diff --git a/chainforge/react-server/src/LLMListComponent.tsx b/chainforge/react-server/src/LLMListComponent.tsx
index b39c11a..78501c4 100644
--- a/chainforge/react-server/src/LLMListComponent.tsx
+++ b/chainforge/react-server/src/LLMListComponent.tsx
@@ -11,6 +11,10 @@ import React, {
 import {
   DragDropContext,
   Draggable,
+  DraggableProvided,
+  DraggableRubric,
+  DraggableStateSnapshot,
+  DroppableProvided,
   OnDragEndResponder,
 } from "react-beautiful-dnd";
 import { Menu } from "@mantine/core";
@@ -205,7 +209,7 @@ export function LLMList({
       <DragDropContext onDragEnd={onDragEnd}>
         <StrictModeDroppable
           droppableId="llm-list-droppable"
-          renderClone={(provided, snapshot, rubric) => (
+          renderClone={(provided: DraggableProvided, snapshot: DraggableStateSnapshot, rubric: DraggableRubric) => (
             <LLMListItemClone
               provided={provided}
               snapshot={snapshot}
@@ -214,10 +218,10 @@ export function LLMList({
             />
           )}
         >
-          {(provided) => (
+          {(provided: DroppableProvided) => (
             <div {...provided.droppableProps} ref={provided.innerRef}>
               {items.map((item, index) => (
-                <Draggable key={item.key} draggableId={item.key} index={index}>
+                <Draggable key={item.key} draggableId={item.key ?? index.toString()} index={index}>
                   {(provided, snapshot) => (
                     <LLMListItem
                       provided={provided}
@@ -240,7 +244,27 @@ export function LLMList({
   );
 }
 
-export const LLMListContainer = forwardRef(function LLMListContainer(
+export interface LLMListContainerHandle {
+  resetLLMItemsProgress: () => void;
+  setZeroPercProgress: () => void;
+  updateProgress: (itemProcessorFunc: (llm: LLMSpec) => LLMSpec) => void;
+  ensureLLMItemsErrorProgress: (llm_keys_w_errors: string[]) => void;
+  getLLMListItemForKey: (key: string) => LLMSpec | undefined;
+  refreshLLMProviderList: () => void;
+}
+
+export interface LLMListContainerProps {
+  description: string;
+  modelSelectButtonText: string;
+  initLLMItems: LLMSpec[];
+  onSelectModel: (llm: LLMSpec, new_llms: LLMSpec[]) => void;
+  onItemsChange: (new_llms: LLMSpec[], old_llms: LLMSpec[]) => void;
+  hideTrashIcon: boolean;
+  bgColor: string;
+  selectModelAction?: "add" | "replace";
+}
+
+export const LLMListContainer = forwardRef<LLMListContainerHandle, LLMListContainerProps>(function LLMListContainer(
   {
     description,
     modelSelectButtonText,
@@ -293,16 +317,16 @@ export const LLMListContainer = forwardRef(function LLMListContainer(
     );
   }, [llmItemsCurrState]);
   const updateProgress = useCallback(
-    (itemProcessorFunc: (llms: LLMSpec) => LLMSpec) => {
+    (itemProcessorFunc: (llm: LLMSpec) => LLMSpec) => {
       setLLMItems(llmItemsCurrState.map(itemProcessorFunc));
     },
     [llmItemsCurrState],
   );
   const ensureLLMItemsErrorProgress = useCallback(
-    (llm_keys_w_errors) => {
+    (llm_keys_w_errors: string[]) => {
       setLLMItems(
         llmItemsCurrState.map((item) => {
-          if (llm_keys_w_errors.includes(item.key)) {
+          if (item.key !== undefined && llm_keys_w_errors.includes(item.key)) {
             if (!item.progress) item.progress = { success: 0, error: 100 };
             else {
               const succ_perc = item.progress.success;
@@ -321,7 +345,7 @@ export const LLMListContainer = forwardRef(function LLMListContainer(
   );
 
   const getLLMListItemForKey = useCallback(
-    (key) => {
+    (key: string) => {
       return llmItemsCurrState.find((item) => item.key === key);
     },
     [llmItemsCurrState],
@@ -353,7 +377,7 @@ export const LLMListContainer = forwardRef(function LLMListContainer(
       item.name = unique_name;
       item.formData = { shortname: unique_name };
 
