Port FeatureUsage tracking and .NET behavioral tests

[Quim Muntal (qmuntal)]

Summary

• Port process-wide FeatureUsage tracking with a concurrency-safe 128-bit mask, cached versioned hexadecimal tokens, and byte-preserving User-Agent comment replacement.
• Align feature indexes with .NET v1 and track only supported .NET-registered capabilities; add activation marks across agents, context/history providers, skills, tools, workflows, and integrations.
• Emit feature comments only on approved HTTPS origins for each OpenAI/Foundry adapter family, retaining SDK origin/redirect guards, caller transports, and the existing opt-outs.
• Add direct .NET behavioral test ports and record 36 verified FeatureUsage test pairings in the catalog. Unsupported integrations, mixed suites requiring unavailable capabilities, and CLR-specific tests remain unpaired.
• Document the registry, activation points, emission boundaries, and environment controls.

Parity fixes covered by the ports

• Foundry streams remain cold until enumeration; server-agent requests mark both Foundry agent and chat-client bits before sending.
• Empty Foundry memory provider hooks mark participation without making a request.
• Cancelled Copilot runs record usage and return cancellation without starting the runtime.
• Empty Anthropic streams do not fabricate zero-usage updates.

Validation

• 194 focused telemetry tests passed.
• 333 affected OpenAI, Anthropic, Copilot, and Foundry component tests passed.
• Re-ran all 52 activation cases after the final lint cleanup.
• Strict catalog test checks: no unresolved references or invalid Go targets.
• go vet and change-scoped golangci-lint v2.14.0 passed; git diff --check passed.
• Staged changes were checked for binaries, build artifacts, and credential patterns.

Race detection is unsupported on the validation host (Windows ARM64). Full lint still reports unrelated pre-existing issues; change-scoped lint is clean.

[Copilot]

🔵 Needs a closer look

Default-on, process-wide telemetry and HTTP emission boundaries warrant human verification alongside the unresolved correctness issues.

2 open findings

• Feature comment removal breaks nested and escaped User-Agent comments · New
• Workflow feature masks incorrectly include the custom-workflow bit · New

What changed in this PR

Adds process-wide feature tracking to the Go SDK, with .NET-aligned indexes and restricted User-Agent emission.

Changes:

• Tracks capability activation across agents, providers, tools, and workflows.
• Adds approved-origin emission, opt-outs, and provider lifecycle fixes.
• Adds behavioral tests, 36 catalog pairings, and telemetry documentation.

File	Description
workflow/​builder.go	Records successful workflow builds.
workflow/​agentworkflow/​sequential.go	Tracks sequential orchestration.
workflow/​agentworkflow/​groupchat.go	Tracks group-chat orchestration.
workflow/​agentworkflow/​concurrent.go	Tracks concurrent orchestration.
tool/​shelltool/​localshell.go	Tracks shell execution and initialization.
tool/​shelltool/​environment.go	Tracks environment-provider participation.
tool/​mcptool/​mcp.go	Tracks MCP operations.
README.md	Explains telemetry and opt-outs.
provider/​openaiprovider/​responses.go	Tracks Responses usage and applies emission policy.
provider/​openaiprovider/​chat.go	Applies adapter-specific emission policy.
provider/​foundryprovider/​memory.go	Tracks memory-provider participation.
provider/​foundryprovider/​clientheaders.go	Defers activation until enumeration.
provider/​foundryprovider/​agent.go	Distinguishes server-agent targets.
provider/​copilotprovider/​copilot.go	Tracks usage before cancellation handling.
provider/​anthropicprovider/​agent.go	Tracks usage and handles empty streams.
provider/​aguiprovider/​hosting.go	Tracks AG-UI hosting.
provider/​a2aprovider/​handler.go	Tracks A2A request handling.
provider/​a2aprovider/​executor.go	Tracks A2A executor operations.
provider/​a2aprovider/​a2a.go	Tracks A2A client usage.
provider/​a2aprovider/​a2a_test.go	Tests activation and cold streams.
internal/​telemetry/​telemetry_test.go	Tests masks, headers, origins, and opt-outs.
internal/​telemetry/​featureusage.go	Implements accumulation and header emission.
internal/​telemetry/​featureusage_internal_test.go	Tests caching and Foundry policies.
internal/​telemetry/​featureusage_activation_test.go	Tests activation and adapter boundaries.
docs/​feature-usage-telemetry.md	Documents registry and emission controls.
agent/​skills/​provider.go	Tracks skills providers and in-memory sources.
agent/​skills/​fsskills/​source.go	Tracks file-backed skill discovery.
agent/​history.go	Tracks in-memory history participation.
agent/​harness/​toolapproval/​toolapproval.go	Tracks approval middleware.
agent/​harness/​todo/​todo.go	Tracks todo-provider participation.
agent/​harness/​agentmode/​agentmode.go	Tracks agent-mode participation.
agent/​compaction/​provider.go	Tracks context compaction.
agent/​compaction/​historyprovider.go	Tracks history compaction.
agent/​agent.go	Tracks agent invocation.
_catalog/​dotnet-go-sdk-symbol-mapping.json	Records behavioral-test pairings.

