diff --git a/src/Backend/AutopilotMonitor.Functions/Functions/AnalyzeRulesFunction.cs b/src/Backend/AutopilotMonitor.Functions/Functions/AnalyzeRulesFunction.cs
index be545655..4c0e03c4 100644
--- a/src/Backend/AutopilotMonitor.Functions/Functions/AnalyzeRulesFunction.cs
+++ b/src/Backend/AutopilotMonitor.Functions/Functions/AnalyzeRulesFunction.cs
@@ -56,7 +56,9 @@ namespace AutopilotMonitor.Functions.Functions
                 return unauthorized;
             }
 
-            if (req.Body.Length > 1_048_576) // 1 MB limit
+            if (req.Headers.TryGetValues("Content-Length", out var clValues)
+                && long.TryParse(clValues.FirstOrDefault(), out var contentLength)
+                && contentLength > 1_048_576) // 1 MB limit
             {
                 var badRequest = req.CreateResponse(HttpStatusCode.BadRequest);
                 await badRequest.WriteAsJsonAsync(new { success = false, message = "Request body too large" });
@@ -92,7 +94,9 @@ namespace AutopilotMonitor.Functions.Functions
                 return unauthorized;
             }
 
-            if (req.Body.Length > 1_048_576) // 1 MB limit
+            if (req.Headers.TryGetValues("Content-Length", out var clValues2)
+                && long.TryParse(clValues2.FirstOrDefault(), out var contentLength2)
+                && contentLength2 > 1_048_576) // 1 MB limit
             {
                 var badRequest = req.CreateResponse(HttpStatusCode.BadRequest);
                 await badRequest.WriteAsJsonAsync(new { success = false, message = "Request body too large" });
diff --git a/src/Backend/AutopilotMonitor.Functions/Functions/GatherRulesFunction.cs b/src/Backend/AutopilotMonitor.Functions/Functions/GatherRulesFunction.cs
index 3badac54..287c0ca6 100644
--- a/src/Backend/AutopilotMonitor.Functions/Functions/GatherRulesFunction.cs
+++ b/src/Backend/AutopilotMonitor.Functions/Functions/GatherRulesFunction.cs
@@ -56,7 +56,9 @@ namespace AutopilotMonitor.Functions.Functions
                 return unauthorized;
             }
 
-            if (req.Body.Length > 1_048_576) // 1 MB limit
+            if (req.Headers.TryGetValues("Content-Length", out var clValues)
+                && long.TryParse(clValues.FirstOrDefault(), out var contentLength)
+                && contentLength > 1_048_576) // 1 MB limit
             {
                 var badRequest = req.CreateResponse(HttpStatusCode.BadRequest);
                 await badRequest.WriteAsJsonAsync(new { success = false, message = "Request body too large" });
@@ -92,7 +94,9 @@ namespace AutopilotMonitor.Functions.Functions
                 return unauthorized;
             }
 
-            if (req.Body.Length > 1_048_576) // 1 MB limit
+            if (req.Headers.TryGetValues("Content-Length", out var clValues2)
+                && long.TryParse(clValues2.FirstOrDefault(), out var contentLength2)
+                && contentLength2 > 1_048_576) // 1 MB limit
             {
                 var badRequest = req.CreateResponse(HttpStatusCode.BadRequest);
                 await badRequest.WriteAsJsonAsync(new { success = false, message = "Request body too large" });
diff --git a/src/Backend/AutopilotMonitor.Functions/Functions/IngestEventsFunction.cs b/src/Backend/AutopilotMonitor.Functions/Functions/IngestEventsFunction.cs
index 239e4a66..d88dd400 100644
--- a/src/Backend/AutopilotMonitor.Functions/Functions/IngestEventsFunction.cs
+++ b/src/Backend/AutopilotMonitor.Functions/Functions/IngestEventsFunction.cs
@@ -68,7 +68,9 @@ namespace AutopilotMonitor.Functions.Functions
                 {
                     // Legacy format: standard JSON (backwards compatibility)
                     _logger.LogDebug("Parsing legacy JSON request");
-                    if (req.Body.Length > 1_048_576) // 1 MB limit
+                    if (req.Headers.TryGetValues("Content-Length", out var clValues)
+                        && long.TryParse(clValues.FirstOrDefault(), out var contentLength)
+                        && contentLength > 1_048_576) // 1 MB limit
                     {
                         return await CreateErrorResponse(req, HttpStatusCode.BadRequest, "Request body too large");
                     }
diff --git a/src/Backend/AutopilotMonitor.Functions/Functions/RegisterSessionFunction.cs b/src/Backend/AutopilotMonitor.Functions/Functions/RegisterSessionFunction.cs
index 291cdd1d..d2515748 100644
--- a/src/Backend/AutopilotMonitor.Functions/Functions/RegisterSessionFunction.cs
+++ b/src/Backend/AutopilotMonitor.Functions/Functions/RegisterSessionFunction.cs
@@ -38,7 +38,9 @@ namespace AutopilotMonitor.Functions.Functions
             try
             {
                 // Parse request
-                if (req.Body.Length > 1_048_576) // 1 MB limit
+                if (req.Headers.TryGetValues("Content-Length", out var clValues)
+                    && long.TryParse(clValues.FirstOrDefault(), out var contentLength)
+                    && contentLength > 1_048_576) // 1 MB limit
                 {
                     var errorResponse = await CreateErrorResponse(req, HttpStatusCode.BadRequest, "Request body too large");
                     return new RegisterSessionOutput { HttpResponse = errorResponse };
diff --git a/src/Backend/AutopilotMonitor.Functions/Functions/SignalRAddToGroupFunction.cs b/src/Backend/AutopilotMonitor.Functions/Functions/SignalRAddToGroupFunction.cs
index 1babd057..b3094331 100644
--- a/src/Backend/AutopilotMonitor.Functions/Functions/SignalRAddToGroupFunction.cs
+++ b/src/Backend/AutopilotMonitor.Functions/Functions/SignalRAddToGroupFunction.cs
@@ -38,7 +38,9 @@ namespace AutopilotMonitor.Functions.Functions
                 }
 
