Merge pull request '[minor] Add Postgres table adapter with TableRepositoryInterface' (#58) from cursor/postgres-table-adapter into main

Reviewed-on: https://gitea.lille-vemmelund.dk/LilleVemmelund/python-repositories/pulls/58

.env.example

@@ -8,3 +8,8 @@ MINIO_SECRET_KEY=minioadmin
 MINIO_BUCKET=my-bucket
 MINIO_SECURE=false
 MINIO_CREATE_BUCKET_IF_MISSING=true
+
+# Postgres (requires postgres extra)
+POSTGRES_URI=postgresql://localhost/mydb
+POSTGRES_TABLE=users
+POSTGRES_PRIMARY_KEY=id

CHANGELOG.md

@@ -10,9 +10,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## [2.1.0] - 2026-07-11
 
 ### Summary
+
 Add runtime-checkable Protocol typing to public interfaces
 
 ### Changed
+
 - 1cbcc1c Merge pull request '[minor] Add runtime-checkable Protocol typing to public interfaces' (#57) from cursor/protocol-abc-interfaces into main
 - a0e5c9d Document test organization and add Cursor workflow rules.
 - 44b15cb Move structural typing tests into interface unit test files.

README.md

@@ -7,9 +7,9 @@ Subclass an adapter in your own repository to add domain-specific methods while
 ## Architecture
 
 | Layer            | Responsibility                                                                       |
-| ---------------- | ----------------------------------------------------------------- |
+| ---------------- | ------------------------------------------------------------------------------------ |
 | **Interfaces**   | Abstract contracts for connection, context, and CRUD                                 |
-| **Adapters**     | Technology-specific base classes (`RedisAdapter`, `MinioAdapter`) |
+| **Adapters**     | Technology-specific base classes (`RedisAdapter`, `MinioAdapter`, `PostgresAdapter`) |
 | **Your project** | Subclass an adapter and add domain methods                                           |
 
 Each public interface is a `@runtime_checkable` `Protocol` with `@abstractmethod` members. **Subclass an adapter** when you need connection management and shared behavior — explicit subclasses get runtime instantiation guards and inherited default methods (e.g. `scan_keys`). **Type-annotate against an interface** when you want loose coupling — any object with the right methods satisfies the contract for mypy and `isinstance()` checks, without inheriting from this package.
@@ -29,7 +29,8 @@ Install with the extras you need:
 ```bash
 uv add python-repositories[redis]
 uv add python-repositories[minio]
-uv add python-repositories[redis,minio]
+uv add python-repositories[postgres]
+uv add python-repositories[redis,minio,postgres]
 ```
 
 ### Redis (`JsonRepositoryInterface`)
@@ -63,16 +64,33 @@ for key in repo.scan_keys("user:*"):
 | `MINIO_SECURE`                   | Use HTTPS (`true`/`false`; default: `true`)                              |
 | `MINIO_CREATE_BUCKET_IF_MISSING` | Auto-create `MINIO_BUCKET` on connect (`true`/`false`; default: `false`) |
 
-Copy [`.env.example`](.env.example) to `.env` for local development. `RedisConfig.from_env()` and `MinioConfig.from_env()` load `.env` automatically when resolving configuration from the environment.
-
 For production, it is recommended to leave `MINIO_CREATE_BUCKET_IF_MISSING` unset so that `connect()` fails fast if the expected bucket is missing. For local development, you will often want `MINIO_SECURE=false` and `MINIO_CREATE_BUCKET_IF_MISSING=true`.
 
+### Postgres (`TableRepositoryInterface`)
+
+Requires PostgreSQL 10 or later; tested against PostgreSQL 16 in CI. Tables are owned by your migrations — the adapter verifies the configured table exists on connect.
+
+| Environment variable   | Description                             |
+| ---------------------- | --------------------------------------- |
+| `POSTGRES_URI`         | PostgreSQL connection URL               |
+| `POSTGRES_TABLE`       | Table name for CRUD operations          |
+| `POSTGRES_PRIMARY_KEY` | Primary key column name (default: `id`) |
+
+Copy [`.env.example`](.env.example) to `.env` for local development. `RedisConfig.from_env()`, `MinioConfig.from_env()`, and `PostgresConfig.from_env()` load `.env` automatically when resolving configuration from the environment.
+
 ## Configuration injection
 
 Adapters accept optional `config` and `client` keyword arguments for explicit setup and testing:
 
 ```python
-from python_repositories import RedisAdapter, RedisConfig, MinioAdapter, MinioConfig
+from python_repositories import (
+    MinioAdapter,
+    MinioConfig,
+    PostgresAdapter,
+    PostgresConfig,
+    RedisAdapter,
+    RedisConfig,
+)
 
 redis = RedisAdapter(config=RedisConfig(uri="redis://localhost:6379"))
 minio = MinioAdapter(
@@ -85,6 +103,13 @@ minio = MinioAdapter(
         # create_bucket_if_missing=True,  # convenient for local dev
     )
 )
+postgres = PostgresAdapter(
+    config=PostgresConfig(
+        uri="postgresql://localhost/mydb",
+        table="users",
+        primary_key="user_id",
+    )
+)
 ```
 
 When both `config` and `client` are provided, `connect()` skips client creation (the caller owns the client lifecycle). `config` is required whenever `client` is injected.
@@ -97,7 +122,7 @@ from python_repositories import load_dotenv
 load_dotenv()  # optional — from_env() also loads .env by default
 ```
 
-Calling `RedisAdapter()` or `MinioAdapter()` with no arguments still loads configuration from environment variables (and `.env` if present).
+Calling `RedisAdapter()`, `MinioAdapter()`, or `PostgresAdapter()` with no arguments still loads configuration from environment variables (and `.env` if present).
 
 ## Quick start
 
@@ -126,6 +151,17 @@ with ArtifactObjectRepository() as repo:
     data = repo.get_artifact("report-1")
 ```
 