-      let new_items;
+      let new_items: LLMSpec[] = [];
       if (selectModelAction === "add" || selectModelAction === undefined) {
         // Add model to the LLM list (regardless of it's present already or not).
         new_items = llmItemsCurrState.concat([item]);
diff --git a/chainforge/react-server/src/LLMListItem.tsx b/chainforge/react-server/src/LLMListItem.tsx
index c393dda..fc3c64f 100644
--- a/chainforge/react-server/src/LLMListItem.tsx
+++ b/chainforge/react-server/src/LLMListItem.tsx
@@ -80,10 +80,10 @@ export interface LLMListItemProps {
   item: LLMSpec;
   provided: DraggableProvided;
   snapshot: DraggableStateSnapshot;
-  removeCallback: (key: string) => void;
-  onClickSettings: () => void;
+  removeCallback?: (key: string) => void;
+  onClickSettings?: () => void;
   progress?: QueryProgress;
-  hideTrashIcon: boolean;
+  hideTrashIcon?: boolean;
 }
 
 const LLMListItem: React.FC<LLMListItemProps> = ({
@@ -136,7 +136,7 @@ const LLMListItem: React.FC<LLMListItemProps> = ({
           )}
         </CardHeader>
         <LLMItemButtonGroup
-          onClickTrash={() => removeCallback(item.key ?? "undefined")}
+          onClickTrash={() => removeCallback && removeCallback(item.key ?? "undefined")}
           ringProgress={progress}
           onClickSettings={onClickSettings}
           hideTrashIcon={hideTrashIcon}
diff --git a/chainforge/react-server/src/LLMResponseInspector.js b/chainforge/react-server/src/LLMResponseInspector.tsx
similarity index 89%
rename from chainforge/react-server/src/LLMResponseInspector.js
rename to chainforge/react-server/src/LLMResponseInspector.tsx
index 3304d0d..e3b0af1 100644
--- a/chainforge/react-server/src/LLMResponseInspector.js
+++ b/chainforge/react-server/src/LLMResponseInspector.tsx
@@ -38,13 +38,14 @@ import {
   genResponseTextsDisplay,
 } from "./ResponseBoxes";
 import { getLabelForResponse } from "./ResponseRatingToolbar";
+import { Dict, LLMResponse } from "./backend/typing";
 
 // Helper funcs
-const getLLMName = (resp_obj) =>
+const getLLMName = (resp_obj: LLMResponse) =>
   typeof resp_obj?.llm === "string" ? resp_obj.llm : resp_obj?.llm?.name;
-const escapeRegExp = (txt) => txt.replace(/[-[\]{}()*+?.,\\^$|#\s]/g, "\\$&");
+const escapeRegExp = (txt: string) => txt.replace(/[-[\]{}()*+?.,\\^$|#\s]/g, "\\$&");
 
-function getIndicesOfSubstringMatches(s, substr, caseSensitive) {
+function getIndicesOfSubstringMatches(s: string, substr: string, caseSensitive?: boolean) {
   const regex = new RegExp(
     escapeRegExp(substr),
     "g" + (caseSensitive ? "" : "i"),
@@ -56,7 +57,7 @@ function getIndicesOfSubstringMatches(s, substr, caseSensitive) {
 }
 
 // Splits a string by a substring or regex, but includes the delimiter (substring/regex match) elements in the returned array.
-function splitAndIncludeDelimiter(s, substr, caseSensitive) {
+function splitAndIncludeDelimiter(s: string, substr: string, caseSensitive?: boolean) {
   const indices = getIndicesOfSubstringMatches(s, substr, caseSensitive);
   if (indices.length === 0) return [s];
 
@@ -78,7 +79,7 @@ function splitAndIncludeDelimiter(s, substr, caseSensitive) {
 }
 
