram",
-      Provider: "telegram",
-      Surface: "telegram",
-      ChatType: "direct",
-    } as TemplateContext);
+    const prompt = buildInboundMetaSystemPrompt(
+      {
+        MessageSid: "123",
+        MessageSidFull: "123",
+        ReplyToId: "99",
+        OriginatingTo: "telegram:5494292670",
+        AccountId: " work ",
+        OriginatingChannel: "telegram",
+        Provider: "telegram",
+        Surface: "telegram",
+        ChatType: "direct",
+      } as TemplateContext,
+      EMPTY_CFG,
+    );
 
     const payload = parseInboundMetaPayload(prompt);
     expect(payload["schema"]).toBe("openclaw.inbound_meta.v2");
@@ -132,39 +148,48 @@ describe("buildInboundMetaSystemPrompt", () => {
   });
 
   it("keeps task-scoped chat ids out of the system prompt for cache stability", () => {
-    const first = buildInboundMetaSystemPrompt({
-      OriginatingTo: "paperclip:issue:c585d0cc",
-      OriginatingChannel: "paperclip",
-      Provider: "paperclip",
-      Surface: "paperclip",
-      ChatType: "direct",
-      AccountId: "default",
-    } as TemplateContext);
-    const second = buildInboundMetaSystemPrompt({
-      OriginatingTo: "paperclip:issue:ca527062",
-      OriginatingChannel: "paperclip",
-      Provider: "paperclip",
-      Surface: "paperclip",
-      ChatType: "direct",
-      AccountId: "default",
-    } as TemplateContext);
+    const first = buildInboundMetaSystemPrompt(
+      {
+        OriginatingTo: "paperclip:issue:c585d0cc",
+        OriginatingChannel: "paperclip",
+        Provider: "paperclip",
+        Surface: "paperclip",
+        ChatType: "direct",
+        AccountId: "default",
+      } as TemplateContext,
+      EMPTY_CFG,
+    );
+    const second = buildInboundMetaSystemPrompt(
+      {
+        OriginatingTo: "paperclip:issue:ca527062",
+        OriginatingChannel: "paperclip",
+        Provider: "paperclip",
+        Surface: "paperclip",
+        ChatType: "direct",
+        AccountId: "default",
+      } as TemplateContext,
+      EMPTY_CFG,
+    );
 
     expect(parseInboundMetaPayload(first)["chat_id"]).toBeUndefined();
     expect(first).toBe(second);
   });
 
   it("does not include per-turn message identifiers (cache stability)", () => {
-    const prompt = buildInboundMetaSystemPrompt({
-      MessageSid: "123",
-      MessageSidFull: "123",
-      ReplyToId: "99",
-      SenderId: "289522496",
-      OriginatingTo: "telegram:5494292670",
-      OriginatingChannel: "telegram",
-      Provider: "telegram",
-      Surface: "telegram",
-      ChatType: "direct",
-    } as TemplateContext);
+    const prompt = buildInboundMetaSystemPrompt(
+      {
+        MessageSid: "123",
+        MessageSidFull: "123",
+        ReplyToId: "99",
+        SenderId: "289522496",
+        OriginatingTo: "telegram:5494292670",
+        OriginatingChannel: "telegram",
+        Provider: "telegram",
+        Surface: "telegram",
+        ChatType: "direct",
+      } as TemplateContext,
+      EMPTY_CFG,
+    );
 
     const payload = parseInboundMetaPayload(prompt);
     expect(payload["message_id"]).toBeUndefined();
@@ -174,33 +199,39 @@ describe("buildInboundMetaSystemPrompt", () => {
   });
 
