diff --git a/src/Sdk/Cerbos/Sdk/Builder/CerbosClientBuilder.cs b/src/Sdk/Cerbos/Sdk/Builder/CerbosClientBuilder.cs
index bd19452..142cdcf 100644
--- a/src/Sdk/Cerbos/Sdk/Builder/CerbosClientBuilder.cs
+++ b/src/Sdk/Cerbos/Sdk/Builder/CerbosClientBuilder.cs
@@ -20,6 +20,7 @@ public sealed class CerbosClientBuilder
         private StreamReader TlsCertificate { get; set; }
         private StreamReader TlsKey { get; set; }
         private GrpcChannelOptions GrpcChannelOptions { get; set; }
+        private Metadata Metadata { get; set; }
 
         private CerbosClientBuilder(string target) {
             Target = target;
@@ -30,6 +31,12 @@ public static CerbosClientBuilder ForTarget(string target)
             return new CerbosClientBuilder(target);
         }
 
+        public CerbosClientBuilder WithMetadata(Metadata headers)
+        {
+            Metadata = headers;
+            return this;
+        }
+
         public CerbosClientBuilder WithPlaintext() {
             Plaintext = true;
             return this;
@@ -87,6 +94,14 @@ public CerbosClient Build()
                 callCredentials = CallCredentials.FromInterceptor((context, metadata) =>
                 {
                     metadata.Add(PlaygroundInstanceHeader, PlaygroundInstanceId.Trim());
+                    if (Metadata != null)
+                    {
+                        foreach (var m in Metadata)
+                        {
+                            metadata.Add(m);
+                        }
+                    }
+
                     return Task.CompletedTask;
                 });
             }
diff --git a/src/Sdk/Cerbos/Sdk/CerbosClient.cs b/src/Sdk/Cerbos/Sdk/CerbosClient.cs
index f004093..085f7c9 100644
--- a/src/Sdk/Cerbos/Sdk/CerbosClient.cs
+++ b/src/Sdk/Cerbos/Sdk/CerbosClient.cs
@@ -4,6 +4,7 @@
 using System;
 using System.Threading.Tasks;
 using Cerbos.Sdk.Response;
+using Grpc.Core;
 
 namespace Cerbos.Sdk
 {
@@ -22,11 +23,11 @@ public CerbosClient(Api.V1.Svc.CerbosService.CerbosServiceClient cerbosServiceCl
         /// <summary>
         /// Send a request consisting of a principal, resource(s) & action(s) to see if the principal is authorized to do the action(s) on the resource(s).
         /// </summary>
-        public CheckResourcesResponse CheckResources(Builder.CheckResourcesRequest request)
+        public CheckResourcesResponse CheckResources(Builder.CheckResourcesRequest request, Metadata headers = null)
         {
             try
             {
-                return new CheckResourcesResponse(CerbosServiceClient.CheckResources(request.ToCheckResourcesRequest()));
+                return new CheckResourcesResponse(CerbosServiceClient.CheckResources(request.ToCheckResourcesRequest(), headers));
             }
             catch (Exception e)
             {
@@ -37,12 +38,12 @@ public CheckResourcesResponse CheckResources(Builder.CheckResourcesRequest reque
         /// <summary>
         /// Send an async request consisting of a principal, resource(s) & action(s) to see if the principal is authorized to do the action(s) on the resource(s).
         /// </summary>
-        public Task<CheckResourcesResponse> CheckResourcesAsync(Builder.CheckResourcesRequest request)
+        public Task<CheckResourcesResponse> CheckResourcesAsync(Builder.CheckResourcesRequest request, Metadata headers = null)
         {
             try
             {
                 return CerbosServiceClient
-                    .CheckResourcesAsync(request.ToCheckResourcesRequest())
+                    .CheckResourcesAsync(request.ToCheckResourcesRequest(), headers)
                     .ResponseAsync
                     .ContinueWith(
                         r => new CheckResourcesResponse(r.Result)
@@ -57,11 +58,11 @@ public Task<CheckResourcesResponse> CheckResourcesAsync(Builder.CheckResourcesRe
         /// <summary>
         /// Obtain a query plan for performing the given action on the given resource kind.
         /// </summary>
-        public PlanResourcesResponse PlanResources(Builder.PlanResourcesRequest request)
+        public PlanResourcesResponse PlanResources(Builder.PlanResourcesRequest request, Metadata headers = null)
         {
             try
             {
-                return new PlanResourcesResponse(CerbosServiceClient.PlanResources(request.ToPlanResourcesRequest()));
+                return new PlanResourcesResponse(CerbosServiceClient.PlanResources(request.ToPlanResourcesRequest(), headers));
             }
             catch (Exception e)
             {
@@ -72,12 +73,12 @@ public PlanResourcesResponse PlanResources(Builder.PlanResourcesRequest request)
         /// <summary>
         /// Obtain a query plan for performing the given action on the given resource kind.
         /// </summary>
-        public Task<PlanResourcesResponse> PlanResourcesAsync(Builder.PlanResourcesRequest request)
+        public Task<PlanResourcesResponse> PlanResourcesAsync(Builder.PlanResourcesRequest request, Metadata headers = null)
         {
             try
             {
                 return CerbosServiceClient
-                    .PlanResourcesAsync(request.ToPlanResourcesRequest())
+                    .PlanResourcesAsync(request.ToPlanResourcesRequest(), headers)
                     .ResponseAsync
                     .ContinueWith(
                         r => new PlanResourcesResponse(r.Result)