Replay API is now generally available

Webhooks that actually arrive.

Hookline is the delivery layer between your product and every endpoint it talks to. Send, sign, retry and replay from a single SDK, with full visibility into every attempt.

Start for free

Read the docs

$npm install @hookline/sdk

hookline — zsh

$

Trusted by engineering teams at

Northwind

Parcel

Lumen

Quillio

Orbital

Halden

Mosaic

Tidewater

01 — Send

One call. Every endpoint.

Emit an event once. Hookline fans it out to every subscribed endpoint, signs each request with a per-endpoint secret and keeps the receipt. Your code stays a single function call.

SDKs for TypeScript, Python, Go and Ruby

HMAC-SHA256 signatures with secret rotation

Idempotency keys and ordered delivery per endpoint

Explore the SDK

1import { Hookline } from "@hookline/sdk"
2 
3const hooks = new Hookline({
4  apiKey: process.env.HOOKLINE_KEY,
5})
6 
7await hooks.send({
8  event: "invoice.paid",
9  endpoint: "ep_8f2k1",
10  payload: { invoiceId: "inv_1042", amount: 4900 },
11  // signed, retried, replayable
12})

02 — Deliver

Three steps between your event and their server.

Emit an event

Call hooks.send() with an event name and a payload. We validate the schema, assign an id and persist it before we return.

We fan out and sign

Every endpoint subscribed to the event gets its own signed request, with backoff schedules tuned to how that endpoint has behaved before.

Track, retry, replay

Watch each attempt land in the dashboard. Replay a single event or a whole hour with one click or one API call.

03 — Reliability

Built for the endpoints you don’t control.

Customer servers go down, rotate secrets and change their minds. Hookline absorbs all of it so your product never notices.

Retries that learn each endpoint

Exponential backoff with jitter by default. Endpoints that flap get longer windows, endpoints that fail hard get circuit-broken and you get an alert.

attempt 1

502

0.0s

attempt 2

502

+2.1s

attempt 3

429

+6.4s

attempt 4

200

+18.9s

HMAC-signed, always

Every request carries a timestamped SHA-256 signature. Rotate secrets with zero downtime and a grace window you choose.

Replay anything, any time

Pick an event, an endpoint or a time range and resend. Payloads are retained for 30 days on every plan.

Endpoint health, live

See p50 and p99 latency, error rate and the last failing payload for every endpoint without opening a log.

0.00%

delivered in the last 30 days

Alerts where you work

Slack, PagerDuty, email or a webhook about your webhooks. Thresholds per endpoint, quiet hours per team.

0.00%

delivery success rate

0ms

median end-to-end latency

0.0B

events delivered last month

regions with edge delivery

04 — Connect

Plays well with the stack you already run.

Native receivers for the tools your team lives in, and a plain HTTPS endpoint for everything else.

Stripe

Billing events in

Shopify

Order events in

Github

Repo events in

Slack

Alerts out

Discord

Alerts out

Zapier

Any app out

Datadog

Metrics out

Twilio

SMS fallback

05 — Developers

What people say after the migration.

“We deleted 1,400 lines of retry code the week we switched. The replay button alone has saved us two incidents.”

Maya Alvarez

@mayabuilds

“Signature rotation used to be a two-day project with customer comms. Now it’s a toggle with a grace window.”

Daniel Okafor

@dokafor_dev

“The per-endpoint health view is the thing I didn’t know I needed. We spot a flaky customer server before they do.”

Sofia Lindqvist

@sofialq

06 — Open source

The SDKs are open. So is the roadmap.

Every client library, the CLI and the local dev server are MIT licensed. Issues are triaged within a day and the changelog ships every Tuesday.

Star on GitHub12.4k

Join the Discord

Discord members

Contributors

Releases this year

SDK languages

07 — Pricing

Start free. Pay for events, not seats.

Every plan includes signatures, retries, replay and 30-day payload retention. Upgrade when your volume does.

Free

/mo

For side projects and evaluation.

10,000 events per month

3 endpoints

7-day payload retention

Community support

Start free

Pro

Scale

Custom

For platforms and regulated teams.

Volume pricing

SSO and audit log

Dedicated regions

99.99% uptime SLA

Shared Slack channel

Talk to sales

Compare all plans and estimate your bill

Get started

Ship your first webhook in five minutes.

Free up to 10,000 events a month. No credit card, no sales call, no retry code.

$npm install @hookline/sdk

Read the docs

Buy this template

$49