   it("does not include per-turn flags in system metadata", () => {
-    const prompt = buildInboundMetaSystemPrompt({
-      ReplyToBody: "quoted",
-      ForwardedFrom: "sender",
-      ThreadStarterBody: "starter",
-      InboundHistory: [{ sender: "a", body: "b", timestamp: 1 }],
-      WasMentioned: true,
-      OriginatingTo: "telegram:-1001249586642",
-      OriginatingChannel: "telegram",
-      Provider: "telegram",
-      Surface: "telegram",
-      ChatType: "group",
-    } as TemplateContext);
+    const prompt = buildInboundMetaSystemPrompt(
+      {
+        ReplyToBody: "quoted",
+        ForwardedFrom: "sender",
+        ThreadStarterBody: "starter",
+        InboundHistory: [{ sender: "a", body: "b", timestamp: 1 }],
+        WasMentioned: true,
+        OriginatingTo: "telegram:-1001249586642",
+        OriginatingChannel: "telegram",
+        Provider: "telegram",
+        Surface: "telegram",
+        ChatType: "group",
+      } as TemplateContext,
+      EMPTY_CFG,
+    );
 
     const payload = parseInboundMetaPayload(prompt);
     expect(payload["flags"]).toBeUndefined();
   });
 
   it("keeps explicit bot mentions out of the system metadata", () => {
-    const prompt = buildInboundMetaSystemPrompt({
-      OriginatingTo: "telegram:-1001249586642",
-      OriginatingChannel: "telegram",
-      Provider: "telegram",
-      Surface: "telegram",
-      ChatType: "group",
-      BotUsername: "SirPinchALotBot",
-      ExplicitlyMentionedBot: true,
-    } as TemplateContext);
+    const prompt = buildInboundMetaSystemPrompt(
+      {
+        OriginatingTo: "telegram:-1001249586642",
+        OriginatingChannel: "telegram",
+        Provider: "telegram",
+        Surface: "telegram",
+        ChatType: "group",
+        BotUsername: "SirPinchALotBot",
+        ExplicitlyMentionedBot: true,
+      } as TemplateContext,
+      EMPTY_CFG,
+    );
 
     const payload = parseInboundMetaPayload(prompt);
     expect(payload["flags"]).toBeUndefined();
@@ -209,21 +240,25 @@ describe("buildInboundMetaSystemPrompt", () => {
   });
 
   it("omits sender_id when blank", () => {
-    const prompt = buildInboundMetaSystemPrompt({
-      MessageSid: "458",
-      SenderId: "   ",
-      OriginatingTo: "telegram:-1001249586642",
-      OriginatingChannel: "telegram",
-      Provider: "telegram",
-      Surface: "telegram",
-      ChatType: "group",
-    } as TemplateContext);
+    const prompt = buildInboundMetaSystemPrompt(
+      {
+        MessageSid: "458",
+        SenderId: "   ",
+        OriginatingTo: "telegram:-1001249586642",
+        OriginatingChannel: "telegram",
+        Provider: "telegram",
+        Surface: "telegram",
+        ChatType: "group",
+      } as TemplateContext,
+      EMPTY_CFG,
+    );
 
     const payload = parseInboundMetaPayload(prompt);
     expect(payload["sender_id"]).toBeUndefined();
   });
 
-  it("includes Slack mrkdwn response format hints for Slack chats", () => {
+  it("includes Slack mrkdwn response format hints for Slack chats and threads cfg", () => {
+    formattingHintCalls.length = 0;
     resetPluginRuntimeStateForTest();
     setActivePluginRegistry(
       createTestRegistry([
@@ -258,13 +293,20 @@ describe("buildInboundMetaSystemPrompt", () => {
       ]),
     );
 
-    const prompt = buildInboundMetaSystemPrompt({
-      OriginatingTo: "channel:C123",
-      OriginatingChannel: "slack",
-      Provider: "slack",
-      Surface: "slack",
-      ChatType: "channel",
-    } as TemplateContext);
+    const cfg = {
+      channels: { slack: { botToken: "test-token-placeholder" } },
+    } as OpenClawConfig;
+    const prompt = buildInboundMetaSystemPrompt(
+      {
+        OriginatingTo: "channel:C123",
+        OriginatingChannel: "slack",
+        Provider: "slack",
+        Surface: "slack",
+        ChatType: "channel",
+        AccountId: " work ",
+      } as TemplateContext,
+      cfg,
+    );
 
     const payload = parseInboundMetaPayload(prompt);
     expect(payload["response_format"]).toEqual({
@@ -277,16 +319,48 @@ describe("buildInboundMetaSystemPrompt", () => {
         "Do not use markdown headings or pipe tables.",
       ],
     });
+    expect(formattingHintCalls).toEqual([{ cfg, accountId: "work" }]);
   });
 
