diff --git a/src/benchmarks/search/core/solver.test.ts b/src/benchmarks/search/core/solver.test.ts
index df9fc6c..49cbb0e 100644
--- a/src/benchmarks/search/core/solver.test.ts
+++ b/src/benchmarks/search/core/solver.test.ts
@@ -318,9 +318,11 @@ describe("searchSolver", () => {
   });
   it("appends the switchyard-router plugin after the serialized web plugin", async () => {
     let sentOptions: ResponsesSendOptions | undefined;
+    let sent: ResponsesRequest | undefined;
     const solver = searchSolver(
       {
-        send: (_body, options) => {
+        send: (body, options) => {
+          sent = body;
           sentOptions = options;
           return effectSucceed(fixtureResult({ text: "x" }));
         },
@@ -332,7 +334,7 @@ describe("searchSolver", () => {
         switchyardAlgorithm: "stage",
       }
     );
-    await runSolver(
+    const state = await runSolver(
       solver(initialTaskState({ id: "s", input: "q", target: { text: "t" } }))
     );
     expect(sentOptions?.extraBody).toEqual({
@@ -341,6 +343,7 @@ describe("searchSolver", () => {
         { id: "switchyard-router", algorithm: "stage" },
       ],
     });
+    expect(state.requestBody).toEqual({ ...sent, ...sentOptions?.extraBody });
   });
   it("sends only the switchyard-router plugin with server tools, ignoring the variant suffix", async () => {
     let sentOptions: ResponsesSendOptions | undefined;
diff --git a/src/benchmarks/search/core/solver.ts b/src/benchmarks/search/core/solver.ts
index c863321..df157a3 100644
--- a/src/benchmarks/search/core/solver.ts
+++ b/src/benchmarks/search/core/solver.ts
@@ -169,6 +169,7 @@ export function searchSolver(
       return completedState({
         state,
         request: body,
+        extraBody,
         result,
         attemptResults,
         text: result.text.trim(),
@@ -262,12 +263,14 @@ function makeStreamEventReporter(
 function completedState({
   state,
   request,
+  extraBody,
   result,
   attemptResults,
   text,
 }: {
   readonly state: TaskState;
   readonly request: ResponsesRequest;
+  readonly extraBody: Readonly<Record<string, unknown>> | undefined;
   readonly result: ResponsesResult;
   readonly attemptResults: readonly ResponsesResult[];
   readonly text: string;
@@ -304,7 +307,7 @@ function completedState({
         : []),
     ],
     responseItems: responseItemsForCall(request, result),
-    requestBody: { ...request },
+    requestBody: { ...request, ...extraBody },
     output: definedValues({
       completion: text,
       message: { role: MessageRole.Assistant, content: text },