diff --git a/apps/fabro-web/app/components/interview-dock.test.tsx b/apps/fabro-web/app/components/interview-dock.test.tsx
index 9ac272ee8..34a58269f 100644
--- a/apps/fabro-web/app/components/interview-dock.test.tsx
+++ b/apps/fabro-web/app/components/interview-dock.test.tsx
@@ -7,6 +7,7 @@ import {
 } from "@qltysh/fabro-api-client";
 
 import { InterviewDock, displayLabel } from "./interview-dock";
+import { generatedAxios } from "../lib/api-client";
 
 function render(node: React.ReactNode): TestRenderer.ReactTestRenderer {
   let tree: TestRenderer.ReactTestRenderer | undefined;
@@ -81,6 +82,41 @@ describe("InterviewDock", () => {
     expect(buttons.No).toBeDefined();
   });
 
+  test("yes/no question submits typed yes and no answers", async () => {
+    const submitted: unknown[] = [];
+    const originalAdapter = generatedAxios.defaults.adapter;
+    generatedAxios.defaults.adapter = async (config) => {
+      submitted.push(JSON.parse(String(config.data)));
+      return {
+        data: undefined,
+        status: 204,
+        statusText: "No Content",
+        headers: {},
+        config,
+      };
+    };
+
+    try {
+      const tree = render(
+        <InterviewDock runId="run-1" questions={[makeQuestion()]} />,
+      );
+      const buttons = buttonsByText(tree);
+
+      await act(async () => {
+        buttons.Yes.props.onClick();
+        await Promise.resolve();
+      });
+      await act(async () => {
+        buttons.No.props.onClick();
+        await Promise.resolve();
+      });
+
+      expect(submitted).toEqual([{ kind: "yes" }, { kind: "no" }]);
+    } finally {
+      generatedAxios.defaults.adapter = originalAdapter;
+    }
+  });
+
   test("multiple choice question renders option buttons with stripped accelerator prefixes", () => {
     const question = makeQuestion({
       question_type: QuestionType.MULTIPLE_CHOICE,
diff --git a/apps/fabro-web/app/components/interview-dock.tsx b/apps/fabro-web/app/components/interview-dock.tsx
index c45c67492..35eb2fcf5 100644
--- a/apps/fabro-web/app/components/interview-dock.tsx
+++ b/apps/fabro-web/app/components/interview-dock.tsx
@@ -22,6 +22,7 @@ import {
   useSubmitInterviewAnswer,
   type SubmitInterviewAnswerArg,
 } from "../lib/mutations";
+import { ApiError } from "../lib/api-client";
 import { ErrorMessage } from "./ui";
 
 const PRIMARY_BUTTON =
@@ -33,6 +34,8 @@ const CHOICE_BUTTON =
 const CHOICE_BUTTON_SELECTED =
   "inline-flex items-center justify-center gap-1.5 rounded-lg bg-teal-500/15 px-3.5 py-2 text-sm font-medium text-fg outline-1 -outline-offset-1 outline-teal-500/60 transition-colors hover:bg-teal-500/20 focus-visible:outline-2 focus-visible:-outline-offset-1 focus-visible:outline-teal-500";
 
+type SubmitInterviewAnswer = SubmitInterviewAnswerArg["answer"];
+
 export interface InterviewDockProps {
   runId: string;
   questions: ApiQuestion[];
@@ -52,15 +55,13 @@ export function InterviewDock({ runId, questions }: InterviewDockProps) {
   }, [question?.id, submitMutation.reset]);
 
