| GitHub repository | source link | whole report | declared | Primary public source used for repo identity and source paths. |
| DuckDB documentation | source link | whole report | declared | Public docs for SQL, clients, extensions, and engine behavior. |
| DuckDB internals overview | source link | whole report | declared | Public internals documentation for engine orientation. |
| src/parser/ | source_directory | engine | safe_to_share | Turns SQL text into parsed statements. |
| src/planner/ | source_directory | engine | safe_to_share | Binds and plans parsed SQL into logical operators. |
| src/optimizer/ | source_directory | engine | safe_to_share | Rewrites and improves logical plans before physical execution. |
| src/execution/ | source_directory | engine | safe_to_share | Executes physical operators and data pipelines. |
| src/storage/ | source_directory | engine | safe_to_share | Handles table storage, persistence, scans, and writes. |
| src/transaction/ | source_directory | engine | safe_to_share | Coordinates transaction lifecycle and commit boundaries. |
| extension/ | source_directory | extensions | safe_to_share | Hosts built-in and optional extension surfaces such as parquet, json, icu, tpch, and tpcds. |
| test/ | tests | quality | safe_to_share | Protects SQL behavior, storage behavior, extensions, and compatibility. |
| SQLRequest | query_contract | sql_text, connection_context, parameters, transaction_state | contract declared | Represents incoming SQL and execution context before parsing and binding. |
| LogicalPlan | planning_contract | operators, bindings, types, catalog_refs | contract declared | Represents a query after parsing and semantic binding. |
| PhysicalPlan | execution_contract | physical_operators, pipelines, dependencies, estimated_costs | contract declared | Represents executable operator pipelines. |
| DataChunk | vectorized_data_contract | vectors, column_types, cardinality | contract declared | Represents batches of data flowing through vectorized execution. |
| StorageTransaction | storage_contract | catalog_state, table_state, write_set, commit_status | contract declared | Represents storage and transaction state for reads and writes. |
| ExtensionSpec | extension_contract | extension_name, functions, load_policy, compatibility | contract declared | Describes extension-provided functionality and loading boundaries. |