diff --git a/.changeset/middleware-validator-type-cycle.md b/.changeset/middleware-validator-type-cycle.md
new file mode 100644
index 00000000..9218aadc
--- /dev/null
+++ b/.changeset/middleware-validator-type-cycle.md
@@ -0,0 +1,5 @@
+---
+"@marko/run": patch
+---
+
+Fix route middleware and handler types collapsing to `any` when a middleware derives `next()` data from its context while a downstream handler declares validators.
diff --git a/agent-feedback/dx.md b/agent-feedback/dx.md
index 5b7304f2..852912d4 100644
--- a/agent-feedback/dx.md
+++ b/agent-feedback/dx.md
@@ -209,9 +209,3 @@ CodeRabbit's pre-merge checks (configured in the organization UI; the repo has n
 `cspell.json` › `words` | 2026-08-11 | impact:med | effort:low
 
 `pnpm run lint` fails on a clean `main` with a single cspell error: `agent-feedback/cleanup.md` uses "macrotask", which is not in `cspell.json`'s `words` list. The word arrived with 445114c (#256) and the check covers `**/*.{md,ts,marko}`, so every branch cut from main inherits a red lint until the word is added. Re-verify: `npx cspell "**/*.{md,ts,marko}" --no-progress` on main reports one issue.
-
-## A `params` validator on a route with two `$` segments loses its typing
-
-`packages/run/src/runtime/types.ts` › `RouteForFileDef` | 2026-08-17 | impact:low | effort:med
-
-In an app with `api/workspaces/$id/+middleware.ts` (a `Run.ALL` middleware calling `next({ workspace })`) and a leaf `api/workspaces/$id/review/$commentId/+handler.ts` exporting `Run.DELETE({ params({ id, commentId }) { … } }, (ctx) => …)`, `tsc` reports TS7031 (`id` / `commentId` implicitly any) on the validator's destructured argument and TS2554 ("Expected 1 arguments, but got 2") on the `Run.DELETE` call, so the two-argument form is unusable there. The identical shape on a one-segment route with no parent middleware (`api/procs/$pid/+handler.ts`, `Run.DELETE({ params({ pid }) … }, handler)`) type-checks. Something in the merge of the parent middleware's options with the leaf's `params` (`MergedRouteOptionsForFile` → `RouteForFileDef.params`) collapses when the path has two params, since the workaround is simply parsing `ctx.params.commentId` inside the handler. Repro: the two files above in a fixture under `packages/run/src/__tests__/fixtures/`, then `tsc` on it; a passing fixture with the validator form is the fix's test.
diff --git a/packages/run/src/__tests__/fixtures/params-validator-types/.marko-run/routes.d.ts b/packages/run/src/__tests__/fixtures/params-validator-types/.marko-run/routes.d.ts
new file mode 100644
index 00000000..b917c161
--- /dev/null
+++ b/packages/run/src/__tests__/fixtures/params-validator-types/.marko-run/routes.d.ts
@@ -0,0 +1,87 @@
+/*
+  WARNING: This file is automatically generated and any changes made to it will be overwritten without warning.
+  Do NOT manually edit this file or your changes will be lost.