   const submit = useCallback(
-    async (arg: Omit<SubmitInterviewAnswerArg, "questionId">) => {
+    async (answer: SubmitInterviewAnswer) => {
       if (!question) return;
       setError(null);
       try {
-        await submitMutation.trigger({ ...arg, questionId: question.id });
+        await submitMutation.trigger({ questionId: question.id, answer });
       } catch (caught) {
-        setError(
-          caught instanceof Error ? caught.message : "Couldn't submit your answer.",
-        );
+        setError(interviewSubmitErrorMessage(caught));
       }
     },
     [question, submitMutation],
@@ -172,7 +173,7 @@ function QuestionBody({
 }: {
   question: ApiQuestion;
   submitting: boolean;
-  onSubmit: (arg: Omit<SubmitInterviewAnswerArg, "questionId">) => Promise<void>;
+  onSubmit: (answer: SubmitInterviewAnswer) => Promise<void>;
 }) {
   switch (question.question_type) {
     case QuestionType.YES_NO:
@@ -216,14 +217,14 @@ function YesNoBody({
   onSubmit,
 }: {
   submitting: boolean;
-  onSubmit: (arg: Omit<SubmitInterviewAnswerArg, "questionId">) => Promise<void>;
+  onSubmit: (answer: SubmitInterviewAnswer) => Promise<void>;
 }) {
   return (
     <div className="flex flex-wrap items-center gap-2">
       <button
         type="button"
         disabled={submitting}
-        onClick={() => void onSubmit({ value: "no" })}
+        onClick={() => void onSubmit({ kind: "no" })}
         className={CHOICE_BUTTON}
       >
         No
@@ -231,7 +232,7 @@ function YesNoBody({
       <button
         type="button"
         disabled={submitting}
-        onClick={() => void onSubmit({ value: "yes" })}
+        onClick={() => void onSubmit({ kind: "yes" })}
         className={PRIMARY_BUTTON}
       >
         {submitting ? <Spinner /> : <CheckIcon className="size-4" aria-hidden="true" />}
@@ -246,14 +247,14 @@ function ConfirmationBody({
   onSubmit,
 }: {
   submitting: boolean;
-  onSubmit: (arg: Omit<SubmitInterviewAnswerArg, "questionId">) => Promise<void>;
+  onSubmit: (answer: SubmitInterviewAnswer) => Promise<void>;
 }) {
   return (
     <div className="flex flex-wrap items-center gap-2">
       <button
         type="button"
         disabled={submitting}
-        onClick={() => void onSubmit({ value: "yes" })}
+        onClick={() => void onSubmit({ kind: "yes" })}
         className={PRIMARY_BUTTON}
       >
         {submitting ? <Spinner /> : <CheckIcon className="size-4" aria-hidden="true" />}
@@ -272,7 +273,7 @@ function ChoiceBody({
   options: ApiQuestionOption[];
   allowFreeform: boolean;
   submitting: boolean;
-  onSubmit: (arg: Omit<SubmitInterviewAnswerArg, "questionId">) => Promise<void>;
+  onSubmit: (answer: SubmitInterviewAnswer) => Promise<void>;
 }) {
   return (
     <div className="space-y-4">
@@ -283,7 +284,7 @@ function ChoiceBody({
               key={option.key}
               type="button"
               disabled={submitting}
-              onClick={() => void onSubmit({ selected_option_key: option.key })}
+              onClick={() => void onSubmit({ kind: "selected", option_key: option.key })}
               className={CHOICE_BUTTON}
             >
               {displayLabel(option.label)}
@@ -315,7 +316,7 @@ function MultiSelectBody({
 }: {
   options: ApiQuestionOption[];
   submitting: boolean;
-  onSubmit: (arg: Omit<SubmitInterviewAnswerArg, "questionId">) => Promise<void>;
+  onSubmit: (answer: SubmitInterviewAnswer) => Promise<void>;
 }) {
   const [selected, setSelected] = useState<Set<string>>(new Set());
 
@@ -357,7 +358,7 @@ function MultiSelectBody({
         <button
           type="button"
           disabled={submitting || selectedKeys.length === 0}
-          onClick={() => void onSubmit({ selected_option_keys: selectedKeys })}
+          onClick={() => void onSubmit({ kind: "multi_selected", option_keys: selectedKeys })}
           className={PRIMARY_BUTTON}
         >
           {submitting ? <Spinner /> : <CheckIcon className="size-4" aria-hidden="true" />}
@@ -377,7 +378,7 @@ function FreeformBody({
   divider = false,
 }: {
   submitting: boolean;
-  onSubmit: (arg: Omit<SubmitInterviewAnswerArg, "questionId">) => Promise<void>;
+  onSubmit: (answer: SubmitInterviewAnswer) => Promise<void>;
   placeholder: string;
   submitLabel: string;
   autoFocus?: boolean;
@@ -394,7 +395,7 @@ function FreeformBody({
     event.preventDefault();
     const trimmed = value.trim();
     if (!trimmed || submitting) return;
-    await onSubmit({ value: trimmed });
+    await onSubmit({ kind: "text", text: trimmed });
     setValue("");
   }
 
@@ -484,3 +485,12 @@ export function displayLabel(label: string): string {
     .trim();
   return stripped || trimmed;
 }
+
+function interviewSubmitErrorMessage(error: unknown): string {
+  if (error instanceof ApiError) {
+    return error.requestId
+      ? `${error.message} Request ID: ${error.requestId}`
+      : error.message;
+  }
+  return error instanceof Error ? error.message : "Couldn't submit your answer.";
+}
diff --git a/apps/fabro-web/app/lib/api-client.test.ts b/apps/fabro-web/app/lib/api-client.test.ts
index 6a92c8205..ae73ccf40 100644
--- a/apps/fabro-web/app/lib/api-client.test.ts
+++ b/apps/fabro-web/app/lib/api-client.test.ts
@@ -45,7 +45,12 @@ describe("generated Axios adapter", () => {
 
   test("normalizes generated client failures into ApiError", async () => {
     const body = {
-      errors: [{ status: "500", title: "Internal", request_id: "body-req" }],
+      errors: [{
+        status: "500",
+        title: "Internal",
+        detail: "Database is unavailable.",
+        request_id: "body-req",
+      }],
     };
 
     try {
@@ -64,7 +69,7 @@ describe("generated Axios adapter", () => {
       expect(error).toBeInstanceOf(ApiError);
       expect(error).toMatchObject({
         status: 500,
-        message: "Internal Server Error",
+        message: "Database is unavailable.",
         requestId: "header-req",
         body,
       });
diff --git a/apps/fabro-web/app/lib/api-client.ts b/apps/fabro-web/app/lib/api-client.ts
index c68c012bd..934019e4c 100644
--- a/apps/fabro-web/app/lib/api-client.ts
+++ b/apps/fabro-web/app/lib/api-client.ts
@@ -176,12 +176,23 @@ function apiErrorFromAxios(error: unknown): ApiError | null {
   const requestId = requestIdFromHeaders(response.headers) ?? extractRequestId(response.data);
   return new ApiError({
     status: response.status,
-    message: response.statusText || `HTTP ${response.status}`,
+    message: extractErrorDetail(response.data) ?? (response.statusText || `HTTP ${response.status}`),
     requestId,
     body: response.data ?? null,
   });
 }
 
