diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9ad5ddd5c..d260759df 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -51,6 +51,9 @@
 - Web UI: allow reconnect + password URL auth for the control UI and always scrub auth params from the URL. Thanks @oswalpalash for PR #414.
 - Web UI: add Connect button on Overview to apply connection changes. Thanks @wizaj for PR #385.
 - Web UI: keep Focus toggle on the top bar (swap with theme toggle) so it stays visible. Thanks @RobOK2050 for reporting. (#440)
+- Web UI: add Logs tab for gateway file logs with filtering, auto-follow, and export.
+- Web UI: cap tool output + large markdown rendering to avoid UI freezes on huge tool results.
+- Web UI: keep config form edits synced to raw JSON so form saves persist.
 - ClawdbotKit: fix SwiftPM resource bundling path for `tool-display.json`. Thanks @fcatuhe for PR #398.
 - Tools: add Telegram/WhatsApp reaction tools (with per-provider gating). Thanks @zats for PR #353.
 - Tools: flatten literal-union schemas for Claude on Vertex AI. Thanks @carlulsoe for PR #409.
diff --git a/ui/src/ui/app.ts b/ui/src/ui/app.ts
index cb6eac52b..7254738e4 100644
--- a/ui/src/ui/app.ts
+++ b/ui/src/ui/app.ts
@@ -17,6 +17,7 @@ import {
   type ResolvedTheme,
   type ThemeMode,
 } from "./theme";
+import { truncateText } from "./format";
 import {
   startThemeTransition,
   type ThemeTransitionContext,
@@ -88,6 +89,7 @@ type EventLogEntry = {
 };
 
 const TOOL_STREAM_LIMIT = 50;
+const TOOL_OUTPUT_CHAR_LIMIT = 120_000;
 const DEFAULT_LOG_LEVEL_FILTERS: Record<LogLevel, boolean> = {
   trace: true,
   debug: true,
@@ -138,17 +140,25 @@ function extractToolOutputText(value: unknown): string | null {
 
 function formatToolOutput(value: unknown): string | null {
   if (value === null || value === undefined) return null;
-  if (typeof value === "string") return value;
   if (typeof value === "number" || typeof value === "boolean") {
     return String(value);
   }
   const contentText = extractToolOutputText(value);
-  if (contentText) return contentText;
-  try {
-    return JSON.stringify(value, null, 2);
-  } catch {
-    return String(value);
+  let text: string;
+  if (typeof value === "string") {
+    text = value;
+  } else if (contentText) {
+    text = contentText;
+  } else {
+    try {
+      text = JSON.stringify(value, null, 2);
+    } catch {
+      text = String(value);
+    }
   }
+  const truncated = truncateText(text, TOOL_OUTPUT_CHAR_LIMIT);
+  if (!truncated.truncated) return truncated.text;
+  return `${truncated.text}\n\n… truncated (${truncated.total} chars, showing first ${truncated.text.length}).`;
 }
 
 declare global {
diff --git a/ui/src/ui/controllers/config.test.ts b/ui/src/ui/controllers/config.test.ts
index 0007d377b..e81c91f00 100644
--- a/ui/src/ui/controllers/config.test.ts
+++ b/ui/src/ui/controllers/config.test.ts
@@ -145,6 +145,25 @@ describe("applyConfigSnapshot", () => {
     expect(state.slackForm.botToken).toBe("");
     expect(state.slackForm.actions).toEqual(defaultSlackActions);
   });
+
+  it("does not clobber form edits while dirty", () => {
+    const state = createState();
+    state.configFormMode = "form";
+    state.configFormDirty = true;
+    state.configForm = { gateway: { mode: "local", port: 18789 } };
+    state.configRaw = "{\n}\n";
+
+    applyConfigSnapshot(state, {
+      config: { gateway: { mode: "remote", port: 9999 } },
+      valid: true,
+      issues: [],
+      raw: "{\n  \"gateway\": { \"mode\": \"remote\", \"port\": 9999 }\n}\n",
+    });
+
+    expect(state.configRaw).toBe(
+      "{\n  \"gateway\": {\n    \"mode\": \"local\",\n    \"port\": 18789\n  }\n}\n",
+    );
+  });
 });
 
 describe("updateConfigFormValue", () => {
@@ -165,6 +184,22 @@ describe("updateConfigFormValue", () => {
       gateway: { mode: "local", port: 18789 },
     });
   });
+
+  it("keeps raw in sync while editing the form", () => {
+    const state = createState();
+    state.configSnapshot = {
+      config: { gateway: { mode: "local" } },
+      valid: true,
+      issues: [],
+      raw: "{\n}\n",
+    };
+
+    updateConfigFormValue(state, ["gateway", "port"], 18789);
+
+    expect(state.configRaw).toBe(
+      "{\n  \"gateway\": {\n    \"mode\": \"local\",\n    \"port\": 18789\n  }\n}\n",
+    );
+  });
 });
 
 describe("applyConfig", () => {
diff --git a/ui/src/ui/controllers/config.ts b/ui/src/ui/controllers/config.ts
index 325bcadfc..249f70bf4 100644
--- a/ui/src/ui/controllers/config.ts
+++ b/ui/src/ui/controllers/config.ts
@@ -92,10 +92,18 @@ export function applyConfigSchema(
 
