// GLOSSARY -- WEB3 INFRASTRUCTURE

What is Webhook?

1 min read Updated

A webhook is an HTTP callback that pushes real-time notifications when blockchain events occur — enabling applications to react to on-chain activity without constantly polling for changes.

WHY IT MATTERS

Webhooks replace polling with pushing. Instead of your application repeatedly asking 'any new transactions?', the infrastructure provider sends an HTTP request to your server when something happens. More efficient, lower latency, and simpler to implement.

Blockchain webhook providers (Alchemy, QuickNode, Moralis) offer notifications for: address activity (incoming/outgoing transactions), contract events, pending transactions, and token transfers.

For agent systems, webhooks enable reactive behavior: trigger an action when a specific on-chain event occurs, rather than continuously scanning the blockchain for changes.

FREQUENTLY ASKED QUESTIONS

Webhooks vs WebSockets vs polling?
Webhooks: push-based, no persistent connection, best for event-driven apps. WebSockets: real-time streaming, persistent connection. Polling: pull-based, simplest but highest latency.
Are blockchain webhooks reliable?
Provider-dependent. Major providers offer retry logic, delivery guarantees, and monitoring. Design your application to handle missed webhooks (idempotent processing, periodic catch-up).
What events can trigger webhooks?
Address activity, smart contract events, token transfers, NFT activity, pending transactions, and more. The specific triggers available depend on your provider.

FURTHER READING

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