Transformations | HookDeploy

HookDeploy’s payload transformation editor lets you modify webhook JSON before it reaches each forward destination. No code, no JSONata — just point, click, and preview.

Configure transformations per destination in Endpoint → Settings → Forward destinations → Configure transform.

Transformation modes

	Passthrough	Allowlist
Default behavior	Forward all fields	Forward only selected fields
Best for	Tweaking a few fields on an otherwise complete payload	Strict PII control, analytics pipelines
Unselected fields	Included unchanged	Dropped from output
Strip PII	Toggle “Strip field” on specific paths	Uncheck fields you don’t want
Static fields	Added on top of forwarded payload	Added to allowlisted output

When to use passthrough

Your webhook sender sends a rich payload and you only need to rename amount to amount_usd, mask an email, or add a source field. Most fields pass through untouched.

When to use allowlist

You’re forwarding to a third-party analytics tool and want to send only event_type and amount — nothing else. Allowlist mode ensures no accidental PII leakage.

Field path syntax

Paths use dot notation to reach nested fields:

amount                    → top-level field
data.amount               → nested object
customer.email            → deeply nested
items.0.price             → first array element's price field

In the visual editor, click any field in the JSON tree to add a transform rule. The editor loads your latest captured webhook as sample data so you can preview changes live.

Formatter reference

Formatters run in the order you add them. Chain multiple formatters on one field — for example, cents_to_dollars then prefix with value "USD ".

Numeric

Formatter	Options	Input example	Output example
`cents_to_dollars`	—	`4200`	`"$42.00"`
`dollars_to_cents`	—	`42.00`	`4200`
`multiply`	`value` (number)	`100` × 1.5	`150`
`divide`	`value` (number)	`100` ÷ 4	`25`
`round`	`decimals` (0–10)	`3.14159`	`3.14`
`abs`	—	`-42`	`42`

String

Formatter	Options	Input example	Output example
`uppercase`	—	`"hello"`	`"HELLO"`
`lowercase`	—	`"HELLO"`	`"hello"`
`titlecase`	—	`"hello world"`	`"Hello World"`
`trim`	—	`" hello "`	`"hello"`
`prefix`	`value` (string)	`"123"` + prefix `"order_"`	`"order_123"`
`suffix`	`value` (string)	`"123"` + suffix `"-v2"`	`"123-v2"`
`truncate`	`max` (length)	`"hello world"` max 5	`"hello"`
`mask`	`show_chars`, `position` (`start`/`end`)	`"john@example.com"` show 3 start	`"joh*************"`
`hash`	—	`"john@example.com"`	SHA-256 hex digest

Date / time

Formatter	Options	Input example	Output example
`unix_to_iso`	—	`1716912060`	`"2024-05-28T14:01:00Z"`
`unix_to_date`	—	`1716912060`	`"2024-05-28"`
`iso_to_unix`	—	`"2024-05-28T14:01:00Z"`	`1716912060`

Type conversion

Formatter	Options	Input example	Output example
`to_string`	—	`42`	`"42"`
`to_number`	—	`"42.5"`	`42.5`
`to_boolean`	—	`"true"`	`true`

Value override

Formatter	Options	Input example	Output example
`set_value`	`value` (any)	any	your configured value
`set_null`	—	any	`null`

Static fields

Add key-value pairs that appear in every forwarded payload regardless of the source webhook. Useful for injecting tenant IDs, source labels, or schema version markers:

{
  "source": "hookdeploy",
  "tenant_id": "acme-corp"
}

Static fields appear in the live preview in green. They are merged into the transformed output after field rules are applied.

Common recipes

Strip PII before forwarding to analytics

Mode: Passthrough

Load a sample webhook in the transform editor
Click customer.email in the field tree
Enable Strip field (PII) on the rule card
Repeat for customer.phone, customer.name, etc.
Save the transform

Your analytics destination receives the full event minus sensitive customer fields.

Convert Stripe amounts from cents to dollars

Mode: Passthrough

Click data.object.amount (or your amount field path)
Rename to amount_usd
Add formatter: cents_to_dollars
Preview shows "$42.00" from input 4200

Normalize timestamp formats

Mode: Passthrough

Click your Unix timestamp field (e.g. created)
Add formatter: unix_to_iso
Output becomes ISO 8601: "2024-05-28T14:01:00Z"

For date-only fields, use unix_to_date instead.

Add tenant context to every payload

Mode: Either

Scroll to Static fields in the transform editor
Add key tenant_id, value "acme-corp"
Add key source, value "stripe"

Every forwarded payload includes these fields regardless of what the sender sent.

Allowlist only the fields your server needs

Mode: Allowlist

Switch mode to Allowlist
Check only the fields your server expects: event_type, data.id, data.amount
Add formatters as needed (e.g. cents_to_dollars on data.amount)
Preview confirms only selected fields appear in output

Everything else — including unexpected PII — is dropped.

Live preview

The editor runs your transformation against sample data in real time:

Unchanged fields — default text color
Transformed fields — orange/warning color
Static fields — green/success color
Removed fields — shown as comments in passthrough mode

Load your latest captured request or paste custom JSON to test against Stripe, GitHub, or any provider payload.

Plan availability

Payload transformation availability is plan-controlled. Check the current HookDeploy dashboard or pricing page for the features enabled for your organization while plan enforcement details are being reconciled.

Next steps

Forwarding — Multiple destinations and header injection
Stripe webhooks — Stripe-specific transformation example
REST API — Manage destinations programmatically