 export function applyConfigSnapshot(state: ConfigState, snapshot: ConfigSnapshot) {
   state.configSnapshot = snapshot;
-  if (typeof snapshot.raw === "string") {
-    state.configRaw = snapshot.raw;
-  } else if (snapshot.config && typeof snapshot.config === "object") {
-    state.configRaw = `${JSON.stringify(snapshot.config, null, 2).trimEnd()}\n`;
+  const rawFromSnapshot =
+    typeof snapshot.raw === "string"
+      ? snapshot.raw
+      : snapshot.config && typeof snapshot.config === "object"
+        ? serializeConfigForm(snapshot.config as Record<string, unknown>)
+        : state.configRaw;
+  if (!state.configFormDirty || state.configFormMode === "raw") {
+    state.configRaw = rawFromSnapshot;
+  } else if (state.configForm) {
+    state.configRaw = serializeConfigForm(state.configForm);
+  } else {
+    state.configRaw = rawFromSnapshot;
   }
   state.configValid = typeof snapshot.valid === "boolean" ? snapshot.valid : null;
   state.configIssues = Array.isArray(snapshot.issues) ? snapshot.issues : [];
@@ -388,7 +396,7 @@ export async function saveConfig(state: ConfigState) {
   try {
     const raw =
       state.configFormMode === "form" && state.configForm
-        ? `${JSON.stringify(state.configForm, null, 2).trimEnd()}\n`
+        ? serializeConfigForm(state.configForm)
         : state.configRaw;
     await state.client.request("config.set", { raw });
     state.configFormDirty = false;
@@ -407,7 +415,7 @@ export async function applyConfig(state: ConfigState) {
   try {
     const raw =
       state.configFormMode === "form" && state.configForm
-        ? `${JSON.stringify(state.configForm, null, 2).trimEnd()}\n`
+        ? serializeConfigForm(state.configForm)
         : state.configRaw;
     await state.client.request("config.apply", {
       raw,
@@ -448,6 +456,9 @@ export function updateConfigFormValue(
   setPathValue(base, path, value);
   state.configForm = base;
   state.configFormDirty = true;
+  if (state.configFormMode === "form") {
+    state.configRaw = serializeConfigForm(base);
+  }
 }
 
 export function removeConfigFormValue(
@@ -460,6 +471,9 @@ export function removeConfigFormValue(
   removePathValue(base, path);
   state.configForm = base;
   state.configFormDirty = true;
+  if (state.configFormMode === "form") {
+    state.configRaw = serializeConfigForm(base);
+  }
 }
 
 function cloneConfigObject<T>(value: T): T {
@@ -469,6 +483,10 @@ function cloneConfigObject<T>(value: T): T {
   return JSON.parse(JSON.stringify(value)) as T;
 }
 
+function serializeConfigForm(form: Record<string, unknown>): string {
+  return `${JSON.stringify(form, null, 2).trimEnd()}\n`;
+}
+
 function setPathValue(
   obj: Record<string, unknown> | unknown[],
   path: Array<string | number>,
diff --git a/ui/src/ui/format.ts b/ui/src/ui/format.ts
index e1f55e817..26ebf7a8a 100644
--- a/ui/src/ui/format.ts
+++ b/ui/src/ui/format.ts
@@ -40,6 +40,21 @@ export function clampText(value: string, max = 120): string {
   return `${value.slice(0, Math.max(0, max - 1))}…`;
 }
 
+export function truncateText(value: string, max: number): {
+  text: string;
+  truncated: boolean;
+  total: number;
+} {
+  if (value.length <= max) {
+    return { text: value, truncated: false, total: value.length };
+  }
+  return {
+    text: value.slice(0, Math.max(0, max)),
+    truncated: true,
+    total: value.length,
+  };
+}
+
 export function toNumber(value: string, fallback: number): number {
   const n = Number(value);
   return Number.isFinite(n) ? n : fallback;
@@ -51,4 +66,3 @@ export function parseList(input: string): string[] {
     .map((v) => v.trim())
     .filter((v) => v.length > 0);
 }
-
diff --git a/ui/src/ui/markdown.ts b/ui/src/ui/markdown.ts
index 6c638d22f..f83fd18a7 100644
--- a/ui/src/ui/markdown.ts
+++ b/ui/src/ui/markdown.ts
@@ -1,5 +1,6 @@
 import DOMPurify from "dompurify";
 import { marked } from "marked";
+import { truncateText } from "./format";
 
 marked.setOptions({
   gfm: true,
@@ -39,6 +40,8 @@ const allowedTags = [
 const allowedAttrs = ["class", "href", "rel", "target", "title"];
 
 let hooksInstalled = false;
+const MARKDOWN_CHAR_LIMIT = 140_000;
+const MARKDOWN_PARSE_LIMIT = 40_000;
 
 function installHooks() {
   if (hooksInstalled) return;
@@ -57,10 +60,30 @@ export function toSanitizedMarkdownHtml(markdown: string): string {
   const input = markdown.trim();
   if (!input) return "";
   installHooks();
-  const rendered = marked.parse(input) as string;
+  const truncated = truncateText(input, MARKDOWN_CHAR_LIMIT);
+  const suffix = truncated.truncated
+    ? `\n\n… truncated (${truncated.total} chars, showing first ${truncated.text.length}).`
+    : "";
+  if (truncated.text.length > MARKDOWN_PARSE_LIMIT) {
+    const escaped = escapeHtml(`${truncated.text}${suffix}`);
+    const html = `<pre class="code-block">${escaped}</pre>`;
+    return DOMPurify.sanitize(html, {
+      ALLOWED_TAGS: allowedTags,
+      ALLOWED_ATTR: allowedAttrs,
+    });
+  }
+  const rendered = marked.parse(`${truncated.text}${suffix}`) as string;
   return DOMPurify.sanitize(rendered, {
     ALLOWED_TAGS: allowedTags,
     ALLOWED_ATTR: allowedAttrs,
   });
 }
 
+function escapeHtml(value: string): string {
+  return value
+    .replace(/&/g, "&amp;")
+    .replace(/</g, "&lt;")
+    .replace(/>/g, "&gt;")
+    .replace(/"/g, "&quot;")
+    .replace(/'/g, "&#39;");
+}