diff --git a/server/src/app.ts b/server/src/app.ts
index fb3c333a0..9598f67da 100644
--- a/server/src/app.ts
+++ b/server/src/app.ts
@@ -1005,10 +1005,11 @@ export function createApp(
         return context.json({ error: "This endpoint is the worker's." }, 401);
       }
       const body = await context.req.json().catch(() => null);
-      if (
-        typeof (body as { routineRunId?: unknown } | null)?.routineRunId !==
-        "string"
-      ) {
+      const routineRunId = (body as { routineRunId?: unknown } | null)
+        ?.routineRunId;
+      // An empty id is a string and used to answer 202 Accepted while the worker swallows the
+      // failure. Only a non-empty id is accepted for dispatch.
+      if (typeof routineRunId !== "string" || !routineRunId.trim()) {
         return context.json({ error: "A routineRunId is required." }, 400);
       }
       /*
@@ -1018,9 +1019,7 @@ export function createApp(
        * the fatigue rule owns it. `run()` never throws by contract; this swallow only guards against
        * that contract being wrong without turning a bug there into an unhandled rejection here.
        */
-      void routineRunner
-        .run((body as { routineRunId: string }).routineRunId)
-        .catch(() => {});
+      void routineRunner.run(routineRunId).catch(() => {});
       return context.json({ accepted: true }, 202);
     });
   }
diff --git a/server/src/computer/routes.ts b/server/src/computer/routes.ts
index a7ad2a4c8..bad163f9f 100644
--- a/server/src/computer/routes.ts
+++ b/server/src/computer/routes.ts
@@ -549,10 +549,17 @@ export function createComputerRoutes(
    */
   routes.get("/:botId/page-frame/:toolCallId", async (context) => {
     if (!pageFrames) return context.json({ frame: null });
-    const stored = await pageFrames.load(
-      context.req.param("botId"),
-      context.req.param("toolCallId"),
-    );
+    // Unvalidated params reach the frame table as-is. Blank or overlong ids can never name a
+    // stored frame, so they are refused here instead of becoming junk reads.
+    const botId = context.req.param("botId");
+    const toolCallId = context.req.param("toolCallId");
+    if (!botId.trim() || !toolCallId.trim()) {
+      return context.json({ error: "A Bot and a turn are required." }, 400);
+    }
+    if (botId.length > 200 || toolCallId.length > 200) {
+      return context.json({ error: "A Bot and a turn are required." }, 400);
+    }
+    const stored = await pageFrames.load(botId, toolCallId);
     return context.json({ frame: stored });
   });
 
diff --git a/server/src/routing/routes.ts b/server/src/routing/routes.ts
index 9f1462890..1948f61d9 100644
--- a/server/src/routing/routes.ts
+++ b/server/src/routing/routes.ts
@@ -111,6 +111,14 @@ export function createRoutingRoutes(
     } | null;
     const text = typeof body?.text === "string" ? body.text.trim() : "";
     if (!text) return context.json({ error: "A message is required." }, 400);
+    // Unbounded text becomes the model prompt. Cap it so a multi-megabyte body cannot be used
+    // to force a timeout or OOM in the router.
+    if (text.length > 10000) {
+      return context.json(
+        { error: "A message of at most 10000 characters is required." },
+        400,
+      );
+    }
     const named =
       typeof body?.agentId === "string" && body.agentId.trim()
         ? body.agentId.trim()
diff --git a/server/tests/routing-limits-validation.test.ts b/server/tests/routing-limits-validation.test.ts
new file mode 100644
index 000000000..0fd8e6bc4
--- /dev/null
+++ b/server/tests/routing-limits-validation.test.ts
@@ -0,0 +1,182 @@
+import { describe, expect, test } from "bun:test";
+import type { MiddlewareHandler } from "hono";
+import { Hono } from "hono";
+import type { AppVariables } from "../src/auth/guards";
+import { createApp } from "../src/app";
+import { loadConfig } from "../src/config";
+import { createRoutingRoutes } from "../src/routing/routes";
+import { createComputerRoutes } from "../src/computer/routes";
+import type { RoutineRunner } from "../src/routines/runner";
+import { testEnvironment } from "./support/environment";
+
+const requireUser: MiddlewareHandler<{ Variables: AppVariables }> = async (
+  context,
+  next,
+) => {
+  context.set("actor", {
+    id: "user-1",
+    email: "user@openbot.test",
+    role: "admin",
+  });
+  await next();
+};
+
+/**
+ * Unbounded `text` becomes the model prompt in the router. A multi-megabyte body would force a
+ * timeout or OOM; over 10000 characters is now a 400 before the roster is read or the model is
+ * asked.
