# Npgsql 4.1 Release Notes

Npgsql 4.1 is out and available at nuget.org.

## New Features

The major new features of 4.1 are:

- Support for reading and writing your types as JSON via the new, high-perf System.Text.Json API (#2306).
- Support for the new async methods introduced in .NET Standard 2.1 (#2481).
- Expose performance statistics via the new .NET event counters (#1725).
- Async support for binary imports and exports (#1632).
- Easier and PostgreSQL standard ways to provide client certificates for authentication (#2129).

Many other small improvements and performance optimizations have been introduced as well - you can track progress here.

## Breaking changes from 4.0

- .NET Framework 4.5, 4.5.1 and 4.5.2 are no longer supported. .NET Framework 4.6.1 and .NET Standard 2.0 are the lowest supported versions.
- The spatial plugin, Npgsql.NetTopologySuite, has been updated to depend on NetTopologySuite 2.0.0, which is a major version introducing breaking changes. Specifically, EF Core 3.0 is the first version supporting NetTopologySuite 2.0.0; it is not possible to use EF Core 2.x with the new version of Npgsql.NetTopologySuite.
- The `UseSslStream` property of `NpgsqlConnectionStringBuilder` is now marked as `Obselete`. `SslStream` is always used.
- A fix was done to Npgsql's snake case naming converter (#2152); this could break code that relies on the previous conversion logic.

## Contributors

Thank you very much to the following people who have contributed to the individual 4.1.x. releases.

### Milestone 4.1.12

Contributor | Assigned issues
--- | ---
@roji | 1

### Milestone 4.1.9

Contributor | Assigned issues
--- | ---
@YohDeadfall | 1

### Milestone 4.1.8

Contributor | Assigned issues
--- | ---
@YohDeadfall | 1

### Milestone 4.1.7

Contributor | Assigned issues
--- | ---
@YohDeadfall | 3
@vonzshik | 1

### Milestone 4.1.6

Contributor | Assigned issues
--- | ---
@loop-evgeny | 1
@mm3141 | 1
@roji | 1
@vonzshik | 1
@YohDeadfall | 1

### Milestone 4.1.5

Contributor | Assigned issues
--- | ---
@calexander3 | 1
@roji | 1
@romanov-is-here | 1
@vonzshik | 1
@warcha | 1
@YohDeadfall | 1

### Milestone 4.1.4

Contributor | Assigned issues
--- | ---
@roji | 6
@YohDeadfall | 6
@warcha | 3
@dwat001 | 1
@elipatov | 1
@manandre | 1
@williamdenton | 1

### Milestone 4.1.3

Contributor | Assigned issues
--- | ---
@roji | 5
@YohDeadfall | 4
@NinoFloris | 1
@nycdotnet | 1

### Milestone 4.1.2

Contributor | Assigned issues
--- | ---
@YohDeadfall | 4
@NinoFloris | 2
@austindrenski | 1

### Milestone 4.1.1

Contributor | Assigned issues
--- | ---
@roji | 7

### Milestone 4.1.0

Contributor | Assigned issues
--- | ---
@roji | 27
@YohDeadfall | 6
@austindrenski | 2
@NinoFloris | 2
@afkos | 1
@baronfel | 1
@shortspider | 1
@williamdenton | 1
@zabulus | 1