+### Relational rows with Postgres
+
+```python
+from python_repositories.examples.user_table_repository import UserTableRepository
+
+with UserTableRepository() as repo:
+    repo.save_user("alice", {"name": "Alice", "email": "[email protected]"})
+    user = repo.get_user("alice")
+    repo.delete_user("alice")
+```
+
 ### Subclassing in your own project
 
 ```python
@@ -154,8 +190,11 @@ from python_repositories import (
     MinioAdapter,
     MinioConfig,
     ObjectRepositoryInterface,
+    PostgresAdapter,
+    PostgresConfig,
     RedisAdapter,
     RedisConfig,
+    TableRepositoryInterface,
     load_dotenv,
 )
 ```
@@ -169,10 +208,11 @@ uv run pytest tests/unit/ -v                          # fast, no Docker
 uv run pytest -m "not integration" -v                 # all non-Docker tests
 uv run pytest tests/integration/redis/ -v             # Redis container only
 uv run pytest tests/integration/minio/ -v             # MinIO container only
+uv run pytest tests/integration/postgres/ -v          # Postgres container only
 uv run pytest -v                                      # full suite (requires Docker)
 ```
 
-Integration tests are marked with `@pytest.mark.integration` and require Docker (testcontainers). Backend-specific markers (`needs_redis`, `needs_minio`) let you run only the containers a test module needs. Run unit tests alone for quick local feedback.
+Integration tests are marked with `@pytest.mark.integration` and require Docker (testcontainers). Backend-specific markers (`needs_redis`, `needs_minio`, `needs_postgres`) let you run only the containers a test module needs. Run unit tests alone for quick local feedback.
 
 ### Test organization
 

pyproject.toml

@@ -32,6 +32,9 @@ redis = [
 minio = [
     "minio>=7.2.16",
 ]
+postgres = [
+    "psycopg[binary]>=3.2.0",
+]
 
 [build-system]
 requires = ["hatchling"]
@@ -44,6 +47,7 @@ markers = [
     "integration: tests requiring Docker containers (deselect with '-m \"not integration\"')",
     "needs_redis: integration test requiring a Redis container",
     "needs_minio: integration test requiring a MinIO container",
+    "needs_postgres: integration test requiring a Postgres container",
 ]
 
 [tool.coverage.run]

python_repositories/__init__.py

@@ -6,17 +6,19 @@ from typing import TYPE_CHECKING
 
 # Interfaces are always available; they have no optional backend dependencies.
 from . import adapters
-from .config import MinioConfig, RedisConfig, load_dotenv
+from .config import MinioConfig, PostgresConfig, RedisConfig, load_dotenv
 from .interfaces import (
     ConnectionAwareInterface,
     ContextAwareInterface,
     JsonRepositoryInterface,
     ObjectRepositoryInterface,
+    TableRepositoryInterface,
 )
 
 # Adapters are imported only for static type checkers; runtime loading is delegated below.
 if TYPE_CHECKING:
     from .adapters.minio_adapter import MinioAdapter as MinioAdapter
+    from .adapters.postgres_adapter import PostgresAdapter as PostgresAdapter
     from .adapters.redis_adapter import RedisAdapter as RedisAdapter
 
 __all__ = [
@@ -25,7 +27,9 @@ __all__ = [
     "JsonRepositoryInterface",
     "MinioConfig",
     "ObjectRepositoryInterface",
+    "PostgresConfig",
     "RedisConfig",
+    "TableRepositoryInterface",
     "load_dotenv",
     *adapters.__all__,
 ]

python_repositories/adapters/__init__.py

@@ -12,6 +12,7 @@ from typing import TYPE_CHECKING
 # Adapters are imported only for static type checkers; runtime loading is deferred below.
 if TYPE_CHECKING:
     from .minio_adapter import MinioAdapter
+    from .postgres_adapter import PostgresAdapter
     from .redis_adapter import RedisAdapter
 
 # Map public adapter names to their defining module and class.
@@ -20,11 +21,13 @@ if TYPE_CHECKING:
 _LAZY_EXPORTS = {
     "RedisAdapter": (".redis_adapter", "RedisAdapter"),
     "MinioAdapter": (".minio_adapter", "MinioAdapter"),
+    "PostgresAdapter": (".postgres_adapter", "PostgresAdapter"),
 }
 
 __all__ = [
     "RedisAdapter",
     "MinioAdapter",
+    "PostgresAdapter",
 ]
 
 

python_repositories/adapters/postgres_adapter.py

@@ -0,0 +1,230 @@
+"""Definition of PostgresAdapter class."""
+
+from __future__ import annotations
+
+from typing import Any
+
+from python_repositories.adapters.connection_aware_adapter import (
+    ConnectionAwareAdapter,
+)
+from python_repositories.config import PostgresConfig
+from python_repositories.interfaces import TableRepositoryInterface
+
+try:
+    import psycopg
+    from psycopg import sql
+    from psycopg.errors import UndefinedTable
+    from psycopg.rows import dict_row
+except ImportError as exc:
+    raise ImportError(
+        "Postgres support requires the postgres extra. "
+        "Install with: pip install python-repositories[postgres]"
+    ) from exc
+
+
+class PostgresAdapter(ConnectionAwareAdapter, TableRepositoryInterface):
+    """Postgres adapter exposing basic table CRUD functionality."""
+
+    uri_env_var_name: str = "POSTGRES_URI"
+    table_env_var_name: str = "POSTGRES_TABLE"
+    primary_key_env_var_name: str = "POSTGRES_PRIMARY_KEY"
+    connection_name: str = "Postgres"
+
+    def __init__(
+        self,
+        *,
+        config: PostgresConfig | None = None,
+        client: psycopg.Connection[Any] | None = None,
+    ) -> None:
+        super().__init__()
+        if client is not None and config is None:
+            raise ValueError("config is required when client is provided")
+        if config is None:
+            config = PostgresConfig.from_env(
+                self.uri_env_var_name,
+                self.table_env_var_name,
+                self.primary_key_env_var_name,
+            )
+        self._config = config
+        self._client_injected = client is not None
+        self._client: psycopg.Connection[Any] | None = client
+        if self._client_injected:
+            self._invalidate_health_cache()
+
+    def _is_client_ready(self) -> bool:
+        return self._client is not None
+
+    def _table_identifier(self) -> sql.Identifier:
+        return sql.Identifier(self._config.table)
+
+    def _primary_key_identifier(self) -> sql.Identifier:
+        return sql.Identifier(self._config.primary_key)
+
+    def _validate_injected_client(self) -> None:
+        if self._client is None:
+            return
+        try:
+            self._run_connection_probe()
+        except (psycopg.Error, ConnectionError) as exc:
+            raise ConnectionError(
+                f"Could not connect to Postgres at {self._config.uri}"
+            ) from exc
+
+    def _establish_connection(self) -> None:
+        uri = self._config.uri
+        try:
+            client = psycopg.connect(
+                uri,
+                row_factory=dict_row,
+                connect_timeout=10,
+                autocommit=True,
+            )
+            self._client = client
+            self._run_connection_probe()
+        except ConnectionError:
+            self._client = None
+            raise
+        except psycopg.Error as exc:
+            self._client = None
+            raise ConnectionError(f"Could not connect to Postgres at {uri}") from exc
+
+    def _run_connection_probe(self) -> None:
+        assert self._client is not None
+        with self._client.cursor() as cursor:
+            cursor.execute("SELECT 1")
+            try:
+                cursor.execute(
+                    sql.SQL("SELECT 1 FROM {} LIMIT 0").format(self._table_identifier())
+                )
+            except UndefinedTable as exc:
+                raise ConnectionError(
+                    f"Table '{self._config.table}' does not exist on Postgres at "
+                    f"{self._config.uri}"
+                ) from exc
+
+    def disconnect(self) -> None:
+        """Disconnect from the Postgres server."""
+        if self._client is not None and not self._client_injected:
+            self._client.close()
+        self._client = None
+        self._invalidate_health_cache()
+
+    def _probe_connection(self) -> bool:
+        assert self._client is not None
+        try:
+            self._run_connection_probe()
+        except (psycopg.Error, ConnectionError):
+            return False
+        return True
+
+    def _validate_pk(self, pk: Any) -> None:
+        if pk is None:
+            raise ValueError("Primary key must not be None")
+
+    def _validate_row(self, row: dict[str, Any]) -> None:
+        if not isinstance(row, dict):
+            raise ValueError("Row must be a dictionary")
+        if self._config.primary_key not in row:
+            raise ValueError(
+                f"Row must include primary key column '{self._config.primary_key}'"
+            )
+
+    def _validate_limit(self, limit: int | None) -> None:
+        if limit is not None and (not isinstance(limit, int) or limit < 0):
+            raise ValueError("Limit must be a non-negative integer or None")
+
+    def fetch_one(self, pk: Any) -> dict[str, Any] | None:
+        """Fetch a single row by primary key."""
+        self._validate_pk(pk)
+        self._require_connected()
+        assert self._client is not None
+        query = sql.SQL("SELECT * FROM {} WHERE {} = %s").format(
+            self._table_identifier(),
+            self._primary_key_identifier(),
+        )
+        with self._client.cursor() as cursor:
+            cursor.execute(query, (pk,))
