HookFlow 2.4: preview transformations against real payloads

Transformations have been the most-requested area of HookFlow since we launched them last spring. Teams use them to strip personal data before events hit a logging pipeline, to flatten deeply nested Shopify orders into the shape their CRM expects, and to fan a single Stripe event out to Slack with only the fields a human needs. What they told us, consistently, was that writing a mapping felt like coding blind.

HookFlow 2.4 fixes that with a preview pane. Pick any delivery from the last 30 days, or paste a payload of your own, and the dashboard shows the transformed output side by side as you type. Fields that resolve to nothing are highlighted so you notice a typo in a dotted path before it ships. The same capability is available over the API at POST /api/v1/transforms/{id}/preview, which makes it easy to put mappings under test in CI.

We also added version history. Every change to a transformation is stored with the author and a diff, and you can roll back to any previous version in one click. Combined with the audit log, this answers the question every on-call engineer eventually asks: who changed what this event looks like, and when?

Finally, transformations can now be scoped to a single endpoint instead of applying globally to a provider. If you have separate staging and production endpoints for GitHub, each can have its own mapping. Existing transformations keep their current behaviour; nothing changes until you edit them.