                 // Parse request
-                if (req.Body.Length > 1_048_576) // 1 MB limit
+                if (req.Headers.TryGetValues("Content-Length", out var clValues)
+                    && long.TryParse(clValues.FirstOrDefault(), out var contentLength)
+                    && contentLength > 1_048_576) // 1 MB limit
                 {
                     var errorResponse = req.CreateResponse(HttpStatusCode.BadRequest);
                     await errorResponse.WriteAsJsonAsync(new { success = false, message = "Request body too large" });
diff --git a/src/Backend/AutopilotMonitor.Functions/Functions/SignalRRemoveFromGroupFunction.cs b/src/Backend/AutopilotMonitor.Functions/Functions/SignalRRemoveFromGroupFunction.cs
index 09be71c4..19e3274c 100644
--- a/src/Backend/AutopilotMonitor.Functions/Functions/SignalRRemoveFromGroupFunction.cs
+++ b/src/Backend/AutopilotMonitor.Functions/Functions/SignalRRemoveFromGroupFunction.cs
@@ -38,7 +38,9 @@ namespace AutopilotMonitor.Functions.Functions
                 }
 
                 // Parse request
-                if (req.Body.Length > 1_048_576) // 1 MB limit
+                if (req.Headers.TryGetValues("Content-Length", out var clValues)
+                    && long.TryParse(clValues.FirstOrDefault(), out var contentLength)
+                    && contentLength > 1_048_576) // 1 MB limit
                 {
                     var errorResponse = req.CreateResponse(HttpStatusCode.BadRequest);
                     await errorResponse.WriteAsJsonAsync(new { success = false, message = "Request body too large" });
diff --git a/src/Backend/AutopilotMonitor.Functions/Functions/UpdateAdminConfigurationFunction.cs b/src/Backend/AutopilotMonitor.Functions/Functions/UpdateAdminConfigurationFunction.cs
index 92dd4ee4..bfe1367c 100644
--- a/src/Backend/AutopilotMonitor.Functions/Functions/UpdateAdminConfigurationFunction.cs
+++ b/src/Backend/AutopilotMonitor.Functions/Functions/UpdateAdminConfigurationFunction.cs
@@ -67,7 +67,9 @@ namespace AutopilotMonitor.Functions.Functions
                 _logger.LogInformation($"UpdateAdminConfiguration by Galactic Admin user {userIdentifier}");
 
                 // Parse request body
-                if (req.Body.Length > 1_048_576) // 1 MB limit
+                if (req.Headers.TryGetValues("Content-Length", out var clValues)
+                    && long.TryParse(clValues.FirstOrDefault(), out var contentLength)
+                    && contentLength > 1_048_576) // 1 MB limit
                 {
                     var badRequest = req.CreateResponse(HttpStatusCode.BadRequest);
                     await badRequest.WriteAsJsonAsync(new { success = false, message = "Request body too large" });
diff --git a/src/Backend/AutopilotMonitor.Functions/Functions/UpdateTenantConfigurationFunction.cs b/src/Backend/AutopilotMonitor.Functions/Functions/UpdateTenantConfigurationFunction.cs
index b023c248..d1108e1b 100644
--- a/src/Backend/AutopilotMonitor.Functions/Functions/UpdateTenantConfigurationFunction.cs
+++ b/src/Backend/AutopilotMonitor.Functions/Functions/UpdateTenantConfigurationFunction.cs
@@ -65,7 +65,9 @@ namespace AutopilotMonitor.Functions.Functions
                 _logger.LogInformation($"UpdateTenantConfiguration: {tenantId} by user {userIdentifier}");
 
                 // Parse request body
-                if (req.Body.Length > 1_048_576) // 1 MB limit
+                if (req.Headers.TryGetValues("Content-Length", out var clValues)
+                    && long.TryParse(clValues.FirstOrDefault(), out var contentLength)
+                    && contentLength > 1_048_576) // 1 MB limit
                 {
                     var badRequest = req.CreateResponse(HttpStatusCode.BadRequest);
                     await badRequest.WriteAsJsonAsync(new { success = false, message = "Request body too large" });