 // Returns an HTML version of text where 'searchValue' is highlighted.
-function genSpansForHighlightedValue(text, searchValue, caseSensitive) {
+function genSpansForHighlightedValue(text: string, searchValue: string, caseSensitive?: boolean) {
   // Split texts by searchValue and map to <span> and <mark> elements
   return splitAndIncludeDelimiter(text, searchValue, caseSensitive).map(
     (s, idx) => {
@@ -94,7 +95,7 @@ function genSpansForHighlightedValue(text, searchValue, caseSensitive) {
 }
 
 // Export the JSON responses to an excel file (downloads the file):
-export const exportToExcel = (jsonResponses, filename) => {
+export const exportToExcel = (jsonResponses: LLMResponse[], filename: string) => {
   if (!filename) filename = "responses.xlsx";
 
   // Check that there are responses to export:
@@ -123,7 +124,7 @@ export const exportToExcel = (jsonResponses, filename) => {
       };
       const eval_res_items = res_obj.eval_res ? res_obj.eval_res.items : null;
       return res_obj.responses.map((r, r_idx) => {
-        const row = {
+        const row: Dict<string | number | boolean> = {
           LLM: llm,
           Prompt: prompt,
           Response: r,
@@ -173,17 +174,23 @@ export const exportToExcel = (jsonResponses, filename) => {
   XLSX.writeFile(wb, filename);
 };
 
-const LLMResponseInspector = ({ jsonResponses, wideFormat }) => {
+
+export interface LLMResponseInspectorProps {
+  jsonResponses: LLMResponse[];
+  wideFormat?: boolean;
+}
+
+const LLMResponseInspector: React.FC<LLMResponseInspectorProps> = ({ jsonResponses, wideFormat }) => {
   // Responses
-  const [responses, setResponses] = useState([]);
+  const [responseDivs, setResponseDivs] = useState<React.ReactNode>([]);
   const [receivedResponsesOnce, setReceivedResponsesOnce] = useState(false);
 
   // The type of view to use to display responses. Can be either hierarchy or table.
   const [viewFormat, setViewFormat] = useState("hierarchy");
 
   // The MultiSelect so people can dynamically set what vars they care about
-  const [multiSelectVars, setMultiSelectVars] = useState([]);
-  const [multiSelectValue, setMultiSelectValue] = useState([]);
+  const [multiSelectVars, setMultiSelectVars] = useState<{value: string; label: string}[]>([]);
+  const [multiSelectValue, setMultiSelectValue] = useState<string[]>([]);
 
   // Search bar functionality
   const [searchValue, setSearchValue] = useState("");
@@ -236,13 +243,13 @@ const LLMResponseInspector = ({ jsonResponses, wideFormat }) => {
       return;
 
     // Find all vars in responses
-    let found_vars = new Set();
-    let found_metavars = new Set();
-    let found_llms = new Set();
+    let found_vars: Array<string> | Set<string> = new Set<string>();
+    let found_metavars: Array<string> | Set<string> = new Set<string>();
+    let found_llms: Array<string> | Set<string> = new Set<string>();
     batchedResponses.forEach((res_obj) => {
-      Object.keys(res_obj.vars).forEach((v) => found_vars.add(v));
-      Object.keys(res_obj.metavars).forEach((v) => found_metavars.add(v));
-      found_llms.add(getLLMName(res_obj));
+      Object.keys(res_obj.vars).forEach((v) => (found_vars as Set<string>).add(v));
+      Object.keys(res_obj.metavars).forEach((v) => (found_metavars as Set<string>).add(v));
+      (found_llms as Set<string>).add(getLLMName(res_obj));
     });
     found_vars = Array.from(found_vars);
     found_metavars = Array.from(found_metavars).filter(cleanMetavarsFilterFunc);
@@ -256,7 +263,7 @@ const LLMResponseInspector = ({ jsonResponses, wideFormat }) => {
 