+            row = cursor.fetchone()
+        self.logger.debug("Fetched row", pk=pk, found=row is not None)
+        return row
+
+    def fetch_all(self, *, limit: int | None = None) -> list[dict[str, Any]]:
+        """Fetch all rows from the configured table."""
+        self._validate_limit(limit)
+        self._require_connected()
+        assert self._client is not None
+        query = sql.SQL("SELECT * FROM {}").format(self._table_identifier())
+        params: tuple[Any, ...] = ()
+        if limit is not None:
+            query = sql.Composed([query, sql.SQL(" LIMIT %s")])
+            params = (limit,)
+        with self._client.cursor() as cursor:
+            cursor.execute(query, params)
+            rows = cursor.fetchall()
+        self.logger.debug("Fetched rows", count=len(rows), limit=limit)
+        return list(rows)
+
+    def upsert(self, row: dict[str, Any]) -> None:
+        """Insert or update a row by primary key."""
+        self._validate_row(row)
+        self._require_connected()
+        assert self._client is not None
+        pk_col = self._config.primary_key
+        columns = list(row.keys())
+        identifiers = [sql.Identifier(column) for column in columns]
+        placeholders = sql.SQL(", ").join(sql.Placeholder() * len(columns))
+        column_list = sql.SQL(", ").join(identifiers)
+        update_columns = [column for column in columns if column != pk_col]
+        on_conflict: sql.Composed | sql.SQL
+        if update_columns:
+            update_assignments = sql.SQL(", ").join(
+                sql.SQL("{} = EXCLUDED.{}").format(
+                    sql.Identifier(column),
+                    sql.Identifier(column),
+                )
+                for column in update_columns
+            )
+            on_conflict = sql.SQL("DO UPDATE SET {}").format(update_assignments)
+        else:
+            on_conflict = sql.SQL("DO NOTHING")
+        query = sql.SQL("INSERT INTO {} ({}) VALUES ({}) ON CONFLICT ({}) {}").format(
+            self._table_identifier(),
+            column_list,
+            placeholders,
+            self._primary_key_identifier(),
+            on_conflict,
+        )
+        with self._client.cursor() as cursor:
+            cursor.execute(query, tuple(row[column] for column in columns))
+        self.logger.debug("Upserted row", pk=row[pk_col], columns=columns)
+
+    def delete(self, pk: Any) -> None:
+        """Delete a row by primary key."""
+        self._validate_pk(pk)
+        self._require_connected()
+        assert self._client is not None
+        query = sql.SQL("DELETE FROM {} WHERE {} = %s").format(
+            self._table_identifier(),
+            self._primary_key_identifier(),
+        )
+        with self._client.cursor() as cursor:
+            cursor.execute(query, (pk,))
+        self.logger.debug("Deleted row", pk=pk)
+
+    def execute(
+        self,
+        sql_text: str,
+        params: tuple[Any, ...] = (),
+    ) -> list[dict[str, Any]]:
+        """Run a read SQL statement and return rows as dicts."""
+        if not isinstance(sql_text, str) or len(sql_text) == 0:
+            raise ValueError("SQL must be a non-empty string")
+        if not isinstance(params, tuple):
+            raise ValueError("Params must be a tuple")
+        self._require_connected()
+        assert self._client is not None
+        with self._client.cursor() as cursor:
+            cursor.execute(sql_text, params)
+            rows = cursor.fetchall()
+        self.logger.debug("Executed SQL", row_count=len(rows))
+        return list(rows)

python_repositories/config/__init__.py

@@ -1,9 +1,11 @@
 from .dotenv_loader import load_dotenv as load_dotenv
 from .minio_config import MinioConfig as MinioConfig
+from .postgres_config import PostgresConfig as PostgresConfig
 from .redis_config import RedisConfig as RedisConfig
 
 __all__ = [
     "MinioConfig",
+    "PostgresConfig",
     "RedisConfig",
     "load_dotenv",
 ]

python_repositories/config/postgres_config.py

@@ -0,0 +1,42 @@
+"""PostgreSQL connection configuration."""
+
+from __future__ import annotations
+
+from dataclasses import dataclass
+import os
+
+from python_utils import check_env
+
+from python_repositories.config.dotenv_loader import load_dotenv
+
+
+@dataclass(frozen=True)
+class PostgresConfig:
+    """Configuration for connecting to PostgreSQL."""
+
+    uri: str
+    table: str
+    primary_key: str = "id"
+
+    @classmethod
+    def from_env(
+        cls,
+        uri_env_var_name: str = "POSTGRES_URI",
+        table_env_var_name: str = "POSTGRES_TABLE",
+        primary_key_env_var_name: str = "POSTGRES_PRIMARY_KEY",
+        *,
+        use_dotenv: bool = True,
+    ) -> PostgresConfig:
+        """Load configuration from environment variables."""
+        if use_dotenv:
+            load_dotenv()
+        env_var_names = {uri_env_var_name, table_env_var_name}
+        check_env(env_var_names)
+        primary_key = os.getenv(primary_key_env_var_name)
+        if primary_key is None or primary_key == "":
+            primary_key = "id"
+        return cls(
+            uri=str(os.getenv(uri_env_var_name)),
+            table=str(os.getenv(table_env_var_name)),
+            primary_key=primary_key,
+        )

python_repositories/examples/user_table_repository.py

@@ -0,0 +1,19 @@
+"""Example domain repository backed by Postgres tables."""
+
+from typing import Any
+
+from python_repositories.adapters.postgres_adapter import PostgresAdapter
+
+
+class UserTableRepository(PostgresAdapter):
+    """Example: domain repository backed by a Postgres table."""
+
+    def get_user(self, user_id: str) -> dict[str, Any] | None:
+        return self.fetch_one(user_id)
+
+    def save_user(self, user_id: str, user: dict[str, Any]) -> None:
+        row = {self._config.primary_key: user_id, **user}
+        self.upsert(row)
+
+    def delete_user(self, user_id: str) -> None:
+        self.delete(user_id)

python_repositories/interfaces/__init__.py

@@ -8,10 +8,14 @@ from .json_repository_interface import (
 from .object_repository_interface import (
     ObjectRepositoryInterface as ObjectRepositoryInterface,
 )
+from .table_repository_interface import (
+    TableRepositoryInterface as TableRepositoryInterface,
+)
 
 __all__ = [
     "ConnectionAwareInterface",
     "ContextAwareInterface",
     "JsonRepositoryInterface",
     "ObjectRepositoryInterface",
+    "TableRepositoryInterface",
 ]

python_repositories/interfaces/table_repository_interface.py

@@ -0,0 +1,55 @@
+"""Definition of TableRepositoryInterface protocol."""
+
+from abc import abstractmethod
+from typing import Any, Protocol, runtime_checkable
+
+
+@runtime_checkable
+class TableRepositoryInterface(Protocol):
+    """Interface that defines relational table CRUD methods."""
+
+    @abstractmethod
+    def fetch_one(self, pk: Any) -> dict[str, Any] | None:
+        """Fetch a single row by primary key.
+
+        Returns ``None`` when no row matches. Use ``value is not None`` to test
+        existence; avoid truthiness checks.
+        """
+        ...
+
+    @abstractmethod
+    def fetch_all(self, *, limit: int | None = None) -> list[dict[str, Any]]:
+        """Fetch all rows from the configured table.
+
+        Returns an empty list when the table has no rows.
+        """
+        ...
+
+    @abstractmethod
+    def upsert(self, row: dict[str, Any]) -> None:
+        """Insert or update a row by primary key.
+
+        ``row`` must include the configured primary key column. Raises
+        ``ValueError`` for a non-dict row or a missing primary key.
+        """
+        ...
+
+    @abstractmethod
+    def delete(self, pk: Any) -> None:
+        """Delete a row by primary key.
+
+        Idempotent: no error when the row is already absent.
+        """
+        ...
+
+    @abstractmethod
+    def execute(
+        self,
+        sql: str,
+        params: tuple[Any, ...] = (),
+    ) -> list[dict[str, Any]]:
+        """Run a read SQL statement and return rows as dicts.
+
+        Escape hatch for joins, filters, and other queries in subclasses.
+        """
+        ...

tests/conftest.py

@@ -1,6 +1,6 @@
 """Shared test configuration constants."""
 
-from python_repositories.config import MinioConfig, RedisConfig
+from python_repositories.config import MinioConfig, PostgresConfig, RedisConfig
 
 TEST_REDIS_CONFIG = RedisConfig(uri="redis://localhost:6379")
 TEST_MINIO_CONFIG = MinioConfig(
@@ -10,3 +10,8 @@ TEST_MINIO_CONFIG = MinioConfig(
     bucket="test-bucket",
     secure=False,
 )
+TEST_POSTGRES_CONFIG = PostgresConfig(
+    uri="postgresql://localhost/mydb",
+    table="test_items",
+    primary_key="id",
+)

tests/integration/examples/conftest.py

@@ -6,12 +6,17 @@ from minio import Minio
 import pytest
 import redis
 
-from python_repositories.config import MinioConfig, RedisConfig
+from python_repositories.config import MinioConfig, PostgresConfig, RedisConfig
 from tests.integration.minio._containers import (
     minio_config_from_env,
     minio_env,
     raw_minio_client_from_env,
 )
+from tests.integration.postgres._containers import (
+    postgres_config_from_container,
+    postgres_uri,
+    raw_postgres_client_from_container,
+)
 from tests.integration.redis._containers import (
     raw_redis_client_from_container,
     redis_config_from_container,
