Destination specifications are under active development. Please contact your Prequel Representative to confirm the current version before implementation.
request_template field when creating a destination. Prequel renders the template and makes the HTTP request on each delivery.
This page covers what your endpoint must implement and what Prequel sends. For the API call to register a destination with Prequel, including a complete example, see Create Destination.
Record API
webhook_record destinations deliver one HTTP request per record. Upserts and deletions go to the same endpoint; use the {{.IsDeleted}} template variable in your body to distinguish them.
Request template fields
Set destination.webhook_record.request_template when creating a webhook_record destination:
| Field | Required | Description |
|---|
method | Yes | HTTP method. One of GET, POST, PUT, PATCH, DELETE. |
uri | Yes | The endpoint URL Prequel delivers to. Supports Go template variables. |
headers | No | Additional headers to include in each request. Values support Go template variables. |
body | No | Request body as a Go template string. If omitted, Prequel sends the record as a JSON object. |
Template variables
The following variables are available in uri, headers, and body:
| Variable | Description |
|---|
{{.Record.<field>}} | Value of a specific field from the delivered record (e.g. {{.Record.email}}). |
{{.Record.AsJson}} | The full record serialized as a JSON object. |
{{.IsDeleted}} | Boolean; true when Prequel is delivering a record deletion. |
{"data": {{.Record.AsJson}}, "is_deleted": {{.IsDeleted}}}
Batch API
webhook_batch destinations deliver multiple records in a single HTTP request. The format field on the destination controls how records are packaged.
Request template fields
Set destination.webhook_batch.request_template when creating a webhook_batch destination:
| Field | Required | Description |
|---|
method | Yes | HTTP method. One of POST, PUT, PATCH. |
uri | Yes | The endpoint URL Prequel delivers to. |
headers | No | Additional headers to include in each request. Values support Go template variables. |
body | No | Request body as a Go template string. Used when format is json. |
format field determines how Prequel packages records in each request:
| Format | Delivery |
|---|
json | Records delivered inline in the request body via Go template. |
csv | Request contains a presigned URL to a CSV file in object storage. |
parquet | Request contains a presigned URL to a Parquet file in object storage. |
iceberg | Request contains a presigned URL to the Iceberg manifest file for the applied record updates. |
uri, headers, and body when format is json:
| Variable | Description |
|---|
{{.Records}} | The slice of records in this batch. |
{{.Records[N].<field>}} | Value of a specific field from the Nth record (e.g. {{.Records[0].timezone}}). |
[{{range $i, $rec := .Records}}{{if $i}},{{end}}{"email": "{{$rec.email}}", "is_deleted": {{$rec.IsDeleted}}}{{end}}]
Prequel includes the following headers on every delivery request. You should validate these to confirm authenticity.
| Header | Description |
|---|
X-Prequel-Webhook-Signature | SHA-256 RSA PKCS1 v1.5 signature of the payload. |
X-Prequel-Webhook-Timestamp | RFC 3339 timestamp of when the request was sent, used to prevent replay attacks. |
X-Prequel-Webhook-Digest | SHA-256 hash of the raw request body. |
X-Prequel-Provider | Identifier for the provider whose data is being delivered. |
X-Prequel-Load | Identifier for the active load job. |
Response codes
Your endpoint should respond with an appropriate HTTP status code. Prequel uses the response to determine whether to retry delivery.
| Code | Description |
|---|
200 | Success. Record was processed and an existing record was updated. |
201 | Created. Record was processed and a new record was inserted. |
400 | Bad Request. Malformed or missing fields. Prequel will not retry. |
403 | Forbidden. Invalid signature or credentials. Prequel will not retry. |
404 | Not Found. Endpoint or resource could not be found. |
413 | Payload Too Large. Request body exceeds your endpoint’s size limit. |
422 | Unprocessable Entity. Validation failed for specific fields. Prequel will not retry. |
429 | Too Many Requests. Rate limit exceeded. Prequel will back off and retry. |
500 | Internal Server Error. Unexpected error during processing. Prequel will retry. |
502 | Bad Gateway. Upstream error. Prequel will retry. |
504 | Gateway Timeout. Request timed out. Prequel will retry. |
