# Postback API v2

The Postback API v2 is the next-generation Postback ingestion endpoint for Treasure AI. It uses the same path contract as the legacy Postback API but is served from the new `records.in.treasuredata.com` host and supports only header-based authentication.

Use this API for custom webhooks, environments where the JS SDK or TD Logger cannot run, or single-record imports triggered by an external application.

## Get started

- [Quickstart](/ja/apis/postback-v2/quickstart) — Send your first request in minutes
- [API Reference](/ja/apis/postback-v2/openapi) — Full OpenAPI specification


## Key differences from the legacy Postback API

- **New host**: `<region>.records.in.treasuredata.com` (replaces `in.treasuredata.com`)
- **Header-only auth**: Supports `Authorization: TD1 <key>` and `X-TD-Write-Key: <key>`. URL-parameter auth (`?td_write_key=...`) is **not** supported.
- **Payload limit**: Maximum request body is 1,048,064 bytes.


## Related resources

- [Legacy Postback API Quickstart](/apis/postback/quickstart)
- [Treasure AI Sites and API Endpoints](/apis/endpoints/endpoints)
- [Data Ingestion API](/products/customer-data-platform/integration-hub/streaming/importing-table-records-using-the-data-ingestion-api)