     // Set the variables accessible in the MultiSelect for 'group by'
     const msvars = found_vars
-      .map((name) =>
+      .map((name: string) =>
         // We add a $ prefix to mark this as a prompt parameter, and so
         // in the future we can add special types of variables without name collisions
         ({ value: name, label: name }),
@@ -310,7 +317,7 @@ const LLMResponseInspector = ({ jsonResponses, wideFormat }) => {
       );
 
     // Functions to associate a color to each LLM in responses
-    const color_for_llm = (llm) => getColorForLLMAndSetIfNotFound(llm) + "99";
+    const color_for_llm = (llm: string) => getColorForLLMAndSetIfNotFound(llm) + "99";
     const header_bg_colors = ["#e0f4fa", "#c0def9", "#a9c0f9", "#a6b2ea"];
     const response_box_colors = [
       "#eee",
@@ -321,11 +328,11 @@ const LLMResponseInspector = ({ jsonResponses, wideFormat }) => {
       "#ddd",
       "#eee",
     ];
-    const rgroup_color = (depth) =>
+    const rgroup_color = (depth: number) =>
       response_box_colors[depth % response_box_colors.length];
 
-    const getHeaderBadge = (key, val, depth) => {
-      if (val) {
+    const getHeaderBadge = (key: string, val: string | undefined, depth: number) => {
+      if (val !== undefined) {
         const s = truncStr(val.trim(), 1024);
         return (
           <div
@@ -346,11 +353,11 @@ const LLMResponseInspector = ({ jsonResponses, wideFormat }) => {
       }
     };
 
-    const generateResponseBoxes = (resps, eatenvars, fixed_width) => {
+    const generateResponseBoxes = (resps: LLMResponse[], eatenvars: string[], fixed_width: number) => {
       const hide_llm_name = eatenvars.includes("LLM");
       return resps.map((res_obj, res_idx) => {
         // If user has searched for something, further filter the response texts by only those that contain the search term
-        const respsFilterFunc = (responses) => {
+        const respsFilterFunc = (responses: string[]) => {
           if (searchValue.length === 0) return responses;
           const filtered_resps = responses.filter(
             search_regex.test.bind(search_regex),
@@ -399,8 +406,8 @@ const LLMResponseInspector = ({ jsonResponses, wideFormat }) => {
     if (viewFormat === "table") {
       // Generate a table, with default columns for: input vars, LLMs queried
       // First get column names as input vars + LLMs:
-      let var_cols, colnames, getColVal, found_sel_var_vals;
-      let metavar_cols = []; // found_metavars; -- Disabling this functionality for now, since it is usually annoying.
+      let var_cols: string[], colnames: string[], getColVal: (r: LLMResponse) => string | number | boolean | undefined, found_sel_var_vals: string[];
+      let metavar_cols: string[] = []; // found_metavars; -- Disabling this functionality for now, since it is usually annoying.
       if (tableColVar === "LLM") {
         var_cols = found_vars;
         getColVal = getLLMName;
@@ -418,16 +425,16 @@ const LLMResponseInspector = ({ jsonResponses, wideFormat }) => {
           responses.reduce((acc, res_obj) => {
             acc.add(
               tableColVar in res_obj.vars
-                ? res_obj.vars[tableColVar]
+                ? res_obj.vars[tableColVar] as string
                 : "(unspecified)",
             );
             return acc;
-          }, new Set()),
+          }, new Set<string>()),
         );
         colnames = var_cols.concat(found_sel_var_vals);
       }
 
-      const getVar = (r, v) => (v === "LLM" ? getLLMName(r) : r.vars[v]);
+      const getVar = (r: LLMResponse, v: string) => (v === "LLM" ? getLLMName(r) : r.vars[v]);
 
       // Then group responses by prompts. Each prompt will become a separate row of the table (will be treated as unique)
       const responses_by_prompt = groupResponsesBy(responses, (r) =>
@@ -486,7 +493,7 @@ const LLMResponseInspector = ({ jsonResponses, wideFormat }) => {
         },
       );
 
