Migrating from Svix

Svix and Hookgres share the same model: applications or tenants, endpoints, messages, signed deliveries with retries. Both sign with the Standard Webhooks scheme. Most of a migration is renaming calls. The one change your receivers will notice is the request body format, covered below.

Concepts

Svix	Hookgres
Application (uid)	tenantId
Endpoint	Endpoint
filterTypes	eventTypes
Message eventType	eventType
Message payload	payload
Message eventId	idempotencyKey
Message attempt	Attempt
Resend / recover	replayDelivery
Endpoint secret (whsec_...)	Endpoint secret (whsec_...)
Channels, transformations, portal	Not built in

Code

// Svix
await svix.application.create({ name: "Acme", uid: "acme" });
const ep = await svix.endpoint.create("acme", {
  url: "https://acme.example.com/webhooks",
  filterTypes: ["invoice.paid"],
});
await svix.message.create("acme", {
  eventType: "invoice.paid",
  eventId: "evt_123",
  payload: { invoiceId: "in_123" },
});

// Hookgres (no application step: a tenant is just a string)
const endpoint = await hookgres.createEndpoint({
  tenantId: "acme",
  url: "https://acme.example.com/webhooks",
  eventTypes: ["invoice.paid"],
});
await hookgres.send({
  tenantId: "acme",
  eventType: "invoice.paid",
  idempotencyKey: "evt_123",
  payload: { invoiceId: "in_123" },
});

Keep your customers' secrets

Endpoints can be imported with their existing secrets, so receivers don't have to change anything:

for (const ep of endpointsExportedFromSvix) {
  await hookgres.createEndpoint({
    tenantId: ep.appUid,
    url: ep.url,
    eventTypes: ep.filterTypes ?? null,
    secret: ep.secret, // whsec_...
  });
}

Hookgres accepts whsec_ secrets of 24 to 64 bytes and rejects anything else. If an imported secret is rejected, create the endpoint with a new secret and ask that customer to update theirs.

What receivers will notice

Headers. Hookgres sends webhook-id, webhook-timestamp and webhook-signature. Svix sends svix-id, svix-timestamp and svix-signature, with the same values and the same signing scheme. Receivers using a Standard Webhooks library work unchanged. Receivers reading the svix-* headers themselves need to read the webhook-* ones. Check whether the version of the Svix library they use accepts webhook-* headers.

Body. Svix posts your payload as the body exactly as you sent it. Hookgres wraps it in an envelope:

{
  "type": "invoice.paid",
  "timestamp": "2026-11-08T15:04:05.000Z",
  "data": { "invoiceId": "in_123" }
}

so receivers find your payload under data. Tell your customers before you switch, or move tenants over gradually while they update.

Retries. The default schedule is the same shape as Svix's: 5s, 5m, 30m, 2h, 5h, 10h, 10h.

Idempotency. Svix answers a repeated eventId with a 409 Conflict error. Hookgres doesn't throw: it returns the original message with deduplicated: true, so code that catches Svix's 409 can check that flag instead. Hookgres keeps an idempotency key for as long as the message exists, until your cleanup job deletes it.

Switching over

1. Run Hookgres alongside Svix and import endpoints with their secrets.
2. Tell customers about the body envelope and the header names.
3. Switch send() calls per tenant, or all at once, behind a flag.
4. Keep Svix running until its retries have finished, which takes about a day.