NuGet Docs — Package API Inspector

Inspect any NuGet package's public API surface with full C# source and XML documentation comments.

Prerequisites

The nuget-docs .NET global tool must be installed:

dotnet tool install -g nuget-docs

If the command fails with "not found", install it first, then retry.

When to Use This Skill

Use nuget-docs when you need to:

• Explore an unfamiliar NuGet package — see all public types at a glance
• Check method signatures and XML docs — understand interface contracts before implementing
• Find types by pattern — search across types and members with wildcards
• Inspect package metadata — check dependencies, frameworks, and licensing
• Implement against a library — get full decompiled source with /// doc comments
• Compare API between versions — identify breaking changes, new types, and modifications

Commands

List all public types

nuget-docs list <Package> [--version <ver>] [--framework <tfm>] [--all] [--namespace <prefix>] [--format table|csv] [--json] [--output json]

Shows all public types grouped by kind (Interfaces, Classes, Structs, Enums, Delegates) with one-line XML doc summaries. Use --all (-a) to include internal types. Use --namespace (-n) to filter by namespace prefix. Use --format table for aligned columns or --format csv for CSV output.

Show a specific type

nuget-docs show <Package> <TypeName> [--version <ver>] [--framework <tfm>] [--all] [--member <name>] [--assembly] [--namespace <prefix>] [--json] [--output json]

Decompiles the full type to C# source with /// XML documentation comments. Short names work — IChatClient automatically resolves to Microsoft.Extensions.AI.IChatClient. By default shows only public/protected members; use --all (-a) to include private and internal members. Use --member (-m) to show only a specific member. Use --assembly to show assembly-level attributes instead of a type. Use --namespace (-n) with --assembly to filter attributes by their type's namespace prefix.

Search types and members

nuget-docs search <Package> <pattern> [--version <ver>] [--framework <tfm>] [--all] [--namespace <prefix>] [--format table|csv] [--json] [--output json]

Searches types and members using glob patterns (* and ? wildcards). Results show [Kind.MemberKind] labels. By default searches only public/protected members; use --all (-a) to include private and internal. Use --namespace (-n) to filter by namespace prefix. Use --format table for aligned columns or --format csv for CSV output.

Compare API between versions

nuget-docs diff <Package> --from <ver> --to <ver> [--framework <tfm>] [--type-only] [--breaking] [--member-diff] [--no-additive] [--ignore-docs] [--json] [--output json]

Compares the public API surface between two versions of a package. Use latest as a version value to auto-resolve the latest stable version from NuGet.org (e.g., --to latest). Shows added, removed, and changed types with a unified diff (Myers algorithm) including @@ -line,count +line,count @@ hunk headers. Use --type-only (-t) for a quick summary without decompiling. Use --breaking (-b) to show only potentially breaking changes. Use --member-diff (-m) to show structured member-level changes (added/removed/changed methods/properties) instead of full source diff. Use --no-additive to hide purely additive changes and show only removals/modifications for upgrade safety checks (also available as --include-additive false). Use --ignore-docs to ignore XML doc comment changes in source-level diff. Works with both source-level and member-level diffs. Exit codes: 0 = no breaking changes, 1 = error, 2 = breaking changes detected (useful for CI).

Package metadata

nuget-docs info <Package> [--version <ver>] [--json] [--output json]

Shows package ID, version, authors, description, license, frameworks, and dependencies.

Dependency tree

nuget-docs deps <Package> [--version <ver>] [--framework <tfm>] [--depth <n>] [--format table|csv] [--json] [--output json]

Shows the dependency tree of a package with tree-style output. Use --depth (-d) to control transitive resolution depth (default: 1 = direct only). Use --depth 2 or higher for transitive dependencies. Shared dependencies are marked with (already listed) to avoid confusion. Use --format table for aligned columns or --format csv for CSV output.

List available versions

nuget-docs versions <Package> [--stable] [--prerelease] [--latest] [--since <ver>] [--count] [--deprecated] [--format table|csv] [--limit <n>] [--json] [--output json]

Lists all available versions of a package from NuGet.org, newest first. Use --stable (-s) to show only stable versions. Use --prerelease (-p) to show only prerelease versions. Use --latest to show only the latest stable and latest prerelease versions. Use --since to show only versions newer than the specified version. Use --count (-c) to output only the count of matching versions (useful for CI). Use --deprecated to show deprecation and vulnerability info for each version. Use --format table for aligned columns or --format csv for CSV output. Use --limit (-l) to control how many to show (default: 20, 0 = all).