@@ -53,3 +58,23 @@ def minio_config(minio_container: dict[str, str]) -> MinioConfig:
 def raw_minio_client(minio_container: dict[str, str]) -> Generator[Minio, None, None]:
     """Provide a raw Minio client connected to the test Minio container."""
     yield from raw_minio_client_from_env(minio_container)
+
+
+@pytest.fixture(scope="session")
+def postgres_container() -> Generator[str, None, None]:
+    """Set up a Postgres container for testing and yield the Postgres URI."""
+    yield from postgres_uri()
+
+
+@pytest.fixture(scope="session")
+def postgres_config(postgres_container: str) -> PostgresConfig:
+    """Provide PostgresConfig built from the test container."""
+    return postgres_config_from_container(postgres_container)
+
+
+@pytest.fixture(scope="session")
+def raw_postgres_client(
+    postgres_container: str,
+) -> Generator[object, None, None]:
+    """Provide a raw Postgres client connected to the test Postgres container."""
+    yield from raw_postgres_client_from_container(postgres_container)

tests/integration/examples/examples_test.py

@@ -6,12 +6,15 @@ import os
 import random
 
 from minio import Minio
+import psycopg
 import pytest
 
 from python_repositories.examples.artifact_object_repository import (
     ArtifactObjectRepository,
 )
 from python_repositories.examples.user_json_repository import UserJsonRepository
+from python_repositories.examples.user_table_repository import UserTableRepository
+from tests.integration.postgres._containers import TEST_TABLE
 
 pytestmark = [
     pytest.mark.integration,
@@ -36,6 +39,24 @@ def set_example_env(
         _ = os.environ.pop(key, default=None)
 
 
+@pytest.fixture(scope="module", autouse=True)
+def set_postgres_example_env(
+    postgres_container: str,
+    raw_postgres_client: psycopg.Connection,
+) -> Generator[None, None, None]:
+    """Set Postgres env vars for example repositories using from_env() defaults."""
+    env_vars = {
+        "POSTGRES_URI": postgres_container,
+        "POSTGRES_TABLE": TEST_TABLE,
+        "POSTGRES_PRIMARY_KEY": "id",
+    }
+    for key, value in env_vars.items():
+        os.environ[key] = value
+    yield
+    for key in env_vars:
+        _ = os.environ.pop(key, default=None)
+
+
 @pytest.fixture(scope="module")
 def user_data() -> Generator[dict[str, str], None, None]:
     """Provide sample user data for tests."""
@@ -77,3 +98,27 @@ def test_artifact_object_repository_store_and_get(
         assert received is not None
         artifact_data.seek(0)
         assert received.read() == artifact_data.read()
+
+
+@pytest.mark.needs_postgres
+def test_user_table_repository_save_and_get(
+    user_data: dict[str, str],
+) -> None:
+    """Test that UserTableRepository can save and retrieve a user."""
+    with UserTableRepository() as repo:
+        repo.save_user("alice", user_data)
+        user = repo.get_user("alice")
+        assert user is not None
+        assert user["name"] == user_data["name"]
+        assert user["email"] == user_data["email"]
+
+
+@pytest.mark.needs_postgres
+def test_user_table_repository_delete(
+    user_data: dict[str, str],
+) -> None:
+    """Test that UserTableRepository can delete a user."""
+    with UserTableRepository() as repo:
+        repo.save_user("alice", user_data)
+        repo.delete_user("alice")
+        assert repo.get_user("alice") is None

tests/integration/postgres/_containers.py

@@ -0,0 +1,76 @@
+"""Postgres container session helpers for integration tests."""
+
+from collections.abc import Generator
+
+import psycopg
+from psycopg.rows import dict_row
+from testcontainers.postgres import PostgresContainer
+
+from python_repositories.config import PostgresConfig
+
+POSTGRES_IMAGE = "postgres:16"
+TEST_TABLE = "test_items"
+
+
+_postgres_uri: str | None = None
+_postgres_container: PostgresContainer | None = None
+_raw_postgres_client: psycopg.Connection | None = None
+_postgres_uri_refs = 0
+_raw_postgres_client_refs = 0
+
+
+def postgres_uri() -> Generator[str, None, None]:
+    """Yield a session-scoped Postgres URI, starting the container once."""
+    global _postgres_uri, _postgres_container, _postgres_uri_refs
+    if _postgres_uri is None:
+        _postgres_container = PostgresContainer(POSTGRES_IMAGE, driver=None)
+        _postgres_container.start()
+        _postgres_uri = _postgres_container.get_connection_url()
+
+    _postgres_uri_refs += 1
+    yield _postgres_uri
+    _postgres_uri_refs -= 1
+
+    if _postgres_uri_refs == 0 and _postgres_container is not None:
+        _postgres_container.stop()
+        _postgres_container = None
+        _postgres_uri = None
+
+
+def postgres_config_from_container(uri: str) -> PostgresConfig:
+    """Build PostgresConfig from a container URI."""
+    return PostgresConfig(uri=uri, table=TEST_TABLE, primary_key="id")
+
+
+def raw_postgres_client_from_container(
+    uri: str,
+) -> Generator[psycopg.Connection, None, None]:
+    """Yield a session-scoped raw Postgres client, reusing one client per session."""
+    global _raw_postgres_client, _raw_postgres_client_refs
+    if _raw_postgres_client is None:
+        _raw_postgres_client = psycopg.connect(
+            uri,
+            row_factory=dict_row,  # type: ignore[arg-type]
+            autocommit=True,
+        )
+        with _raw_postgres_client.cursor() as cursor:
+            cursor.execute(
+                f"""
+                CREATE TABLE IF NOT EXISTS {TEST_TABLE} (
+                    id TEXT PRIMARY KEY,
+                    name TEXT NOT NULL,
+                    value INTEGER,
+                    email TEXT
+                )
+                """
+            )
+
+    _raw_postgres_client_refs += 1
+    yield _raw_postgres_client
+    _raw_postgres_client_refs -= 1
+
+    if _raw_postgres_client_refs == 0 and _raw_postgres_client is not None:
+        with _raw_postgres_client.cursor() as cursor:
+            cursor.execute(f"TRUNCATE TABLE {TEST_TABLE}")
+        _raw_postgres_client.close()
+        _raw_postgres_client = None

tests/integration/postgres/conftest.py

@@ -0,0 +1,33 @@
+"""Postgres integration test fixtures."""
+
+from collections.abc import Generator
+
+import psycopg
+import pytest
+
+from python_repositories.config import PostgresConfig
+from tests.integration.postgres._containers import (
+    postgres_config_from_container,
+    postgres_uri,
+    raw_postgres_client_from_container,
+)
+
+
+@pytest.fixture(scope="session")
+def postgres_container() -> Generator[str, None, None]:
+    """Set up a Postgres container for testing and yield the Postgres URI."""
+    yield from postgres_uri()
+
+
+@pytest.fixture(scope="session")
+def postgres_config(postgres_container: str) -> PostgresConfig:
+    """Provide PostgresConfig built from the test container."""
+    return postgres_config_from_container(postgres_container)
+
+
+@pytest.fixture(scope="session")
+def raw_postgres_client(
+    postgres_container: str,
+) -> Generator[psycopg.Connection, None, None]:
+    """Provide a raw Postgres client connected to the test container."""
+    yield from raw_postgres_client_from_container(postgres_container)

tests/integration/postgres/postgres_adapter_test.py

@@ -0,0 +1,318 @@
+"""Integration tests for the PostgresAdapter."""
+
+from collections.abc import Generator
+import logging
+
+import psycopg
+import pytest
+
+from python_repositories.adapters.postgres_adapter import PostgresAdapter
+from python_repositories.config import PostgresConfig
+from tests.integration.postgres._containers import TEST_TABLE
+
+pytestmark = [pytest.mark.integration, pytest.mark.needs_postgres]
+
+
+@pytest.fixture(scope="module")
+def row() -> Generator[dict[str, object], None, None]:
+    """Provide a sample row for tests."""
+    yield {"id": "test-id", "name": "Alice", "value": 42}
+
+
+@pytest.fixture(scope="function")
+def row_in_postgres(
+    raw_postgres_client: psycopg.Connection,
+    row: dict[str, object],
+) -> Generator[tuple[str, dict[str, object]], None, None]:
+    """Fixture to set up a known row in Postgres before each test."""
+    with raw_postgres_client.cursor() as cursor:
+        cursor.execute(
+            f"INSERT INTO {TEST_TABLE} (id, name, value) VALUES (%s, %s, %s)",
+            (row["id"], row["name"], row["value"]),
+        )
+
+    yield str(row["id"]), row
+
+    with raw_postgres_client.cursor() as cursor:
+        cursor.execute(f"DELETE FROM {TEST_TABLE} WHERE id = %s", (row["id"],))
+
+
+@pytest.fixture(scope="module")
+def postgres_adapter(
+    postgres_config: PostgresConfig,
+    raw_postgres_client: psycopg.Connection,
+) -> Generator[PostgresAdapter, None, None]:
+    """Fixture to provide a connected PostgresAdapter instance."""
+    _ = raw_postgres_client  # ensure test table exists before connect probe
+    adapter = PostgresAdapter(config=postgres_config)
+    adapter.connect()
+    yield adapter
+    adapter.disconnect()
+
+
+@pytest.fixture(scope="function", autouse=True)
+def clear_postgres(raw_postgres_client: psycopg.Connection) -> None:
+    """Fixture to clear all rows before each test."""
+    with raw_postgres_client.cursor() as cursor:
+        cursor.execute(f"TRUNCATE TABLE {TEST_TABLE}")
+
+
+def test_should_log_info_when_already_connected(
+    postgres_adapter: PostgresAdapter,
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    """Test that PostgresAdapter logs info when connect is called while connected."""
