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Webhooks

This page covers the webhook infrastructure, cryptographic verification, and inbound event routing for the Meta Cloud API.

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Webhook Verification Challenge

Content coming soon.

• Meta handshake parameters (hub.mode, hub.challenge, hub.verify_token)
• Handshake endpoint validation

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Cryptographic Security (HMAC-SHA256)

Content coming soon.

• Verifying the X-Hub-Signature-256 header
• Meta App Secret hashing
• Constant-time string comparison (timingSafeEqual) to prevent timing attacks

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Idempotency & Deduplication

Content coming soon.

• Handling Meta’s at-least-once delivery guarantees
• Redis-based locking and message ID (wamid) deduplication
• Asynchronous queueing for inbound message processors