This Val Town script automatically cross-posts your Farcaster casts to Twitter/X using webhooks. When you create a new cast on Farcaster, it gets automatically posted to your Twitter account.

• Receives Farcaster webhooks: Listens for cast.created events from Neynar
• Filters content: Only processes original casts (skips replies/responses)
• Handles media: Downloads images from Farcaster and uploads them to Twitter
• Manages text length: Ensures posts stay within Twitter's 280-character limit
• Cross-posts: Automatically posts your Farcaster content to Twitter/X

• ✅ Automatic cross-posting from Farcaster to Twitter
• ✅ Image support (up to 2 images per post)
• ✅ URL preservation in posts
• ✅ Character limit validation
• ✅ Error handling and logging
• ✅ Skips replies to avoid spam

1. Fork this Val Town script to your account
2. Note your Val's URL (you'll need this for the webhook setup)

1. Go to Twitter Developer Portal
2. Create a developer account if you don't have one
3. Create a new app/project

Before generating your access tokens, you must configure user authentication:

1. In your Twitter app settings, go to "User authentication settings"
2. Set up OAuth 1.0a with Read and Write permissions
3. Add your website URL and callback URL (can be placeholder URLs)
4. Save the settings

After setting up authentication with read/write permissions:

1. Go to "Keys and Tokens" tab
2. Generate/copy these credentials:
   • API Key (TWITTER_API_KEY)
   • API Secret (TWITTER_API_SECRET)
   • Access Token (TWITTER_ACCESS_TOKEN)
   • Access Token Secret (TWITTER_ACCESS_TOKEN_SECRET)

Note: Free plan limits: 100 posts read + 500 writes per month

In your Val Town script, add these environment variables:

• TWITTER_API_KEY
• TWITTER_API_SECRET
• TWITTER_ACCESS_TOKEN
• TWITTER_ACCESS_TOKEN_SECRET

1. Go to Neynar Webhook Setup
2. Create a new webhook with these settings:
   • Event Type: cast.created
   • Target URL: Your Val Town script URL (e.g., https://yourname-scriptname.web.val.run)
   • Filter: Configure to only receive your own casts (set your FID)

Note: Neynar webhooks require a paid plan

1. You create a cast on Farcaster
2. Neynar sends a webhook to your Val Town script
3. The script processes the cast:
   • Skips if it's a reply
   • Downloads any images and uploads them to Twitter
   • Appends non-image URLs to the text
   • Validates character count
4. Posts the content to Twitter/X automatically

• Twitter Free Plan: 100 reads + 500 writes per month
• Neynar webhooks require paid subscription
• Maximum 2 images per post (Farcaster limit)
• 280 character limit for Twitter posts
• Only processes original casts (not replies)

Check the Val Town logs if posts aren't appearing on Twitter:

• Verify all environment variables are set
• Ensure Twitter API keys have read/write permissions
• Check that webhook URL is correctly configured in Neynar
• Verify your Neynar webhook is active and properly filtered

For issues with:

• Twitter API: Check Twitter Developer Documentation
• Neynar Webhooks: Check Neynar Documentation
• Val Town: Check Val Town Documentation