How to integrate Neynar webhooks for real-time events

Incoming webhooks allow you to receive real-time notifications about Farcaster events. Consider the following use cases.

watch a channel - get events for any new casts on a specific channel
watch a user - get events for any new casts from a specific user
watch a mention - get events when a specific user gets @ mentioned in a cast

You’ll need to configure 2 things before you can start receiving Farcaster events via webhooks.

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It’s not possible to use webhooks on frontend-only apps

1. Create a webhook

Create a REST API route with the POST method on your backend to handle the webhook events. It should be able to handle incoming data with Content-Type set to application/json format.

To test that your webhook is set up correctly, try this curl

curl -X POST \
	-d '{"event" : "test"}' \
	-H 'Content-Type: application/json' \
https://api.your-farcaster-app.com/webhooks/neynar

2. Register the webhook details on the Neynar Dev Portal

Set this outgoing webhook URL on the Neynar developer portal. See here for how.

https://api.your-farcaster-app.com/webhooks/neynar

A webhook should be configured with at least 1 valid event subscription. Each webhook can support multiple event types and/or multiple subscriptions for the same type. Some subscriptions require one or more parameters to be configured before you can start receiving the relevant events.

Event types supported

cast.created
Subscriptions supported
1. Authors - Get events for new casts & replies by a specific user
2. Root Parent Url - Get events for new casts & replies in a specific channel
3. Parent Url - Get events for new casts (but not replies) in a specific channel
4. Mentions - Get events when a specific user gets @ mentioned in a cast
user.updated
Subscriptions supported
1. User - Get profile update events for specific users

You’re all set! You’ll start receiving events on your backend.