-      setResponses([
+      setResponseDivs([
         <Table key="table" fontSize={wideFormat ? "sm" : "xs"}>
           <thead>
             <tr>
@@ -506,7 +513,7 @@ const LLMResponseInspector = ({ jsonResponses, wideFormat }) => {
       // :: nested divs first grouped by LLM (first level), then by var1, then var2 (deepest level).
       let leaf_id = 0;
       let first_opened = false;
-      const groupByVars = (resps, varnames, eatenvars, header) => {
+      const groupByVars = (resps: LLMResponse[], varnames: string[], eatenvars: string[], header: React.ReactNode) => {
         if (resps.length === 0) return [];
         if (varnames.length === 0) {
           // Base case. Display n response(s) to each single prompt, back-to-back:
@@ -560,16 +567,16 @@ const LLMResponseInspector = ({ jsonResponses, wideFormat }) => {
               );
         const get_header =
           group_name === "LLM"
-            ? (key, val) => (
+            ? (key: string, val?: string) => (
                 <div
                   key={val}
-                  style={{ backgroundColor: color_for_llm(val) }}
+                  style={{ backgroundColor: val ? color_for_llm(val) : "#eee" }}
                   className="response-llm-header"
                 >
                   {val}
                 </div>
               )
-            : (key, val) => getHeaderBadge(key, val, eatenvars.length);
+            : (key: string, val?: string) => getHeaderBadge(key, val, eatenvars.length);
 
         // Now produce nested divs corresponding to the groups
         const remaining_vars = varnames.slice(1);
@@ -630,7 +637,7 @@ const LLMResponseInspector = ({ jsonResponses, wideFormat }) => {
 
       // Produce DIV elements grouped by selected vars
       const divs = groupByVars(responses, selected_vars, [], null);
-      setResponses(divs);
+      setResponseDivs(divs);
     }
 
     setNumMatches(numResponsesDisplayed);
@@ -651,15 +658,14 @@ const LLMResponseInspector = ({ jsonResponses, wideFormat }) => {
 
   // When the user clicks an item in the drop-down,
   // we want to autoclose the multiselect drop-down:
-  const multiSelectRef = useRef(null);
-  const handleMultiSelectValueChange = (new_val) => {
-    if (multiSelectRef) {
+  const multiSelectRef = useRef<HTMLInputElement>(null);
+  const handleMultiSelectValueChange = (new_val: string[]) => {
+    if (multiSelectRef?.current) 
       multiSelectRef.current.blur();
-    }
     setMultiSelectValue(new_val);
   };
 
-  const handleSearchValueChange = (content) => {
+  const handleSearchValueChange = (content: React.ChangeEvent<HTMLInputElement>) => {
     setSearchValue(content.target.value);
   };
 
@@ -730,7 +736,7 @@ const LLMResponseInspector = ({ jsonResponses, wideFormat }) => {
     <div style={{ height: "100%" }}>
       <Tabs
         value={viewFormat}
-        onTabChange={setViewFormat}
+        onTabChange={(val) => setViewFormat(val ?? "hierarchy")}
         styles={{ tabLabel: { fontSize: wideFormat ? "12pt" : "9pt" } }}
       >
         <Tabs.List>
@@ -804,7 +810,7 @@ const LLMResponseInspector = ({ jsonResponses, wideFormat }) => {
         </Tabs.Panel>
       </Tabs>
 
-      <div className="nowheel nodrag">{responses}</div>
+      <div className="nowheel nodrag">{responseDivs}</div>
     </div>
   );
 };
diff --git a/chainforge/react-server/src/ModelSettingsModal.tsx b/chainforge/react-server/src/ModelSettingsModal.tsx
index 235d6f8..4b39ecd 100644
--- a/chainforge/react-server/src/ModelSettingsModal.tsx
+++ b/chainforge/react-server/src/ModelSettingsModal.tsx
@@ -29,7 +29,9 @@ export interface ModelSettingsModalRef {
 }
 export interface ModelSettingsModalProps {
   model?: LLMSpec;
-  onSettingsSubmit?: () => void;
+  onSettingsSubmit?: (savedItem: LLMSpec,
+    formData: Dict<JSONCompatible>,
+    settingsData: Dict<JSONCompatible>) => void;
 }
 type FormData = LLMSpec["formData"];
 
