Configuration

Connecting to a data source needs two kinds of input: connection details (host, database, catalog, …), which live in the contract's servers block, and credentials and connection options (usernames, passwords, tokens, timeouts, …), which are configuration. Every configuration option has a canonical name, its environment variable, such as DATACONTRACT_SNOWFLAKE_USERNAME. The data source pages list the options each source supports.

There are five ways to provide configuration. All of them address options by the same names, and all of them end up in the same place: a Config object that is passed through to the connection.

Environment variables

The default, and the right choice for CI/CD:

export DATACONTRACT_SNOWFLAKE_USERNAME=svc_test
export DATACONTRACT_SNOWFLAKE_PASSWORD=...
datacontract test datacontract.yaml

Environment variables work in every context: CLI, Python library, and API server.

.env file

The CLI loads a .env file from the current working directory, or the nearest parent directory containing one. Values from .env fill in missing environment variables; variables that are already set take precedence.

# .env
DATACONTRACT_POSTGRES_USERNAME=postgres
DATACONTRACT_POSTGRES_PASSWORD=postgres

The .env values are exported into the process environment, so they also reach tools that read the environment directly, such as boto3 (AWS_PROFILE), the Databricks SDK, and Snowflake's SNOWFLAKE_HOME.

Variables in the data contract

Since ODCS v3.2.0, any string value in a data contract may reference an environment variable as ${VAR_NAME}, with an optional default: ${VAR_NAME:-default}. This keeps environment-specific values such as hostnames and bucket paths out of the contract.

servers:
  - server: production
    type: postgresql
    host: ${DB_HOST}
    port: ${DB_PORT:-5432}
    database: ${DB_NAME:-orders}
schema:
  - name: orders
    quality:
      - type: sql
        query: SELECT COUNT(*) FROM orders WHERE created_at > '${CUTOFF_DATE}'
        mustBe: 0

Values come from the environment, including a loaded .env file. If a variable is unset or empty and has no default, the run fails. References are resolved only when testing: lint, export and publish leave them as written. Per-source override options such as DATACONTRACT_POSTGRES_HOST take precedence over the contract.

On the API server, a posted contract can't read the operator's environment unless you allow it. Pass a comma-separated list of glob patterns with --contract-variables (or DATACONTRACT_CLI_API_CONTRACT_VARIABLES):

datacontract api --contract-variables 'TABLE_*,CUTOFF_DATE'

Variables not on the list are treated as unset. * exposes every variable, credentials included.

Config file (YAML)

A YAML config file groups options in sections per data source. String values may contain ${VAR} and ${VAR:-default} references, resolved when the file is loaded. Pass it with the global --config-file option, or place it at one of the default locations: ./datacontract-config.yaml or ~/.datacontract/config.yaml.

# datacontract-config.yaml
snowflake:
  username: svc_test
  password: ${SNOWFLAKE_PASSWORD}
  role: TESTER
  login_timeout: 30
max_errors: 10

datacontract --config-file datacontract-config.yaml test datacontract.yaml

Section and key join to form the option name (snowflake.username is DATACONTRACT_SNOWFLAKE_USERNAME). ${VAR} references resolve from the environment when the file is loaded, so the file can be committed without holding secrets; add it to .gitignore if it contains literal credentials. Unknown option names fail with an error naming the key, so typos surface immediately.

In the Python library, load the same file with Config.from_yaml("datacontract-config.yaml").

Python library

Pass configuration programmatically via the config argument, without touching the process environment:

from datacontract import Config
from datacontract.data_contract import DataContract

run = DataContract(
    data_contract_file="datacontract.yaml",
    server="production",
    config=Config(
        snowflake_username="svc_test",
        snowflake_password=get_secret("snowflake"),
        snowflake_role="TESTER",
    ),
).test()

The Config class declares every option as a typed field. Field names match the environment variable names (snowflake_username for DATACONTRACT_SNOWFLAKE_USERNAME), unknown keyword arguments raise immediately, and secrets are held as SecretStr so they stay out of logs and reprs. A plain dict keyed by the environment variable names is accepted as well. DataContract.import_from_source() takes the same argument. See Python Library for details.

Because the config object is passed explicitly through the connection layer, concurrent operations with different credentials in one process do not interfere.

