NeoReports

NeoReports is an open-source .NET library for generating reports from data sources, with a typed fluent API, constant-memory streaming, resilience, and upload to destinations.

Status: v1 is an MVP under active development by a single maintainer. The public contract (NeoReports.Abstractions) is treated as a frozen ABI; see the architecture notes before depending on internals.

Why NeoReports

• Typed, code-first. A report is defined in C# over your own POCO — no dictionaries, no string-keyed rows, full compile-time safety.
• Constant memory. Sources are read in batches and streamed straight to the output; nothing materializes the whole report in memory (CSV is fully streaming).
• Resilient. Batch reads are wrapped in Polly retries, with a pluggable failure strategy (abort or skip-and-log) and escalation thresholds.
• Pluggable. Sources, formats, and destinations are small, independent packages.

Packages (v1)

Area	Package	Description
Contracts	NeoReports.Abstractions	Public, frozen contract (typed-only)
Engine	NeoReports.Core	Fluent builder, pipeline, projection, resilience, DI
Source	NeoReports.Sources.Sql	SQL Server with keyset pagination
Format	NeoReports.Formats.Csv	Streaming CSV writer (RFC 4180)
Format	NeoReports.Formats.Xlsx	XLSX writer (ClosedXML)
Destination	NeoReports.Destinations.Local	Local filesystem (atomic publish)
Destination	NeoReports.Destinations.S3	Amazon S3 (all-or-nothing upload)

Quick start

using Microsoft.Extensions.DependencyInjection;
using NeoReports.Core.DependencyInjection;
using NeoReports.Core.Pipeline;
using NeoReports.Destinations.Local;
using NeoReports.Sources.Sql;
using static NeoReports.Core.Building.ReportColumns;
using static NeoReports.Formats.Csv.Format;

public sealed record Venda(long Id, string Cliente, decimal Valor, DateTime Data);

var services = new ServiceCollection();
services.AddLogging();

services.AddReport<Venda>("vendas-mensal", b => b
    .From(Source.Sql(connectionString,
            "SELECT Id, Cliente, Valor, Data FROM Vendas " +
            "WHERE (@cursor IS NULL OR Id > @cursor) ORDER BY Id")
        .Keyset<Venda, long>(v => v.Id, pageSize: 1000))
    .Filter(v => v.Valor > 0)
    .Columns(
        Col<Venda, long>(v => v.Id, "ID Venda"),
        Col<Venda, string>(v => v.Cliente, "Cliente"),
        Col<Venda, decimal>(v => v.Valor, "Valor", format: "C2", culture: "pt-BR"),
        Col<Venda, DateTime>(v => v.Data, "Data Venda", format: "yyyy-MM-dd"))
    .To(Csv(o => o.Delimiter(';')))
    .UploadTo(Destination.Local("./out/{name}-{date:yyyy-MM-dd}.{ext}")));

var provider = services.BuildServiceProvider();
var runner = provider.GetRequiredService<IReportRunner>();
var result = await runner.RunAsync("vendas-mensal");

Runnable end-to-end samples live in samples/.

Building from source

Requires the .NET 8 and .NET 9 SDKs.

dotnet build          # build the solution
dotnet test           # run all tests (SQL integration tests need Docker)
dotnet format         # apply the .editorconfig style

The SQL integration tests use Testcontainers and require a running Docker daemon; they skip automatically when Docker is unavailable.

Contributing

Contributions are welcome — please read CONTRIBUTING.md and the Code of Conduct. Security issues should follow SECURITY.md.

License

MIT © NeoReports Contributors