dotnet-inspect

CLI tool for inspecting .NET libraries and NuGet packages. It is for .NET what docker inspect and kubectl describe are for container land — view metadata, APIs, vulnerabilities, provenance, and compare versions.

Installation

dotnet tool install -g dotnet-inspect

Or run without installing (like npx):

dnx dotnet-inspect -y -- <command>

Quick Reference

Command	Purpose
package X	Package metadata, dependencies, files, versions
library X	Library metadata, symbols, SourceLink audit, dependency tree
type	Discover types (terse, no docs) — use --shape for hierarchy
member X	Inspect members (docs on by default, supports dotted syntax)
diff X	Compare versions with breaking/additive classification
extensions X	Find extension methods/properties for a type
implements X	Find types implementing an interface or extending a class
find X	Search for types across packages, frameworks, and local assets
source X	SourceLink URLs — type or member level, --cat to fetch content

Bare Names

A bare name like dotnet-inspect System.Text.Json uses a router to pick the best source. Platform libraries (System.*, Microsoft.AspNetCore) resolve to the installed SDK by default. Other names resolve to NuGet packages. Use explicit package or library --package to override.

Common Flags

Flag	Description
-v:q/m/n/d	Verbosity: quiet, minimal (default), normal, detailed
--oneline	Compact columnar output, one result per line
--platform	Search all platform frameworks (find, extensions, implements)
--json	JSON output
-s Name	Include section (glob-capable: -s Ext*)
-x Name	Exclude section
--shape	Type shape diagram (hierarchy + members) — type command
--all	Include non-public, hidden, and obsolete members
--docs / --no-docs	Control XML docs — member has docs on by default
--source-link-audit	SourceLink/determinism audit
-T:q/d	Tips verbosity (contextual hints on stderr)
-n N / --head N / -N	First N lines of output (like head)
--tail N	Last N lines of output (like tail)

Commands

package

Inspect NuGet packages. This is the default command for bare names that don't match platform libraries.

dotnet-inspect package System.Text.Json                     # Metadata (latest version)
dotnet-inspect package System.Text.Json@8.0.0 -v:d          # Detailed (shows vulnerabilities)
dotnet-inspect package System.Text.Json --versions          # List available versions
dotnet-inspect package System.Text.Json --version 11.0.0-preview*  # Wildcard version
dotnet-inspect package System.Text.Json --layout --lib      # File tree (lib/ only)
dotnet-inspect package System.Text.Json --dependencies      # Package dependency tree
dotnet-inspect package System.Text.Json --tfms              # List target frameworks

Multi-library packages

Some packages bundle multiple libraries per TFM (e.g., Microsoft.Azure.SignalR).

dotnet-inspect package Microsoft.Azure.SignalR              # Shows Libraries: 2
dotnet-inspect package Microsoft.Azure.SignalR --layout     # File tree
dotnet-inspect member Microsoft.Azure.SignalR -v:q --library Microsoft.Azure.SignalR.Common.dll  # Secondary library

Custom NuGet sources

dotnet-inspect package MyPackage --source https://my-feed/v3/index.json
dotnet-inspect package MyPackage --add-source https://dev-feed/v3/index.json --prerelease
dotnet-inspect package MyPackage --nugetconfig ./nuget.config

library

Inspect a library — from platform, NuGet package, or local file.

dotnet-inspect library System.Text.Json                     # Platform library (runtime)
dotnet-inspect library --package System.Text.Json            # Library from NuGet package
dotnet-inspect library ./bin/MyLib.dll                       # Local file
dotnet-inspect library --package System.Text.Json -s         # List 13 available sections
dotnet-inspect library --package System.Text.Json --source-link-audit  # SourceLink audit
dotnet-inspect library Microsoft.Extensions.AI.OpenAI --dependencies   # Dependency tree (visual)
dotnet-inspect library System.Text.Json --references -s Lib*           # Direct references
dotnet-inspect library --package System.Text.Json --extract-resources resources/  # Extract resources

type

Discover types in a package or library — terse output, no docs by default.

dotnet-inspect type --package System.Text.Json                   # All types in package
dotnet-inspect type -t "JsonS*" --package System.Text.Json       # Types matching glob
dotnet-inspect type 'HashSet<T>' --platform System.Collections --shape  # Type shape diagram
dotnet-inspect type --platform System.Text.Json                  # Platform library
dotnet-inspect type --package System.Text.Json --json            # JSON output

member

Inspect type members — docs on by default, supports dotted syntax.

dotnet-inspect member JsonSerializer --package System.Text.Json         # All members (docs on)
dotnet-inspect member JsonSerializer --package System.Text.Json --no-docs  # Suppress docs
dotnet-inspect member JsonSerializer --package System.Text.Json -m Serialize  # Filter to member
dotnet-inspect member -m JsonSerializer.Deserialize --package System.Text.Json  # Dotted syntax
dotnet-inspect member 'Option<T>' --package System.CommandLine          # Generic types (quote!)