+function extractErrorDetail(body: unknown): string | null {
+  if (!body || typeof body !== "object") return null;
+  const errors = (body as Record<string, unknown>).errors;
+  if (!Array.isArray(errors) || errors.length === 0) return null;
+
+  const first = errors[0];
+  if (!first || typeof first !== "object") return null;
+  const detail = (first as Record<string, unknown>).detail;
+  return typeof detail === "string" && detail.length > 0 ? detail : null;
+}
+
 function redirectToLogin(error: ApiError, options: ApiCallOptions) {
   if (error.status !== 401 || options.redirectOnUnauthorized === false) return;
   if (typeof window !== "undefined") {
diff --git a/apps/fabro-web/app/lib/mutations.ts b/apps/fabro-web/app/lib/mutations.ts
index 8a553cc14..7b2d78615 100644
--- a/apps/fabro-web/app/lib/mutations.ts
+++ b/apps/fabro-web/app/lib/mutations.ts
@@ -101,7 +101,10 @@ function useLifecycleMutation(
   );
 }
 
-export type SubmitInterviewAnswerArg = SubmitAnswerRequest & { questionId: string };
+export type SubmitInterviewAnswerArg = {
+  questionId: string;
+  answer: SubmitAnswerRequest;
+};
 
 export function useSubmitInterviewAnswer(runId: string | undefined) {
   const { mutate } = useSWRConfig();
@@ -109,8 +112,9 @@ export function useSubmitInterviewAnswer(runId: string | undefined) {
     runId ? `interview-answer:${runId}` : null,
     async (_key: string, { arg }: { arg: SubmitInterviewAnswerArg }) => {
       if (!runId) throw new Error("runId is required");
-      const { questionId, ...body } = arg;
-      await apiData(() => humanInTheLoopApi.submitRunAnswer(runId, questionId, body));
+      await apiData(() =>
+        humanInTheLoopApi.submitRunAnswer(runId, arg.questionId, arg.answer),
+      );
     },
     {
       onSuccess: () => {
diff --git a/docs/public/api-reference/fabro-api.yaml b/docs/public/api-reference/fabro-api.yaml
index 9b55d4610..2736d6846 100644
--- a/docs/public/api-reference/fabro-api.yaml
+++ b/docs/public/api-reference/fabro-api.yaml
@@ -5177,25 +5177,90 @@ components:
 
     SubmitAnswerRequest:
       description: >
-        Request body for submitting an answer to a pending question.
-        At least one of `value`, `selected_option_key`, or `selected_option_keys` must be provided.
+        Request body for submitting an answer to a pending question. The
+        `kind` discriminator determines which answer shape is submitted.
+      oneOf:
+        - $ref: "#/components/schemas/SubmitAnswerYesRequest"
+        - $ref: "#/components/schemas/SubmitAnswerNoRequest"
+        - $ref: "#/components/schemas/SubmitAnswerSelectedRequest"
+        - $ref: "#/components/schemas/SubmitAnswerMultiSelectedRequest"
+        - $ref: "#/components/schemas/SubmitAnswerTextRequest"
+      discriminator:
+        propertyName: kind
+        mapping:
+          "yes": "#/components/schemas/SubmitAnswerYesRequest"
+          "no": "#/components/schemas/SubmitAnswerNoRequest"
+          selected: "#/components/schemas/SubmitAnswerSelectedRequest"
+          multi_selected: "#/components/schemas/SubmitAnswerMultiSelectedRequest"
+          text: "#/components/schemas/SubmitAnswerTextRequest"
+
+    SubmitAnswerYesRequest:
       type: object
+      required:
+        - kind
       properties:
-        value:
+        kind:
           type: string
-          description: Freeform answer text.
-          example: "Yes, proceed with the changes."
-        selected_option_key:
+          enum: ["yes"]
+          description: Affirmative answer for yes/no and confirmation questions.
+
+    SubmitAnswerNoRequest:
+      type: object
+      required:
+        - kind
+      properties:
+        kind:
           type: string
-          description: Key of the selected option (for single-select multiple-choice questions).
+          enum: ["no"]
+          description: Negative answer for yes/no questions.
+
+    SubmitAnswerSelectedRequest:
+      type: object
+      required:
+        - kind
+        - option_key
+      properties:
+        kind:
+          type: string
+          enum: [selected]
+          description: Single selected option answer.
+        option_key:
+          type: string
+          description: Key of the selected option.
           example: option_a
-        selected_option_keys:
+
+    SubmitAnswerMultiSelectedRequest:
+      type: object
+      required:
+        - kind
+        - option_keys
+      properties:
+        kind:
+          type: string
+          enum: [multi_selected]
+          description: Multiple selected option answer.
+        option_keys:
           type: array
           items:
             type: string
-          description: Keys of selected options (for multi-select questions).
+          description: Keys of selected options.
           example: ["option_a", "option_b"]
 