API server

The API server reads its configuration from environment variables set before startup. In addition, POST /test accepts per-request credentials via datacontract-* headers, matched case-insensitively and mapped to the option names:

curl -X POST https://datacontract.example.com/test \
  -H "Content-Type: application/yaml" \
  -H "datacontract-snowflake-username: svc_test" \
  -H "datacontract-snowflake-password: $SNOWFLAKE_PASSWORD" \
  --data-binary @datacontract.yaml

Header values apply to that request only, so one server can test contracts for different tenants without sharing credentials through the process environment. Unknown option names are rejected with a 400.

All options

Every option, by its environment variable name and the matching Config field. The data source pages explain how each source uses them. ${VAR}-style config file keys drop the DATACONTRACT_ prefix and the section name (snowflake.username for DATACONTRACT_SNOWFLAKE_USERNAME); API headers are the environment variable name in lowercase with dashes (datacontract-snowflake-username).

Entropy Data (publishing, remote contracts)

Environment variable	Config field	Type	Notes
ENTROPY_DATA_API_KEY	entropy_data_api_key	string (secret)
ENTROPY_DATA_HOST	entropy_data_host	string
DATAMESH_MANAGER_API_KEY	datamesh_manager_api_key	string (secret)	Deprecated, use ENTROPY_DATA_API_KEY
DATAMESH_MANAGER_HOST	datamesh_manager_host	string	Deprecated, use ENTROPY_DATA_HOST
DATACONTRACT_MANAGER_API_KEY	datacontract_manager_api_key	string (secret)	Deprecated, use ENTROPY_DATA_API_KEY
DATACONTRACT_MANAGER_HOST	datacontract_manager_host	string	Deprecated, use ENTROPY_DATA_HOST

General

Environment variable	Config field	Type	Notes
DATACONTRACT_API_HEADER_AUTHORIZATION	api_header_authorization	string (secret)
DATACONTRACT_API_HEADER_X_API_KEY	api_header_x_api_key	string (secret)
DATACONTRACT_CUSTOM_QUALITY_CHECKS	custom_quality_checks	string
DATACONTRACT_MAX_ERRORS	max_errors	integer
DATACONTRACT_CONNECT_TIMEOUT	connect_timeout	integer

Athena

Environment variable	Config field	Type	Notes
DATACONTRACT_ATHENA_CATALOG	athena_catalog	string	Overrides catalog from the contract's servers block
DATACONTRACT_ATHENA_SCHEMA	athena_schema	string	Overrides schema from the contract's servers block
DATACONTRACT_ATHENA_STAGING_DIR	athena_staging_dir	string	Overrides stagingDir from the contract's servers block
DATACONTRACT_ATHENA_WORKGROUP	athena_workgroup	string	Overrides workgroup from the contract's servers block

Azure

Environment variable	Config field	Type	Notes
DATACONTRACT_AZURE_CONNECTION_STRING	azure_connection_string	string (secret)
DATACONTRACT_AZURE_STORAGE_ACCOUNT_KEY	azure_storage_account_key	string (secret)
DATACONTRACT_AZURE_TENANT_ID	azure_tenant_id	string
DATACONTRACT_AZURE_CLIENT_ID	azure_client_id	string
DATACONTRACT_AZURE_CLIENT_SECRET	azure_client_secret	string (secret)

BigQuery

Environment variable	Config field	Type	Notes
DATACONTRACT_BIGQUERY_ACCOUNT_INFO_JSON_PATH	bigquery_account_info_json_path	string
DATACONTRACT_BIGQUERY_BILLING_PROJECT	bigquery_billing_project	string
DATACONTRACT_BIGQUERY_IMPERSONATION_ACCOUNT	bigquery_impersonation_account	string
DATACONTRACT_BIGQUERY_PROJECT	bigquery_project	string	Overrides project from the contract's servers block
DATACONTRACT_BIGQUERY_DATASET	bigquery_dataset	string	Overrides dataset from the contract's servers block

ClickHouse

Environment variable	Config field	Type	Notes
DATACONTRACT_CLICKHOUSE_USERNAME	clickhouse_username	string
DATACONTRACT_CLICKHOUSE_PASSWORD	clickhouse_password	string (secret)
DATACONTRACT_CLICKHOUSE_SECURE	clickhouse_secure	boolean
DATACONTRACT_CLICKHOUSE_HOST	clickhouse_host	string	Overrides host from the contract's servers block
DATACONTRACT_CLICKHOUSE_PORT	clickhouse_port	integer	Overrides port from the contract's servers block
DATACONTRACT_CLICKHOUSE_DATABASE	clickhouse_database	string	Overrides database from the contract's servers block