diff --git a/chainforge/react-server/src/ResponseRatingToolbar.js b/chainforge/react-server/src/ResponseRatingToolbar.tsx
similarity index 81%
rename from chainforge/react-server/src/ResponseRatingToolbar.js
rename to chainforge/react-server/src/ResponseRatingToolbar.tsx
index d071b00..e987b67 100644
--- a/chainforge/react-server/src/ResponseRatingToolbar.js
+++ b/chainforge/react-server/src/ResponseRatingToolbar.tsx
@@ -11,8 +11,10 @@ import StorageCache from "./backend/cache";
 import useStore from "./store";
 import { deepcopy } from "./backend/utils";
 
-const getRatingKeyForResponse = (uid, label_name) => `r.${uid}.${label_name}`;
-const collapse_ratings = (rating_dict, idxs) => {
+type RatingDict = Record<number, boolean | string | undefined>;
+
+const getRatingKeyForResponse = (uid: string, label_name: string) => `r.${uid}.${label_name}`;
+const collapse_ratings = (rating_dict: RatingDict, idxs: number[]) => {
   if (rating_dict === undefined) return undefined;
   for (let j = 0; j < idxs.length; j++) {
     if (idxs[j] in rating_dict && rating_dict[idxs[j]] !== undefined)
@@ -21,14 +23,20 @@ const collapse_ratings = (rating_dict, idxs) => {
   return undefined;
 };
 
-export const getLabelForResponse = (uid, label_name) => {
+export const getLabelForResponse = (uid: string, label_name: string) => {
   return StorageCache.get(getRatingKeyForResponse(uid, label_name));
 };
-export const setLabelForResponse = (uid, label_name, payload) => {
+export const setLabelForResponse = (uid: string, label_name: string, payload: RatingDict) => {
   StorageCache.store(getRatingKeyForResponse(uid, label_name), payload);
 };
 
-const ToolbarButton = forwardRef(function ToolbarButton(
+interface ToolbarButtonProps {
+  selected: boolean;
+  onClick: () => void;
+  children: React.ReactNode;
+}
+
+const ToolbarButton = forwardRef<HTMLButtonElement, ToolbarButtonProps>(function ToolbarButton(
   { selected, onClick, children },
   ref,
 ) {
@@ -47,7 +55,14 @@ const ToolbarButton = forwardRef(function ToolbarButton(
   );
 });
 
-const ResponseRatingToolbar = ({
+export interface ResponseRatingToolbarProps {
+  uid: string;
+  wideFormat?: boolean;
+  innerIdxs: number[];
+  onUpdateResponses: () => void;
+}
+
+const ResponseRatingToolbar: React.FC<ResponseRatingToolbarProps> = ({
   uid,
   wideFormat,
   innerIdxs,
@@ -62,10 +77,10 @@ const ResponseRatingToolbar = ({
   // :: for this component changes.
   // const state = useStore((store) => store.state);
   const setState = useStore((store) => store.setState);
-  const gradeState = useStore((store) => store.state[gradeKey]);
-  const noteState = useStore((store) => store.state[noteKey]);
+  const gradeState = useStore<RatingDict>((store) => store.state[gradeKey]);
+  const noteState = useStore<RatingDict>((store) => store.state[noteKey]);
   const setRating = useCallback(
-    (uid, label, payload) => {
+    (uid: string, label: string, payload: RatingDict) => {
       const key = getRatingKeyForResponse(uid, label);
       const safe_payload = deepcopy(payload);
       setState(key, safe_payload);
@@ -91,7 +106,7 @@ const ResponseRatingToolbar = ({
 
   // Override the text in the internal textarea whenever upstream annotation changes.
   useEffect(() => {
-    setNoteText(note);
+    setNoteText(note !== undefined ? note.toString() : "");
   }, [note]);
 
   // The label for the pop-up comment box.
@@ -107,22 +122,22 @@ const ResponseRatingToolbar = ({
   }, [wideFormat]);
 
