Binding

binding specifies where the data is stored. parcel supports a Parquet file or directory, or an Iceberg table. It is required unless the contract inherits it from a parent contract. See Contract inheritance.

Parquet file or directory

contract: purchasing/orders
version: 1.0.0
binding:
  parquet: data/orders/

parquet accepts a file path, directory path, or URL. In this example, data/orders/ contains the order files. A single file can be specified as parquet: data/orders-2026-10.parquet.

Iceberg table

contract: finance/invoices
version: 2.0.0
binding:
  iceberg: finance.invoices

An Iceberg table is identified as namespace.table. In this example, finance is the namespace—a group of tables—and invoices is the table containing the data.

Partition columns

Data can be stored in separate groups by values such as region or month. partitioned_by lists the columns used for those groups:

binding:
  iceberg: finance.invoices
  partitioned_by: [region, invoice_month]

Here, invoices are stored in separate groups by region and month. partitioned_by records those columns in the contract. It applies to both Parquet and Iceberg data.