+*/
+
+import { NotHandled, NotMatched, GetPaths, PostPaths, GetablePath, GetableHref, PostablePath, PostableHref, Platform } from "@marko/run/namespace";
+import type * as $ from "@marko/run";
+
+
+declare module "@marko/run" {
+	interface App extends $.DefineRoutes<{
+		"/api/procs/$pid": [H1];
+		"/api/workspaces/$id/review/$commentId": [M1, H2];
+	}> {}
+}
+
+type M1 = $.Middleware<"M1", typeof import("../src/routes/api/workspaces/$id/+middleware")>;
+declare module "../src/routes/api/workspaces/$id/+middleware" {
+  const Run: $.Namespace<M1>;
+  namespace Run {
+    type Context = $.ContextForFile<M1>;
+  }
+
+  /** @deprecated use `Run` namespace instead */
+  namespace MarkoRun {
+    export { NotHandled, NotMatched, GetPaths, PostPaths, GetablePath, GetableHref, PostablePath, PostableHref, Platform };
+    export type Route = $.Routes["/api/workspaces/$id/review/$commentId"];
+    export type Context = $.MultiRouteContext<Route>;
+    export type Handler = $.HandlerLike<Route>;
+    export type GET = $.HandlerLike<Route, "GET">;
+    export type HEAD = $.HandlerLike<Route, "HEAD">;
+    export type POST = $.HandlerLike<Route, "POST">;
+    export type PUT = $.HandlerLike<Route, "PUT">;
+    export type DELETE = $.HandlerLike<Route, "DELETE">;
+    export type PATCH = $.HandlerLike<Route, "PATCH">;
+    export type OPTIONS = $.HandlerLike<Route, "OPTIONS">;
+    export type QUERY = $.HandlerLike<Route, "QUERY">;
+  }
+}
+
+type H1 = $.Handler<"H1", typeof import("../src/routes/api/procs/$pid/+handler")>;
+declare module "../src/routes/api/procs/$pid/+handler" {
+  const Run: $.Namespace<H1>;
+  namespace Run {
+    type Context = $.ContextForFile<H1>;
+  }
+
+  /** @deprecated use `Run` namespace instead */
+  namespace MarkoRun {
+    export { NotHandled, NotMatched, GetPaths, PostPaths, GetablePath, GetableHref, PostablePath, PostableHref, Platform };
+    export type Route = $.Routes["/api/procs/$pid"];
+    export type Context = $.MultiRouteContext<Route>;
+    export type Handler = $.HandlerLike<Route>;
+    export type GET = $.HandlerLike<Route, "GET">;
+    export type HEAD = $.HandlerLike<Route, "HEAD">;
+    export type POST = $.HandlerLike<Route, "POST">;
+    export type PUT = $.HandlerLike<Route, "PUT">;
+    export type DELETE = $.HandlerLike<Route, "DELETE">;
+    export type PATCH = $.HandlerLike<Route, "PATCH">;
+    export type OPTIONS = $.HandlerLike<Route, "OPTIONS">;
+    export type QUERY = $.HandlerLike<Route, "QUERY">;
+  }
+}
+
+type H2 = $.Handler<"H2", typeof import("../src/routes/api/workspaces/$id/review/$commentId/+handler")>;
+declare module "../src/routes/api/workspaces/$id/review/$commentId/+handler" {
+  const Run: $.Namespace<H2>;
+  namespace Run {
+    type Context = $.ContextForFile<H2>;
+  }
+
+  /** @deprecated use `Run` namespace instead */
+  namespace MarkoRun {
+    export { NotHandled, NotMatched, GetPaths, PostPaths, GetablePath, GetableHref, PostablePath, PostableHref, Platform };
+    export type Route = $.Routes["/api/workspaces/$id/review/$commentId"];
+    export type Context = $.MultiRouteContext<Route>;
+    export type Handler = $.HandlerLike<Route>;
+    export type GET = $.HandlerLike<Route, "GET">;
+    export type HEAD = $.HandlerLike<Route, "HEAD">;
+    export type POST = $.HandlerLike<Route, "POST">;
+    export type PUT = $.HandlerLike<Route, "PUT">;
+    export type DELETE = $.HandlerLike<Route, "DELETE">;
+    export type PATCH = $.HandlerLike<Route, "PATCH">;
+    export type OPTIONS = $.HandlerLike<Route, "OPTIONS">;
+    export type QUERY = $.HandlerLike<Route, "QUERY">;
+  }
+}
diff --git a/packages/run/src/__tests__/fixtures/params-validator-types/__snapshots__/dev.expected.md b/packages/run/src/__tests__/fixtures/params-validator-types/__snapshots__/dev.expected.md
new file mode 100644
index 00000000..df97ae65
--- /dev/null
+++ b/packages/run/src/__tests__/fixtures/params-validator-types/__snapshots__/dev.expected.md
@@ -0,0 +1,5 @@
+# Loading
+
+# Step 0
+ctx=>deleteComment(ctx)
+
diff --git a/packages/run/src/__tests__/fixtures/params-validator-types/__snapshots__/preview.expected.md b/packages/run/src/__tests__/fixtures/params-validator-types/__snapshots__/preview.expected.md
new file mode 100644
index 00000000..df97ae65
--- /dev/null
+++ b/packages/run/src/__tests__/fixtures/params-validator-types/__snapshots__/preview.expected.md
@@ -0,0 +1,5 @@
+# Loading
+
+# Step 0
+ctx=>deleteComment(ctx)
+
diff --git a/packages/run/src/__tests__/fixtures/params-validator-types/src/routes/api/procs/$pid/+handler.ts b/packages/run/src/__tests__/fixtures/params-validator-types/src/routes/api/procs/$pid/+handler.ts
new file mode 100644
index 00000000..cd14bed2
--- /dev/null
+++ b/packages/run/src/__tests__/fixtures/params-validator-types/src/routes/api/procs/$pid/+handler.ts
@@ -0,0 +1,21 @@
+export const DELETE = Run.DELETE(
+  {
+    params({ pid }) {
+      return { pid };
+    },
+  },
+  (ctx) => {
+    return Response.json({ pid: ctx.params.pid });
+  },
+);
+
+// No middleware runs upstream, so this file's handlers get return checking.