+    with caplog.at_level(logging.INFO):
+        postgres_adapter.connect()
+    assert "Already connected" in caplog.text
+    assert "Postgres" in caplog.text
+
+
+def test_should_raise_connection_error_when_unable_to_connect() -> None:
+    """Test that PostgresAdapter raises ConnectionError when unable to connect."""
+    adapter = PostgresAdapter(
+        config=PostgresConfig(
+            uri="postgresql://invalid:5432/nodb",
+            table=TEST_TABLE,
+        )
+    )
+    with pytest.raises(ConnectionError):
+        adapter.connect()
+    assert adapter._client is None
+    assert not adapter.is_connected()
+
+
+def test_should_raise_connection_error_when_table_missing(
+    postgres_config: PostgresConfig,
+) -> None:
+    """Test that PostgresAdapter raises ConnectionError when the table is missing."""
+    config = PostgresConfig(
+        uri=postgres_config.uri,
+        table="missing_table",
+        primary_key="id",
+    )
+    adapter = PostgresAdapter(config=config)
+    with pytest.raises(ConnectionError, match="does not exist"):
+        adapter.connect()
+
+
+def test_should_log_error_on_exception_during_exit(
+    postgres_config: PostgresConfig,
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    """Test that PostgresAdapter logs an error when an exception occurs during exit."""
+    try:
+        with PostgresAdapter(config=postgres_config) as adapter:
+            assert adapter.is_connected()
+            raise ValueError("Simulated error")
+    except ValueError:
+        pass
+    assert "Error while exiting context" in caplog.text
+
+
+def test_should_have_context_manager(postgres_config: PostgresConfig) -> None:
+    """Test that PostgresAdapter can be used as a context manager."""
+    with PostgresAdapter(config=postgres_config) as adapter:
+        assert adapter._client is not None
+    assert adapter._client is None
+
+
+def test_should_fetch_one(
+    row_in_postgres: tuple[str, dict[str, object]],
+    postgres_adapter: PostgresAdapter,
+) -> None:
+    """Test that PostgresAdapter can fetch a row by primary key."""
+    pk, row = row_in_postgres
+    fetched = postgres_adapter.fetch_one(pk)
+    assert fetched is not None
+    assert fetched["id"] == row["id"]
+    assert fetched["name"] == row["name"]
+    assert fetched["value"] == row["value"]
+
+
+def test_should_fetch_none_for_missing_row(
+    postgres_adapter: PostgresAdapter,
+) -> None:
+    """Test that fetching a non-existent row returns None."""
+    assert postgres_adapter.fetch_one("missing-id") is None
+
+
+def test_should_raise_value_error_on_invalid_fetch_one_pk(
+    postgres_adapter: PostgresAdapter,
+) -> None:
+    """Test that PostgresAdapter raises ValueError for an invalid primary key."""
+    with pytest.raises(ValueError):
+        postgres_adapter.fetch_one(None)
+
+
+def test_should_raise_connection_error_on_fetch_one_when_not_connected(
+    postgres_config: PostgresConfig,
+) -> None:
+    """Test that fetch_one raises ConnectionError when not connected."""
+    adapter = PostgresAdapter(config=postgres_config)
+    with pytest.raises(ConnectionError):
+        adapter.fetch_one("some-id")
+
+
+def test_should_upsert_row(
+    row: dict[str, object],
+    postgres_adapter: PostgresAdapter,
+) -> None:
+    """Test that PostgresAdapter can insert a row."""
+    assert postgres_adapter.fetch_one(row["id"]) is None
+    postgres_adapter.upsert(row)
+    fetched = postgres_adapter.fetch_one(row["id"])
+    assert fetched is not None
+    assert fetched["name"] == row["name"]
+
+
+def test_should_update_row(
+    row_in_postgres: tuple[str, dict[str, object]],
+    postgres_adapter: PostgresAdapter,
+) -> None:
+    """Test that PostgresAdapter can update an existing row."""
+    pk, _ = row_in_postgres
+    new_row = {"id": pk, "name": "Bob", "value": 99}
+    postgres_adapter.upsert(new_row)
+    fetched = postgres_adapter.fetch_one(pk)
+    assert fetched is not None
+    assert fetched["name"] == "Bob"
+    assert fetched["value"] == 99
+
+
+def test_should_raise_value_error_on_invalid_upsert_row(
+    postgres_adapter: PostgresAdapter,
+) -> None:
+    """Test that PostgresAdapter raises ValueError for invalid upsert data."""
+    with pytest.raises(ValueError):
+        postgres_adapter.upsert({"name": "Alice"})  # missing primary key
+
+
+def test_should_raise_value_error_on_non_dict_upsert_row(
+    postgres_adapter: PostgresAdapter,
+) -> None:
+    """Test that PostgresAdapter raises ValueError when upsert row is not a dict."""
+    with pytest.raises(ValueError):
+        postgres_adapter.upsert("not-a-dict")  # type: ignore[arg-type]
+
+
+def test_should_raise_connection_error_on_upsert_when_not_connected(
+    postgres_config: PostgresConfig,
+    row: dict[str, object],
+) -> None:
+    """Test that upsert raises ConnectionError when not connected."""
+    adapter = PostgresAdapter(config=postgres_config)
+    with pytest.raises(ConnectionError):
+        adapter.upsert(row)
+
+
+def test_should_fetch_all_rows(
+    postgres_adapter: PostgresAdapter,
+) -> None:
+    """Test that PostgresAdapter can fetch all rows."""
+    postgres_adapter.upsert({"id": "a", "name": "Alice", "value": 1})
+    postgres_adapter.upsert({"id": "b", "name": "Bob", "value": 2})
+    rows = postgres_adapter.fetch_all()
+    assert len(rows) == 2
+    ids = {row["id"] for row in rows}
+    assert ids == {"a", "b"}
+
+
+def test_should_fetch_all_with_limit(
+    postgres_adapter: PostgresAdapter,
+) -> None:
+    """Test that PostgresAdapter respects fetch_all limit."""
+    postgres_adapter.upsert({"id": "a", "name": "Alice", "value": 1})
+    postgres_adapter.upsert({"id": "b", "name": "Bob", "value": 2})
+    rows = postgres_adapter.fetch_all(limit=1)
+    assert len(rows) == 1
+
+
+def test_should_return_empty_list_for_empty_table(
+    postgres_adapter: PostgresAdapter,
+) -> None:
+    """Test that fetch_all returns an empty list for an empty table."""
+    assert postgres_adapter.fetch_all() == []
+
+
+def test_should_raise_value_error_on_invalid_fetch_all_limit(
+    postgres_adapter: PostgresAdapter,
+) -> None:
+    """Test that PostgresAdapter raises ValueError for an invalid limit."""
+    with pytest.raises(ValueError):
+        postgres_adapter.fetch_all(limit=-1)
+
+
+def test_should_raise_connection_error_on_fetch_all_when_not_connected(
+    postgres_config: PostgresConfig,
+) -> None:
+    """Test that fetch_all raises ConnectionError when not connected."""
+    adapter = PostgresAdapter(config=postgres_config)
+    with pytest.raises(ConnectionError):
+        adapter.fetch_all()
+
+
+def test_should_delete_row(
+    row_in_postgres: tuple[str, dict[str, object]],
+    postgres_adapter: PostgresAdapter,
+) -> None:
+    """Test that deleting a row removes it from the table."""
+    pk, _ = row_in_postgres
+    assert postgres_adapter.fetch_one(pk) is not None
+    postgres_adapter.delete(pk)
+    assert postgres_adapter.fetch_one(pk) is None
+
+
+def test_should_delete_idempotently(
+    postgres_adapter: PostgresAdapter,
+) -> None:
+    """Test that deleting a missing row does not raise."""
+    postgres_adapter.delete("missing-id")
+
+
+def test_should_raise_value_error_on_invalid_delete_pk(
+    postgres_adapter: PostgresAdapter,
+) -> None:
+    """Test that PostgresAdapter raises ValueError for an invalid delete pk."""
+    with pytest.raises(ValueError):
+        postgres_adapter.delete(None)
+
+
+def test_should_raise_connection_error_on_delete_when_not_connected(
+    postgres_config: PostgresConfig,
+) -> None:
+    """Test that delete raises ConnectionError when not connected."""
+    adapter = PostgresAdapter(config=postgres_config)
+    with pytest.raises(ConnectionError):
+        adapter.delete("some-id")
+
+
+def test_should_execute_sql(
+    row_in_postgres: tuple[str, dict[str, object]],
+    postgres_adapter: PostgresAdapter,
+) -> None:
+    """Test that PostgresAdapter can execute read SQL."""
+    pk, _ = row_in_postgres
+    rows = postgres_adapter.execute(
+        f"SELECT * FROM {TEST_TABLE} WHERE id = %s",
+        (pk,),
+    )
+    assert len(rows) == 1
+    assert rows[0]["id"] == pk
+
+
+def test_should_raise_value_error_on_invalid_execute_sql(
+    postgres_adapter: PostgresAdapter,
+) -> None:
+    """Test that PostgresAdapter raises ValueError for invalid SQL."""
+    with pytest.raises(ValueError):
+        postgres_adapter.execute("")
+
+
+def test_should_raise_connection_error_on_execute_when_not_connected(
+    postgres_config: PostgresConfig,
+) -> None:
+    """Test that execute raises ConnectionError when not connected."""
+    adapter = PostgresAdapter(config=postgres_config)
+    with pytest.raises(ConnectionError):
+        adapter.execute("SELECT 1")

tests/unit/adapters_test.py

@@ -45,6 +45,7 @@ from python_repositories import JsonRepositoryInterface
 assert JsonRepositoryInterface is not None
 assert "python_repositories.adapters.redis_adapter" not in sys.modules
 assert "python_repositories.adapters.minio_adapter" not in sys.modules
+assert "python_repositories.adapters.postgres_adapter" not in sys.modules
 """
     result = subprocess.run(
         [sys.executable, "-c", script],
@@ -58,10 +59,11 @@ assert "python_repositories.adapters.minio_adapter" not in sys.modules
 