Efficient Usage Patterns

1. Start broad: nuget-docs list <pkg> to see all public types
2. Narrow down: nuget-docs search <pkg> "Chat*" to find types/members matching a pattern
3. Deep dive: nuget-docs show <pkg> <TypeName> for full type details
4. Compare versions: nuget-docs diff <pkg> --from 1.0 --to 2.0 to see what changed
5. Check dependencies: nuget-docs deps <pkg> to see what a package depends on
6. Find versions: nuget-docs versions <pkg> --stable to pick a version for diff or show

Tips for AI Agents

• Short names resolve automatically: IChatClient → Microsoft.Extensions.AI.IChatClient, ChatRole.Converter → nested type
• Packages auto-download: No need to pre-install — packages are fetched from NuGet if not cached
• Framework auto-selection: Picks the best TFM (prefers net10.0 > net9.0 > net8.0 > netstandard2.1 > netstandard2.0)
• Public API by default: list, show, and search strip non-public items — use --all to see everything
• Member focus: Use --member Name with show to extract a single method/property (all overloads) instead of the full type
• Namespace filter: Use --namespace Prefix with list or search to filter by namespace
• Assembly attributes: Use show <pkg> --assembly to see [assembly:] attributes (TargetFramework, InternalsVisibleTo, etc.)
• Assembly namespace filter: Use --namespace with show --assembly to filter attributes by their type's namespace (e.g., --namespace System.Runtime.Versioning)
• API diff: Use diff <pkg> --from <v1> --to <v2> to compare public API between versions — shows added/removed/changed types with unified diff. Supports latest, latest-stable, latest-prerelease keywords (e.g., --from latest-stable --to latest-prerelease)
• Quick diff: Use --type-only (-t) with diff for a fast summary without decompiling — shows only added/removed type names
• Breaking changes: Use --breaking (-b) with diff to filter to only breaking changes (removed types, member removals/signature changes)
• Member-level diff: Use --member-diff (-m) with diff for structured member changes (added/removed/changed methods/properties) instead of full source diff — formats Nullable<T> as T? and resolves generic type arguments cleanly
• Skip additive changes: Use --no-additive with diff to hide purely additive changes (new types, additive-only type modifications) and show only removals/modifications — works with both source-level and member-level diffs
• Ignore doc changes: Use --ignore-docs with diff to skip XML doc comment changes — reduces noise when only code changes matter
• CI integration: diff returns exit code 2 when breaking changes are detected (0 = clean, 1 = error)
• Dependency tree: Use deps <pkg> to see direct dependencies; --depth 2 for transitive; shared deps show (already listed)
• Version listing: Use versions <pkg> to see all versions; --stable for stable only; --prerelease for prerelease only; --latest for quick lookup of latest stable + prerelease; --since <ver> to see only versions released after a specific version (supports latest, latest-stable, latest-prerelease keywords); --count for just the number; --deprecated to show deprecation/vulnerability markers; useful before diff
• Deprecation check: Use --deprecated with versions to see which versions are deprecated or have known vulnerabilities. The info command always shows deprecation status automatically
• Alternative output formats: Use --format table with list, search, versions, deps, or diff for aligned columns, or --format csv for CSV output (useful for piping to other tools)
• JSON output: Use --json (-j) or --output json (-o json) on any command for structured JSON output
• Output is AI-friendly: Plain text with /// XML doc comments — compact and informative
• For large packages: Use search before show to narrow down
• Version pinning: Use --version to inspect a specific version. Supports latest, latest-stable, and latest-prerelease keywords on any command

