dotnet-inspect

dotnet-inspect

Use dotnet-inspect when you need evidence instead of guesses for .NET packages, platform libraries, local assemblies, APIs, dependencies, SourceLink/source, or version-to-version API changes.

dnx dotnet-inspect -y -- <command>

Common starts

Goal	Command
Find an API	find Pattern, then reuse the reported --platform, --package, or --library.
Inspect overloads	member Type --platform Lib -m Name -S "Member Index"
Select an overload	member Type --platform Lib Name:1 or Name~digest
Source/implementation	type Type -S "Source Files"; member Type -m Name -S "Source Locations"; member Type Name:1 -S @Source; library/package Foo -S "Source Files"
Inspect a type	type Type --package Foo; add --all for non-public/hidden/extra members.
Compare APIs	diff --package [email protected] --breaking; use --additive for new APIs.
Inspect packages	package Foo -S Signals, -S "Library Files", --library
Inspect libraries	library Foo or library path/to.dll; add --platform, --package, -S Signals.
Relationships	depends Type, extensions Type, implements Interface; add package/platform/project scope.

Member lookup workflow

Member lookup is a common flow. Use find when scope is unknown, then inspect the type, then use Member Index to find the overload to select. The bare router also accepts source-qualified member syntax when the source is obvious.

dnx dotnet-inspect -y -- find JsonSerializer
dnx dotnet-inspect -y -- type JsonSerializer --platform System.Text.Json
dnx dotnet-inspect -y -- member JsonSerializer --platform System.Text.Json -m Serialize -S "Member Index"
dnx dotnet-inspect -y -- System.Text.Json.JsonSerializer.Serialize:1 -S Signature
dnx dotnet-inspect -y -- member JsonSerializer --platform System.Text.Json Serialize:1 -S Signature
dnx dotnet-inspect -y -- member JsonSerializer --platform System.Text.Json Serialize~1dc14dd1fb -S @Source
dnx dotnet-inspect -y -- member JsonSerializer --platform System.Text.Json Serialize:1 -S Calls
dnx dotnet-inspect -y -- member string IndexOf:7 -S Callers --caller-package [email protected] --tfm net9.0

Selector syntax: first run member Type --platform Lib -m Name -S "Member Index" (or the package/library source find reported). Then pass either Name:N (1-based, for the current index) or Name~digest (stable, from the Stable column) as the positional member selector. Canonical Signature is the printed digest input. Prefer Name~digest in notes, scripts, issues, and handoffs; use Name:N for immediate drill-in. --show-index is an alias for -S "Member Index".

A selected overload defaults to Signature; bare -S adds Decompiled Source. Use -S "Source Locations" for member file/line URLs without fetching source bodies. Use -S @Source for source and IL evidence: Decompiled Source (raised C#), Annotated Source (C# with hidden-fact comments and interleaved IL), Original Source, and IL. Use Annotated Source or IL when exact opcodes, offsets, branches, tokens, or calls matter.

Use -S Calls for direct call-site evidence, -S Callers for reverse edges (widen with --bin, --project, or --caller-package), -S "Call Graph" for a bounded outbound tree, -S "Caller Graph" for a bounded reverse tree that shows which entry points or callers reach the selected method (its root is labelled target, far entry points entrypoint, and loop call marks a caller that invokes toward the target inside a loop), -S "Unsafe Operations" for unsafe evidence, and -S Facts --tsv for structured hidden facts.

For perf or correctness triage, rank by call-graph leverage (direct callers, root reach, fanout, depth, loop calls): library MyLib.dll -S "Top Leverage" ranks across the whole assembly, or type T --library MyLib.dll --all -S "Top Leverage" ranks one type's members. The Root Reach column counts the distinct roots (entry points / public API with no in-assembly caller) that transitively reach a member, so a low-fanin helper sitting under many roots still shows wide inbound scale. Both library- and type-scope rows carry a copyable Stable selector (Name~digest), a Visibility column, and a Selector (Name:N), and mark compiler-Generated rows; copy the Stable selector to drill straight in. Then drill the top candidates with -S "Call Graph,Facts" (outbound cost) and -S "Caller Graph" (inbound reach). On either graph, project the kind of cost per node with --fields "Fanout,Fanin,Depth,Loop,Alloc,Copy,Unsafe,Reflection,Throw,Exceptions,Catch,Finally,EvidenceIL" (signals are opt-in and annotate only the nodes that carry them; for exception-risk triage read Throw/Catch/Finally over Caller Graph). Add --tsv or -n to trim to the top rows. The ranking surfaces non-public helpers, so add --all when drilling a private/internal candidate (otherwise member selection can't resolve it). -S "Optimization Opportunities" shares the same Root Reach column and sorts by it, so leveraged methods that also carry an actionable rewrite shape (small non-escaping array, temporary byte-array copy, capturing delegate, stateless instance method) surface first — the high-value intersection.

