ADR 0004: Runtime ports and bootstrap

Status: accepted

Context

dpone supports many optional systems: Postgres, MSSQL, ClickHouse, BigQuery, Kafka, REST APIs, Vault, and provider SDKs. Importing all runtime dependencies eagerly would make the base package fragile and heavy.

Decision

Use explicit runtime ports and lazy bootstrap wiring. Factories create sources, sinks, state backends, quality checks, and schema evolution services only when the resolved manifest requires them.

Consequences

• import dpone stays lightweight.
• Missing optional extras fail with actionable runtime diagnostics.
• Connector packages can be tested independently.
• CLI commands that do not execute a connector remain usable without all extras installed.

Related docs

• Import rules
• Connector overview
• Doctor command