Examples

Exploring Microsoft.Extensions.AI

# See all types
nuget-docs list Microsoft.Extensions.AI.Abstractions

# Inspect IChatClient interface
nuget-docs show Microsoft.Extensions.AI.Abstractions IChatClient

# Find all Chat-related types
nuget-docs search Microsoft.Extensions.AI.Abstractions "Chat*"

Checking a library before using it

# See what's in the package
nuget-docs list Humanizer

# Check metadata and dependencies
nuget-docs info Humanizer

# See what it depends on
nuget-docs deps Humanizer

# Full transitive dependency tree
nuget-docs deps Microsoft.Extensions.AI --depth 3

# Check available versions (stable only)
nuget-docs versions Humanizer --stable

# Show only prerelease versions
nuget-docs versions Humanizer --prerelease

# Quick lookup: latest stable + prerelease
nuget-docs versions Humanizer --latest

# See what's been released since a specific version
nuget-docs versions Newtonsoft.Json --since 13.0.1

# Combine: stable versions since a specific release
nuget-docs versions Newtonsoft.Json --since 13.0.1 --stable

# Use version keywords: what's newer than the latest stable?
nuget-docs versions Newtonsoft.Json --since latest-stable

# Just count matching versions (useful for CI scripts)
nuget-docs versions Newtonsoft.Json --count --since 13.0.1
nuget-docs versions Newtonsoft.Json --count --stable

Inspecting a specific member

# Show just the GetResponseAsync method signature and docs
nuget-docs show Microsoft.Extensions.AI.Abstractions IChatClient --member GetResponseAsync

# Show all overloads of SerializeObject
nuget-docs show Newtonsoft.Json JsonConvert --member SerializeObject

Filtering by namespace

# Show only types in the Linq namespace
nuget-docs list Newtonsoft.Json --namespace Newtonsoft.Json.Linq

# Search within a namespace
nuget-docs search Newtonsoft.Json "*Token*" --namespace Newtonsoft.Json.Linq

Assembly-level attributes

# Check target framework, InternalsVisibleTo, etc.
nuget-docs show Newtonsoft.Json --assembly

# Filter assembly attributes by namespace
nuget-docs show Newtonsoft.Json --assembly --namespace System.Runtime.Versioning

Comparing API between versions

# See what changed between versions (full unified diff with hunk headers)
nuget-docs diff Microsoft.Extensions.AI.Abstractions --from 10.3.0 --to 10.4.0

# Use "latest" to auto-resolve the latest stable version
nuget-docs diff Microsoft.Extensions.AI.Abstractions --from 10.3.0 --to latest

# Compare latest stable vs latest prerelease
nuget-docs diff Microsoft.Extensions.AI.Abstractions --from latest-stable --to latest-prerelease

# Quick overview — just added/removed types, no decompilation
nuget-docs diff Microsoft.Extensions.AI.Abstractions --from 10.4.0 --to 10.4.1 --type-only

# Show only breaking changes (removed types, removed/changed members)
nuget-docs diff Microsoft.Extensions.AI.Abstractions --from 10.3.0 --to 10.4.0 --breaking

# Member-level changes (added/removed/changed methods/properties)
nuget-docs diff Microsoft.Extensions.AI.Abstractions --from 10.4.0 --to 10.4.1 --member-diff

# Show only removals/modifications (skip purely additive changes)
nuget-docs diff Microsoft.Extensions.AI.Abstractions --from 10.4.0 --to 10.4.1 --no-additive

# Ignore doc comment changes — show only code changes
nuget-docs diff Microsoft.Extensions.AI.Abstractions --from 10.4.0 --to 10.4.1 --ignore-docs

# CI usage — exit code 2 means breaking changes detected
nuget-docs diff MyPackage --from 1.0.0 --to 2.0.0 --type-only || echo "Breaking changes!"

# Get structured diff output
nuget-docs diff Newtonsoft.Json --from 13.0.3 --to 13.0.4 --output json

Alternative output formats

# Table format with aligned columns
nuget-docs list Newtonsoft.Json --format table
nuget-docs search Newtonsoft.Json "*Token*" --format table

# CSV format (pipe to other tools)
nuget-docs list Newtonsoft.Json --format csv
nuget-docs search Newtonsoft.Json "*Convert*" --format csv

Checking for deprecated/vulnerable packages

# Show deprecation markers on all versions
nuget-docs versions WindowsAzure.Storage --deprecated

# Check if a specific package version is deprecated
nuget-docs info WindowsAzure.Storage

# Find versions with known vulnerabilities
nuget-docs versions System.Text.RegularExpressions --deprecated --stable

Version-specific inspection

# Check a specific version
nuget-docs show Microsoft.Extensions.AI.Abstractions ChatOptions --version 10.4.0

# Use "latest" keyword (works on any command)
nuget-docs list Microsoft.Extensions.AI.Abstractions --version latest
nuget-docs show Microsoft.Extensions.AI.Abstractions IChatClient --version latest-prerelease