diff --git a/apps/builder/app/builder/features/settings-panel/resource-panel.tsx b/apps/builder/app/builder/features/settings-panel/resource-panel.tsx
index a902ea12b76d..fa70518756d3 100644
--- a/apps/builder/app/builder/features/settings-panel/resource-panel.tsx
+++ b/apps/builder/app/builder/features/settings-panel/resource-panel.tsx
@@ -66,18 +66,17 @@ import {
   type InstancePath,
 } from "~/shared/awareness";
 import { updateWebstudioData } from "~/shared/instance-utils";
-import {
-  computeExpression,
-  rebindTreeVariablesMutable,
-} from "~/shared/data-variables";
+import { rebindTreeVariablesMutable } from "~/shared/data-variables";
 import { parseCurl, type CurlRequest } from "./curl";
 
 export const parseResource = ({
   id,
+  control,
   name,
   formData,
 }: {
   id: string;
+  control?: string;
   name?: string;
   formData: FormData;
 }) => {
@@ -87,6 +86,7 @@ export const parseResource = ({
   const headerValues = formData.getAll("header-value") as string[];
   return Resource.parse({
     id,
+    control,
     name: name ?? formData.get("name"),
     url: formData.get("url"),
     searchParams: searchParamNames
@@ -253,7 +253,7 @@ const SearchParamPair = ({
 }) => {
   const evaluatedValue = evaluateExpressionWithinScope(value, scope);
   // expressions with variables or objects cannot be edited from input
-  const isValueUnbound =
+  const isValueUnboundString =
     isLiteralExpression(value) && typeof evaluatedValue === "string";
   return (
     <Grid
@@ -274,7 +274,7 @@ const SearchParamPair = ({
         <InputField
           placeholder="Value"
           name="search-param-value-literal"
-          disabled={!isValueUnbound}
+          disabled={!isValueUnboundString}
           value={serializeValue(evaluatedValue)}
           // update text value as string literal
           onChange={(event) =>
@@ -284,7 +284,7 @@ const SearchParamPair = ({
         <BindingPopover
           scope={scope}
           aliases={aliases}
-          variant={isValueUnbound ? "default" : "bound"}
+          variant={isLiteralExpression(value) ? "default" : "bound"}
           value={value}
           onChange={(newValue) => onChange(name, newValue)}
           onRemove={(evaluatedValue) =>
@@ -377,7 +377,7 @@ const HeaderPair = ({
 }) => {
   const evaluatedValue = evaluateExpressionWithinScope(value, scope);
   // expressions with variables or objects cannot be edited from input
-  const isValueUnbound =
+  const isValueUnboundString =
     isLiteralExpression(value) && typeof evaluatedValue === "string";
   return (
     <Grid
@@ -398,7 +398,7 @@ const HeaderPair = ({
         <InputField
           placeholder="Value"
           name="header-value-validator"
-          disabled={!isValueUnbound}
+          disabled={!isValueUnboundString}
           value={serializeValue(evaluatedValue)}
           // update text value as string literal
           onChange={(event) =>
@@ -408,7 +408,7 @@ const HeaderPair = ({
         <BindingPopover
           scope={scope}
           aliases={aliases}
-          variant={isValueUnbound ? "default" : "bound"}
+          variant={isLiteralExpression(value) ? "default" : "bound"}
           value={value}
           onChange={(newValue) => onChange(name, newValue)}
           onRemove={(evaluatedValue) =>
@@ -558,7 +558,7 @@ export const getResourceScopeForInstance = ({
         const name = encodeDataVariableId(dataSourceId);
         scope[name] = value;
         aliases.set(name, dataSource.name);
-        variableValues.set(dataSource.name, value);
+        variableValues.set(dataSourceId, value);
       }
     }
   }
@@ -621,7 +621,7 @@ export const useResourceScope = ({ variable }: { variable?: DataSource }) => {
               const key = encodeDataVariableId(variable.id);
               delete newScope[key];
               newAliases.delete(key);
-              newVariableValues.delete(variable.name);
+              newVariableValues.delete(variable.id);
             }
             return {
               scope: newScope,
@@ -796,7 +796,10 @@ const parseHeaders = (headers: Resource["headers"]) => {
   let maxAge: undefined | string;
   let bodyType: BodyType;
   const newHeaders = headers.filter((header) => {
-    const value = computeExpression(header.value, new Map()).toLowerCase();
+    // cast raw expression result to string
+    const value = String(
+      evaluateExpressionWithinScope(header.value, {})
+    ).toLowerCase();
     if (isCacheControl(header.name)) {
       // move simple header like Cache-Control: max-age=10 to dedicated input
       // preserve more complex cache-control
@@ -818,7 +821,7 @@ const parseHeaders = (headers: Resource["headers"]) => {
         return false;
       }
     }
-    return false;
+    return true;
   });
   return { headers: newHeaders, maxAge, bodyType };
 };
@@ -980,8 +983,6 @@ export const SystemResourceForm = forwardRef<
       ? resources.get(variable.resourceId)
       : undefined;
 
