NewHow the Agent Session Protocol builds trust between autonomous systems.
Use Case

Reliable webhook delivery

Send once, deliver to every endpoint with retries and proof.

You send a webhook.

The endpoint is down.

You retry once. Twice.

Still down.

The event is gone.

Your customer opens a ticket.

npayload retries, recovers, and proves delivery.

No event is ever lost.

See how it flows

Guaranteed delivery

Six retries with exponential backoff. Circuit breaker for persistent failures. Dead letter queue for anything that still fails.

Delivery Attempts
1
POST /webhook
503
retry
+0s
2
POST /webhook
503
retry
+2s
3
POST /webhook
503
retry
+8s
4
POST /webhook
200
delivered
+32s
Exponential backoff. Never lost.

Delivery proof

Timestamps, response codes, and retry history for every delivery. Your customers can verify everything.

Delivery Proof
api.acme.com/hooks200
sha256=a3f8...14:22:08
events.partner.io200
sha256=7e2b...14:22:09
hooks.client.dev200
sha256=b91c...14:22:09

Signature verification

Every webhook is signed. Recipients verify authenticity without extra work.

Delivery Proof
api.acme.com/hooks200
sha256=a3f8...14:22:08
events.partner.io200
sha256=7e2b...14:22:09
hooks.client.dev200
sha256=b91c...14:22:09

Independent endpoints

One slow endpoint does not affect the others. Each delivery is tracked and retried independently.

Billing API42ms
Shipping Service38ms
Analytics51ms
Notification Hub29ms

How it works

1

Register your endpoints

Tell npayload where to deliver. Set retry preferences and failure thresholds.

2

Events are delivered with proof

Every delivery is signed and tracked. Response codes and retry history are recorded.

3

Failures recover on their own

Retries with backoff. Circuit breaker for persistent failures. Dead letter queue for anything that still fails.

Webhook Delivery: Before and After

Without npayload

  • Failed webhooks disappear silently and customers file support tickets days later
  • No way to prove to a customer that you delivered a webhook at a specific time
  • Building retry logic with exponential backoff and circuit breakers takes months
  • Monitoring webhook health across hundreds of customer endpoints is a full time job
  • A single unhealthy endpoint causes cascading delays for all other deliveries

With npayload

  • Every webhook delivery is tracked with status, timestamps, and retry history
  • Cryptographic delivery receipts provide proof of delivery for dispute resolution
  • Automatic retries with exponential backoff and circuit breakers out of the box
  • Dashboard shows endpoint health, delivery rates, and failure patterns across all customers
  • Circuit breakers isolate unhealthy endpoints so they never affect other deliveries

npayload vs Building Webhook Delivery Yourself

FeaturenpayloadBuild it yourself
Retry logicConfigurable retries with exponential backoff, jitter, and max attemptsCustom retry code that misses edge cases
Circuit breakersAutomatic circuit breaking per endpoint with configurable thresholdsBuild, test, and maintain circuit breaker logic
Delivery proofHMAC signatures and cryptographic receiptsLogs that customers can dispute
Dead letter queueAutomatic DLQ with inspection, filtering, and replayFailed events written to a database table, manually reprocessed
Endpoint monitoringReal time health scores and alerting per endpointCustom dashboards and alert rules per customer
Signature verificationHMAC verification with key rotation supportStatic shared secrets, manual rotation

Frequently asked questions

How does npayload handle webhook endpoint failures?+
npayload retries failed deliveries with exponential backoff and jitter. If an endpoint fails repeatedly, a circuit breaker opens to stop sending traffic. Failed events go to a DLQ where you can inspect, filter, and replay them when the endpoint recovers.
Can customers verify that a webhook came from us?+
Yes. Every webhook is signed with HMAC. Customers verify the signature using your shared secret. npayload also supports key rotation so you can update secrets without downtime.
How do we prove we delivered a webhook?+
npayload provides cryptographic delivery receipts with timestamps. When a dispute arises about whether an event was delivered, you have verifiable proof.
What is the maximum retry window?+
You configure the retry policy per channel: number of attempts, backoff strategy, and maximum retry window. Typical configurations range from minutes to 72 hours depending on the use case.