Imported from signalfx/splunk-otel-dotnet (AGENTS.md). Install upstream with npx skills add signalfx/splunk-otel-dotnet. Copyright stays with the author.

Agents

Context

This repo builds a Splunk plugin/distribution layer on top of OpenTelemetry .NET automatic instrumentation.
Main code lives in one plugin assembly that configures Splunk defaults, profiling, snapshots and resource attributes.
Full validation downloads/unpacks the upstream auto-instrumentation distribution, copies Splunk plugin binaries into it, then runs unit and integration tests.

Commands

Command	Purpose
`.\build.cmd Workflow`	Full CI-like build: clean, restore, unpack upstream distribution, compile, test, and package
`.\build.cmd NuGetWorkflow`	Build and test the NuGet package workflow
`dotnet test <project> --framework net8.0 --filter "FullyQualifiedName~MyTestName"`	Use to target single test
`dotnet test test\Splunk.OpenTelemetry.AutoInstrumentation.Tests\Splunk.OpenTelemetry.AutoInstrumentation.Tests.csproj --framework net8.0 --no-restore -v minimal`	Focused unit test pass on `net8.0`
`dotnet test test\Splunk.OpenTelemetry.AutoInstrumentation.IntegrationTests\Splunk.OpenTelemetry.AutoInstrumentation.IntegrationTests.csproj --framework net8.0 --filter "Category!=NuGetPackage" --no-restore -v minimal`	Focused integration test pass after distribution is prepared
`dotnet format .\Splunk.OpenTelemetry.AutoInstrumentation.slnx --no-restore --verify-no-changes`	Formatting check used by CI
`dotnet format .\Splunk.OpenTelemetry.AutoInstrumentation.slnx --no-restore`	Apply formatting fixes
`dotnet build src\Splunk.OpenTelemetry.AutoInstrumentation\Splunk.OpenTelemetry.AutoInstrumentation.csproj --framework net8.0`	Fast plugin build for local iteration

net8.0 is a TFM used as a local iteration target; Use ./build.sh on Linux for running Nuke targets.

Testing

Integration tests use mock collectors and test applications under test/test-applications/integrations/.
Smoke tests expect OpenTelemetryDistribution/ to contain freshly built plugin; run the Nuke workflow or the relevant build targets before relying on smoke results.

Rules & Patterns

Prefer focused dotnet test commands for local iteration; use .\build.cmd Workflow before broad validation or packaging.
Treat OpenTelemetryDistribution/, NuGetPackage/, bin/Matrix/, bin/InstallationScripts/, and test-artifacts/ as generated outputs.
Do not edit files under src/Splunk.OpenTelemetry.AutoInstrumentation/Vendors unless the task is explicitly about vendored code.
Follow the Splunk GDI specification for distribution defaults, configuration behavior, telemetry conventions, and profiling semantics; document intentional differences.
Keep implementation, docs, YAML fixtures, and smoke tests in sync.
Keep generated distribution structure snapshots intentional; update verified files only when packaging output really changed.

Related repositories

The repositories below are reference material. Consult them to understand or verify upstream behavior, specifications, and dependency internals.

Upstream (this repo builds on top of it)

Upstream auto-instrumentation version is pinned in Build.cs. Behavior questions should be answered against that exact tag/commit, not main branch.

open-telemetry/opentelemetry-dotnet-instrumentation: auto-instrumentation plugin hooks, settings parsing, distribution layout, startup/shutdown behavior.

Transitive dependencies (consumed via NuGet)

open-telemetry/opentelemetry-dotnet: SDK, exporters, provider behavior, OTLP defaults.
open-telemetry/opentelemetry-dotnet-contrib: contrib packages used by the distribution, including related exporter/instrumentation packages when relevant.

Specifications

signalfx/gdi-specification: Splunk GDI requirements for distribution defaults, configuration behavior, telemetry conventions, and profiling semantics.
open-telemetry/opentelemetry-specification: the parent spec the GDI spec extends.

Definition of done

Focused unit tests pass.
Focused integration tests pass (distribution populated).
dotnet format --verify-no-changes is clean.
Docs / YAML fixtures / verified snapshots updated if behavior or packaging changed.
No edits under Vendors/ unless task requires it.

splunk-otel-dotnet

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