-  const method = "get";
-
   const localResources = [
     {
       label: "Sitemap",
@@ -1006,19 +1007,15 @@ export const SystemResourceForm = forwardRef<
       if (scopeInstanceId === undefined) {
         return;
       }
-      const name = z.string().parse(formData.get("name"));
-      const newResource: Resource = {
+      const newResource: Resource = parseResource({
         id: resource?.id ?? nanoid(),
-        name,
         control: "system",
-        url: localResource.value,
-        method,
-        headers: [],
-      };
+        formData,
+      });
       const newVariable: DataSource = {
         id: variable?.id ?? nanoid(),
         scopeInstanceId,
-        name,
+        name: newResource.name,
         type: "resource",
         resourceId: newResource.id,
       };
@@ -1037,6 +1034,8 @@ export const SystemResourceForm = forwardRef<
 
   return (
     <>
+      <input type="hidden" name="method" value="get" />
+      <input type="hidden" name="url" value={localResource.value} />
       <Flex direction="column" css={{ gap: theme.spacing[3] }}>
         <Label htmlFor={resourceId}>Resource</Label>
         <Select
@@ -1116,29 +1115,15 @@ export const GraphqlResourceForm = forwardRef<
       if (scopeInstanceId === undefined) {
         return;
       }
-      const name = z.string().parse(formData.get("name"));
-      const body = generateObjectExpression(
-        new Map([
-          ["query", JSON.stringify(query)],
-          ["variables", variables],
-        ])
-      );
-      const newResource: Resource = {
+      const newResource = parseResource({
         id: resource?.id ?? nanoid(),
-        name,
         control: "graphql",
-        url,
-        method: "post",
-        headers: [
-          ...headers,
-          { name: "Content-Type", value: "application/json" },
-        ],
-        body,
-      };
+        formData,
+      });
       const newVariable: DataSource = {
         id: variable?.id ?? nanoid(),
         scopeInstanceId,
-        name,
+        name: newResource.name,
         type: "resource",
         resourceId: newResource.id,
       };
@@ -1155,6 +1140,28 @@ export const GraphqlResourceForm = forwardRef<
 
   return (
     <>
+      <input type="hidden" name="method" value="post" />
+      {!headers.some(({ name }) => isContentType(name)) && (
+        <>
+          <input type="hidden" name="header-name" value="Content-Type" />
+          <input
+            type="hidden"
+            name="header-value"
+            value={`"application/json"`}
+          />
+        </>
+      )}
+      <input
+        type="hidden"
+        name="body"
+        value={generateObjectExpression(
+          new Map([
+            ["query", JSON.stringify(query)],
+            ["variables", variables],
+          ])
+        )}
+      />
+
       <UrlField
         scope={scope}
         aliases={aliases}
diff --git a/packages/sdk/src/resource-loader.ts b/packages/sdk/src/resource-loader.ts
index 26bef82d4cbf..b49d0606eba6 100644
--- a/packages/sdk/src/resource-loader.ts
+++ b/packages/sdk/src/resource-loader.ts
@@ -25,13 +25,19 @@ export const loadResource = async (
 ) => {
   try {
     const { method, searchParams, headers, body } = resourceRequest;
-    // cloudflare workers fail when fetching url contains spaces
-    // even though new URL suppose to trim them on parsing by spec
-    const url = new URL(resourceRequest.url.trim());
-    if (searchParams) {
-      for (const { name, value } of searchParams) {
-        url.searchParams.append(name, serializeValue(value));
+    let href = resourceRequest.url;
+    try {
+      // cloudflare workers fail when fetching url contains spaces
+      // even though new URL suppose to trim them on parsing by spec
+      const url = new URL(resourceRequest.url.trim());
+      if (searchParams) {
+        for (const { name, value } of searchParams) {
+          url.searchParams.append(name, serializeValue(value));
+        }
       }
+      href = url.href;
+    } catch {
+      // empty block
     }
     const requestHeaders = new Headers(
       headers.map(({ name, value }): [string, string] => [
@@ -46,7 +52,7 @@ export const loadResource = async (
     if (method !== "get" && body !== undefined) {
       requestInit.body = serializeValue(body);
     }
-    const response = await customFetch(url.href, requestInit);
+    const response = await customFetch(href, requestInit);
 
     let data = await response.text();
 
@@ -59,7 +65,7 @@ export const loadResource = async (
 
     if (!response.ok) {
       console.error(
-        `Failed to load resource: ${url} - ${response.status}: ${JSON.stringify(data).slice(0, 300)}`
+        `Failed to load resource: ${href} - ${response.status}: ${JSON.stringify(data).slice(0, 300)}`
       );
     }