+    SubmitAnswerTextRequest:
+      type: object
+      required:
+        - kind
+        - text
+      properties:
+        kind:
+          type: string
+          enum: [text]
+          description: Freeform text answer.
+        text:
+          type: string
+          description: Freeform answer text.
+          example: "Yes, proceed with the changes."
+
     ErrorResponseEntry:
       description: A single error entry in an error response.
       type: object
diff --git a/lib/crates/fabro-api/tests/submit_answer_request_round_trip.rs b/lib/crates/fabro-api/tests/submit_answer_request_round_trip.rs
new file mode 100644
index 000000000..bf810cfb7
--- /dev/null
+++ b/lib/crates/fabro-api/tests/submit_answer_request_round_trip.rs
@@ -0,0 +1,25 @@
+use fabro_api::types::SubmitAnswerRequest;
+use serde_json::json;
+
+#[test]
+fn typed_answer_variants_round_trip_through_json() {
+    let cases = [
+        json!({ "kind": "yes" }),
+        json!({ "kind": "no" }),
+        json!({ "kind": "selected", "option_key": "approve" }),
+        json!({ "kind": "multi_selected", "option_keys": ["approve", "notify"] }),
+        json!({ "kind": "text", "text": "Looks good to me." }),
+    ];
+
+    for payload in cases {
+        let request: SubmitAnswerRequest = serde_json::from_value(payload.clone()).unwrap();
+        assert_eq!(serde_json::to_value(request).unwrap(), payload);
+    }
+}
+
+#[test]
+fn legacy_answer_fields_are_not_part_of_the_wire_contract() {
+    let result = serde_json::from_value::<SubmitAnswerRequest>(json!({ "value": "yes" }));
+
+    assert!(result.is_err());
+}
diff --git a/lib/crates/fabro-cli/src/commands/run/attach.rs b/lib/crates/fabro-cli/src/commands/run/attach.rs
index 5684932b1..62af35a32 100644
--- a/lib/crates/fabro-cli/src/commands/run/attach.rs
+++ b/lib/crates/fabro-cli/src/commands/run/attach.rs
@@ -313,12 +313,30 @@ async fn submit_server_interview_answer(
     qid: &str,
     answer: &fabro_interview::Answer,
 ) -> Result<bool> {
-    let (value, selected_option_key, selected_option_keys) = match &answer.value {
-        AnswerValue::Text(text) => (Some(text.clone()), None, Vec::new()),
-        AnswerValue::Selected(key) => (None, Some(key.clone()), Vec::new()),
-        AnswerValue::MultiSelected(keys) => (None, None, keys.clone()),
-        AnswerValue::Yes => (Some("yes".to_string()), None, Vec::new()),
-        AnswerValue::No => (Some("no".to_string()), None, Vec::new()),
+    let body = match &answer.value {
+        AnswerValue::Text(text) => types::SubmitAnswerTextRequest {
+            kind: types::SubmitAnswerTextRequestKind::Text,
+            text: text.clone(),
+        }
+        .into(),
+        AnswerValue::Selected(key) => types::SubmitAnswerSelectedRequest {
+            kind:       types::SubmitAnswerSelectedRequestKind::Selected,
+            option_key: key.clone(),
+        }
+        .into(),
+        AnswerValue::MultiSelected(keys) => types::SubmitAnswerMultiSelectedRequest {
+            kind:        types::SubmitAnswerMultiSelectedRequestKind::MultiSelected,
+            option_keys: keys.clone(),
+        }
+        .into(),
+        AnswerValue::Yes => types::SubmitAnswerYesRequest {
+            kind: types::SubmitAnswerYesRequestKind::Yes,
+        }
+        .into(),
+        AnswerValue::No => types::SubmitAnswerNoRequest {
+            kind: types::SubmitAnswerNoRequestKind::No,
+        }
+        .into(),
         AnswerValue::Cancelled
         | AnswerValue::Interrupted
         | AnswerValue::Skipped
@@ -326,15 +344,7 @@ async fn submit_server_interview_answer(
             return Ok(false);
         }
     };
-    client
-        .submit_run_answer(
-            run_id,
-            qid,
-            value,
-            selected_option_key,
-            selected_option_keys,
-        )
-        .await?;
+    client.submit_run_answer(run_id, qid, body).await?;
     Ok(true)
 }
 