Query and output

Default output is Markdown. Use --table for compact aligned rows, --tsv for stable snake_case headers with no embedded tabs/newlines, --jsonl for one JSON object per row, --json for structured documents, --bare for one undecorated payload or URL list, --count for a bare row count, and --mermaid for graph-shaped output.

Use -D to discover sections/columns, -S Section to select sections by name or wildcard, and --columns/--fields to project values. Discover first instead of guessing names.

dnx dotnet-inspect -y -- member JsonSerializer --platform System.Text.Json -D --tsv
dnx dotnet-inspect -y -- member JsonSerializer --platform System.Text.Json -m Serialize -D "Member Index" --tsv
dnx dotnet-inspect -y -- member JsonSerializer --platform System.Text.Json -m Serialize -S "Member Index" --columns "Selector;Stable;Canonical Signature" --tsv

@ names a category: -S @All, -S @Source, -S @Audit, -S @Integrations, -S @Switches. Row formats (--tsv/--jsonl/--table) work best with one concrete section, not a category.

Limits

Prefer built-in limits to shell pipes. -n N and numeric shorthand like -6 cap output lines; --tail N shows the end; --rows makes -n cap Markdown table data rows; --count counts rows in one selected table. Command-specific caps: -t N for type/find rows, -m N for members, and --versions N for package versions.

Package docs, libraries, and signals

For agent-readable package docs, use --path @readme --content; the resolver exposes the best README content for agents, preferring AGENTS.md over README.md when present. For multi-package doc surveys, pass multiple package IDs with --path @readme --jsonl for metadata rows or --path @readme --content --jsonl for content rows. Add --frontmatter/--yaml-header or --body with --content; keep --readme for single-package reads.

dnx dotnet-inspect -y -- package Microsoft.Extensions.AI -S Signals
dnx dotnet-inspect -y -- package Microsoft.Extensions.AI --path @readme --content --frontmatter
dnx dotnet-inspect -y -- package Microsoft.Extensions.AI Microsoft.Extensions.AI.OpenAI --path @readme --content --jsonl
dnx dotnet-inspect -y -- project ./App --agents-index --jsonl
dnx dotnet-inspect -y -- package Microsoft.Extensions.AI --library -S @Integrations
dnx dotnet-inspect -y -- library System.Text.Json -S "Source Files"

Use package Foo --library for the primary DLL when unambiguous; add a DLL name or use --all-libraries for multi-library packages. Use -S "Source Files" for SourceLink type-to-URL rows. Signals reports observations, not trust: SourceLink, determinism, trim/AOT, memory-safety metadata, unsafe/PInvoke, references, TFMs, manifest/docs, license, vulnerabilities, package age, and dependency risk.

Other workflows

Use diff --package [email protected] --breaking for migration work, --additive for release-note work, and -t Type to narrow. For platform APIs, compare individual libraries: diff --platform [email protected] --additive.

For unsafe audits, start with library MyLib.dll -S @Audit, then drill into member Type Method:1 --library MyLib.dll -S "Unsafe Operations,IL".

Use --bare to extract one undecorated payload: type Name -S "Decompiled Source" --bare, member Type Method:1 -S "Source Locations" --bare, or package Foo --readme --bare. SourceLink URLs default to raw/fetchable form; add --blob for browser URLs. Use library Foo --il-offset 0x06000001+0x5 for crash diagnostics with MethodDef token plus IL offset. If decompiled output looks wrong, capture Decompiled Source, Annotated Source, Original Source, and IL; maintainers diagnose pipeline state with DecompilerHarness.

General tips

• Built-in aliases and common BCL types resolve without scope: type string, type 'List<T>'.
• Quote generic type names and shell patterns: member 'Dictionary<TKey,TValue>', -S "Async*".
• After find, reuse the package/library it reports; add --library for multi-library packages.
• type uses -t for type filters; member uses -m for member filters.
• Unpinned packages use latest stable; add --preview for prerelease APIs.
• If behavior is surprising, rerun with --trace-mermaid and include stderr in bug reports.