Sample: MicroservicesHttpGrpc¶

Scenario¶

Gateway receives HTTP traffic and calls:

Service A over HTTP
Service B over gRPC

Both paths must carry the same context model without duplicating mapping logic.

Why this matters¶

mixed transport stacks are common in modern .NET systems
teams often implement inconsistent header/metadata adapters
debugging is easier when correlation model is shared

Context contract¶

public sealed class CorrelationContext
{
    public string? TraceId { get; set; }
    public string? SpanId { get; set; }
    public List<string>? Tags { get; set; }
}

Registration¶

builder.Services.AddContextR(ctx =>
{
    ctx.Add<CorrelationContext>(reg => reg
        .UseInlineJsonPayloads<CorrelationContext>(o =>
        {
            o.MaxPayloadBytes = 256;
            o.OversizeBehavior = ContextOversizeBehavior.SkipProperty;
        })
        .UseChunkingPayloads<CorrelationContext>()
        .UseStrategyPolicy<CorrelationContext>(sp => policyContext =>
            policyContext.Key == "X-Tags"
                ? ContextOversizeBehavior.ChunkProperty
                : ContextOversizeBehavior.SkipProperty)
        .MapProperty(c => c.TraceId, "X-Trace-Id")
        .MapProperty(c => c.SpanId, "X-Span-Id")
        .MapProperty(c => c.Tags, "X-Tags")
        .UseAspNetCore()
        .UseGlobalHttpPropagation()
        .UseGlobalGrpcPropagation());
});

Flow¶

HTTP middleware extracts context at gateway boundary.
Outgoing HTTP handler injects mapped values for Service A.
gRPC interceptors inject/extract same context for Service B.
Oversize Tags follow runtime strategy policy.

Suggested integration tests¶

HTTP request round-trips trace/span across gateway and Service A
gRPC call round-trips same trace/span to Service B
oversize Tags are chunked and reassembled
malformed payload follows configured failure policy