diff --git a/lib/crates/fabro-cli/tests/it/cmd/attach.rs b/lib/crates/fabro-cli/tests/it/cmd/attach.rs
index 6b244188a..37dd18b57 100644
--- a/lib/crates/fabro-cli/tests/it/cmd/attach.rs
+++ b/lib/crates/fabro-cli/tests/it/cmd/attach.rs
@@ -977,7 +977,7 @@ fn attach_json_errors_without_prompting_for_human_input() {
                 .post(format!(
                     "{base_url}/api/v1/runs/{run_id}/questions/{question_id}/answer"
                 ))
-                .json(&serde_json::json!({ "selected_option_key": "A" }))
+                .json(&serde_json::json!({ "kind": "selected", "option_key": "A" }))
                 .send()
                 .await
                 .expect("answer submission should succeed");
diff --git a/lib/crates/fabro-cli/tests/it/cmd/runner.rs b/lib/crates/fabro-cli/tests/it/cmd/runner.rs
index 56e929ff0..0fb3de155 100644
--- a/lib/crates/fabro-cli/tests/it/cmd/runner.rs
+++ b/lib/crates/fabro-cli/tests/it/cmd/runner.rs
@@ -781,7 +781,7 @@ fn detached_run_answers_pending_question_without_interview_scratch_files() {
             .post(format!(
                 "{base_url}/api/v1/runs/{run_id}/questions/{question_id}/answer"
             ))
-            .json(&serde_json::json!({ "selected_option_key": "A" }))
+            .json(&serde_json::json!({ "kind": "selected", "option_key": "A" }))
             .send()
             .await
             .expect("answer submission should succeed");
diff --git a/lib/crates/fabro-client/src/client.rs b/lib/crates/fabro-client/src/client.rs
index 576161ae3..0ce392396 100644
--- a/lib/crates/fabro-client/src/client.rs
+++ b/lib/crates/fabro-client/src/client.rs
@@ -1159,20 +1159,14 @@ impl Client {
         &self,
         run_id: &RunId,
         qid: &str,
-        value: Option<String>,
-        selected_option_key: Option<String>,
-        selected_option_keys: Vec<String>,
+        body: types::SubmitAnswerRequest,
     ) -> Result<()> {
         self.send_api(|client| async move {
             client
                 .submit_run_answer()
                 .id(run_id.to_string())
                 .qid(qid)
-                .body(types::SubmitAnswerRequest {
-                    value:                value.clone(),
-                    selected_option_key:  selected_option_key.clone(),
-                    selected_option_keys: selected_option_keys.clone(),
-                })
+                .body(body.clone())
                 .send()
                 .await
         })
diff --git a/lib/crates/fabro-server/src/server.rs b/lib/crates/fabro-server/src/server.rs
index f1b56c0fc..78766fe96 100644
--- a/lib/crates/fabro-server/src/server.rs
+++ b/lib/crates/fabro-server/src/server.rs
@@ -2590,9 +2590,10 @@ fn validate_answer_for_question(
 ) -> Result<(), Response> {
     match (&question.question_type, &answer.value) {
         (
-            QuestionType::YesNo | QuestionType::Confirmation,
+            QuestionType::YesNo,
             fabro_interview::AnswerValue::Yes | fabro_interview::AnswerValue::No,
         )
+        | (QuestionType::Confirmation, fabro_interview::AnswerValue::Yes)
         | (
             _,
             fabro_interview::AnswerValue::Interrupted
@@ -2692,31 +2693,31 @@ fn answer_from_request(
     req: SubmitAnswerRequest,
     question: &InterviewQuestionRecord,
 ) -> Result<Answer, Response> {
-    if let Some(key) = req.selected_option_key {
-        let option = question
-            .options
-            .iter()
-            .find(|option| option.key == key)
-            .cloned();
-        match option {
-            Some(option) => Ok(Answer::selected(key, option)),
-            None => Err(ApiError::bad_request("Invalid option key.").into_response()),
-        }
-    } else if !req.selected_option_keys.is_empty() {
-        for key in &req.selected_option_keys {
-            let valid = question.options.iter().any(|option| option.key == *key);
-            if !valid {
-                return Err(ApiError::bad_request("Invalid option key.").into_response());
+    match req {
+        SubmitAnswerRequest::YesRequest(_) => Ok(Answer::yes()),
+        SubmitAnswerRequest::NoRequest(_) => Ok(Answer::no()),
+        SubmitAnswerRequest::SelectedRequest(req) => {
+            let key = req.option_key;
+            let option = question
+                .options
+                .iter()
+                .find(|option| option.key == key)
+                .cloned();
+            match option {
+                Some(option) => Ok(Answer::selected(key, option)),
+                None => Err(ApiError::bad_request("Invalid option key.").into_response()),
             }
         }
-        Ok(Answer::multi_selected(req.selected_option_keys))
-    } else if let Some(value) = req.value {
-        Ok(Answer::text(value))
-    } else {
-        Err(ApiError::bad_request(
-            "One of value, selected_option_key, or selected_option_keys is required.",
-        )
-        .into_response())
+        SubmitAnswerRequest::MultiSelectedRequest(req) => {
+            for key in &req.option_keys {
+                let valid = question.options.iter().any(|option| option.key == *key);
+                if !valid {
+                    return Err(ApiError::bad_request("Invalid option key.").into_response());
+                }
+            }
+            Ok(Answer::multi_selected(req.option_keys))
+        }
+        SubmitAnswerRequest::TextRequest(req) => Ok(Answer::text(req.text)),
     }
 }
 
diff --git a/lib/crates/fabro-server/src/server/tests.rs b/lib/crates/fabro-server/src/server/tests.rs
index 3c2cf6b2e..5a51b50d4 100644
--- a/lib/crates/fabro-server/src/server/tests.rs
+++ b/lib/crates/fabro-server/src/server/tests.rs
@@ -3983,7 +3983,7 @@ async fn submit_answer_not_found_run() {
         .uri(api(&format!("/runs/{missing_run_id}/questions/q1/answer")))
         .header("content-type", "application/json")
         .body(Body::from(
-            serde_json::to_string(&serde_json::json!({"value": "yes"})).unwrap(),
+            serde_json::to_string(&serde_json::json!({"kind": "yes"})).unwrap(),
         ))
         .unwrap();
 