Databricks

Environment variable	Config field	Type	Notes
DATACONTRACT_DATABRICKS_SERVER_HOSTNAME	databricks_server_hostname	string	Overrides host from the contract's servers block
DATACONTRACT_DATABRICKS_HTTP_PATH	databricks_http_path	string
DATACONTRACT_DATABRICKS_TOKEN	databricks_token	string (secret)
DATACONTRACT_DATABRICKS_CLIENT_ID	databricks_client_id	string
DATACONTRACT_DATABRICKS_CLIENT_SECRET	databricks_client_secret	string (secret)
DATACONTRACT_DATABRICKS_PROFILE	databricks_profile	string
DATACONTRACT_DATABRICKS_AUTH_TYPE	databricks_auth_type	string
DATACONTRACT_DATABRICKS_CATALOG	databricks_catalog	string	Overrides catalog from the contract's servers block
DATACONTRACT_DATABRICKS_SCHEMA	databricks_schema	string	Overrides schema from the contract's servers block

DuckDB

Environment variable	Config field	Type	Notes
DATACONTRACT_DUCKDB_DATABASE	duckdb_database	string	Overrides database from the contract's servers block
DATACONTRACT_DUCKDB_SCHEMA	duckdb_schema	string	Overrides schema from the contract's servers block

GCS

Environment variable	Config field	Type	Notes
DATACONTRACT_GCS_KEY_ID	gcs_key_id	string
DATACONTRACT_GCS_SECRET	gcs_secret	string (secret)

SAP HANA

Environment variable	Config field	Type	Notes
DATACONTRACT_HANA_USERNAME	hana_username	string
DATACONTRACT_HANA_PASSWORD	hana_password	string (secret)
DATACONTRACT_HANA_ENCRYPT	hana_encrypt	boolean
DATACONTRACT_HANA_SSL_VALIDATE_CERTIFICATE	hana_ssl_validate_certificate	boolean
DATACONTRACT_HANA_SSL_HOSTNAME_IN_CERTIFICATE	hana_ssl_hostname_in_certificate	string

Hive

Environment variable	Config field	Type	Notes
DATACONTRACT_HIVE_USERNAME	hive_username	string
DATACONTRACT_HIVE_PASSWORD	hive_password	string (secret)
DATACONTRACT_HIVE_AUTH_MECHANISM	hive_auth_mechanism	string
DATACONTRACT_HIVE_USE_SSL	hive_use_ssl	boolean
DATACONTRACT_HIVE_USE_HTTP_TRANSPORT	hive_use_http_transport	boolean
DATACONTRACT_HIVE_HTTP_PATH	hive_http_path	string
DATACONTRACT_HIVE_HOST	hive_host	string	Overrides host from the contract's servers block
DATACONTRACT_HIVE_PORT	hive_port	integer	Overrides port from the contract's servers block
DATACONTRACT_HIVE_DATABASE	hive_database	string	Overrides database from the contract's servers block

Iceberg

Environment variable	Config field	Type	Notes
DATACONTRACT_ICEBERG_CATALOG_TYPE	iceberg_catalog_type	string
DATACONTRACT_ICEBERG_CREDENTIAL	iceberg_credential	string (secret)
DATACONTRACT_ICEBERG_TOKEN	iceberg_token	string (secret)
DATACONTRACT_ICEBERG_S3_ENDPOINT	iceberg_s3_endpoint	string
DATACONTRACT_ICEBERG_SIGNING_NAME	iceberg_signing_name	string
DATACONTRACT_ICEBERG_PROPERTIES	iceberg_properties	string
DATACONTRACT_ICEBERG_CATALOG_URL	iceberg_catalog_url	string	Overrides catalogUrl from the contract's servers block
DATACONTRACT_ICEBERG_CATALOG	iceberg_catalog	string	Overrides catalog from the contract's servers block
DATACONTRACT_ICEBERG_NAMESPACE	iceberg_namespace	string	Overrides namespace from the contract's servers block
DATACONTRACT_ICEBERG_WAREHOUSE	iceberg_warehouse	string	Overrides warehouse from the contract's servers block