+export const validReturns = [
+  Run.GET(() => new Response("ok")),
+  Run.GET(async () => Response.json({ ok: true })),
+  Run.GET((ctx, next) => next()),
+];
+// @ts-expect-error a handler cannot return a bare number
+export const badNumber = Run.GET(() => 42);
+// @ts-expect-error a handler cannot return a bare object in place of a Response
+export const badObject = Run.GET(() => ({ plain: "object" }));
diff --git a/packages/run/src/__tests__/fixtures/params-validator-types/src/routes/api/workspaces/$id/+middleware.ts b/packages/run/src/__tests__/fixtures/params-validator-types/src/routes/api/workspaces/$id/+middleware.ts
new file mode 100644
index 00000000..6dbe77bb
--- /dev/null
+++ b/packages/run/src/__tests__/fixtures/params-validator-types/src/routes/api/workspaces/$id/+middleware.ts
@@ -0,0 +1,16 @@
+export default Run.ALL(
+  {
+    search({ limit }) {
+      return { limit: limit ? Number(limit) : 0 };
+    },
+  },
+  (ctx, next) => {
+    if ("commentId" in ctx.params) {
+      const merged: number = ctx.params.commentId;
+      // @ts-expect-error the DELETE validator types commentId as number
+      const bad: boolean = ctx.params.commentId;
+      void merged, void bad;
+    }
+    return next({ workspace: `ws-${ctx.params.id}` });
+  },
+);
diff --git a/packages/run/src/__tests__/fixtures/params-validator-types/src/routes/api/workspaces/$id/review/$commentId/+handler.ts b/packages/run/src/__tests__/fixtures/params-validator-types/src/routes/api/workspaces/$id/review/$commentId/+handler.ts
new file mode 100644
index 00000000..7ee11261
--- /dev/null
+++ b/packages/run/src/__tests__/fixtures/params-validator-types/src/routes/api/workspaces/$id/review/$commentId/+handler.ts
@@ -0,0 +1,37 @@
+import type { Context, GetContext } from "@marko/run";
+
+export const DELETE = Run.DELETE(
+  {
+    params({ id, commentId }) {
+      return { id, commentId: Number(commentId) };
+    },
+  },
+  (ctx) => {
+    const asPlainContext: Context = ctx;
+    const asScopedContext: GetContext<"/api/workspaces/$id/review/$commentId"> =
+      ctx;
+    // @ts-expect-error the deprecated MarkoRun.Context types params as raw
+    // strings, so a context whose validator produced a number never fit it
+    const asLegacyContext: MarkoRun.Context = ctx;
+    void asPlainContext, void asScopedContext, void asLegacyContext;
+    const validated: number = ctx.params.commentId;
+    const upstream: string = ctx.data.workspace;
+    const fromMiddleware: number = ctx.search.limit;
+    // @ts-expect-error the validator types commentId as number
+    const badParam: boolean = ctx.params.commentId;
+    // @ts-expect-error the middleware data types workspace as string
+    const badData: boolean = ctx.data.workspace;
+    // @ts-expect-error the middleware search validator types limit as number
+    const badSearch: boolean = ctx.search.limit;
+    void validated, void upstream, void fromMiddleware, void badParam;
+    void badData, void badSearch;
+    return Response.json({
+      id: ctx.params.id,
+      commentId: ctx.params.commentId,
+    });
+  },
+);
+
+export const routeLevel: number = null as unknown as Run.Context["params"]["commentId"];
+// @ts-expect-error route-level params keep the validated number type
