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Live Playground

Experience NexJob directly in your browser without spinning up local databases or installing any packages.

The playground is a live deployment of the NexJob Standalone Dashboard running on Fly.io, with a Scenarios drawer that enqueues real jobs so you can watch them move through the dashboard.

Interactive Scenario Simulator

The playground features a dedicated Scenarios drawer (accessible from the top header) that triggers real runtime events with a single click:

  • Order Batch

    Enqueues order jobs (one, or a batch of five) and lets you follow them from Enqueued to Succeeded on the Overview and Jobs pages.

  • Retry Recovery

    Enqueues a flaky API job that fails on its first attempt and succeeds on a retry. The dashboard opens the job detail so you can inspect the failed attempt and the recovery.

  • Dead-Letter

    Enqueues a job that fails for good. The dashboard opens its detail page, where the execution timeline shows the retry budget exhausted and the move to dead-letter.

  • Concurrency Burst

    Enqueues 20 order jobs at once, tagged traffic-spike, so you can watch the workers take them concurrently and the metrics update live.

  • Recurring Sweep

    Makes every recurring job due immediately, so the scheduler fires them on its next cycle.

Each scenario is a POST to {pathPrefix}/api/scenarios/{scenario} on the dashboard.

Enabling Playground in Local Development

For security and operational integrity, the scenario simulator is disabled by default (EnablePlayground = false). When it is disabled, the Scenarios button is hidden and the scenario endpoint is not served.

You can opt in during local development or staging:

using NexJob;
using NexJob.Dashboard;

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddNexJob();

var app = builder.Build();

app.UseNexJobDashboard("/dashboard", options =>
{
    // Opt in to the interactive scenarios drawer (dev/staging only)
    options.EnablePlayground = app.Environment.IsDevelopment();
    options.DefaultTheme = "semi-dark";
});

app.Run();

using NexJob;
using NexJob.Dashboard.Standalone;

var builder = Host.CreateApplicationBuilder(args);

builder.Services.AddNexJob();

builder.Services.AddNexJobStandaloneDashboard(options =>
{
    options.Port = 5005;
    options.EnablePlayground = builder.Environment.IsDevelopment();
    options.DefaultTheme = "semi-dark";
});

var host = builder.Build();
host.Run();

DefaultTheme sets the theme used when the browser has no stored preference: blue-theme (default), semi-dark, dark, light or bordered-theme. See Dashboard configuration options.

Deploying Your Own Playground

You can containerize and deploy your own playground instance using Docker and cloud platforms like Fly.io. This Dockerfile publishes the NexJob.Sample.WorkerService sample from the NexJob repository:

FROM mcr.microsoft.com/dotnet/sdk:8.0-alpine AS build
WORKDIR /src
COPY . .
RUN dotnet publish samples/NexJob.Sample.WorkerService -c Release -o /app/publish

FROM mcr.microsoft.com/dotnet/runtime:8.0-alpine
WORKDIR /app
RUN apk add --no-cache tzdata icu-libs
COPY --chown=$APP_UID:$APP_UID --from=build /app/publish .
USER $APP_UID
ENV PORT=8080
ENV NexJob__Dashboard__LocalhostOnly=false
EXPOSE 8080
ENTRYPOINT ["dotnet", "NexJob.Sample.WorkerService.dll"]

Warning

LocalhostOnly=false exposes the dashboard on every interface. Anyone who can reach the port can read job payloads and run actions, including the scenarios. Use it only for a demo with no real data, or register an IDashboardAuthorizationHandler (see Dashboard Authorization).