Blazor CRM (ASP.NET Core / .NET 9)

A compact but complete CRM sample built with Blazor Server, EF Core (PostgreSQL), ASP.NET Core Identity, JWT, SignalR, Quartz, OpenTelemetry, and a layered architecture.

The solution demonstrates real-world practices: CQRS via MediatR, multi-tenancy, caching, rate limiting, telemetry, and background jobs.

Solution layout

• src/Crm.Domain — domain models and enums
• src/Crm.Application — application layer (CQRS/MediatR, interfaces, validation, permissions)
• src/Crm.Infrastructure — infrastructure (EF Core DbContext, migrations, Identity, services, Quartz, SignalR hub)
• src/Presentation/Crm.Web — Blazor Server app + minimal APIs
• src/Presentation/Crm.UI — shared Blazor UI components
• src/Background/Crm.Worker — .NET Worker (BackgroundService)
• tests/* — test projects

Features

• Blazor Server UI: Companies, Contacts, Deals, Tasks, Activities, Dashboard and details pages
• EF Core + PostgreSQL; migrations applied on startup (Database.Migrate)
• ASP.NET Core Identity + roles (Admin/Manager/User), Cookie login (web) and JWT (API)
• Multi-tenancy via TenantId + global EF filters (claim "tenant")
• MediatR pipeline behavior for permissions (PermissionBehavior)
• SignalR NotificationsHub for realtime notifications
• Quartz scheduled jobs (RemindersSweepJob every 5 min) with persistent store (PostgreSQL)
• Output caching, Response compression, CORS, Rate limiting, Health checks
• OpenTelemetry (traces/metrics) with OTLP exporter
• File storage (IAttachmentService, LocalFileStorage) + download endpoint

Screenshots

Tech stack

• .NET 9, ASP.NET Core, Blazor Server
• Entity Framework Core (Npgsql)
• ASP.NET Core Identity, JWT Bearer, Policy scheme (Cookie/JWT)
• MediatR, Quartz.NET, SignalR
• OpenTelemetry (OTLP)

Quick start

Prerequisites

• .NET 9 SDK
• PostgreSQL database (local or container)

Configuration (appsettings.*)

• ConnectionStrings:DefaultConnection — Npgsql connection string
• Jwt:Key, Jwt:Issuer, Jwt:Audience — JWT settings
• Cors:AllowedOrigins — CORS origins for policy "maui"
• Seed:AdminEmail / Seed:AdminPassword / Seed:AdminRoles — initial user and roles
• Quartz:SchemaSqlPath — optional path to the Quartz SQL schema script

Example (appsettings.Development.json):

{
  "ConnectionStrings": {
    "DefaultConnection": "Host=localhost;Port=5432;Database=blazor_crm;Username=postgres;Password=postgres"
  },
  "Jwt": {
    "Key": "dev-key-please-set",
    "Issuer": "BlazorCrm",
    "Audience": "BlazorCrm"
  },
  "Cors": { "AllowedOrigins": ["https://localhost:5001", "http://localhost:5000"] },
  "Seed": {
    "AdminEmail": "admin@local",
    "AdminPassword": "Admin123$",
    "AdminRoles": ["Admin"]
  }
}

Notes:

• In Development, if the connection string is missing, a dev fallback to local PostgreSQL is used.
• On startup: EF migrations are applied, IdentitySeeder runs (roles/admin), DemoDataSeeder runs in Development only.
• Data Protection keys are stored in the database.

Quartz schema (PostgreSQL)

Quartz uses a persistent store. On first startup the app checks for Quartz tables and, if missing, looks for a SQL script and applies it automatically. Place the official Quartz PostgreSQL SQL script at one of:

• /sql/quartz_postgres.sql
• /quartz_postgres.sql
• or point to it via configuration: Quartz:SchemaSqlPath

Run

• Web (Blazor + API):
  • dotnet run --project src/Presentation/Crm.Web/Crm.Web.csproj
  • Open https://localhost:
• Worker (optional):
  • dotnet run --project src/Background/Crm.Worker/Crm.Worker.csproj

Default login (after seed):

• Email: admin@local
• Password: Admin123$

Database and migrations

• DbContext: Crm.Infrastructure.Persistence.CrmDbContext
• Entities: Tenant, Company, Contact, Pipeline, Stage, Deal, Activity, TaskItem, Attachment, Team, UserTeam, RefreshToken, AuditEntry
• Company/Contact have Tags (List) with a custom ValueComparer and string conversion
• Global TenantId filters applied to most tables
• Useful indexes for common queries (e.g., Deal: StageId/OwnerId/CompanyId/ContactId; Activity/TaskItem: RelatedId; etc.)