+export const routeLevelBad: boolean = null as unknown as Run.Context["params"]["commentId"];
diff --git a/packages/run/src/__tests__/fixtures/params-validator-types/test.config.ts b/packages/run/src/__tests__/fixtures/params-validator-types/test.config.ts
new file mode 100644
index 00000000..7951a292
--- /dev/null
+++ b/packages/run/src/__tests__/fixtures/params-validator-types/test.config.ts
@@ -0,0 +1,15 @@
+import assert from "assert";
+
+import type { Step, StepContext } from "../../main.test";
+
+export const path = "/api/procs/42";
+
+async function deleteComment({ page }: StepContext) {
+  const res = await page.fetch(
+    new URL("/api/workspaces/w1/review/7", page.url()).href,
+    { method: "DELETE" },
+  );
+  assert.deepEqual(await res.json(), { id: "w1", commentId: 7 });
+}
+
+export const steps: Step[] = [(ctx) => deleteComment(ctx)];
diff --git a/packages/run/src/__tests__/fixtures/params-validator-types/tsconfig.check.json b/packages/run/src/__tests__/fixtures/params-validator-types/tsconfig.check.json
new file mode 100644
index 00000000..be7e4d43
--- /dev/null
+++ b/packages/run/src/__tests__/fixtures/params-validator-types/tsconfig.check.json
@@ -0,0 +1,11 @@
+{
+  "extends": "./tsconfig.json",
+  "compilerOptions": {
+    "noEmit": true,
+    "baseUrl": ".",
+    "paths": {
+      "@marko/run": ["../../../runtime/index.ts"],
+      "@marko/run/namespace": ["../../../runtime/namespace.ts"]
+    }
+  }
+}
diff --git a/packages/run/src/__tests__/fixtures/params-validator-types/tsconfig.json b/packages/run/src/__tests__/fixtures/params-validator-types/tsconfig.json
new file mode 100644
index 00000000..03ff88a5
--- /dev/null
+++ b/packages/run/src/__tests__/fixtures/params-validator-types/tsconfig.json
@@ -0,0 +1,4 @@
+{
+  "extends": "../../tsconfig-base.json",
+  "include": ["src/**/*", ".marko-run/*"],
+}
\ No newline at end of file
diff --git a/packages/run/src/__tests__/typecheck.test.ts b/packages/run/src/__tests__/typecheck.test.ts
index 41d46982..61658a1f 100644
--- a/packages/run/src/__tests__/typecheck.test.ts
+++ b/packages/run/src/__tests__/typecheck.test.ts
@@ -57,3 +57,37 @@ describe("test sources type-check", () => {
     );
   });
 });
+
+describe("route type generation type-checks", () => {
+  // The fixture's middleware and handler each need the other's inferred
+  // module type — the shape that collapses both to `any` (TS7022). Its
+  // `@ts-expect-error` probes make silent widening fail this compile too.
+  it("keeps middleware and validator types across the module cycle", function () {
+    this.timeout(120000);
+    const result = spawnSync(
+      process.execPath,
+      [
+        require.resolve("typescript/lib/tsc.js"),
+        "-p",
+        path.join(
+          __dirname,
+          "fixtures",
+          "params-validator-types",
+          "tsconfig.check.json",
+        ),
+        "--pretty",
+        "false",
+      ],
+      { encoding: "utf-8", timeout: 90000 },
+    );
+
+    const localErrors = (result.stdout || "")
+      .split("\n")
+      // The compile pulls in the whole workspace graph, which carries known
+      // declaration-level noise; only errors in the fixture's sources are
+      // the reproduction.