   // For human labeling of responses in the inspector
-  const onGrade = (grade) => {
+  const onGrade = (grade: boolean | undefined) => {
     if (uid === undefined) return;
     const new_grades = gradeState ?? {};
-    innerIdxs.forEach((idx) => {
+    innerIdxs.forEach((idx: number) => {
       new_grades[idx] = grade;
     });
     setRating(uid, "grade", new_grades);
     if (onUpdateResponses) onUpdateResponses();
   };
 
-  const onAnnotate = (label) => {
+  const onAnnotate = (label?: string) => {
     if (uid === undefined) return;
     if (typeof label === "string" && label.trim().length === 0)
       label = undefined; // empty strings are undefined
     const new_notes = noteState ?? {};
-    innerIdxs.forEach((idx) => {
+    innerIdxs.forEach((idx: number) => {
       new_notes[idx] = label;
     });
     setRating(uid, "note", new_notes);
diff --git a/chainforge/react-server/src/backend/utils.ts b/chainforge/react-server/src/backend/utils.ts
index e2933dd..5dbf92a 100644
--- a/chainforge/react-server/src/backend/utils.ts
+++ b/chainforge/react-server/src/backend/utils.ts
@@ -23,6 +23,7 @@ import {
   TemplateVarInfo,
   BaseLLMResponseObject,
   LLMSpec,
+  EvaluationScore,
 } from "./typing";
 import { v4 as uuid } from "uuid";
 import { StringTemplate } from "./template";
@@ -1786,10 +1787,10 @@ export const truncStr = (
 
 export const groupResponsesBy = (
   responses: LLMResponse[],
-  keyFunc: (item: LLMResponse) => string | null | undefined,
-) => {
-  const responses_by_key: Dict = {};
-  const unspecified_group: Dict[] = [];
+  keyFunc: (item: LLMResponse) => string | number | null | undefined,
+): [Dict<LLMResponse[]>, LLMResponse[]] => {
+  const responses_by_key: Dict<LLMResponse[]> = {};
+  const unspecified_group: LLMResponse[] = [];
   responses.forEach((item) => {
     const key = keyFunc(item);
     if (key === null || key === undefined) {
@@ -1802,22 +1803,28 @@ export const groupResponsesBy = (
   return [responses_by_key, unspecified_group];
 };
 
-export const batchResponsesByUID = (responses: LLMResponse[]) => {
+/**
+ * Merges inner .responses and eval_res.items properties for LLMResponses with the same
+ * uid, returning the (smaller) list of merged items.
+ * @param responses 
+ * @returns 
+ */
+export const batchResponsesByUID = (responses: LLMResponse[]): LLMResponse[] => {
   const [batches, unspecified_id_group] = groupResponsesBy(
     responses,
     (resp_obj) => resp_obj.uid,
   );
   return Object.values(batches)
-    .map((resp_objs: Dict[]) => {
+    .map((resp_objs: LLMResponse[]) => {
       if (resp_objs.length === 1) {
         return resp_objs[0];
       } else {
         const batched = deepcopy_and_modify(resp_objs[0], {
           responses: resp_objs.map((resp_obj) => resp_obj.responses).flat(),
-        });
-        if (batched.eval_res !== undefined) {
+        }) as LLMResponse;
+        if (batched.eval_res?.items !== undefined) {
           batched.eval_res.items = resp_objs
-            .map((resp_obj) => resp_obj.eval_res.items)
+            .map((resp_obj) => resp_obj?.eval_res?.items as EvaluationScore[])
             .flat();
         }
         return batched;
@@ -1911,8 +1918,8 @@ export async function retryAsyncFunc<T>(
 
 // Filters internally used keys LLM_{idx} and __{str} from metavar dictionaries.
 // This method is used to pass around information hidden from the user.
-export function cleanMetavarsFilterFunc() {
-  return (key: string) => !(key.startsWith("LLM_") || key.startsWith("__pt"));
+export function cleanMetavarsFilterFunc(key: string) {
+  return !(key.startsWith("LLM_") || key.startsWith("__pt"));
 }
 
 // Verify data integrity: check that uids are present for all responses.