# modern-di

Powerful dependency-injection framework with IoC container and scopes.

## Quickstart

- [Quick-Start](https://modern-di.modern-python.org/index.md): How to install and a minimal container example

## Introduction

- [About DI](https://modern-di.modern-python.org/introduction/about-di/index.md): What dependency injection is and the problem it solves
- [Resolving](https://modern-di.modern-python.org/introduction/resolving/index.md): Resolving dependencies by type or by provider reference
- [Design decisions](https://modern-di.modern-python.org/introduction/design-decisions/index.md): The deliberate API choices behind modern-di
- [Comparison](https://modern-di.modern-python.org/introduction/comparison/index.md): How modern-di compares to other DI approaches, including that-depends
- [Performance](https://modern-di.modern-python.org/introduction/performance/index.md): Comparative benchmarks vs other DI frameworks, and how to reproduce them
- [modern-di for FastAPI users](https://modern-di.modern-python.org/introduction/for-fastapi-users/index.md): Translating FastAPI's Depends idioms to modern-di

## Providers

- [Scopes](https://modern-di.modern-python.org/providers/scopes/index.md): The five built-in scopes and the resolution rule
- [Lifecycle](https://modern-di.modern-python.org/providers/lifecycle/index.md): How instances are created, cached, and cleaned up
- [Factories](https://modern-di.modern-python.org/providers/factories/index.md): Regular vs cached Factory providers
- [Context](https://modern-di.modern-python.org/providers/context/index.md): Injecting runtime context values with ContextProvider
- [Container](https://modern-di.modern-python.org/providers/container/index.md): The auto-registered provider that resolves to the Container itself
- [Alias](https://modern-di.modern-python.org/providers/alias/index.md): Binding one type to an already-registered provider
- [Errors and exceptions](https://modern-di.modern-python.org/providers/errors-and-exceptions/index.md): The ModernDIError exception hierarchy
- [Advanced / low-level API](https://modern-di.modern-python.org/providers/advanced-api/index.md): Low-level extension points for library authors

## Integrations

- [aiogram](https://modern-di.modern-python.org/integrations/aiogram/index.md)
- [aiohttp](https://modern-di.modern-python.org/integrations/aiohttp/index.md)
- [arq](https://modern-di.modern-python.org/integrations/arq/index.md)
- [Celery](https://modern-di.modern-python.org/integrations/celery/index.md)
- [FastAPI](https://modern-di.modern-python.org/integrations/fastapi/index.md)
- [FastStream](https://modern-di.modern-python.org/integrations/faststream/index.md)
- [Flask](https://modern-di.modern-python.org/integrations/flask/index.md)
- [gRPC](https://modern-di.modern-python.org/integrations/grpc/index.md)
- [Litestar](https://modern-di.modern-python.org/integrations/litestar/index.md)
- [Pytest](https://modern-di.modern-python.org/integrations/pytest/index.md): Usage with pytest, with and without modern-di-pytest
- [Starlette](https://modern-di.modern-python.org/integrations/starlette/index.md)
- [taskiq](https://modern-di.modern-python.org/integrations/taskiq/index.md)
- [Typer](https://modern-di.modern-python.org/integrations/typer/index.md)
- [Writing an integration](https://modern-di.modern-python.org/integrations/writing-integrations/index.md): Specification for building a new framework integration

## Recipes

- [Async SQLAlchemy](https://modern-di.modern-python.org/recipes/sqlalchemy/index.md): Wiring an async SQLAlchemy engine, session, and repositories
- [Async resources via lifespan](https://modern-di.modern-python.org/recipes/async-lifespan/index.md): Constructing async resources via the framework lifespan
- [Multi-Group organization](https://modern-di.modern-python.org/recipes/multi-group/index.md): Organizing a large container with multiple Groups
- [Testing with overrides](https://modern-di.modern-python.org/recipes/testing-overrides/index.md): Swapping dependencies in tests with overrides
- [Request-scoped engine selection](https://modern-di.modern-python.org/recipes/request-scoped-engine/index.md): Routing requests to different engines by scope
- [Good and bad practices](https://modern-di.modern-python.org/recipes/good-and-bad-practices/index.md): Common DI footguns and how modern-di catches them