-  it("omits response format hints for non-Slack chats", () => {
-    const prompt = buildInboundMetaSystemPrompt({
-      OriginatingTo: "telegram:123",
-      OriginatingChannel: "telegram",
-      Provider: "telegram",
-      Surface: "telegram",
-      ChatType: "direct",
-    } as TemplateContext);
+  it("resolves response format hints from formattingHintsCtx for system-event turns", () => {
+    const prompt = buildInboundMetaSystemPrompt(
+      {
+        OriginatingChannel: "heartbeat",
+        Provider: "heartbeat",
+        Surface: "heartbeat",
+        ChatType: "direct",
+      } as TemplateContext,
+      EMPTY_CFG,
+      {
+        formattingHintsCtx: {
+          OriginatingChannel: "slack",
+          Provider: "slack",
+          Surface: "slack",
+          ChatType: "channel",
+          AccountId: "work",
+        } as TemplateContext,
+      },
+    );
+
+    const payload = parseInboundMetaPayload(prompt);
+    const responseFormat = payload["response_format"] as { text_markup?: string } | undefined;
+    expect(responseFormat?.text_markup).toBe("slack_mrkdwn");
+    // Trusted metadata still identifies the system event; only authoring hints
+    // follow the delivery channel.
+    expect(payload["channel"]).toBe("heartbeat");
+  });
+
+  it("omits response format hints when the channel plugin has no formatting hook", () => {
+    const prompt = buildInboundMetaSystemPrompt(
+      {
+        OriginatingTo: "telegram:123",
+        OriginatingChannel: "telegram",
+        Provider: "telegram",
+        Surface: "telegram",
+        ChatType: "direct",
+      } as TemplateContext,
+      EMPTY_CFG,
+    );
 
     const payload = parseInboundMetaPayload(prompt);
     expect(payload["response_format"]).toBeUndefined();
diff --git a/src/auto-reply/reply/inbound-meta.ts b/src/auto-reply/reply/inbound-meta.ts
index 030fac08d6d4..7fa109c56acf 100644
--- a/src/auto-reply/reply/inbound-meta.ts
+++ b/src/auto-reply/reply/inbound-meta.ts
@@ -9,6 +9,7 @@ import type { ChannelPlugin } from "../../channels/plugins/types.plugin.js";
 import { normalizeAnyChannelId } from "../../channels/registry.js";
 import { resolveSessionGoalDisplayState } from "../../config/sessions/goals.js";
 import type { SessionEntry } from "../../config/sessions/types.js";
+import type { OpenClawConfig } from "../../config/types.openclaw.js";
 import { sliceUtf16Safe, truncateUtf16Safe } from "../../utils.js";
 import type { EnvelopeFormatOptions } from "../envelope.js";
 import { formatEnvelopeTimestamp } from "../envelope.js";
@@ -543,7 +544,10 @@ function resolveInboundSourceModality(ctx: TemplateContext): string | undefined
   return resolveMediaType(ctx.MediaType) ?? ctx.MediaTypes?.map(resolveMediaType).find(Boolean);
 }
 
-function resolveInboundFormattingHints(ctx: TemplateContext):
+function resolveInboundFormattingHints(
+  ctx: TemplateContext,
+  cfg: OpenClawConfig,
+):
   | {
       text_markup: string;
       rules: string[];
@@ -557,6 +561,7 @@ function resolveInboundFormattingHints(ctx: TemplateContext):
   const agentPrompt = (getLoadedChannelPluginById(normalizedChannel) as ChannelPlugin | undefined)
     ?.agentPrompt;
   return agentPrompt?.inboundFormattingHints?.({
+    cfg,
     accountId: normalizePromptMetadataString(ctx.AccountId) ?? undefined,
   });
 }
@@ -564,7 +569,8 @@ function resolveInboundFormattingHints(ctx: TemplateContext):
 /** Builds trusted system metadata for the inbound channel and formatting hints. */
 export function buildInboundMetaSystemPrompt(
   ctx: TemplateContext,
-  options?: { includeFormattingHints?: boolean },
+  cfg: OpenClawConfig,
+  options?: { includeFormattingHints?: boolean; formattingHintsCtx?: TemplateContext },
 ): string {
   const chatType = normalizeChatType(ctx.ChatType);
   const isDirect = !chatType || chatType === "direct";
@@ -587,8 +593,13 @@ export function buildInboundMetaSystemPrompt(
     provider: normalizePromptMetadataString(ctx.Provider),
     surface: normalizePromptMetadataString(ctx.Surface),
     chat_type: chatType ?? (isDirect ? "direct" : undefined),
+    // Authoring hints follow the reply delivery channel, not the inbound event:
+    // system-event turns (heartbeat/cron) carry the persisted channel/account in
+    // formattingHintsCtx while ctx still identifies the system provider.
     response_format:
-      options?.includeFormattingHints === false ? undefined : resolveInboundFormattingHints(ctx),
+      options?.includeFormattingHints === false
+        ? undefined
+        : resolveInboundFormattingHints(options?.formattingHintsCtx ?? ctx, cfg),
   };
 