 def test_lazy_adapter_load_succeeds_when_extra_present() -> None:
     """Adapters load when their optional dependencies are installed."""
-    from python_repositories import MinioAdapter, RedisAdapter
+    from python_repositories import MinioAdapter, PostgresAdapter, RedisAdapter
 
     assert RedisAdapter.__name__ == "RedisAdapter"
     assert MinioAdapter.__name__ == "MinioAdapter"
+    assert PostgresAdapter.__name__ == "PostgresAdapter"
 
 
 def test_redis_adapter_import_error_without_extra() -> None:
@@ -86,6 +88,17 @@ def test_minio_adapter_import_error_without_extra() -> None:
     importlib.reload(minio_adapter_module)
 
 
+def test_postgres_adapter_import_error_without_extra() -> None:
+    """Missing postgres extra raises ImportError with install hint."""
+    import python_repositories.adapters.postgres_adapter as postgres_adapter_module
+
+    with patch.object(builtins, "__import__", new=_block_backend_import("psycopg")):
+        with pytest.raises(ImportError, match=r"python-repositories\[postgres\]"):
+            importlib.reload(postgres_adapter_module)
+
+    importlib.reload(postgres_adapter_module)
+
+
 def test_top_level_lazy_import_propagates_redis_import_error() -> None:
     """Top-level RedisAdapter access surfaces adapter import errors."""
     with patch(
@@ -112,6 +125,19 @@ def test_top_level_lazy_import_propagates_minio_import_error() -> None:
             _ = python_repositories.MinioAdapter
 
 
+def test_top_level_lazy_import_propagates_postgres_import_error() -> None:
+    """Top-level PostgresAdapter access surfaces adapter import errors."""
+    with patch(
+        "importlib.import_module",
+        side_effect=ImportError(
+            "Postgres support requires the postgres extra. "
+            "Install with: pip install python-repositories[postgres]"
+        ),
+    ):
+        with pytest.raises(ImportError, match=r"python-repositories\[postgres\]"):
+            _ = python_repositories.PostgresAdapter
+
+
 def test_adapters_subpackage_lazy_import_succeeds() -> None:
     """Adapter subpackage imports delegate to the same lazy loader."""
     from python_repositories.adapters import RedisAdapter
@@ -123,7 +149,9 @@ def test_adapters_dir_exposes_lazy_exports() -> None:
     """dir(adapters) includes lazy adapter names for tab completion."""
     import python_repositories.adapters as adapters
 
-    assert {"RedisAdapter", "MinioAdapter"}.issubset(set(dir(adapters)))
+    assert {"RedisAdapter", "MinioAdapter", "PostgresAdapter"}.issubset(
+        set(dir(adapters))
+    )
 
 
 def test_adapters_getattr_raises_for_unknown() -> None:
@@ -138,3 +166,4 @@ def test_top_level_dir_exposes_lazy_exports() -> None:
     """dir(python_repositories) includes lazy adapter names for tab completion."""
     assert "RedisAdapter" in dir(python_repositories)
     assert "MinioAdapter" in dir(python_repositories)
+    assert "PostgresAdapter" in dir(python_repositories)

tests/unit/conftest.py

@@ -5,12 +5,14 @@ from __future__ import annotations
 from unittest.mock import MagicMock
 
 from minio import Minio
+import psycopg
 import pytest
 import redis
 
 from python_repositories.adapters.minio_adapter import MinioAdapter
+from python_repositories.adapters.postgres_adapter import PostgresAdapter
 from python_repositories.adapters.redis_adapter import RedisAdapter
-from tests.conftest import TEST_MINIO_CONFIG, TEST_REDIS_CONFIG
+from tests.conftest import TEST_MINIO_CONFIG, TEST_POSTGRES_CONFIG, TEST_REDIS_CONFIG
 
 
 @pytest.fixture
@@ -25,3 +27,14 @@ def minio_adapter() -> MinioAdapter:
     """Provide a MinioAdapter with an injected mock client."""
     mock_client = MagicMock(spec=Minio)
     return MinioAdapter(config=TEST_MINIO_CONFIG, client=mock_client)
+
+
+@pytest.fixture
+def postgres_adapter() -> PostgresAdapter:
+    """Provide a PostgresAdapter with an injected mock client."""
+    mock_client = MagicMock(spec=psycopg.Connection)
+    mock_cursor = MagicMock()
+    mock_cursor.__enter__ = MagicMock(return_value=mock_cursor)
+    mock_cursor.__exit__ = MagicMock(return_value=False)
+    mock_client.cursor.return_value = mock_cursor
+    return PostgresAdapter(config=TEST_POSTGRES_CONFIG, client=mock_client)

tests/unit/connection_aware_adapter_test.py

@@ -5,11 +5,13 @@ from __future__ import annotations
 from typing import cast
 from unittest.mock import MagicMock, patch
 
+import psycopg
 import redis
 
 from python_repositories.adapters.minio_adapter import MinioAdapter
+from python_repositories.adapters.postgres_adapter import PostgresAdapter
 from python_repositories.adapters.redis_adapter import RedisAdapter
-from tests.conftest import TEST_MINIO_CONFIG, TEST_REDIS_CONFIG
+from tests.conftest import TEST_MINIO_CONFIG, TEST_POSTGRES_CONFIG, TEST_REDIS_CONFIG
 
 
 class TestRedisConnectionHealth:
@@ -161,3 +163,74 @@ class TestMinioConnectionHealth:
             assert reinjected.is_connected()
 
         assert mock_client.bucket_exists.call_count == 2
+
+
+class TestPostgresConnectionHealth:
+    def test_not_connected_when_no_client(self) -> None:
+        adapter = PostgresAdapter(config=TEST_POSTGRES_CONFIG)
+        assert not adapter.is_connected()
+
+    def test_connected_when_probe_succeeds(
+        self, postgres_adapter: PostgresAdapter
+    ) -> None:
+        assert postgres_adapter.is_connected()
+        cast(MagicMock, postgres_adapter._client).cursor.assert_called()
+
+    def test_stale_connection_when_probe_fails(
+        self, postgres_adapter: PostgresAdapter
+    ) -> None:
+        mock_cursor = cast(MagicMock, postgres_adapter._client).cursor.return_value
+        mock_cursor.execute.side_effect = psycopg.OperationalError("connection lost")
+
+        assert not postgres_adapter.is_connected()
+
+    def test_cache_hit_avoids_second_probe(
+        self, postgres_adapter: PostgresAdapter
+    ) -> None:
+        mock_client = cast(MagicMock, postgres_adapter._client)
+
+        with patch(
+            "python_repositories.adapters.connection_aware_adapter.time.monotonic",
+            return_value=100.0,
+        ):
+            assert postgres_adapter.is_connected()
+            assert postgres_adapter.is_connected()
+
+        assert mock_client.cursor.call_count == 1
+
+    def test_cache_miss_runs_probe_again(
+        self, postgres_adapter: PostgresAdapter
+    ) -> None:
+        mock_client = cast(MagicMock, postgres_adapter._client)
+
+        with patch(
+            "python_repositories.adapters.connection_aware_adapter.time.monotonic",
+            side_effect=[100.0, 102.0],
+        ):
+            assert postgres_adapter.is_connected()
+            assert postgres_adapter.is_connected()
+
+        assert mock_client.cursor.call_count == 2
+
+    def test_disconnect_clears_cache(self, postgres_adapter: PostgresAdapter) -> None:
+        mock_client = cast(MagicMock, postgres_adapter._client)
+
+        with patch(
+            "python_repositories.adapters.connection_aware_adapter.time.monotonic",
+            return_value=100.0,
+        ):
+            assert postgres_adapter.is_connected()
+
+        postgres_adapter.disconnect()
+        reinjected = PostgresAdapter(
+            config=postgres_adapter._config,
+            client=mock_client,
+        )
+
+        with patch(
+            "python_repositories.adapters.connection_aware_adapter.time.monotonic",
+            return_value=100.0,
+        ):
+            assert reinjected.is_connected()
+
+        assert mock_client.cursor.call_count == 2

tests/unit/postgres_adapter_test.py

@@ -0,0 +1,237 @@
+"""Unit tests for PostgresAdapter instantiation and injection."""
+
+from __future__ import annotations
+
+from unittest.mock import MagicMock
+
+import psycopg
+import pytest
+
+from python_repositories.adapters.postgres_adapter import PostgresAdapter
+from python_repositories.interfaces import TableRepositoryInterface
+from tests.conftest import TEST_POSTGRES_CONFIG
+
+
+def _mock_cursor() -> MagicMock:
+    mock_cursor = MagicMock()
+    mock_cursor.__enter__ = MagicMock(return_value=mock_cursor)
+    mock_cursor.__exit__ = MagicMock(return_value=False)
+    return mock_cursor
+
+
+def _mock_client(*, probe_raises: Exception | None = None) -> MagicMock:
+    mock_client = MagicMock(spec=psycopg.Connection)
+    mock_cursor = _mock_cursor()
+    if probe_raises is not None:
+        mock_cursor.execute.side_effect = probe_raises
+    mock_client.cursor.return_value = mock_cursor
+    return mock_client
+
+
+def test_should_adhere_to_interface() -> None:
+    assert issubclass(PostgresAdapter, TableRepositoryInterface)
+    _ = PostgresAdapter(config=TEST_POSTGRES_CONFIG)
+
+
+def test_should_have_logger_when_instantiated() -> None:
+    adapter = PostgresAdapter(config=TEST_POSTGRES_CONFIG)
+    assert hasattr(adapter, "logger")
+    assert adapter.logger is not None
+
+
+def test_should_not_be_connected_when_instantiated() -> None:
+    adapter = PostgresAdapter(config=TEST_POSTGRES_CONFIG)
+    assert adapter._client is None
+    assert not adapter.is_connected()
+
+
+def test_constructs_with_injected_config_without_env(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    monkeypatch.delenv("POSTGRES_URI", raising=False)
+    monkeypatch.delenv("POSTGRES_TABLE", raising=False)
+    adapter = PostgresAdapter(config=TEST_POSTGRES_CONFIG)
+    assert adapter._config == TEST_POSTGRES_CONFIG
