diff --git a/lib/utils/farcaster-helpers.js b/lib/utils/farcaster-helpers.js
new file mode 100644
--- /dev/null
+++ b/lib/utils/farcaster-helpers.js
@@ -0,0 +1,79 @@
+// @flow
+
+import { FCCache } from './fc-cache.js';
+
+type BaseFCInfo = {
+  +fid?: ?string,
+  +farcasterUsername?: ?string,
+  ...
+};
+export type GetFCNames = <T: ?BaseFCInfo>(
+  users: $ReadOnlyArray<T>,
+) => Promise<T[]>;
+
+async function getFCNames<T: ?BaseFCInfo>(
+  fcCache: FCCache,
+  users: $ReadOnlyArray<T>,
+): Promise<T[]> {
+  const info = users.map(user => {
+    if (!user) {
+      return user;
+    }
+    const { fid, farcasterUsername } = user;
+    let cachedResult = null;
+    if (farcasterUsername) {
+      cachedResult = farcasterUsername;
+    } else if (fid) {
+      cachedResult = fcCache.getCachedFarcasterUsernameForFID(fid);
+    }
+    return {
+      input: user,
+      fid,
+      cachedResult,
+    };
+  });
+
+  const needFetch = info
+    .map(user => {
+      if (!user) {
+        return null;
+      }
+      const { fid, cachedResult } = user;
+      if (cachedResult || !fid) {
+        return null;
+      }
+      return fid;
+    })
+    .filter(Boolean);
+
+  const farcasterUsernames = new Map<string, string>();
+  if (needFetch.length > 0) {
+    const results = await fcCache.getFarcasterUsernamesForFIDs(needFetch);
+    for (let i = 0; i < needFetch.length; i++) {
+      const fid = needFetch[i];
+      const result = results[i];
+      if (result) {
+        farcasterUsernames.set(fid, result);
+      }
+    }
+  }
+
+  return info.map(user => {
+    if (!user) {
+      return user;
+    }
+    const { input, fid, cachedResult } = user;
+    if (cachedResult) {
+      return { ...input, farcasterUsername: cachedResult };
+    } else if (!fid) {
+      return input;
+    }
+    const farcasterUsername = farcasterUsernames.get(fid);
+    if (farcasterUsername) {
+      return { ...input, farcasterUsername };
+    }
+    return input;
+  });
+}
+
+export { getFCNames };