Context System

A thread safe, async safe context management system with built-in security boundaries for .NET applications.

Features

• Thread-Safe & Async-Safe - Built on AsyncLocal<T> for automatic context isolation
• Security Boundaries - Defensive copy pattern prevents untrusted code from accessing sensitive data
• Multi-Tenant Ready - Perfect for SaaS applications requiring tenant isolation
• Plugin-Friendly - Safe context exposure to third-party plugins
• Distributed Tracing - Built-in support for correlation IDs and trace context
• High Performance - Minimal overhead (~100ns per operation)

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Quick Start

usingModularityKit.Context.Abstractions;usingModularityKit.Context.Extensions;// 1. Define your contextpublicclassMyContext:IContext{publicstringId{get;}publicDateTimeOffsetCreatedAt{get;}publicstringUserId{get;}publicstringTenantId{get;}}// 2. Register in DIservices.AddContext<MyContext>();// 3. Use in your codepublicclassOrderService(IContextAccessor<MyContext>context){publicvoidProcessOrder(){varctx=context.RequireCurrent();Console.WriteLine($"Processing for user: {ctx.UserId}");}}// 4. Execute with contextvarcontext=newMyContext("ctx-1","user-123","tenant-456");awaitcontextManager.ExecuteInContext(context,async()=>{orderService.ProcessOrder();});

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🎯 Why Use Context System?

Without Context System ❌

publicclassOrderService{// Passing context everywhere - painful!publicasyncTaskCreateOrder(stringuserId,stringtenantId,stringcorrelationId){awaitValidateOrder(userId,tenantId,correlationId);awaitProcessPayment(userId,tenantId,correlationId);awaitSendEmail(userId,tenantId,correlationId);}}

With Context System ✅

publicclassOrderService(IContextAccessor<MyContext>context){// Clean API - context flows automaticallypublicasyncTaskCreateOrder(){awaitValidateOrder();// Context flows automaticallyawaitProcessPayment();awaitSendEmail();}}

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Documentation

Getting Started

• Installation & Setup - Complete setup guide
• Basic Usage - Learn the fundamentals
• Core Concepts - Understanding the architecture

Guides

• Multi-Tenant Applications - Building SaaS applications

Reference

• API Reference - Complete API documentation
• Best Practices - Tips and recommendations

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Multi Tenant SaaS

publicclassDocumentService(IContextAccessor<MyContext>context){publicasyncTaskGetDocument(stringdocumentId){varctx=context.RequireCurrent();// Automatic tenant filteringreturnawait_db.Documents.Where(d =>d.TenantId==ctx.TenantId).Where(d =>d.Id==documentId).FirstOrDefaultAsync();}}

Automatic tenant isolation using IContextAccessor ensures security and data separation.

See full example →

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Architecture

 Application Layer
├─ Trusted Code (Full Access)-> IContextAccessor<MyContext>
└─ Untrusted Code (Read-Only) -> IContextAccessor<IReadOnlyContext>
│
▼
Context Infrastructure
├─ ContextStore (AsyncLocal)
├─ ContextAccessor
└─ ContextManager
│
▼
Security Boundary
└─ ReadOnlyContextSnapshot (Defensive Copy)

Learn more about architecture →

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Best Practices

DO ✅

• Create context per operation (request/job)
• Use RequireCurrent() when context is expected
• Let ExecuteInContext handle cleanup
• Treat contexts as immutable

DON'T ❌

• Share context across operations
• Mutate context properties
• Use Current without null check
• Store context in static fields

Read full best practices guide →

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API Reference

Core Interfaces

• IContext - Base context interface
• IContextAccessor<TContext> - Access current context
• IContextManager<TContext> - Manage context lifecycle

Extension Methods

• AddContext<TContext>() - Register context infrastructure
• AddReadOnlyContextAccessor<TContext>() - Register read-only accessor

View complete API reference →

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