Manual EF commands:

• Add migration: dotnet ef migrations add <Name> -p src/Crm.Infrastructure -s src/Presentation/Crm.Web
• Update DB: dotnet ef database update -p src/Crm.Infrastructure -s src/Presentation/Crm.Web

Security and permissions

• Authentication: Cookie (web) and JWT (API). A policy scheme chooses based on Authorization header.
• Policies/Permissions: see Crm.Application.Security.Permissions and Program.cs
• Roles: Admin/Manager/User (seeded)
• Multi-tenancy: ITenantProvider (HttpTenantProvider) reads claim "tenant"; defaults to Guid.Empty when missing

API (v1) — endpoints and examples

All /api routes are protected and use CORS policy "maui" and fixed-window rate limiting (60 req/min). Use Bearer for protected routes.

Auth

• POST /api/auth/login — issue JWT + refresh token
• POST /api/auth/refresh — rotate refresh token
• POST /api/auth/logout — revoke refresh token(s)

Example: login (JWT)

curl -X POST https://localhost:5001/api/auth/login \
  -H "Content-Type: application/json" \
  -d '{
    "userName": "admin@local",
    "password": "Admin123$"
  }'

Response:

{
  "accessToken": "eyJhbGciOi...",
  "refreshToken": "6cfd...",
  "expiresIn": 3600
}

Example: refresh

curl -X POST https://localhost:5001/api/auth/refresh \
  -H "Content-Type: application/json" \
  -d '{"refreshToken": "<refreshToken>"}'

Example: logout (revoke a single refresh token)

curl -X POST https://localhost:5001/api/auth/logout \
  -H "Authorization": "Bearer <accessToken>" \
  -H "Content-Type: application/json" \
  -d '{"refreshToken": "<refreshToken>"}'

Companies

• GET /api/companies — search/filter/sort/pagination
• POST /api/companies — create
• PUT /api/companies/{id} — update
• DELETE /api/companies/{id} — delete
• GET /api/companies/industries — distinct industries

Example: list companies with filter/sort/paging

curl "https://localhost:5001/api/companies?search=soft&industry=SaaS&sort=Name&asc=true&page=1&pageSize=10" \
  -H "Authorization: Bearer <accessToken>"

Response:

{
  "items": [
    { "id": "...", "name": "Acme", "industry": "SaaS", "tags": ["key"], "address": "...", "tenantId": "..." }
  ],
  "total": 1
}

Example: create company

curl -X POST https://localhost:5001/api/companies \
  -H "Authorization: Bearer <accessToken>" \
  -H "Content-Type: application/json" \
  -d '{
    "name": "Contoso",
    "industry": "Manufacturing",
    "tags": ["partner","priority"]
  }'

Response: "<new-company-guid>"

Example: update company

curl -X PUT https://localhost:5001/api/companies/<id> \
  -H "Authorization: Bearer <accessToken>" \
  -H "Content-Type: application/json" \
  -d '{
    "id": "<id>",
    "name": "Contoso Ltd",
    "industry": "Manufacturing",
    "tags": ["partner"]
  }'

Contacts

• POST /api/contacts, PUT /api/contacts/{id}, DELETE /api/contacts/{id}

Deals

• POST /api/deals, PUT /api/deals/{id}, DELETE /api/deals/{id}

Activities

• POST /api/activities, PUT /api/activities/{id}, DELETE /api/activities/{id}

Tasks

• POST /api/tasks, PUT /api/tasks/{id}, DELETE /api/tasks/{id}

Attachments

• GET /attachments/{id} — download attachment

Example: download attachment

curl -L "https://localhost:5001/attachments/<id>" \
  -H "Authorization: Bearer <accessToken>" -o file.bin

Health

• GET /health/live, GET /health/ready

Form login (web)

• POST /auth/login — Cookie sign-in for Blazor UI form

Telemetry

• OpenTelemetry tracing and metrics (ASP.NET Core, HttpClient, EF Core) with OTLP exporter.
• Configure via standard env vars, e.g. OTEL_EXPORTER_OTLP_ENDPOINT.

Files and attachments

• IAttachmentService with LocalFileStorage. Download: GET /attachments/{id}.

UI and safety

• Blazor components in src/Presentation/Crm.Web/Components and src/Presentation/Crm.UI
• Tightened CSP (no inline scripts), static assets from wwwroot
• Compression and output cache enabled

Testing

• dotnet test (tests/*)

Troubleshooting

• Missing Quartz tables: add/point to quartz_postgres.sql (see Quartz schema above)
• Missing Jwt:Key in Production: set a value (otherwise startup throws InvalidOperationException)
• DB connection: set ConnectionStrings:DefaultConnection