Preview link

Open a sent push, email or SMS with its signed preview link — no sign-in, 30 days.

What the preview link opens

Every push, email and SMS that Norbix sends gets its own preview link. The link opens a page with the content of that one message, as the recipient got it — tokens already filled in:

channel	what the preview shows
Push	title and body
Email	subject and the HTML body
SMS	the text

The preview never shows the recipients, device tokens, provider settings or any other message of the campaign.

For email, the link is what the View in web block of a template points at: https://<your cloud address>/notifications/emails/preview?hash=<hash>. For push and SMS, the hash is stored on the message (Campaign.NotificationHash in the message model) and read with GET /v3/notifications/push/preview?hash=<hash> or GET /v3/notifications/sms/preview?hash=<hash> (email: GET /v3/notifications/email/preview?hash=<hash>).

No sign-in needed

The link needs no sign-in and no API key. The hash in the link is the key: it is signed by Norbix, so it cannot be changed or made up, and it opens only the message it was made for.

Anyone who has the link can see the content. Treat it like the message itself: do not put a preview link where the message would not be allowed.

Members of the project can also open a preview by id when signed in: GET /v3/notifications/push/preview?projectId=<id>&notificationId=<id> needs the push:read permission (email: email:read, SMS: sms:read).

What the link contains

The hash has two parts, <part 1>.<part 2>, both URL-safe base64:

part	content	readable by anyone with the link?
1	<key version>:<encrypted payload> — the payload is JSON with the project id, notification id, environment and expiry time, encrypted with the server's AES key	only the key version (for example v2). The project id, notification id, environment and expiry are encrypted.
2	HMAC-SHA256 signature of part 1	no — it only proves part 1 was not changed

The signature key is derived (HKDF-SHA256) from the server secret NORBIX_GATEWAY_AUTH_JWT_AESKEYBASE64 with the purpose label notification-preview-link-v1, so it is different from every other key. A link also opens only when it is exactly the link stored on that message.

Self-hosted installations: the AES encryption keys ship inside the Norbix binaries, so someone who has the binaries can read the payload of a link (project id, notification id, environment, expiry). They still cannot open a message without its exact link. Set NORBIX_GATEWAY_AUTH_JWT_AESKEYBASE64 on every host (Hub, Api and the workers) to the same value. Without it, a host that is not a Development host sends messages without a preview link (the "View in web" block is left out) and refuses every preview link with 401; it prints one [ERROR] … is not set line with the reason. Only a host whose ASPNETCORE_ENVIRONMENT is explicitly Development (and that is not a release edition build) falls back to a built-in key, so a local checkout works without the secret. An unset ASPNETCORE_ENVIRONMENT counts as Production.

The link answer is sent with Referrer-Policy: no-referrer and Cache-Control: no-store, and the "View in web" page tells the browser not to send the link on to other sites.

The "View in web" page shows the email inside a sandboxed frame: nothing in the email can run scripts or reach the page. Links in the email open in a new tab, as they would from a mail client.

It expires after 30 days

A preview link works for 30 days after the message was sent. After that it answers "This preview link has expired." Links made before preview links were signed (September 2026) no longer open; they answer the same way.

Error codes

HTTP	error code	when
401	CM-ERRORS-NOTIFICATIONS-PREVIEW-001	the link is not valid: it was changed, it is for another message or project, or the message is gone. The answer is the same in every case, so it does not tell whether a message exists.
401	CM-ERRORS-NOTIFICATIONS-PREVIEW-002	the link has expired (30 days after sending).
401	CM-ERRORS-NOTIFICATIONS-PREVIEW-003	no link and not signed in.
400	CM-ERRORS-SECRETS-011	the hash is not a preview link at all.
400	CM-ERRORS-SECRETS-001	the hash is empty.
403	CM-ERRORS-MEMBERSHIP-039	signed in, asked by id, but without push:read / email:read / sms:read.
404	CM-ERRORS-NOTIFICATIONS-INBOX-001	signed in with the permission, asked by an id that does not exist.
429	—	too many preview requests from one address (60 per minute).