+      .filter((line) => /params-validator-types[/\\]src[/\\]/.test(line));
+
+    assert.deepEqual(localErrors, []);
+  });
+});
diff --git a/packages/run/src/runtime/index.ts b/packages/run/src/runtime/index.ts
index 3cfe955b..55baf1b7 100644
--- a/packages/run/src/runtime/index.ts
+++ b/packages/run/src/runtime/index.ts
@@ -77,10 +77,15 @@ export type {
 export type {
   App,
   Context,
+  ContextBase,
   ContextForFile,
+  DefinedHandler,
+  DefinedHandlerTypes,
+  DefineHandler,
   DefineRoutes,
   Empty,
   Fetch,
+  FileContext,
   GetContext,
   Handler,
   HandlerTypes,
diff --git a/packages/run/src/runtime/types.ts b/packages/run/src/runtime/types.ts
index 9a77f580..d36a288f 100644
--- a/packages/run/src/runtime/types.ts
+++ b/packages/run/src/runtime/types.ts
@@ -472,6 +472,12 @@ type ComposedHandlerData<Handlers extends readonly unknown[]> = MergeTuple<{
   [K in keyof Handlers]: HandlerValueData<Handlers[K]>;
 }>;
 type Exact<T, Shape> = T & Record<Exclude<keyof T, keyof Shape>, never>;
+/**
+ * Bars a function from matching the all-optional options parameter — every
+ * function has `apply` — so a mistyped handler argument fails the overload
+ * instead of being accepted as an options object.
+ */
+type NotAFunction = { apply?: never };
 type DefineHandlerOptions<Verb extends HttpVerbOrAll, Ctx> = [Verb] extends [
   HttpVerbWithoutBody,
 ]
@@ -555,6 +561,27 @@ export interface RouteForFileDef<
     ? T
     : Record<string, unknown>;
 }
+/**
+ * A file's view of one route context. Deliberately not `Context<...>`: its
+ * constraint check forces every member — including `data`, and with it
+ * another file's possibly mid-resolution export. A standalone interface
+ * resolves each member only when read, after the exports it needs can
+ * resolve body-free.
+ */
+export interface FileContext<
+  F extends File,
+  Path extends keyof AppPaths,
+  Verb extends HttpVerb,
+  Options,
+> extends ContextBase {
+  readonly route: Path;
+  readonly method: Verb;
+  readonly meta: RouteForFileDef<F, Path, Verb, Options>["meta"];
+  readonly params: RouteForFileDef<F, Path, Verb, Options>["params"];
+  readonly search: RouteForFileDef<F, Path, Verb, Options>["search"];
+  readonly body: RouteForFileDef<F, Path, Verb, Options>["body"];
+  readonly data: RouteForFileDef<F, Path, Verb, Options>["data"];
+}
 type ContextForFileWithOptions<
   F extends File,
   Verb extends HttpVerbOrAll,
@@ -562,105 +589,141 @@ type ContextForFileWithOptions<
 > = Union<{
   [Path in PathsForFile<F>]: Union<{
     [V in VerbsForPath<Path, Verb>]: V extends HttpVerb
-      ? Context<RouteForFileDef<F, Path & keyof AppPaths, V, Options>>
+      ? FileContext<F, Path & keyof AppPaths, V, Options>
       : never;
   }>;
 }>;
-export type DefineHandler<F extends File, Verb extends HttpVerbOrAll> = {
-  <const Handlers extends readonly unknown[], Return extends unknown[]>(
-    handlers: HandlerArray<
-      ContextForFileWithOptions<F, Verb, Empty> & {},
+type FileHandlerOptions<
+  F extends File,
+  Verb extends HttpVerbOrAll,
+> = DefineHandlerOptions<Verb, ContextForFileWithOptions<F, Verb, Empty>>;
+type OptionsArg<Options, F extends File, Verb extends HttpVerbOrAll> = Exact<
+  Options,
+  FileHandlerOptions<F, Verb>
+> &
+  NotAFunction;
+type DefinedHandlerFunction<Ctx, Return> = (
+  ctx: Ctx,
+  next: NextFunction,
+) => Return;
+type DefinedHandlerArray<Ctx, Return> = readonly (
+  | {
+      [__run__.TYPES]: {
+        options: any;
+        data: any;
+      };
+    }
+  | DefinedHandlerFunction<Ctx, Return>
+)[];
+/**
+ * Spelled as an object literal: a deferred conditional stays lazy as a
+ * structural member but is forced as a direct type argument to a named
+ * generic like HandlerTypes, which would type the handler body while another
+ * file's export is still resolving.
