Webhooks in Guides: Events

Symmetry Guides offers webhook events so clients can programmatically receive tax updates in real time. Each webhook includes what changed, when it changed, and which tax it applies to. The webhook is sent to the identified URL in JSON format.

Event Types

Symmetry Guides currently has two webhook event types.

Event	Description
`tax_rate.rate_updated`	Occurs whenever a tax rate is updated in Symmetry Guides.
`tax_rate.tax_created`	Occurs whenever a tax rate is added in Symmetry Guides.

Event Payload

The event payload fields are defined as follows:

Field	Type	Description	Example
`apiVersion`	string	Version of the webhook delivery contract.	`"2026-05-23"`
`eventId`	string	Unique identifier for the event, in the format `guides-{schema}-{itemIdentifier}`.	`"guides-tax_rate-04-000-0000-sit-000_20260101"`
`eventType`	string	The type of change that occurred, in the format `{schema}.{action}`.	`"tax_rate.rate_updated"`
`occurredAt`	string	Timestamp of when the change occurred (UTC, RFC 3339).	`"2026-06-08T19:59:39Z"`
`data.resource.type`	string	The content type that changed.	`"tax_rate"`
`data.resource.id`	string	Unique identifier for the tax item.	`"04-000-0000-sit-000"`
`data.resource.title`	string	Display name of the tax item.	`"AZ SIT - Effective 2026-01-01"`
`data.resource.effectiveDate`	string	Effective date of the change (ISO 8601).	`"2026-01-01"`
`data.resource.jurisdiction`	object	Jurisdiction details.
`data.resource.jurisdiction.stateFips`	string	State FIPS code.	`"4"`
`data.resource.jurisdiction.abbreviation`	string	State abbreviation.	`"AZ"`
`data.changes`	array	Array of field-level changes. Included when a prior version exists to compare against; omitted for newly created taxes.
`data.changes[].path`	string	The field that changed.	`"res_rate"`
`data.changes[].op`	string	The type of change: `add`, `replace`, or `remove`.	`"replace"`
`data.changes[].previous`	number	The prior value. Omitted for `add` operations.	`2.1`
`data.changes[].value`	number	The new value.	`1.1`
`data.summary`	string	Human-readable description of the change.	`"The rate decreased from 2.1% to 1.1%"`

Payload Samples

The fields included in a webhook payload vary depending on the nature of the change. The changes array and jurisdiction details are included when available.

Example: Rate update on an existing tax

This payload is delivered when an existing tax rate is updated. The changes array shows the previous and new values.

{
  "apiVersion": "2026-05-23",
  "eventId": "guides-tax_rate-04-000-0000-sit-000_20260101",
  "eventType": "tax_rate.rate_updated",
  "occurredAt": "2026-06-08T19:59:39Z",
  "data": {
    "resource": {
      "type": "tax_rate",
      "id": "04-000-0000-sit-000",
      "title": "AZ SIT - Effective 2026-01-01",
      "effectiveDate": "2026-01-01",
      "jurisdiction": {
        "stateFips": "4",
        "abbreviation": "AZ"
      }
    },
    "changes": [
      {
        "path": "res_rate",
        "op": "replace",
        "previous": 2.1,
        "value": 1.1
      }
    ],
    "summary": "The rate decreased from 2.1% to 1.1%"
  }
}

Example: New tax added

{
  "apiVersion": "2026-05-23",
  "eventId": "guides-tax_rate-06-000-0000-sit-000_20260102",
  "eventType": "tax_rate.tax_created",
  "occurredAt": "2026-06-15T18:15:14Z",
  "data": {
    "resource": {
      "type": "tax_rate",
      "id": "CA_SIT_20260102",
      "title": "California SIT",
      "effectiveDate": "2026-01-01"
    },
    "changes": [
      {
        "path": "wage_base",
        "op": "add"
      },
      {
        "path": "res_rate",
        "op": "add",
        "value": 1.8
      },
      {
        "path": "non_res_rate",
        "op": "add",
        "value": 2.2
      },
      {
        "path": "tax_id",
        "op": "add",
        "value": "06-000-0000-SIT-000"
      },
      {
        "path": "rate_effective_date",
        "op": "add"
      }
    ],
    "summary": "The rate is 1.8%"
  }
}

Activity

Events can be viewed within the Activity tab in Symmetry Guides. Click the Details button to see a copy of the payload, and click the Retry button to resend a failed webhook.