Impala

Environment variable	Config field	Type	Notes
DATACONTRACT_IMPALA_USERNAME	impala_username	string
DATACONTRACT_IMPALA_PASSWORD	impala_password	string (secret)
DATACONTRACT_IMPALA_AUTH_MECHANISM	impala_auth_mechanism	string
DATACONTRACT_IMPALA_HTTP_PATH	impala_http_path	string
DATACONTRACT_IMPALA_USE_SSL	impala_use_ssl	boolean
DATACONTRACT_IMPALA_USE_HTTP_TRANSPORT	impala_use_http_transport	boolean
DATACONTRACT_IMPALA_HOST	impala_host	string	Overrides host from the contract's servers block
DATACONTRACT_IMPALA_PORT	impala_port	integer	Overrides port from the contract's servers block
DATACONTRACT_IMPALA_DATABASE	impala_database	string	Overrides database from the contract's servers block

Kafka

Environment variable	Config field	Type	Notes
DATACONTRACT_KAFKA_SASL_USERNAME	kafka_sasl_username	string
DATACONTRACT_KAFKA_SASL_PASSWORD	kafka_sasl_password	string (secret)
DATACONTRACT_KAFKA_SASL_MECHANISM	kafka_sasl_mechanism	string
DATACONTRACT_KAFKA_SCHEMA_REGISTRY_URL	kafka_schema_registry_url	string
DATACONTRACT_KAFKA_SCHEMA_REGISTRY_USERNAME	kafka_schema_registry_username	string
DATACONTRACT_KAFKA_SCHEMA_REGISTRY_PASSWORD	kafka_schema_registry_password	string (secret)
DATACONTRACT_KAFKA_MAX_MESSAGES	kafka_max_messages	integer
DATACONTRACT_KAFKA_TIMEOUT	kafka_timeout	integer
DATACONTRACT_KAFKA_GROUP_PREFIX	kafka_group_prefix	string

MySQL

Environment variable	Config field	Type	Notes
DATACONTRACT_MYSQL_USERNAME	mysql_username	string
DATACONTRACT_MYSQL_PASSWORD	mysql_password	string (secret)
DATACONTRACT_MYSQL_HOST	mysql_host	string	Overrides host from the contract's servers block
DATACONTRACT_MYSQL_PORT	mysql_port	integer	Overrides port from the contract's servers block
DATACONTRACT_MYSQL_DATABASE	mysql_database	string	Overrides database from the contract's servers block

Oracle

Environment variable	Config field	Type	Notes
DATACONTRACT_ORACLE_USERNAME	oracle_username	string
DATACONTRACT_ORACLE_PASSWORD	oracle_password	string (secret)
DATACONTRACT_ORACLE_CLIENT_DIR	oracle_client_dir	string
DATACONTRACT_ORACLE_HOST	oracle_host	string	Overrides host from the contract's servers block
DATACONTRACT_ORACLE_PORT	oracle_port	integer	Overrides port from the contract's servers block
DATACONTRACT_ORACLE_SERVICE_NAME	oracle_service_name	string	Overrides serviceName from the contract's servers block

Postgres

Environment variable	Config field	Type	Notes
DATACONTRACT_POSTGRES_USERNAME	postgres_username	string
DATACONTRACT_POSTGRES_PASSWORD	postgres_password	string (secret)
DATACONTRACT_POSTGRES_HOST	postgres_host	string	Overrides host from the contract's servers block
DATACONTRACT_POSTGRES_PORT	postgres_port	integer	Overrides port from the contract's servers block
DATACONTRACT_POSTGRES_DATABASE	postgres_database	string	Overrides database from the contract's servers block
DATACONTRACT_POSTGRES_SCHEMA	postgres_schema	string	Overrides schema from the contract's servers block