🧠 Review effort: Balanced

---

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[Copilot]

🔵 Needs a closer look

Default-on telemetry crosses provider emission boundaries and concurrent execution paths, warranting human validation, especially without race-detector coverage.

0 open findings

2 resolved since last review

• Workflow feature masks incorrectly include the custom-workflow bit
• Feature comment removal breaks nested and escaped User-Agent comments

🧠 Review effort: Balanced

---

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[github-actions]

API consistency review

Result	Scope
aligned	public API / user-visible behavior

Changed Go contract

• New internal/telemetry package: MarkUsed(index int), ApplyToUserAgent(userAgent string, includeFeatureToken bool) string, ApplyToHTTPRequest/ApplyToFoundryHTTPRequest (origin-gated User-Agent feature-comment injection), feature index constants (FeatureAgent, FeatureWorkflow, FeatureToolApproval, FeatureCompactionProvider, FeatureSkillsProvider, FeatureFileSkillsSource, FeatureInMemorySkillsSource, FeatureMCP, FeatureTodoProvider, FeatureAgentModeProvider, FeatureInMemoryHistoryProvider, FeatureSequentialOrchestration, FeatureConcurrentOrchestration, FeatureGroupChatOrchestration, FeatureFoundryChatClient, FeatureFoundryAgent, FeatureFoundryMemory, FeatureOpenAI, FeatureAnthropic, FeatureGitHubCopilot, FeatureA2A, FeatureHostingAGUI, FeatureShell, FeatureHostingA2A).
• New AGENT_FRAMEWORK_FEATURE_MASK_DISABLED environment-variable opt-out (mask-only), documented alongside the existing AGENT_FRAMEWORK_USER_AGENT_DISABLED.
• Observable behavior changes: the OpenAI/Foundry adapters' outbound User-Agent header now carries an additional (feat=vN.hex) comment on approved HTTPS Azure/Foundry hosts only; foundryprovider.clientheadersMiddleware now marks agent/chat-client bits and preserves "cold until enumeration" semantics for streaming; copilotprovider now checks ctx.Err() before starting the client so a cancelled run returns promptly without starting the runtime; anthropicprovider streaming no longer emits a trailing zero-usage update when the stream produced no events.
• docs/feature-usage-telemetry.md added; README.md updated to describe the mask and opt-outs.

Upstream evidence reviewed

Implementation	Source	Contract checked
.NET	dotnet/src/Microsoft.Agents.AI.Abstractions/FeatureUsage.cs	MarkUsed idempotency/range, AGENT_FRAMEWORK_FEATURE_MASK_DISABLED semantics, ApplyToUserAgent/token caching/comment removal algorithm
.NET	docs/specs/feature-usage-bit-registry.md	Index table — .NET version 1 (indexes 0–74); Go reuses only the subset it has equivalents for, with identical numbering
.NET	dotnet/src/Microsoft.Agents.AI.OpenAI/UserAgentPolicies.cs + UserAgentPolicyTests.cs	Approved OpenAI host suffixes (cognitiveservices.azure.com, openai.azure.com, services.ai.azure.com), HTTPS-only, subdomain match, lookalike-host rejection
.NET	dotnet/src/Microsoft.Agents.AI.Foundry/AgentFrameworkUserAgentPolicy.cs	Approved Foundry host suffixes (services.ai.azure.com, inference.ai.azure.com)
.NET	ClientHeadersAgent.cs + FoundryChatClient.cs (MarkRequestFeatures)	Server-agent path marks both FoundryAgent and FoundryChatClient; marking happens per-request, not at construction
.NET	GitHubCopilotAgent.cs	Feature mark placed before client-start/session creation in the streaming run path
.NET	AnthropicClientExtensions.cs (streaming loop, usageDetails is not null guard)	Trailing usage update is only yielded when upstream usage data was actually observed

Assessment

This PR is a direct, well-evidenced port of the .NET FeatureUsage v1 registry and its emission policy. Feature indexes, the registry version/token format (v1.<hex>), the dedicated AGENT_FRAMEWORK_FEATURE_MASK_DISABLED opt-out (mask-only, distinct from the existing whole-User-Agent opt-out), per-adapter-family approved HTTPS host suffixes, and the Foundry agent+chat-client dual-marking all match upstream exactly. The accompanying parity fixes (Copilot cancellation check before client start, Anthropic no-fabricated-usage-on-empty-stream, Foundry memory/stream "cold until enumeration" semantics) are each supported by the corresponding upstream source reviewed above. No Go-only public surface, default divergence, or unconditionally-enabled behavior beyond upstream's equivalent was found. examples/ were not touched by this PR.

Warning

Firewall blocked 4 domains

The following domains were blocked by the firewall during workflow execution:

• github.com
• proxy.golang.org
• storage.googleapis.com
• sum.golang.org

To allow these domains, add them to the network.allowed list in your workflow frontmatter:

network:
  allowed:
    - defaults
    - "github.com"
    - "proxy.golang.org"
    - "storage.googleapis.com"
    - "sum.golang.org"

See Network Configuration for more information.

Generated by Go API Consistency Review Agent for #1269 · copilot · auto · 227.7 AIC · ⌖ 13.9 AIC · ⊞ 13.9K · ◷