+
+
+def test_constructs_with_injected_client_without_env(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    monkeypatch.delenv("POSTGRES_URI", raising=False)
+    monkeypatch.delenv("POSTGRES_TABLE", raising=False)
+    mock_client = _mock_client()
+    adapter = PostgresAdapter(config=TEST_POSTGRES_CONFIG, client=mock_client)
+    assert adapter._client is mock_client
+    assert adapter._client_injected is True
+
+
+def test_raises_when_client_provided_without_config() -> None:
+    mock_client = MagicMock(spec=psycopg.Connection)
+    with pytest.raises(ValueError, match="config is required"):
+        PostgresAdapter(client=mock_client)
+
+
+def test_disconnect_does_not_close_injected_client() -> None:
+    mock_client = _mock_client()
+    adapter = PostgresAdapter(config=TEST_POSTGRES_CONFIG, client=mock_client)
+    adapter.disconnect()
+    mock_client.close.assert_not_called()
+    assert adapter._client is None
+
+
+class CustomEnvPostgresAdapter(PostgresAdapter):
+    uri_env_var_name = "CUSTOM_POSTGRES_URI"
+    table_env_var_name = "CUSTOM_POSTGRES_TABLE"
+    primary_key_env_var_name = "CUSTOM_POSTGRES_PRIMARY_KEY"
+
+
+def test_subclass_custom_env_var_names(monkeypatch: pytest.MonkeyPatch) -> None:
+    monkeypatch.setenv("CUSTOM_POSTGRES_URI", "postgresql://custom/mydb")
+    monkeypatch.setenv("CUSTOM_POSTGRES_TABLE", "items")
+    monkeypatch.setenv("CUSTOM_POSTGRES_PRIMARY_KEY", "item_id")
+    adapter = CustomEnvPostgresAdapter()
+    assert adapter._config.uri == "postgresql://custom/mydb"
+    assert adapter._config.table == "items"
+    assert adapter._config.primary_key == "item_id"
+
+
+def test_connect_with_injected_client_succeeds_when_probe_ok() -> None:
+    mock_client = _mock_client()
+    adapter = PostgresAdapter(config=TEST_POSTGRES_CONFIG, client=mock_client)
+
+    adapter.connect()
+
+    assert mock_client.cursor.return_value.execute.call_count == 2
+
+
+def test_connect_with_injected_client_raises_on_probe_failure() -> None:
+    mock_client = _mock_client(probe_raises=psycopg.OperationalError("connection lost"))
+    adapter = PostgresAdapter(config=TEST_POSTGRES_CONFIG, client=mock_client)
+
+    with pytest.raises(ConnectionError, match="Could not connect to Postgres"):
+        adapter.connect()
+
+
+def test_connect_with_injected_client_skips_validation_when_client_cleared() -> None:
+    mock_client = _mock_client()
+    adapter = PostgresAdapter(config=TEST_POSTGRES_CONFIG, client=mock_client)
+    adapter.disconnect()
+
+    adapter.connect()
+
+    mock_client.cursor.assert_not_called()
+
+
+def test_connect_reconnects_when_existing_client_unhealthy(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    stale_client = _mock_client(
+        probe_raises=psycopg.OperationalError("connection lost")
+    )
+    new_client = _mock_client()
+    adapter = PostgresAdapter(config=TEST_POSTGRES_CONFIG)
+    adapter._client = stale_client
+
+    monkeypatch.setattr("psycopg.connect", lambda *args, **kwargs: new_client)
+
+    adapter.connect()
+
+    stale_client.close.assert_called_once()
+    assert adapter._client is new_client
+
+
+def test_connect_skips_reconnect_when_already_connected(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    healthy_client = _mock_client()
+    adapter = PostgresAdapter(config=TEST_POSTGRES_CONFIG)
+    adapter._client = healthy_client
+
+    connect = MagicMock()
+    monkeypatch.setattr("psycopg.connect", connect)
+
+    adapter.connect()
+
+    healthy_client.close.assert_not_called()
+    connect.assert_not_called()
+    assert adapter._client is healthy_client
+
+
+def test_fetch_one_raises_value_error_on_invalid_pk() -> None:
+    mock_client = _mock_client()
+    adapter = PostgresAdapter(config=TEST_POSTGRES_CONFIG, client=mock_client)
+
+    with pytest.raises(ValueError, match="Primary key must not be None"):
+        adapter.fetch_one(None)
+
+
+def test_fetch_one_raises_connection_error_when_not_connected() -> None:
+    adapter = PostgresAdapter(config=TEST_POSTGRES_CONFIG)
+
+    with pytest.raises(ConnectionError):
+        adapter.fetch_one("some-id")
+
+
+def test_upsert_raises_value_error_on_invalid_row() -> None:
+    mock_client = _mock_client()
+    adapter = PostgresAdapter(config=TEST_POSTGRES_CONFIG, client=mock_client)
+
+    with pytest.raises(ValueError, match="Row must be a dictionary"):
+        adapter.upsert("not-a-dict")  # type: ignore[arg-type]
+
+
+def test_upsert_raises_value_error_when_primary_key_missing() -> None:
+    mock_client = _mock_client()
+    adapter = PostgresAdapter(config=TEST_POSTGRES_CONFIG, client=mock_client)
+
+    with pytest.raises(ValueError, match="Row must include primary key column 'id'"):
+        adapter.upsert({"name": "Alice"})
+
+
+def test_upsert_raises_connection_error_when_not_connected() -> None:
+    adapter = PostgresAdapter(config=TEST_POSTGRES_CONFIG)
+
+    with pytest.raises(ConnectionError):
+        adapter.upsert({"id": "alice", "name": "Alice"})
+
+
+def test_fetch_all_raises_value_error_on_invalid_limit() -> None:
+    mock_client = _mock_client()
+    adapter = PostgresAdapter(config=TEST_POSTGRES_CONFIG, client=mock_client)
+
+    with pytest.raises(ValueError, match="Limit must be a non-negative integer"):
+        adapter.fetch_all(limit=-1)
+
+
+def test_execute_raises_value_error_on_invalid_sql() -> None:
+    mock_client = _mock_client()
+    adapter = PostgresAdapter(config=TEST_POSTGRES_CONFIG, client=mock_client)
+
+    with pytest.raises(ValueError, match="SQL must be a non-empty string"):
+        adapter.execute("")
+
+
+def test_execute_raises_value_error_on_invalid_params() -> None:
+    mock_client = _mock_client()
+    adapter = PostgresAdapter(config=TEST_POSTGRES_CONFIG, client=mock_client)
+
+    with pytest.raises(ValueError, match="Params must be a tuple"):
+        adapter.execute("SELECT 1", [])  # type: ignore[arg-type]
+
+
+def test_upsert_with_primary_key_only_uses_do_nothing() -> None:
+    mock_client = _mock_client()
+    adapter = PostgresAdapter(config=TEST_POSTGRES_CONFIG, client=mock_client)
+
+    adapter.upsert({"id": "pk-only"})
+
+    mock_cursor = mock_client.cursor.return_value.__enter__.return_value
+    insert_call = mock_cursor.execute.call_args_list[-1]
+    assert insert_call[0][1] == ("pk-only",)
+
+
+def test_execute_raises_connection_error_when_not_connected() -> None:
+    adapter = PostgresAdapter(config=TEST_POSTGRES_CONFIG)
+
+    with pytest.raises(ConnectionError):
+        adapter.execute("SELECT 1")

tests/unit/postgres_config_test.py

@@ -0,0 +1,69 @@
+"""Unit tests for PostgresConfig."""
+
+from __future__ import annotations
+
+import pytest
+
+from python_repositories.config import PostgresConfig
+
+
+def _set_required_postgres_env(monkeypatch: pytest.MonkeyPatch) -> None:
+    monkeypatch.setenv("POSTGRES_URI", "postgresql://localhost/mydb")
+    monkeypatch.setenv("POSTGRES_TABLE", "users")
+
+
+def test_from_env_loads_all_fields(monkeypatch: pytest.MonkeyPatch) -> None:
+    _set_required_postgres_env(monkeypatch)
+    config = PostgresConfig.from_env(use_dotenv=False)
+    assert config.uri == "postgresql://localhost/mydb"
+    assert config.table == "users"
+    assert config.primary_key == "id"
+
+
+def test_from_env_reads_primary_key_from_env(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    _set_required_postgres_env(monkeypatch)
+    monkeypatch.setenv("POSTGRES_PRIMARY_KEY", "user_id")
+    config = PostgresConfig.from_env(use_dotenv=False)
+    assert config.primary_key == "user_id"
+
+
+def test_from_env_defaults_primary_key_to_id_when_unset(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    _set_required_postgres_env(monkeypatch)
+    monkeypatch.delenv("POSTGRES_PRIMARY_KEY", raising=False)
+    config = PostgresConfig.from_env(use_dotenv=False)
+    assert config.primary_key == "id"
+
+
+def test_from_env_raises_when_uri_missing(monkeypatch: pytest.MonkeyPatch) -> None:
+    monkeypatch.delenv("POSTGRES_URI", raising=False)
+    monkeypatch.setenv("POSTGRES_TABLE", "users")
+    with pytest.raises(Exception):
+        PostgresConfig.from_env(use_dotenv=False)
+
+
+def test_from_env_raises_when_table_missing(monkeypatch: pytest.MonkeyPatch) -> None:
+    monkeypatch.setenv("POSTGRES_URI", "postgresql://localhost/mydb")
+    monkeypatch.delenv("POSTGRES_TABLE", raising=False)
+    with pytest.raises(Exception):
+        PostgresConfig.from_env(use_dotenv=False)
+
+
+def test_from_env_respects_custom_env_var_names(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    monkeypatch.setenv("CUSTOM_POSTGRES_URI", "postgresql://custom/mydb")
+    monkeypatch.setenv("CUSTOM_POSTGRES_TABLE", "items")
+    monkeypatch.setenv("CUSTOM_POSTGRES_PRIMARY_KEY", "item_id")
+    config = PostgresConfig.from_env(
+        "CUSTOM_POSTGRES_URI",
+        "CUSTOM_POSTGRES_TABLE",
+        "CUSTOM_POSTGRES_PRIMARY_KEY",
+        use_dotenv=False,
+    )
+    assert config.uri == "postgresql://custom/mydb"
+    assert config.table == "items"
+    assert config.primary_key == "item_id"

tests/unit/table_repository_interface_test.py

@@ -0,0 +1,162 @@
+"""Unit tests for TableRepositoryInterface."""
+
+from typing import Any
+
+import pytest
+
+from python_repositories.interfaces.table_repository_interface import (
+    TableRepositoryInterface,
+)
+
+
+class InMemoryTableRepo:
