Grabbed dndbeyond's source code

```
~/go/bin/sourcemapper -output ddb -jsurl https://media.dndbeyond.com/character-app/static/js/main.90aa78c5.js
```

ddb_main/contexts/FeatureFlag/FeatureFlag.tsx

@@ -0,0 +1,84 @@
+import { FC, createContext, useContext, useEffect, useState } from "react";
+
+import { toCamelCase } from "~/helpers/casing";
+import { getFeatureFlagsFromCharacterService } from "~/helpers/characterServiceApi";
+
+const featureFlagsToGet = [
+  "release-gate-ims",
+  "release-gate-gfs-blessings-ui",
+  "release-gate-character-sheet-tour",
+  "release-gate-premade-characters",
+];
+
+export const defaultFlags = {
+  imsFlag: false,
+  gfsBlessingsUiFlag: false,
+  characterSheetTourFlag: false,
+  premadeCharactersFlag: false,
+};
+
+export type FeatureFlags = typeof defaultFlags;
+
+export interface FeatureFlagContextType extends FeatureFlags {
+  featureFlags: FeatureFlags;
+}
+
+export const FeatureFlagContext = createContext<FeatureFlagContextType>(null!);
+
+interface ProviderProps {
+  defaultOverrides?: Partial<FeatureFlags>;
+}
+
+export const FeatureFlagProvider: FC<ProviderProps> = ({
+  children,
+  defaultOverrides,
+}) => {
+  const [featureFlags, setFeatureFlags] = useState({
+    ...defaultFlags,
+    ...defaultOverrides,
+  });
+
+  const convertFlagsToKeys = (flags: Object) => {
+    return Object.keys(flags).reduce((acc, flag) => {
+      // Perform any manipulations to remove unwanted characters
+      const formattedFlag = flag
+        // Remove `character-app` from the flag name
+        .replace(/character-app\./i, "")
+        // Remove `release-gate` from the flag name
+        .replace(/release-gate\W/i, "")
+        // Remove `character-sheet` from flag name if not the tour flag
+        .replace(/character-sheet\W(?!tour)/i, "")
+        // Change `2d` to `tactical` since var can't start with number
+        .replace(/2d/i, "tactical");
+
+      const key = toCamelCase(`${formattedFlag}Flag`);
+      return { ...acc, [key]: flags[flag] };
+    }, {});
+  };
+
+  const getFeatureFlags = async () => {
+    try {
+      const req = await getFeatureFlagsFromCharacterService(featureFlagsToGet);
+      const res = await req.json();
+      const flags = convertFlagsToKeys(res.data) as FeatureFlags;
+      setFeatureFlags(flags);
+    } catch (err) {
+      console.error(err);
+    }
+  };
+
+  useEffect(() => {
+    if (!defaultOverrides) getFeatureFlags();
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [defaultOverrides]);
+
+  return (
+    <FeatureFlagContext.Provider value={{ ...featureFlags, featureFlags }}>
+      {children}
+    </FeatureFlagContext.Provider>
+  );
+};
+
+export const useFeatureFlags = () => {
+  return useContext(FeatureFlagContext);
+};