@@ -4026,6 +4026,109 @@ async fn submit_pending_interview_answer_rejects_invalid_answer_shape() {
     assert_status!(response, StatusCode::BAD_REQUEST).await;
 }
 
+#[test]
+fn answer_from_typed_yes_request_maps_to_yes_answer() {
+    let question = InterviewQuestionRecord {
+        id:              "q-1".to_string(),
+        text:            "Continue?".to_string(),
+        stage:           "gate".to_string(),
+        question_type:   QuestionType::YesNo,
+        options:         vec![],
+        allow_freeform:  false,
+        timeout_seconds: None,
+        context_display: None,
+    };
+    let req: SubmitAnswerRequest = serde_json::from_value(json!({ "kind": "yes" })).unwrap();
+
+    let answer = answer_from_request(req, &question).unwrap();
+
+    assert_eq!(answer.value, AnswerValue::Yes);
+}
+
+#[test]
+fn answer_from_typed_no_request_maps_to_no_answer() {
+    let question = InterviewQuestionRecord {
+        id:              "q-1".to_string(),
+        text:            "Continue?".to_string(),
+        stage:           "gate".to_string(),
+        question_type:   QuestionType::YesNo,
+        options:         vec![],
+        allow_freeform:  false,
+        timeout_seconds: None,
+        context_display: None,
+    };
+    let req: SubmitAnswerRequest = serde_json::from_value(json!({ "kind": "no" })).unwrap();
+
+    let answer = answer_from_request(req, &question).unwrap();
+
+    assert_eq!(answer.value, AnswerValue::No);
+}
+
+#[test]
+fn answer_from_typed_selected_request_validates_and_attaches_option() {
+    let question = InterviewQuestionRecord {
+        id:              "q-1".to_string(),
+        text:            "Choose one.".to_string(),
+        stage:           "gate".to_string(),
+        question_type:   QuestionType::MultipleChoice,
+        options:         vec![fabro_types::run_event::InterviewOption {
+            key:   "approve".to_string(),
+            label: "Approve".to_string(),
+        }],
+        allow_freeform:  false,
+        timeout_seconds: None,
+        context_display: None,
+    };
+    let req: SubmitAnswerRequest =
+        serde_json::from_value(json!({ "kind": "selected", "option_key": "approve" })).unwrap();
+
+    let answer = answer_from_request(req, &question).unwrap();
+
+    assert_eq!(answer.value, AnswerValue::Selected("approve".to_string()));
+    assert_eq!(
+        answer
+            .selected_option
+            .as_ref()
+            .map(|option| option.label.as_str()),
+        Some("Approve")
+    );
+}
+
+#[test]
+fn answer_from_typed_multi_selected_request_validates_option_keys() {
+    let question = InterviewQuestionRecord {
+        id:              "q-1".to_string(),
+        text:            "Choose many.".to_string(),
+        stage:           "gate".to_string(),
+        question_type:   QuestionType::MultiSelect,
+        options:         vec![
+            fabro_types::run_event::InterviewOption {
+                key:   "approve".to_string(),
+                label: "Approve".to_string(),
+            },
+            fabro_types::run_event::InterviewOption {
+                key:   "notify".to_string(),
+                label: "Notify".to_string(),
+            },
+        ],
+        allow_freeform:  false,
+        timeout_seconds: None,
+        context_display: None,
+    };
+    let req: SubmitAnswerRequest = serde_json::from_value(json!({
+        "kind": "multi_selected",
+        "option_keys": ["approve", "notify"],
+    }))
+    .unwrap();
+
+    let answer = answer_from_request(req, &question).unwrap();
+
+    assert_eq!(
+        answer.value,
+        AnswerValue::MultiSelected(vec!["approve".to_string(), "notify".to_string()])
+    );
+}
+
 #[tokio::test]
 async fn get_events_not_found() {
     let app = test_app_with();
@@ -8106,7 +8209,7 @@ async fn submit_answer_to_queued_run_returns_conflict() {
         .uri(api(&format!("/runs/{run_id}/questions/q1/answer")))
         .header("content-type", "application/json")
         .body(Body::from(
-            serde_json::to_string(&serde_json::json!({"value": "yes"})).unwrap(),
+            serde_json::to_string(&serde_json::json!({"kind": "yes"})).unwrap(),
         ))
         .unwrap();
 