+ */
+export type DefinedHandlerTypes<
+  F extends File,
+  Verb extends HttpVerbOrAll,
+  Options,
+  Handlers extends readonly unknown[],
+> = {
+  context: ContextForFileWithOptions<F, Verb, Options>;
+  verb: Verb;
+  options: Options;
+  data: ComposedHandlerData<Handlers> extends infer Data
+    ? [Data] extends [never]
+      ? Empty
+      : Data extends Record<string, unknown>
+        ? Data
+        : Empty
+    : never;
+  passthrough: [ComposedHandlerData<Handlers>] extends [never] ? false : true;
+};
+export type DefinedHandler<
+  F extends File,
+  Verb extends HttpVerbOrAll,
+  Options,
+  Handlers extends readonly unknown[],
+> = Typed<
+  NormalizedHandlerFunction<Verb, Options>,
+  DefinedHandlerTypes<F, Verb, Options, Handlers>
+>;
+/**
+ * True when middleware shares any of the file's routes, so resolving its
+ * export while another is mid-flight is possible. Namespace resolves this —
+ * not a `Return` default — because the deferred form needs the literal `any`
+ * type for the checker to skip return comparison.
+ */
+type FileHasUpstream<F extends File> =
+  true extends Union<{
+    [P in PathsForFile<F>]: AppPaths[P]["files"]["middleware"] extends []
+      ? false
+      : true;
+  }>
+    ? true
+    : false;
+/**
+ * Captures whole function types rather than their returns: a function type's
+ * return resolves lazily and an `any` return target never asks for it, so
+ * other files can read this export's merged options without its body ever
+ * being typed. Body-derived data reaches the export as conditionals typed
+ * only when something reads them.
+ *
+ * `Return` is the callbacks' return target: `any` keeps the export
+ * resolvable body-free, required wherever another route file's inference can
+ * entangle this one; `HandlerReturn` checks the return position, safe only
+ * when nothing else can be mid-resolution.
+ */
+export type DefineHandler<
+  F extends File,
+  Verb extends HttpVerbOrAll,
+  Return = any,
+> = {
+  <const Handlers extends readonly unknown[]>(
+    handlers: DefinedHandlerArray<
+      ContextForFileWithOptions<F, Verb, Empty>,
       Return
     > &
       Handlers,
-  ): Typed<
-    NormalizedHandlerFunction<Verb, ComposedHandlerOptions<Handlers>>,
-    HandlerTypes<
-      ContextForFileWithOptions<F, Verb, Empty> & {},
-      Verb,
-      ComposedHandlerOptions<Handlers>,
-      ComposedHandlerData<Handlers>
-    >
-  >;
+  ): DefinedHandler<F, Verb, ComposedHandlerOptions<Handlers>, Handlers>;
   <
-    const Options extends DefineHandlerOptions<
-      Verb,
-      ContextForFileWithOptions<F, Verb, Empty> & {}
-    >,
+    const Options extends FileHandlerOptions<F, Verb>,
     const Handlers extends readonly unknown[],
-    Return extends unknown[],
   >(
-    options: Exact<
-      Options,
-      DefineHandlerOptions<Verb, ContextForFileWithOptions<F, Verb, Empty> & {}>
-    >,
-    handlers: HandlerArray<
-      ContextForFileWithOptions<F, Verb, Options> & {},
+    options: OptionsArg<Options, F, Verb>,
+    handlers: DefinedHandlerArray<
+      ContextForFileWithOptions<F, Verb, Options>,
       Return
     > &
       Handlers,
-  ): Typed<
-    NormalizedHandlerFunction<
-      Verb,
-      MergeHandlerOptions<ComposedHandlerOptions<Handlers>, Options>
-    >,
-    HandlerTypes<
-      ContextForFileWithOptions<F, Verb, Options> & {},
-      Verb,
-      MergeHandlerOptions<ComposedHandlerOptions<Handlers>, Options>,
-      ComposedHandlerData<Handlers>
-    >
-  >;
-  <Return>(
-    handler: HandlerFunction<