+ */
+describe("POST /api/route text cap", () => {
+  function app(calls: unknown[]) {
+    const store = { list: async () => [] };
+    const router = {
+      route: async (...a: unknown[]) => {
+        calls.push(a);
+        return { chosen: "bot-1" };
+      },
+    };
+    const app = new Hono<{ Variables: AppVariables }>();
+    app.route(
+      "/",
+      createRoutingRoutes(store as never, router as never, requireUser),
+    );
+    return app;
+  }
+
+  test("refuses oversized text with 400 and never routes", async () => {
+    const calls: unknown[] = [];
+    const response = await app(calls).request("http://openbot.test/", {
+      method: "POST",
+      headers: { "content-type": "application/json" },
+      body: JSON.stringify({ text: "x".repeat(10001) }),
+    });
+    expect(response.status).toBe(400);
+    expect(await response.json()).toEqual({
+      error: "A message of at most 10000 characters is required.",
+    });
+    expect(calls).toEqual([]);
+  });
+
+  test("accepts a message at the cap boundary", async () => {
+    const calls: unknown[] = [];
+    // Empty roster -> 409 "No coworker is available.", which still proves the text passed the
+    // cap and reached the router path.
+    const response = await app(calls).request("http://openbot.test/", {
+      method: "POST",
+      headers: { "content-type": "application/json" },
+      body: JSON.stringify({ text: "x".repeat(10000) }),
+    });
+    expect(response.status).toBe(409);
+  });
+});
+
+const SECRET = "worker-shared-secret";
+
+function internalApp(runner: RoutineRunner | undefined) {
+  const args: Parameters<typeof createApp> = [
+    loadConfig({ ...testEnvironment(), WORKER_SHARED_SECRET: SECRET }),
+    undefined,
+    undefined,
+    undefined,
+    undefined,
+    undefined,
+    undefined,
+    undefined,
+    undefined,
+    undefined,
+    undefined,
+    undefined,
+    undefined,
+    undefined,
+    undefined,
+    undefined,
+    undefined,
+    undefined,
+    undefined,
+    undefined,
+    undefined,
+    runner,
+  ];
+  return createApp(...args);
+}
+
+/**
+ * `""` is a string and used to answer 202 Accepted while the worker swallowed the failure.
+ * Only a non-empty run id is accepted for dispatch now.
+ */
+describe("POST /internal/routines/run id", () => {
+  test.each([
+    ["empty", ""],
+    ["whitespace", "   "],
+  ])(
+    "refuses a %s routineRunId with 400 and never runs",
+    async (_n, routineRunId) => {
+      const calls: string[] = [];
+      const app = internalApp({
+        run: (id: string) => {
+          calls.push(id);
+          return Promise.resolve();
+        },
+      });
+      const response = await app.request(
+        "http://openbot.local/internal/routines/run",
+        {
+          method: "POST",
+          headers: {
+            "content-type": "application/json",
+            authorization: `Bearer ${SECRET}`,
+          },
+          body: JSON.stringify({ routineRunId }),
+        },
+      );
+      expect(response.status).toBe(400);
+      expect(calls).toEqual([]);
+    },
+  );
+});
+
+/**
+ * Blank or overlong frame params can never name a stored frame. Refused here instead of
+ * becoming junk reads against the frame table.
+ */
+describe("GET /api/computers/:botId/page-frame/:toolCallId", () => {
+  function app(calls: unknown[]) {
+    const pageFrames = {
+      load: async (...a: unknown[]) => {
+        calls.push(a);
+        return null;
+      },
+    };
+    const app = new Hono<{ Variables: AppVariables }>();
+    app.route(
+      "/",
+      createComputerRoutes(
+        {} as never,
+        {} as never,
+        requireUser,
+        async () => true,
+        pageFrames as never,
+      ),
+    );
+    return app;
+  }
+
+  test("returns null frame on the happy path", async () => {
+    const calls: unknown[] = [];
+    const response = await app(calls).request(
+      "http://openbot.test/bot-1/page-frame/turn-1",
+    );
+    expect(response.status).toBe(200);
+    expect(await response.json()).toEqual({ frame: null });
+    expect(calls).toEqual([["bot-1", "turn-1"]]);
+  });
+
+  test("refuses an overlong toolCallId with 400 and never reads", async () => {
+    const calls: unknown[] = [];
+    const response = await app(calls).request(
+      `http://openbot.test/bot-1/page-frame/${"t".repeat(201)}`,
+    );
+    expect(response.status).toBe(400);
+    expect(calls).toEqual([]);
+  });
+});