diff --git a/lib/crates/fabro-server/tests/it/scenario/lifecycle.rs b/lib/crates/fabro-server/tests/it/scenario/lifecycle.rs
index c0dfc3e53..488095263 100644
--- a/lib/crates/fabro-server/tests/it/scenario/lifecycle.rs
+++ b/lib/crates/fabro-server/tests/it/scenario/lifecycle.rs
@@ -169,7 +169,11 @@ async fn full_http_lifecycle_approve_and_complete() {
         )))
         .header("content-type", "application/json")
         .body(Body::from(
-            serde_json::to_string(&serde_json::json!({"selected_option_key": "A"})).unwrap(),
+            serde_json::to_string(&serde_json::json!({
+                "kind": "selected",
+                "option_key": "A",
+            }))
+            .unwrap(),
         ))
         .unwrap();
     let response = app.clone().oneshot(req).await.unwrap();
diff --git a/lib/packages/fabro-api-client/src/.openapi-generator/FILES b/lib/packages/fabro-api-client/src/.openapi-generator/FILES
index 367e35bb9..3664ce7ef 100644
--- a/lib/packages/fabro-api-client/src/.openapi-generator/FILES
+++ b/lib/packages/fabro-api-client/src/.openapi-generator/FILES
@@ -312,7 +312,12 @@ models/stage-projection.ts
 models/stage-state.ts
 models/start-run-request.ts
 models/steer-run-request.ts
+models/submit-answer-multi-selected-request.ts
+models/submit-answer-no-request.ts
 models/submit-answer-request.ts
+models/submit-answer-selected-request.ts
+models/submit-answer-text-request.ts
+models/submit-answer-yes-request.ts
 models/success-reason.ts
 models/system-actor-kind.ts
 models/system-features.ts
diff --git a/lib/packages/fabro-api-client/src/models/index.ts b/lib/packages/fabro-api-client/src/models/index.ts
index 44d7a32ee..b5fa16538 100644
--- a/lib/packages/fabro-api-client/src/models/index.ts
+++ b/lib/packages/fabro-api-client/src/models/index.ts
@@ -289,7 +289,12 @@ export * from './stage-projection';
 export * from './stage-state';
 export * from './start-run-request';
 export * from './steer-run-request';
+export * from './submit-answer-multi-selected-request';
+export * from './submit-answer-no-request';
 export * from './submit-answer-request';
+export * from './submit-answer-selected-request';
+export * from './submit-answer-text-request';
+export * from './submit-answer-yes-request';
 export * from './success-reason';
 export * from './system-actor-kind';
 export * from './system-features';
diff --git a/lib/packages/fabro-api-client/src/models/submit-answer-multi-selected-request.ts b/lib/packages/fabro-api-client/src/models/submit-answer-multi-selected-request.ts
new file mode 100644
index 000000000..6dc72c947
--- /dev/null
+++ b/lib/packages/fabro-api-client/src/models/submit-answer-multi-selected-request.ts
@@ -0,0 +1,34 @@
+/* tslint:disable */
+/* eslint-disable */
+/**
+ * Fabro Run API
+ * HTTP API for managing Fabro workflow run executions.
+ *
+ * The version of the OpenAPI document: 0.1.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+
+export interface SubmitAnswerMultiSelectedRequest {
+    /**
+     * Multiple selected option answer.
+     */
+    'kind': SubmitAnswerMultiSelectedRequestKindEnum;
+    /**
+     * Keys of selected options.
+     */
+    'option_keys': Array<string>;
+}
+
+export const SubmitAnswerMultiSelectedRequestKindEnum = {
+    MULTI_SELECTED: 'multi_selected'
+} as const;
+
+export type SubmitAnswerMultiSelectedRequestKindEnum = typeof SubmitAnswerMultiSelectedRequestKindEnum[keyof typeof SubmitAnswerMultiSelectedRequestKindEnum];
+
+
diff --git a/lib/packages/fabro-api-client/src/models/submit-answer-no-request.ts b/lib/packages/fabro-api-client/src/models/submit-answer-no-request.ts
new file mode 100644
index 000000000..465c6ae5e
--- /dev/null
+++ b/lib/packages/fabro-api-client/src/models/submit-answer-no-request.ts
@@ -0,0 +1,30 @@
+/* tslint:disable */
+/* eslint-disable */
+/**
+ * Fabro Run API
+ * HTTP API for managing Fabro workflow run executions.
+ *
+ * The version of the OpenAPI document: 0.1.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+
+export interface SubmitAnswerNoRequest {
+    /**
+     * Negative answer for yes/no questions.
+     */
+    'kind': SubmitAnswerNoRequestKindEnum;
+}
+
+export const SubmitAnswerNoRequestKindEnum = {
+    NO: 'no'
+} as const;
+
+export type SubmitAnswerNoRequestKindEnum = typeof SubmitAnswerNoRequestKindEnum[keyof typeof SubmitAnswerNoRequestKindEnum];
+
+
diff --git a/lib/packages/fabro-api-client/src/models/submit-answer-request.ts b/lib/packages/fabro-api-client/src/models/submit-answer-request.ts
index 5ff839fec..9526d913b 100644
--- a/lib/packages/fabro-api-client/src/models/submit-answer-request.ts
+++ b/lib/packages/fabro-api-client/src/models/submit-answer-request.ts
@@ -13,22 +13,26 @@
  */
 