-      ContextForFileWithOptions<F, Verb, Empty> & {},
-      Return
-    >,
-  ): NormalizedHandler<
-    ContextForFileWithOptions<F, Verb, Empty> & {},
+  ): DefinedHandler<
+    F,
     Verb,
-    Return,
-    {}
+    MergeHandlerOptions<ComposedHandlerOptions<Handlers>, Options>,
+    Handlers
   >;
   <
-    const Options extends DefineHandlerOptions<
-      Verb,
-      ContextForFileWithOptions<F, Verb, Empty> & {}
+    H extends DefinedHandlerFunction<
+      ContextForFileWithOptions<F, Verb, Empty>,
+      Return
     >,
   >(
-    options: Exact<
-      Options,
-      DefineHandlerOptions<Verb, ContextForFileWithOptions<F, Verb, Empty> & {}>
-    >,
-  ): NormalizedHandler<
-    ContextForFileWithOptions<F, Verb, Options> & {},
-    Verb,
-    {},
-    Options
-  >;
+    handler: H,
+  ): DefinedHandler<F, Verb, {}, [H]>;
+  <const Options extends FileHandlerOptions<F, Verb>>(
+    options: OptionsArg<Options, F, Verb>,
+  ): DefinedHandler<F, Verb, Options, []>;
   <
-    const Options extends DefineHandlerOptions<
-      Verb,
-      ContextForFileWithOptions<F, Verb, Empty> & {}
-    >,
-    Return,
-  >(
-    options: Exact<
-      Options,
-      DefineHandlerOptions<Verb, ContextForFileWithOptions<F, Verb, Empty> & {}>
-    >,
-    handler: HandlerFunction<
-      NoInfer<ContextForFileWithOptions<F, Verb, Options>> & {},
+    const Options extends FileHandlerOptions<F, Verb>,
+    H extends DefinedHandlerFunction<
+      NoInfer<ContextForFileWithOptions<F, Verb, Options>>,
       Return
     >,
-  ): NormalizedHandler<
-    ContextForFileWithOptions<F, Verb, Options> & {},
-    Verb,
-    Return,
-    Options
-  >;
+  >(
+    options: OptionsArg<Options, F, Verb>,
+    handler: H,
+  ): DefinedHandler<F, Verb, Options, [H]>;
 };
-
 export type GlobalDefineHandler<Verb extends HttpVerbOrAll> = {
   <const Handlers extends readonly unknown[], Return extends unknown[]>(
     handlers: HandlerArray<Context, Return> & Handlers,
@@ -943,7 +1006,9 @@ export type Namespace<F extends File> = Typed<
       }
     : F["type"] extends "handler"
       ? {
-          [Verb in HttpVerb]: DefineHandler<F, Verb>;
+          [Verb in HttpVerb]: FileHasUpstream<F> extends true
+            ? DefineHandler<F, Verb>
+            : DefineHandler<F, Verb, HandlerReturn>;
         }
       : Empty) &
     NamespaceVerb,
@@ -973,14 +1038,8 @@ export type DefineRoutes<Paths = void> = {
       >;
 };
 export interface Platform {}
-export interface Context<T extends Route = Route> {
-  readonly route: T["path"];
-  readonly method: T["method"];
-  readonly meta: T["meta"];
-  readonly params: T["params"];
-  readonly search: T["search"];
-  readonly body: T["body"];
-  readonly data: T["data"];
+/** The route-independent half of a context, shared with FileContext. */
+export interface ContextBase {
   readonly url: URL;
   readonly request: Request;
   readonly platform: Platform;
@@ -998,6 +1057,15 @@ export interface Context<T extends Route = Route> {
   redirect(to: string | URL, status?: number): Response;
   back(fallback?: string | URL, status?: number): Response;
 }
+export interface Context<T extends Route = Route> extends ContextBase {
+  readonly route: T["path"];
+  readonly method: T["method"];
+  readonly meta: T["meta"];
+  readonly params: T["params"];
+  readonly search: T["search"];
+  readonly body: T["body"];
+  readonly data: T["data"];
+}
 export type GetContext<
   Scope extends keyof AppPaths | `*` | `/${string}*` | object = "*",
   Verb extends