## Troubleshooting

- [Invalid Child Scope](https://modern-di.modern-python.org/troubleshooting/invalid-child-scope-error/index.md): Diagnosing InvalidChildScopeError
- [Max Scope Reached](https://modern-di.modern-python.org/troubleshooting/max-scope-reached-error/index.md): Diagnosing MaxScopeReachedError
- [Scope Not Initialized](https://modern-di.modern-python.org/troubleshooting/scope-not-initialized-error/index.md): Diagnosing ScopeNotInitializedError
- [Scope Skipped](https://modern-di.modern-python.org/troubleshooting/scope-skipped-error/index.md): Diagnosing ScopeSkippedError
- [Invalid Scope Type](https://modern-di.modern-python.org/troubleshooting/invalid-scope-type-error/index.md): Diagnosing InvalidScopeTypeError
- [Container Closed](https://modern-di.modern-python.org/troubleshooting/container-closed-error/index.md): Diagnosing ContainerClosedError
- [Validation Failed](https://modern-di.modern-python.org/troubleshooting/validation-failed-error/index.md): Diagnosing ValidationFailedError
- [Missing Provider For Type](https://modern-di.modern-python.org/troubleshooting/missing-provider/index.md): Diagnosing missing provider registration errors
- [Alias Source Not Registered](https://modern-di.modern-python.org/troubleshooting/alias-source-not-registered-error/index.md): Diagnosing AliasSourceNotRegisteredError
- [Argument Resolution Error](https://modern-di.modern-python.org/troubleshooting/argument-resolution-error/index.md): Diagnosing ArgumentResolutionError
- [Circular Dependency](https://modern-di.modern-python.org/troubleshooting/circular-dependency/index.md): Diagnosing circular dependency errors
- [Creator Call Error](https://modern-di.modern-python.org/troubleshooting/creator-call-error/index.md): Diagnosing CreatorCallError
- [ContextProvider Has No Value](https://modern-di.modern-python.org/troubleshooting/context-not-set/index.md): Diagnosing ContextProvider-has-no-value errors
- [Duplicate Type Error](https://modern-di.modern-python.org/troubleshooting/duplicate-type-error/index.md): Diagnosing duplicate bound_type registration errors
- [Child Container Registration](https://modern-di.modern-python.org/troubleshooting/child-container-registration-error/index.md): Diagnosing ChildContainerRegistrationError
- [Group Scope Conflict](https://modern-di.modern-python.org/troubleshooting/group-scope-conflict-error/index.md): Diagnosing GroupScopeConflictError
- [Provider Scope Frozen](https://modern-di.modern-python.org/troubleshooting/provider-scope-frozen-error/index.md): Diagnosing ProviderScopeFrozenError
- [Unknown Factory Kwarg](https://modern-di.modern-python.org/troubleshooting/unknown-factory-kwarg-error/index.md): Diagnosing UnknownFactoryKwargError
- [Unsupported Creator Parameter](https://modern-di.modern-python.org/troubleshooting/unsupported-creator-parameter-error/index.md): Diagnosing UnsupportedCreatorParameterError
- [Scope Chain Violation](https://modern-di.modern-python.org/troubleshooting/scope-chain/index.md): Diagnosing scope chain violation errors
- [Finalizer Error](https://modern-di.modern-python.org/troubleshooting/finalizer-error/index.md): Diagnosing FinalizerError
- [Async Finalizer In Sync Close](https://modern-di.modern-python.org/troubleshooting/async-finalizer-in-sync-close-error/index.md): Diagnosing AsyncFinalizerInSyncCloseError
- [Group Instantiation Error](https://modern-di.modern-python.org/troubleshooting/group-instantiation-error/index.md): Diagnosing GroupInstantiationError

## Migration

- [To 1.x](https://modern-di.modern-python.org/migration/to-1.x/index.md): Migrating from modern-di 0.x to 1.x
- [To 2.x](https://modern-di.modern-python.org/migration/to-2.x/index.md): Migrating from modern-di 1.x to 2.x
- [To 3.x](https://modern-di.modern-python.org/migration/to-3.x/index.md): Migrating from modern-di 2.x to 3.x
- [From that-depends](https://modern-di.modern-python.org/migration/from-that-depends/index.md): Migrating an existing that-depends codebase to modern-di
- [From dependency-injector](https://modern-di.modern-python.org/migration/from-dependency-injector/index.md): Migrating an existing dependency-injector codebase to modern-di

## Development

- [Contributing](https://modern-di.modern-python.org/dev/contributing/index.md): Contributing guide for local setup and workflow