Redshift

Environment variable	Config field	Type	Notes
DATACONTRACT_REDSHIFT_AUTHENTICATION	redshift_authentication	string
DATACONTRACT_REDSHIFT_USERNAME	redshift_username	string
DATACONTRACT_REDSHIFT_PASSWORD	redshift_password	string (secret)
DATACONTRACT_REDSHIFT_SSLMODE	redshift_sslmode	string
DATACONTRACT_REDSHIFT_DB_USER	redshift_db_user	string
DATACONTRACT_REDSHIFT_DB_GROUPS	redshift_db_groups	string
DATACONTRACT_REDSHIFT_AUTO_CREATE	redshift_auto_create	boolean
DATACONTRACT_REDSHIFT_WORKGROUP	redshift_workgroup	string
DATACONTRACT_REDSHIFT_CLUSTER_IDENTIFIER	redshift_cluster_identifier	string
DATACONTRACT_REDSHIFT_REGION	redshift_region	string
DATACONTRACT_REDSHIFT_DURATION_SECONDS	redshift_duration_seconds	integer
DATACONTRACT_REDSHIFT_HOST	redshift_host	string	Overrides host from the contract's servers block
DATACONTRACT_REDSHIFT_PORT	redshift_port	integer	Overrides port from the contract's servers block
DATACONTRACT_REDSHIFT_DATABASE	redshift_database	string	Overrides database from the contract's servers block
DATACONTRACT_REDSHIFT_SCHEMA	redshift_schema	string	Overrides schema from the contract's servers block

S3 / AWS (also Athena, Redshift IAM, Glue)

Environment variable	Config field	Type	Notes
DATACONTRACT_S3_ACCESS_KEY_ID	s3_access_key_id	string
DATACONTRACT_S3_SECRET_ACCESS_KEY	s3_secret_access_key	string (secret)
DATACONTRACT_S3_SESSION_TOKEN	s3_session_token	string (secret)
DATACONTRACT_S3_REGION	s3_region	string

Snowflake

Environment variable	Config field	Type	Notes
DATACONTRACT_SNOWFLAKE_USERNAME	snowflake_username	string
DATACONTRACT_SNOWFLAKE_PASSWORD	snowflake_password	string (secret)
DATACONTRACT_SNOWFLAKE_AUTHENTICATOR	snowflake_authenticator	string
DATACONTRACT_SNOWFLAKE_ROLE	snowflake_role	string
DATACONTRACT_SNOWFLAKE_TOKEN	snowflake_token	string (secret)
DATACONTRACT_SNOWFLAKE_PASSCODE	snowflake_passcode	string (secret)
DATACONTRACT_SNOWFLAKE_PRIVATE_KEY	snowflake_private_key	string (secret)
DATACONTRACT_SNOWFLAKE_PRIVATE_KEY_FILE	snowflake_private_key_file	string
DATACONTRACT_SNOWFLAKE_PRIVATE_KEY_FILE_PWD	snowflake_private_key_file_pwd	string (secret)
DATACONTRACT_SNOWFLAKE_WAREHOUSE	snowflake_warehouse	string
DATACONTRACT_SNOWFLAKE_CREATE_OBJECT_UDFS	snowflake_create_object_udfs	boolean
DATACONTRACT_SNOWFLAKE_LOGIN_TIMEOUT	snowflake_login_timeout	integer
DATACONTRACT_SNOWFLAKE_NETWORK_TIMEOUT	snowflake_network_timeout	integer
DATACONTRACT_SNOWFLAKE_SOCKET_TIMEOUT	snowflake_socket_timeout	integer
DATACONTRACT_SNOWFLAKE_HOST	snowflake_host	string
DATACONTRACT_SNOWFLAKE_PORT	snowflake_port	integer
DATACONTRACT_SNOWFLAKE_HOME	snowflake_home	string
DATACONTRACT_SNOWFLAKE_CONNECTIONS_FILE	snowflake_connections_file	string
DATACONTRACT_SNOWFLAKE_DEFAULT_CONNECTION_NAME	snowflake_default_connection_name	string
DATACONTRACT_SNOWFLAKE_PRIVATE_KEY_PATH	snowflake_private_key_path	string	Deprecated, use DATACONTRACT_SNOWFLAKE_PRIVATE_KEY_FILE
DATACONTRACT_SNOWFLAKE_PRIVATE_KEY_PASSPHRASE	snowflake_private_key_passphrase	string (secret)	Deprecated, use DATACONTRACT_SNOWFLAKE_PRIVATE_KEY_FILE_PWD
DATACONTRACT_SNOWFLAKE_CONNECTION_TIMEOUT	snowflake_connection_timeout	integer	Deprecated, use DATACONTRACT_SNOWFLAKE_LOGIN_TIMEOUT
DATACONTRACT_SNOWFLAKE_ACCOUNT	snowflake_account	string	Overrides account from the contract's servers block
DATACONTRACT_SNOWFLAKE_DATABASE	snowflake_database	string	Overrides database from the contract's servers block
DATACONTRACT_SNOWFLAKE_SCHEMA	snowflake_schema	string	Overrides schema from the contract's servers block

