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2026-06-23

Bunny Configuration Reference

Bunny is configured entirely via environment variables. This page lists the variables required to connect Bunny to the Cohort Discovery Service.

Full Bunny docs

This page covers the configuration required for Cohort Discovery integration. For full Bunny configuration documentation, see hutch.health/bunny/config.

Cohort Discovery connection variables

Variable Required Description
TASK_API_BASE_URL ✓ Base URL for the Cohort Discovery Task API
TASK_API_USERNAME ✓ Client ID from your Host in Cohort Discovery
TASK_API_PASSWORD ✓ Client Secret from your Host in Cohort Discovery
COLLECTION_ID ✓ Collection ID from your Collection in Cohort Discovery
TASK_API_TYPE ✓ a for availability queries; b for distribution jobs

Production API URL

https://api.cohort-discovery.healthdatagateway.org/api/v1

Database connection variables

Variable Required Description
DATASOURCE_DB_HOST ✓ Hostname or IP of your OMOP database
DATASOURCE_DB_DATABASE ✓ Database name
DATASOURCE_DB_SCHEMA ✓ Schema name containing OMOP tables
DATASOURCE_DB_USERNAME ✓ Database username
DATASOURCE_DB_PASSWORD ✓ Database password
DATASOURCE_DB_PORT ✓ Database port
DATASOURCE_DB_DRIVERNAME ✓ SQLAlchemy driver name (see table below)

Supported database drivers

Database DATASOURCE_DB_DRIVERNAME Default port
PostgreSQL postgresql 5432
SQL Server mssql+pyodbc 1433
DuckDB duckdb —
Snowflake snowflake 443

Additional variables for some drivers

SQL Server and Snowflake may require additional configuration variables. See hutch.health/bunny/config for driver-specific settings.

Example configurations

docker-compose.yml
environment:
  - TASK_API_TYPE=a
  - TASK_API_BASE_URL=https://api.cohort-discovery.healthdatagateway.org/api/v1
  - TASK_API_USERNAME=<your_client_id>
  - TASK_API_PASSWORD=<your_client_secret>
  - COLLECTION_ID=<your_collection_id>
  - DATASOURCE_DB_HOST=<your_db_host>
  - DATASOURCE_DB_DATABASE=<your_db_name>
  - DATASOURCE_DB_SCHEMA=<your_schema>
  - DATASOURCE_DB_USERNAME=<your_db_user>
  - DATASOURCE_DB_PASSWORD=<your_db_password>
  - DATASOURCE_DB_PORT=5432
  - DATASOURCE_DB_DRIVERNAME=postgresql
docker-compose.yml
environment:
  - TASK_API_TYPE=a
  - TASK_API_BASE_URL=https://api.cohort-discovery.healthdatagateway.org/api/v1
  - TASK_API_USERNAME=<your_client_id>
  - TASK_API_PASSWORD=<your_client_secret>
  - COLLECTION_ID=<your_collection_id>
  - DATASOURCE_DB_HOST=<your_db_host>
  - DATASOURCE_DB_DATABASE=<your_db_name>
  - DATASOURCE_DB_SCHEMA=<your_schema>
  - DATASOURCE_DB_USERNAME=<your_db_user>
  - DATASOURCE_DB_PASSWORD=<your_db_password>
  - DATASOURCE_DB_PORT=1433
  - DATASOURCE_DB_DRIVERNAME=mssql+pyodbc
docker-compose.yml
environment:
  - TASK_API_TYPE=a
  - TASK_API_BASE_URL=https://api.cohort-discovery.healthdatagateway.org/api/v1
  - TASK_API_USERNAME=<your_client_id>
  - TASK_API_PASSWORD=<your_client_secret>
  - COLLECTION_ID=<your_collection_id>
  - DATASOURCE_DB_DRIVERNAME=snowflake
  # See hutch.health/bunny/config for full Snowflake variables

Obfuscation settings

Data Custodians should configure obfuscation on their Bunny instance to meet disclosure control requirements:

Setting Recommended value Description
Low count suppression < 10 → return 0 Counts below this threshold are suppressed
Rounding Round to nearest 10 Counts above suppression threshold are rounded

See hutch.health/bunny/config for the environment variables that control obfuscation.