   // Keep the instructions local to the payload so the meaning survives prompt overrides.
diff --git a/src/channels/plugins/types.core.ts b/src/channels/plugins/types.core.ts
index f3fadc826816..350e736daeeb 100644
--- a/src/channels/plugins/types.core.ts
+++ b/src/channels/plugins/types.core.ts
@@ -678,7 +678,7 @@ export type ChannelAgentPromptAdapter = {
     cfg: OpenClawConfig;
     accountId?: string | null;
   }) => string[] | undefined;
-  inboundFormattingHints?: (params: { accountId?: string | null }) =>
+  inboundFormattingHints?: (params: { cfg: OpenClawConfig; accountId?: string | null }) =>
     | {
         text_markup: string;
         rules: string[];
diff --git a/test/helpers/agents/happy-path-prompt-snapshots.ts b/test/helpers/agents/happy-path-prompt-snapshots.ts
index 83601330d5a7..59f511cd83cf 100644
--- a/test/helpers/agents/happy-path-prompt-snapshots.ts
+++ b/test/helpers/agents/happy-path-prompt-snapshots.ts
@@ -342,7 +342,7 @@ function createExtraSystemPrompt(params: {
   intro?: string;
 }): string {
   return [
-    buildInboundMetaSystemPrompt(params.ctx),
+    buildInboundMetaSystemPrompt(params.ctx, {}),
     params.chatContext,
     params.intro,
     params.ctx.GroupSystemPrompt,
diff --git a/test/helpers/agents/prompt-composition-scenarios.ts b/test/helpers/agents/prompt-composition-scenarios.ts
index 784219e5bf84..e4e966e896b9 100644
--- a/test/helpers/agents/prompt-composition-scenarios.ts
+++ b/test/helpers/agents/prompt-composition-scenarios.ts
@@ -147,7 +147,7 @@ function buildAutoReplySystemPrompt(params: {
   groupSystemPrompt?: string;
 }) {
   const extraSystemPromptParts = [
-    buildInboundMetaSystemPrompt(params.sessionCtx),
+    buildInboundMetaSystemPrompt(params.sessionCtx, {}),
     params.sessionCtx.ChatType === "direct" || params.sessionCtx.ChatType === "dm"
       ? buildDirectChatContext({
           sessionCtx: params.sessionCtx,
@@ -699,14 +699,17 @@ async function createMaintenanceScenario(workspaceDir: string): Promise<PromptSc
   ].join("\n");
   const postCompactionSystemPrompt = buildSystemPrompt({
     workspaceDir,
-    extraSystemPrompt: buildInboundMetaSystemPrompt({
-      Provider: "slack",
-      Surface: "slack",
-      OriginatingChannel: "slack",
-      OriginatingTo: "D123",
-      AccountId: "A1",
-      ChatType: "direct",
-    }),
+    extraSystemPrompt: buildInboundMetaSystemPrompt(
+      {
+        Provider: "slack",
+        Surface: "slack",
+        OriginatingChannel: "slack",
+        OriginatingTo: "D123",
+        AccountId: "A1",
+        ChatType: "direct",
+      },
+      {},
+    ),
   });
   return {
     scenario: "maintenance-prompts",