SQL Server

Environment variable	Config field	Type	Notes
DATACONTRACT_SQLSERVER_AUTHENTICATION	sqlserver_authentication	string
DATACONTRACT_SQLSERVER_USERNAME	sqlserver_username	string
DATACONTRACT_SQLSERVER_PASSWORD	sqlserver_password	string (secret)
DATACONTRACT_SQLSERVER_CLIENT_ID	sqlserver_client_id	string
DATACONTRACT_SQLSERVER_CLIENT_SECRET	sqlserver_client_secret	string (secret)
DATACONTRACT_SQLSERVER_DRIVER	sqlserver_driver	string
DATACONTRACT_SQLSERVER_ENCRYPTED_CONNECTION	sqlserver_encrypted_connection	boolean
DATACONTRACT_SQLSERVER_TRUST_SERVER_CERTIFICATE	sqlserver_trust_server_certificate	boolean
DATACONTRACT_SQLSERVER_TRUSTED_CONNECTION	sqlserver_trusted_connection	boolean
DATACONTRACT_SQLSERVER_HOST	sqlserver_host	string	Overrides host from the contract's servers block
DATACONTRACT_SQLSERVER_PORT	sqlserver_port	integer	Overrides port from the contract's servers block
DATACONTRACT_SQLSERVER_DATABASE	sqlserver_database	string	Overrides database from the contract's servers block

Exasol

Environment variable	Config field	Type	Notes
DATACONTRACT_EXASOL_USERNAME	exasol_username	string
DATACONTRACT_EXASOL_PASSWORD	exasol_password	string (secret)
DATACONTRACT_EXASOL_FINGERPRINT	exasol_fingerprint	string
DATACONTRACT_EXASOL_VALIDATE_CERTIFICATE	exasol_validate_certificate	boolean
DATACONTRACT_EXASOL_HOST	exasol_host	string	Overrides host from the contract's servers block
DATACONTRACT_EXASOL_PORT	exasol_port	integer	Overrides port from the contract's servers block
DATACONTRACT_EXASOL_SCHEMA	exasol_schema	string	Overrides schema from the contract's servers block

Trino

Environment variable	Config field	Type	Notes
DATACONTRACT_TRINO_AUTHENTICATION	trino_authentication	string
DATACONTRACT_TRINO_USERNAME	trino_username	string
DATACONTRACT_TRINO_PASSWORD	trino_password	string (secret)
DATACONTRACT_TRINO_JWT_TOKEN	trino_jwt_token	string (secret)
DATACONTRACT_TRINO_HOST	trino_host	string	Overrides host from the contract's servers block
DATACONTRACT_TRINO_PORT	trino_port	integer	Overrides port from the contract's servers block
DATACONTRACT_TRINO_CATALOG	trino_catalog	string	Overrides catalog from the contract's servers block
DATACONTRACT_TRINO_SCHEMA	trino_schema	string	Overrides schema from the contract's servers block

Process-level variables are not Config options and stay environment-only: DATACONTRACT_CLI_DEBUG (debug logging), DATACONTRACT_CLI_API_KEY (see API), and DATACONTRACT_SYSTEM_TRUSTSTORE (see the command reference).

Precedence

Within one operation, resolution is:

1. Explicit config for the options it sets: the Config object or dict passed to DataContract, the loaded --config-file, or the request's datacontract-* headers.
2. Environment variables for everything the explicit config leaves unset.
3. .env fills in environment variables that are not already set (it never overrides).

So a committed team config file can hold defaults, CI can override single values via environment variables, and code can override everything.

Notes for specific sources

• Snowflake: only the documented DATACONTRACT_SNOWFLAKE_* options are passed to the connector. Unknown names are ignored with a warning. datacontract test does not read a connections.toml; only datacontract import snowflake does (see the Snowflake Reference).
• AWS sources (S3, Athena, Redshift IAM, Glue): when no DATACONTRACT_S3_* options are set, boto3's own credential chain applies (aws sso login, AWS_PROFILE, instance roles, GitHub OIDC). The same credential set is used to read data contracts from s3:// locations.