+    """Plain class that satisfies TableRepositoryInterface without inheritance."""
+
+    def fetch_one(self, pk: Any) -> dict[str, Any] | None:
+        return None
+
+    def fetch_all(self, *, limit: int | None = None) -> list[dict[str, Any]]:
+        del limit
+        return []
+
+    def upsert(self, row: dict[str, Any]) -> None:
+        pass
+
+    def delete(self, pk: Any) -> None:
+        pass
+
+    def execute(
+        self,
+        sql: str,
+        params: tuple[Any, ...] = (),
+    ) -> list[dict[str, Any]]:
+        del sql, params
+        return []
+
+
+def accepts_table_repo(repo: TableRepositoryInterface) -> None:
+    """Type-checking hook for TableRepositoryInterface structural subtyping."""
+    repo.fetch_one("pk")
+
+
+def test_instantiation_fails_when_fetch_one_not_implemented() -> None:
+    """Test that instantiation fails if fetch_one is not implemented."""
+
+    class Incomplete(TableRepositoryInterface):
+        def fetch_all(self, *, limit: int | None = None) -> list[dict[str, Any]]:
+            return []
+
+        def upsert(self, row: dict[str, Any]) -> None:
+            pass
+
+        def delete(self, pk: Any) -> None:
+            pass
+
+        def execute(
+            self,
+            sql: str,
+            params: tuple[Any, ...] = (),
+        ) -> list[dict[str, Any]]:
+            return []
+
+    with pytest.raises(TypeError):
+        _ = Incomplete()  # type: ignore
+
+
+def test_instantiation_fails_when_fetch_all_not_implemented() -> None:
+    """Test that instantiation fails if fetch_all is not implemented."""
+
+    class Incomplete(TableRepositoryInterface):
+        def fetch_one(self, pk: Any) -> dict[str, Any] | None:
+            return None
+
+        def upsert(self, row: dict[str, Any]) -> None:
+            pass
+
+        def delete(self, pk: Any) -> None:
+            pass
+
+        def execute(
+            self,
+            sql: str,
+            params: tuple[Any, ...] = (),
+        ) -> list[dict[str, Any]]:
+            return []
+
+    with pytest.raises(TypeError):
+        _ = Incomplete()  # type: ignore
+
+
+def test_instantiation_fails_when_upsert_not_implemented() -> None:
+    """Test that instantiation fails if upsert is not implemented."""
+
+    class Incomplete(TableRepositoryInterface):
+        def fetch_one(self, pk: Any) -> dict[str, Any] | None:
+            return None
+
+        def fetch_all(self, *, limit: int | None = None) -> list[dict[str, Any]]:
+            return []
+
+        def delete(self, pk: Any) -> None:
+            pass
+
+        def execute(
+            self,
+            sql: str,
+            params: tuple[Any, ...] = (),
+        ) -> list[dict[str, Any]]:
+            return []
+
+    with pytest.raises(TypeError):
+        _ = Incomplete()  # type: ignore
+
+
+def test_instantiation_fails_when_delete_not_implemented() -> None:
+    """Test that instantiation fails if delete is not implemented."""
+
+    class Incomplete(TableRepositoryInterface):
+        def fetch_one(self, pk: Any) -> dict[str, Any] | None:
+            return None
+
+        def fetch_all(self, *, limit: int | None = None) -> list[dict[str, Any]]:
+            return []
+
+        def upsert(self, row: dict[str, Any]) -> None:
+            pass
+
+        def execute(
+            self,
+            sql: str,
+            params: tuple[Any, ...] = (),
+        ) -> list[dict[str, Any]]:
+            return []
+
+    with pytest.raises(TypeError):
+        _ = Incomplete()  # type: ignore
+
+
+def test_instantiation_fails_when_execute_not_implemented() -> None:
+    """Test that instantiation fails if execute is not implemented."""
+
+    class Incomplete(TableRepositoryInterface):
+        def fetch_one(self, pk: Any) -> dict[str, Any] | None:
+            return None
+
+        def fetch_all(self, *, limit: int | None = None) -> list[dict[str, Any]]:
+            return []
+
+        def upsert(self, row: dict[str, Any]) -> None:
+            pass
+
+        def delete(self, pk: Any) -> None:
+            pass
+
+    with pytest.raises(TypeError):
+        _ = Incomplete()  # type: ignore
+
+
+def test_structural_subtyping() -> None:
+    """Test that a plain class satisfies TableRepositoryInterface structurally."""
+    repo: TableRepositoryInterface = InMemoryTableRepo()
+    accepts_table_repo(repo)
+    assert isinstance(repo, TableRepositoryInterface)

uv.lock

@@ -1,5 +1,5 @@
 version = 1
-revision = 2
+revision = 3
 requires-python = ">=3.12"
 resolution-markers = [
     "python_full_version >= '3.15'",
@@ -864,6 +864,64 @@ wheels = [
     { url = "https://proxpi.lille-vemmelund.dk/index/pre-commit/pre_commit-4.6.0-py2.py3-none-any.whl", hash = "sha256:e2cf246f7299edcabcf15f9b0571fdce06058527f0a06535068a86d38089f29b" },
 ]
 
+[[package]]
+name = "psycopg"
+version = "3.3.4"
+source = { registry = "https://proxpi.lille-vemmelund.dk/index/" }
+dependencies = [
+    { name = "typing-extensions", marker = "python_full_version < '3.13'" },
+    { name = "tzdata", marker = "sys_platform == 'win32'" },
+]
+sdist = { url = "https://proxpi.lille-vemmelund.dk/index/psycopg/psycopg-3.3.4.tar.gz", hash = "sha256:e21207764952cff81b6b8bdacad9a3939f2793367fdac2987b3aac36a651b5bc" }
+wheels = [
+    { url = "https://proxpi.lille-vemmelund.dk/index/psycopg/psycopg-3.3.4-py3-none-any.whl", hash = "sha256:b6bbc25ccf05c8fad3b061d9db2ef0909a555171b84b07f29458a447253d679a" },
+]
+
+[package.optional-dependencies]
+binary = [
+    { name = "psycopg-binary", marker = "implementation_name != 'pypy'" },
+]
+
+[[package]]
+name = "psycopg-binary"
+version = "3.3.4"
+source = { registry = "https://proxpi.lille-vemmelund.dk/index/" }
+wheels = [
+    { url = "https://proxpi.lille-vemmelund.dk/index/psycopg-binary/psycopg_binary-3.3.4-cp312-cp312-macosx_10_13_x86_64.whl", hash = "sha256:5ab28a2a7649df3b72e6b674b4c190e448e8e77cf496a65bd846472048de2089" },
+    { url = "https://proxpi.lille-vemmelund.dk/index/psycopg-binary/psycopg_binary-3.3.4-cp312-cp312-macosx_11_0_arm64.whl", hash = "sha256:6402a9d8146cf4b3974ded3fd28a971e83dc6a0333eb7822524a3aa20b546578" },
+    { url = "https://proxpi.lille-vemmelund.dk/index/psycopg-binary/psycopg_binary-3.3.4-cp312-cp312-manylinux2014_ppc64le.manylinux_2_17_ppc64le.whl", hash = "sha256:580ae30a5f95ccd90008ec697d3ed6a4a2047a516407ad904283fa42086936e9" },
+    { url = "https://proxpi.lille-vemmelund.dk/index/psycopg-binary/psycopg_binary-3.3.4-cp312-cp312-manylinux2014_x86_64.manylinux_2_17_x86_64.whl", hash = "sha256:e7510c37550f91a187e3660a8cc50d4b760f8c3b8b2f89ebc5698cd2c7f2c85d" },
+    { url = "https://proxpi.lille-vemmelund.dk/index/psycopg-binary/psycopg_binary-3.3.4-cp312-cp312-manylinux_2_27_aarch64.manylinux_2_28_aarch64.whl", hash = "sha256:77df19583501ea288eaf15ac0fe7ad01e6d8091a91d5c41df5c718f307d8e31b" },
+    { url = "https://proxpi.lille-vemmelund.dk/index/psycopg-binary/psycopg_binary-3.3.4-cp312-cp312-manylinux_2_38_riscv64.manylinux_2_39_riscv64.whl", hash = "sha256:018fbed325936da502feb546642c982dcc4b9ffdea32dfef78dbf3b7f7ad4070" },
+    { url = "https://proxpi.lille-vemmelund.dk/index/psycopg-binary/psycopg_binary-3.3.4-cp312-cp312-musllinux_1_2_aarch64.whl", hash = "sha256:17a21953a9e5ff3a16dab692625a3676e2f101db5e40072f39dbee2250194d68" },
+    { url = "https://proxpi.lille-vemmelund.dk/index/psycopg-binary/psycopg_binary-3.3.4-cp312-cp312-musllinux_1_2_ppc64le.whl", hash = "sha256:eb05ee1c2b817d27c537333224c9e83c7afb86fe7296ba970990068baf819b16" },
+    { url = "https://proxpi.lille-vemmelund.dk/index/psycopg-binary/psycopg_binary-3.3.4-cp312-cp312-musllinux_1_2_riscv64.whl", hash = "sha256:773d573e11f437ce0bdb95b7c18dc58390494f96d43f8b45b9760436114f7652" },
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+]
+
 [[package]]
 name = "pycparser"
 version = "3.0"
@@ -1068,6 +1126,9 @@ dependencies = [
 minio = [
     { name = "minio" },
 ]
+postgres = [
+    { name = "psycopg", extra = ["binary"] },
+]
 redis = [
     { name = "redis" },
 ]
@@ -1087,12 +1148,13 @@ dev = [
 [package.metadata]
 requires-dist = [
     { name = "minio", marker = "extra == 'minio'", specifier = ">=7.2.16" },
+    { name = "psycopg", extras = ["binary"], marker = "extra == 'postgres'", specifier = ">=3.2.0" },
     { name = "python-dotenv", specifier = ">=1.0.0" },
     { name = "python-utils", specifier = ">=0.1.0", index = "https://gitea.lille-vemmelund.dk/api/packages/brian/pypi/simple/" },
     { name = "redis", marker = "extra == 'redis'", specifier = ">=6.4.0" },
     { name = "structlog", specifier = ">=25.4.0" },
 ]
-provides-extras = ["redis", "minio"]
+provides-extras = ["redis", "minio", "postgres"]
 
 [package.metadata.requires-dev]
 dev = [
@@ -1514,6 +1576,15 @@ wheels = [
     { url = "https://proxpi.lille-vemmelund.dk/index/typing-inspection/typing_inspection-0.4.2-py3-none-any.whl", hash = "sha256:4ed1cacbdc298c220f1bd249ed5287caa16f34d44ef4e9c3d0cbad5b521545e7" },
 ]
 
+[[package]]
+name = "tzdata"
+version = "2026.3"
+source = { registry = "https://proxpi.lille-vemmelund.dk/index/" }
+sdist = { url = "https://proxpi.lille-vemmelund.dk/index/tzdata/tzdata-2026.3.tar.gz", hash = "sha256:4a1518b8993086a7982523e071643f3c0e5f213e75b21318e78bcabfff9d1415" }
+wheels = [
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+]
+
 [[package]]
 name = "urllib3"
 version = "2.7.0"