diff --git a/CHANGELOG.md b/CHANGELOG.md
index 286311a16d3..aeec5340289 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -16,6 +16,7 @@ Docs: https://docs.openclaw.ai
 ### Fixes
 
 - Google Meet: interrupt Realtime provider output when local barge-in clears playback, so command-pair audio stops model speech instead of only restarting Chrome playback. Fixes #73850. (#73834) Thanks @shhtheonlyperson.
+- Gateway/config: cap oversized plugin-owned schemas in the full `config.schema` response so large installed plugin sets cannot balloon Gateway RSS or crash schema clients. Thanks @vincentkoc.
 - Gateway/sessions: use bounded tail reads for sessions-list transcript usage fallbacks, keeping large session stores responsive when rows request derived previews. Thanks @vincentkoc.
 - Gateway/chat: bound chat-history transcript reads to the requested display window so large session logs no longer OOM the Gateway when clients ask for a small history page. Thanks @vincentkoc.
 - Voice Call/Twilio: honor stored pre-connect TwiML before realtime webhook shortcuts and reject DTMF sequences outside conversation mode, so Meet PIN entry cannot be skipped or silently dropped. Thanks @donkeykong91 and @PfanP.
diff --git a/src/config/schema.test.ts b/src/config/schema.test.ts
index 77ee73c8696..bdfd9557ae5 100644
--- a/src/config/schema.test.ts
+++ b/src/config/schema.test.ts
@@ -179,6 +179,63 @@ describe("config schema", () => {
     expect(res.uiHints["channels.matrix.accessToken"]?.sensitive).toBe(true);
   });
 
+  it("omits a single oversized plugin schema from the full schema response", () => {
+    const res = buildConfigSchema({
+      cache: false,
+      plugins: [
+        {
+          id: "huge",
+          name: "Huge",
+          configSchema: {
+            type: "object",
+            properties: {
+              huge: {
+                type: "string",
+                description: `oversized-marker-${"x".repeat(300_000)}`,
+              },
+            },
+          },
+        },
+      ],
+    });
+
+    const serialized = JSON.stringify(res);
+    expect(serialized).not.toContain("oversized-marker");
+    const lookup = lookupConfigSchema(res, "plugins.entries.huge.config");
+    expect(lookup?.schema).toMatchObject({
+      type: "object",
+      additionalProperties: true,
+      description: expect.stringContaining("omitted"),
+    });
+  });
+
+  it("omits later plugin schemas after the aggregate extension schema budget is exhausted", () => {
+    const res = buildConfigSchema({
+      cache: false,
+      plugins: Array.from({ length: 40 }, (_, index) => ({
+        id: `plugin-${index}`,
+        configSchema: {
+          type: "object",
+          properties: {
+            value: {
+              type: "string",
+              description: `schema-${index}-${"x".repeat(60_000)}`,
+            },
+          },
+        },
+      })),
+    });
+
+    const first = lookupConfigSchema(res, "plugins.entries.plugin-0.config.value");
+    const last = lookupConfigSchema(res, "plugins.entries.plugin-39.config");
+    expect(first?.schema).toMatchObject({ type: "string" });
+    expect(last?.schema).toMatchObject({
+      type: "object",
+      additionalProperties: true,
+      description: expect.stringContaining("omitted"),
+    });
+  });
+
   it("looks up plugin config paths for slash-delimited plugin ids", () => {
     const res = buildConfigSchema({
       plugins: [
diff --git a/src/config/schema.ts b/src/config/schema.ts
index ead14626230..7d754409678 100644
--- a/src/config/schema.ts
+++ b/src/config/schema.ts
@@ -138,6 +138,71 @@ export type ChannelUiMetadata = {
   configUiHints?: Record<string, ConfigUiHint>;
 };
 
+const EXTENSION_SCHEMA_MAX_BYTES = 256 * 1024;
+const EXTENSION_SCHEMA_TOTAL_MAX_BYTES = 2 * 1024 * 1024;
+const EXTENSION_SCHEMA_MAX_ITEMS = 256;
+
+function schemaJsonBytes(schema: JsonSchemaNode): number {
+  try {
+    return Buffer.byteLength(JSON.stringify(schema), "utf-8");
+  } catch {
+    return Number.POSITIVE_INFINITY;
+  }
+}
+
+function buildOmittedExtensionConfigSchema(kind: "plugin" | "channel", id: string): JsonSchemaNode {
+  return {
+    type: "object",
+    additionalProperties: true,
+    description: `${kind} config schema for ${id} was omitted from the full config.schema response because installed extension schemas exceeded the Gateway response budget.`,
+  };
+}
+
+function limitExtensionSchemas(params: {
+  plugins: PluginUiMetadata[];
+  channels: ChannelUiMetadata[];
+}): { plugins: PluginUiMetadata[]; channels: ChannelUiMetadata[] } {
+  let totalBytes = 0;
+  let includedItems = 0;
+
+  const keepSchema = (schema: JsonSchemaNode): boolean => {
+    const bytes = schemaJsonBytes(schema);
+    if (
+      !Number.isFinite(bytes) ||
+      bytes > EXTENSION_SCHEMA_MAX_BYTES ||
+      totalBytes + bytes > EXTENSION_SCHEMA_TOTAL_MAX_BYTES ||
+      includedItems >= EXTENSION_SCHEMA_MAX_ITEMS
+    ) {
+      return false;
+    }
+    totalBytes += bytes;
+    includedItems += 1;
+    return true;
+  };
+
+  const plugins = params.plugins.map((plugin) => {
+    if (!plugin.configSchema || keepSchema(plugin.configSchema)) {
+      return plugin;
+    }
+    return {
+      ...plugin,
+      configSchema: buildOmittedExtensionConfigSchema("plugin", plugin.id),
+    };
+  });
+
+  const channels = params.channels.map((channel) => {
+    if (!channel.configSchema || keepSchema(channel.configSchema)) {
+      return channel;
+    }
+    return {
+      ...channel,
+      configSchema: buildOmittedExtensionConfigSchema("channel", channel.id),
+    };
+  });
+
+  return { plugins, channels };
+}
+
 function collectExtensionHintKeys(
   hints: ConfigUiHints,
   plugins: PluginUiMetadata[],
@@ -487,8 +552,10 @@ export function buildConfigSchema(params?: {
   cache?: boolean;
 }): ConfigSchemaResponse {
   const base = buildBaseConfigSchema();
-  const plugins = params?.plugins ?? [];
-  const channels = params?.channels ?? [];
+  const { plugins, channels } = limitExtensionSchemas({
+    plugins: params?.plugins ?? [],
+    channels: params?.channels ?? [],
+  });
   if (plugins.length === 0 && channels.length === 0) {
     return base;
   }