Member selection and decompilation — use --show-index to see Name:N addressing hints, then drill in:

$ dotnet-inspect member OptionsFactory --package Microsoft.Extensions.Options --show-index
## Constructors

| Select | Name | Signature |
| ------ | ---- | --------- |
| `.ctor:1` | .ctor | `void .ctor(IEnumerable<IConfigureOptions<TOptions>>, ...)` |
| `.ctor:2` | .ctor | `void .ctor(IEnumerable<IConfigureOptions<TOptions>>, ..., IEnumerable<IValidateOptions<TOptions>>)` |

## Methods

| Select | Name | Signature |
| ------ | ---- | --------- |
| `Create` | Create | `TOptions Create(string)` |

Then target a member using the Name:N shorthand to get source, decompiled C#, and IL:

$ dotnet-inspect member OptionsFactory --package Microsoft.Extensions.Options Create
## Source                          # Original C# (via SourceLink)
## Lowered C#                     # Decompiled C# faithful to IL semantics
## IL                             # Raw IL disassembly with resolved tokens
## IL (Annotated)                 # IL with pre-execution stack state at each instruction

diff

Compare API surfaces between versions. Changes are classified as breaking, additive, or potentially breaking.

dotnet-inspect diff System.CommandLine@2.0.0-beta4.22272.1..2.0.3 -v:q  # Full package diff
dotnet-inspect diff JsonSerializer --package System.Text.Json@9.0.0..10.0.2  # Single type
dotnet-inspect diff "*Writer*" --package Markout@0.1.8..0.2.0            # Glob filter
dotnet-inspect diff --platform System.Text.Json@8.0.23..10.0.2           # Platform versions
dotnet-inspect diff System.Text.Json@9.0.0..10.0.2 --oneline            # Compact columnar output
dotnet-inspect diff System.Text.Json@9.0.0..10.0.2 --breaking           # Breaking only

find

Search for types across packages, frameworks, and local assets.

dotnet-inspect find HttpClient                           # Runtime (default scope)
dotnet-inspect find "*Stream*" -n 10                     # Glob, limit results
dotnet-inspect find "*Json*" --package System.Text.Json  # Search in package
dotnet-inspect find "ChatClient*" --oneline                # Compact columnar output
dotnet-inspect find ILogger --aspnetcore                 # ASP.NET Core packages
dotnet-inspect find "*Command*" --project ./MyApp.csproj # Project dependencies

extensions

Find extension methods and properties for a type. Detects both classic extension methods and C# 14 extension properties.

dotnet-inspect extensions HttpClient                         # Runtime (default)
dotnet-inspect extensions HttpClient --reachable             # Include reachable types
dotnet-inspect extensions DbContext                           # Default scope
dotnet-inspect extensions IDistributedApplicationBuilder \
  --package Aspire.Hosting --package Aspire.Hosting.Redis    # Multi-package scan

implements

Find types implementing an interface or extending a base class.

dotnet-inspect implements Stream                             # Default scope
dotnet-inspect implements IDisposable --platform             # All platform frameworks
dotnet-inspect implements IJsonTypeInfoResolver --package System.Text.Json

source

SourceLink URLs for type source files. Supports member-level resolution with line numbers.

dotnet-inspect source JsonSerializer --package System.Text.Json          # Source file URLs
dotnet-inspect source JsonSerializer --package System.Text.Json -m Serialize  # With line numbers
dotnet-inspect source JsonSerializer --package System.Text.Json --cat    # Fetch and print source content
dotnet-inspect source JsonSerializer --package System.Text.Json --verify # Verify URL accessibility

cache

dotnet-inspect cache                                # Show cache size breakdown
dotnet-inspect cache --clean                        # Clear the cache

Help Tree View

dotnet-inspect -v:m                                 # Tree view (command names + descriptions)
dotnet-inspect -v:n                                 # Tree view (commands, args, options)
dotnet-inspect -v:d                                 # Deep view (all levels with descriptions)
dotnet-inspect -v:q                                 # Command names only (oneliner)

Output Control

Format: Default is markdown (headings, tables, field lists). Use --oneline for compact columnar output, --plaintext for plain text, or --json for JSON.

Verbosity (-v): q(uiet) → m(inimal) → n(ormal) → d(etailed). Controls which sections are included.

Sections: Use -s Name to include or -x Name to exclude sections by name. Bare -s lists available sections. Supports glob patterns (-s Ext*).

JSON: --json for full JSON, --json --compact for minified.

LLM Integration

This tool is designed for LLM-driven development. A skill is available in the dotnet/skills marketplace for use with GitHub Copilot and Claude Code.

Requirements

.NET 10.0 SDK or later

License

MIT