Expose telemetry through Rust SDK, C ABI, and .NET binding

[RamonArjona4]

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Summary

Exposes stable telemetry consent and policy through the public Rust SDK, panic-safe C ABI, and managed .NET binding. Adds typed presenter/status/withdrawal APIs, native binding entry points, streaming and state-aware propagation, and binding-codegen coverage.

This is PR 4 of 5 and depends on the stable runtime integration in PR 3.

Stack

Order	Change	PR
1	Normative privacy and telemetry documentation	#818
2	Consent and policy foundation	#819
3	Stable config and executor integration	#820
4	Rust SDK, C ABI, and .NET binding	#821
5	Node.js and .NET SDK refinements	#822

Review only this PR's diff; prerequisite behavior is in the PR above.

[Copilot]

🔵 Needs a closer look

Canonical .NET deserialization can accept invalid input and silently alter network enforcement.

Review details

Suppressed comments (3)

Previously missed (1) — in code that hasn't changed since the last review.

sdk/dotnet/Microsoft.Mxc.Sdk/CanonicalRequestBuilder.cs:26

• The canonical reader currently accepts numeric enum tokens because JsonStringEnumConverter allows integers by default. That lets inputs such as "clipboard": 1 pass managed deserialization and be normalized into valid string JSON before the native parser can reject the noncanonical input. Disable integer enum values so this bridge preserves the canonical wire boundary.

sdk/dotnet/Microsoft.Mxc.Sdk/CanonicalRequestBuilder.cs:352

• enforcementMode is validated here but then discarded. Re-serializing the resulting request recomputes the mode from the current host/containment, so a canonical firewall, both, or capabilities request can silently change network enforcement. Preserve the mode in the managed projection, or reject it as unrepresentable instead of accepting and dropping it.

        if (network.TryGetProperty("enforcementMode", out var enforcementMode))
        {
            _ = ReadString(enforcementMode, "network.enforcementMode") switch
            {
                "capabilities" or "firewall" or "both" => true,

sdk/dotnet/Microsoft.Mxc.Sdk/CanonicalRequestBuilder.cs:539

• Typed nested sections deserialized through this helper do not pass through EnsureKnownProperties, so duplicate keys inside structures such as network.egress are accepted with last-value-wins semantics. The native canonical parser rejects duplicates; managed deserialization therefore normalizes an otherwise rejected policy before execution. Recursively reject duplicate object properties before typed deserialization.

    private static T DeserializeElement<T>(JsonElement element, string location)
    {
        try
        {
            return element.Deserialize<T>(CanonicalReadOptions)
                ?? throw new JsonException($"{location} cannot be null.");

• Files reviewed: 37/38 changed files
• Comments generated: 0 new
• Review effort level: Balanced

[Copilot]

🔵 Needs a closer look

The privacy-sensitive, cross-language ABI change requires final human validation across native and managed runtime environments.

Review details

• Files reviewed: 30/31 changed files
• Comments generated: 0 new
• Review effort level: Balanced

[Copilot]

🟡 Changes recommended

Malformed null consent-prompt fields can be silently rendered as empty strings before a grant is persisted.

Once you've addressed the issues Copilot identified, you can request another Copilot review.

Review details

• Files reviewed: 30/31 changed files
• Comments generated: 1
• Review effort level: Balanced

[RamonArjona4]

Following up on the telemetry placement question in #821 (comment): telemetry is intentionally not a field on the engine SandboxPolicy because it is invocation metadata rather than a sandbox restriction. With the restored architecture, the C# binding envelope carries policy.telemetry.enabled; the FFI RequestSpec parser extracts it and applies it through SandboxRequest::set_telemetry_opt_in.

[Copilot]

🔵 Needs a closer look

Public Rust, C, and .NET documentation incorrectly describes consent alone as effective telemetry authorization despite the separate administrative-policy gate.

Review details

Suppressed comments (4)

Previously missed (4) — in code that hasn't changed since the last review.

sdk/dotnet/Microsoft.Mxc.Sdk/MxcTelemetry.cs:277

• GetConsent() does not include the administrative policy gate, so Granted can be returned while GetPolicy() is Blocked. Calling this state “effective for telemetry authorization” may lead consumers to bypass the required policy check; document it as the validated consent component and direct callers to check policy separately.
  src/core/mxc-sdk/src/telemetry.rs:22
• Granted only reflects the validated MXC consent record; an administrative block or an invocation without telemetry enabled still keeps telemetry off. This example currently teaches callers to equate consent with final authorization, so label it as consent state (or explicitly combine the policy and per-run gates).
  src/core/mxc-sdk/src/telemetry.rs:347
• This description overstates what get_consent() computes. The delegated consent status validates the persisted record and prompt version but does not evaluate the separate administrative policy, so it can return Granted while get_policy() is Blocked. Clarify that callers must evaluate policy as well before treating collection as authorized.
  src/ffi/mxc_ffi/src/lib.rs:542
• This export only returns the validated consent record; it does not apply the administrative policy, so it may return "granted" while mxc_telemetry_get_policy returns "blocked". Calling it effective authorization is misleading for C consumers; explicitly require the policy check as well.

• Files reviewed: 29/30 changed files
• Comments generated: 0 new
• Review effort level: Balanced

[Copilot]

🟡 Changes recommended

The streaming integration-test helper emits the wrong request shape, causing all real streaming tests to fail before process launch.

Once you've addressed the issues Copilot identified, you can request another Copilot review.

Review details

• Files reviewed: 28/29 changed files
• Comments generated: 1
• Review effort level: Balanced

[Copilot]

🟡 Changes recommended

The parity gate loses direct coverage of managed discriminators and the FFI request adapter, and the .NET telemetry version requirement is undocumented.

Once you've addressed the issues Copilot identified, you can request another Copilot review.

Review details

Suppressed comments (1)

Previously missed (1) — in code that hasn't changed since the last review.

sdk/dotnet/Microsoft.Mxc.Sdk/SandboxPolicy.cs:65

• The native binding rejects policy.telemetry for schema versions before 0.9.0-alpha, but this new public property does not disclose that requirement. Existing callers commonly use the documented 0.7.0-alpha example, so adding Telemetry produces a MalformedRequest; document the minimum version here so the failure is predictable.

• Files reviewed: 28/29 changed files
• Comments generated: 1
• Review effort level: Balanced

[Jeff Whiteside (jsidewhite)]

i don't really understand this subtle change, but good enough.

[Jeff Whiteside (jsidewhite)]