diff --git a/keyserver/src/responders/farcaster-webhook-responders.js b/keyserver/src/responders/farcaster-webhook-responders.js
--- a/keyserver/src/responders/farcaster-webhook-responders.js
+++ b/keyserver/src/responders/farcaster-webhook-responders.js
@@ -2,16 +2,77 @@
 
 import { createHmac } from 'crypto';
 import type { $Request } from 'express';
+import { getRustAPI } from 'rust-node-addon';
 
+import { extractKeyserverIDFromID } from 'lib/keyserver-conn/keyserver-call-utils.js';
+import { threadTypes } from 'lib/types/thread-types-enum.js';
+import { type NewThreadResponse } from 'lib/types/thread-types.js';
 import { neynarWebhookCastCreatedEventValidator } from 'lib/types/validators/farcaster-webhook-validators.js';
 import { ServerError } from 'lib/utils/errors.js';
 import { assertWithValidator } from 'lib/utils/validation-utils.js';
 
-import { getNeynarConfig } from '../utils/fc-cache.js';
+import {
+  getFarcasterChannelTagBlob,
+  createOrUpdateFarcasterChannelTag,
+  farcasterChannelTagBlobValidator,
+} from '../creators/farcaster-channel-tag-creator.js';
+import { createThread } from '../creators/thread-creator.js';
+import { verifyUserIDs } from '../fetchers/user-fetchers.js';
+import { createScriptViewer } from '../session/scripts.js';
+import { thisKeyserverAdmin, thisKeyserverID } from '../user/identity.js';
+import { getNeynarConfig, neynarClient } from '../utils/fc-cache.js';
 
 const taggedCommFarcasterInputValidator =
   neynarWebhookCastCreatedEventValidator;
 
+const noChannelCommunityID = '80887273';
+
+async function createTaggedFarcasterCommunity(
+  channelID: string,
+  taggerFID: string,
+): Promise<NewThreadResponse> {
+  const neynarChannel =
+    await neynarClient?.fetchFarcasterChannelByID(channelID);
+  if (!neynarChannel) {
+    throw new ServerError('channel_not_found');
+  }
+
+  const keyserverAdmin = await thisKeyserverAdmin();
+  let communityAdminID = keyserverAdmin.id;
+  const leadFID = neynarChannel.lead.fid.toString();
+
+  const rustAPI = await getRustAPI();
+  const farcasterUsers = await rustAPI.getFarcasterUsers([leadFID, taggerFID]);
+
+  const validUserIDs = await verifyUserIDs(
+    farcasterUsers.map(user => user.userID),
+  );
+
+  const validFarcasterUsers = farcasterUsers.filter(user =>
+    validUserIDs.includes(user.userID),
+  );
+
+  if (validFarcasterUsers.length > 0) {
+    communityAdminID =
+      farcasterUsers.find(user => user.farcasterID === leadFID)?.userID ||
+      farcasterUsers[0].userID;
+  }
+
+  const adminViewer = createScriptViewer(communityAdminID);
+  const newThreadResponse = await createThread(adminViewer, {
+    type: threadTypes.COMMUNITY_ROOT,
+    name: neynarChannel.name,
+    description: neynarChannel.description,
+  });
+
+  await createOrUpdateFarcasterChannelTag(adminViewer, {
+    commCommunityID: newThreadResponse.newThreadID,
+    farcasterChannelID: channelID,
+  });
+
+  return newThreadResponse;
+}
+
 async function taggedCommFarcasterResponder(req: $Request): Promise<void> {
   const body = req.body;
 
@@ -35,6 +96,49 @@
   if (!isValid) {
     throw new ServerError('invalid_webhook_signature');
   }
+
+  const isAuthoritativeFarcasterBot = !!process.env.AUTHORITATIVE_FARCASTER_BOT;
+  const eventChannelID = event.data.channel?.id;
+  const eventTaggerFID = event.data.author.fid;
+
+  if (!eventChannelID && !isAuthoritativeFarcasterBot) {
+    return;
+  }
+
+  let channelCommunityID = noChannelCommunityID;
+  if (eventChannelID) {
+    const blobDownload = await getFarcasterChannelTagBlob(eventChannelID);
+    if (blobDownload.found) {
+      const blobText = await blobDownload.blob.text();
+      const blobObject = JSON.parse(blobText);
+      const farcasterChannelTagBlob = assertWithValidator(
+        blobObject,
+        farcasterChannelTagBlobValidator,
+      );
+
+      const { commCommunityID } = farcasterChannelTagBlob;
+      const commCommunityKeyserverID =
+        extractKeyserverIDFromID(commCommunityID);
+      const keyserverID = await thisKeyserverID();
+
+      if (keyserverID !== commCommunityKeyserverID) {
+        return;
+      }
+      channelCommunityID = commCommunityID.split('|')[1];
+    } else if (!blobDownload.found && blobDownload.status === 404) {
+      if (!isAuthoritativeFarcasterBot) {
+        return;
+      }
+      const newThreadResponse = await createTaggedFarcasterCommunity(
+        eventChannelID,
+        eventTaggerFID.toString(),
+      );
+      channelCommunityID = newThreadResponse.newThreadID;
+    } else {
+      throw new ServerError('blob_fetch_failed');
+    }
+  }
+  console.log(channelCommunityID);
 }
 
 export { taggedCommFarcasterResponder, taggedCommFarcasterInputValidator };