 
+// May contain unused imports in some cases
+// @ts-ignore
+import type { SubmitAnswerMultiSelectedRequest } from './submit-answer-multi-selected-request';
+// May contain unused imports in some cases
+// @ts-ignore
+import type { SubmitAnswerNoRequest } from './submit-answer-no-request';
+// May contain unused imports in some cases
+// @ts-ignore
+import type { SubmitAnswerSelectedRequest } from './submit-answer-selected-request';
+// May contain unused imports in some cases
+// @ts-ignore
+import type { SubmitAnswerTextRequest } from './submit-answer-text-request';
+// May contain unused imports in some cases
+// @ts-ignore
+import type { SubmitAnswerYesRequest } from './submit-answer-yes-request';
 
 /**
- * Request body for submitting an answer to a pending question. At least one of `value`, `selected_option_key`, or `selected_option_keys` must be provided. 
+ * @type SubmitAnswerRequest
+ * Request body for submitting an answer to a pending question. The `kind` discriminator determines which answer shape is submitted. 
  */
-export interface SubmitAnswerRequest {
-    /**
-     * Freeform answer text.
-     */
-    'value'?: string;
-    /**
-     * Key of the selected option (for single-select multiple-choice questions).
-     */
-    'selected_option_key'?: string;
-    /**
-     * Keys of selected options (for multi-select questions).
-     */
-    'selected_option_keys'?: Array<string>;
-}
+export type SubmitAnswerRequest = { kind: 'multi_selected' } & SubmitAnswerMultiSelectedRequest | { kind: 'no' } & SubmitAnswerNoRequest | { kind: 'selected' } & SubmitAnswerSelectedRequest | { kind: 'text' } & SubmitAnswerTextRequest | { kind: 'yes' } & SubmitAnswerYesRequest;
+
 
diff --git a/lib/packages/fabro-api-client/src/models/submit-answer-selected-request.ts b/lib/packages/fabro-api-client/src/models/submit-answer-selected-request.ts
new file mode 100644
index 000000000..6f51edc00
--- /dev/null
+++ b/lib/packages/fabro-api-client/src/models/submit-answer-selected-request.ts
@@ -0,0 +1,34 @@
+/* tslint:disable */
+/* eslint-disable */
+/**
+ * Fabro Run API
+ * HTTP API for managing Fabro workflow run executions.
+ *
+ * The version of the OpenAPI document: 0.1.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+
+export interface SubmitAnswerSelectedRequest {
+    /**
+     * Single selected option answer.
+     */
+    'kind': SubmitAnswerSelectedRequestKindEnum;
+    /**
+     * Key of the selected option.
+     */
+    'option_key': string;
+}
+
+export const SubmitAnswerSelectedRequestKindEnum = {
+    SELECTED: 'selected'
+} as const;
+
+export type SubmitAnswerSelectedRequestKindEnum = typeof SubmitAnswerSelectedRequestKindEnum[keyof typeof SubmitAnswerSelectedRequestKindEnum];
+
+
diff --git a/lib/packages/fabro-api-client/src/models/submit-answer-text-request.ts b/lib/packages/fabro-api-client/src/models/submit-answer-text-request.ts
new file mode 100644
index 000000000..d0c6b56da
--- /dev/null
+++ b/lib/packages/fabro-api-client/src/models/submit-answer-text-request.ts
@@ -0,0 +1,34 @@
+/* tslint:disable */
+/* eslint-disable */
+/**
+ * Fabro Run API
+ * HTTP API for managing Fabro workflow run executions.
+ *
+ * The version of the OpenAPI document: 0.1.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+
+export interface SubmitAnswerTextRequest {
+    /**
+     * Freeform text answer.
+     */
+    'kind': SubmitAnswerTextRequestKindEnum;
+    /**
+     * Freeform answer text.
+     */
+    'text': string;
+}
+
+export const SubmitAnswerTextRequestKindEnum = {
+    TEXT: 'text'
+} as const;
+
+export type SubmitAnswerTextRequestKindEnum = typeof SubmitAnswerTextRequestKindEnum[keyof typeof SubmitAnswerTextRequestKindEnum];
+
+
diff --git a/lib/packages/fabro-api-client/src/models/submit-answer-yes-request.ts b/lib/packages/fabro-api-client/src/models/submit-answer-yes-request.ts
new file mode 100644
index 000000000..4046e0df1
--- /dev/null
+++ b/lib/packages/fabro-api-client/src/models/submit-answer-yes-request.ts
@@ -0,0 +1,30 @@
+/* tslint:disable */
+/* eslint-disable */
+/**
+ * Fabro Run API
+ * HTTP API for managing Fabro workflow run executions.
+ *
+ * The version of the OpenAPI document: 0.1.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+
+export interface SubmitAnswerYesRequest {
+    /**
+     * Affirmative answer for yes/no and confirmation questions.
+     */
+    'kind': SubmitAnswerYesRequestKindEnum;
+}
+
+export const SubmitAnswerYesRequestKindEnum = {
+    YES: 'yes'
+} as const;
+
+export type SubmitAnswerYesRequestKindEnum = typeof SubmitAnswerYesRequestKindEnum[keyof typeof SubmitAnswerYesRequestKindEnum];
+
+