diff --git a/generated/.tailcallrc.schema.json b/generated/.tailcallrc.schema.json
index 70ca3e9258..3939019104 100644
--- a/generated/.tailcallrc.schema.json
+++ b/generated/.tailcallrc.schema.json
@@ -2,9 +2,6 @@
   "$schema": "http://json-schema.org/draft-07/schema#",
   "title": "RuntimeConfig",
   "type": "object",
-  "required": [
-    "links"
-  ],
   "properties": {
     "links": {
       "description": "A list of all links in the schema.",
@@ -15,7 +12,6 @@
     },
     "server": {
       "description": "Dictates how the server behaves and helps tune tailcall for all ingress requests. Features such as request batching, SSL, HTTP2 etc. can be configured here.",
-      "default": {},
       "allOf": [
         {
           "$ref": "#/definitions/Server"
@@ -32,7 +28,6 @@
     },
     "upstream": {
       "description": "Dictates how tailcall should handle upstream requests/responses. Tuning upstream can improve performance and reliability for connections.",
-      "default": {},
       "allOf": [
         {
           "$ref": "#/definitions/Upstream"
diff --git a/src/core/config/config.rs b/src/core/config/config.rs
index 759ee0a9aa..3cf91aa6f6 100644
--- a/src/core/config/config.rs
+++ b/src/core/config/config.rs
@@ -43,17 +43,18 @@ pub struct RuntimeConfig {
     /// Dictates how the server behaves and helps tune tailcall for all ingress
     /// requests. Features such as request batching, SSL, HTTP2 etc. can be
     /// configured here.
-    #[serde(default)]
+    #[serde(default, skip_serializing_if = "is_default")]
     pub server: Server,
 
     ///
     /// Dictates how tailcall should handle upstream requests/responses.
     /// Tuning upstream can improve performance and reliability for connections.
-    #[serde(default)]
+    #[serde(default, skip_serializing_if = "is_default")]
     pub upstream: Upstream,
 
     ///
     /// A list of all links in the schema.
+    #[serde(default, skip_serializing_if = "is_default")]
     pub links: Vec<Link>,
 
     /// Enable [opentelemetry](https://opentelemetry.io) support
diff --git a/src/core/config/transformer/subgraph.rs b/src/core/config/transformer/subgraph.rs
index 0d336d544f..c43e727bef 100644
--- a/src/core/config/transformer/subgraph.rs
+++ b/src/core/config/transformer/subgraph.rs
@@ -59,7 +59,12 @@ impl Transform for Subgraph {
                             let key = Key { fields };
 
                             to_directive(key.to_directive()).map(|directive| {
-                                ty.directives.push(directive);
+                                // Prevent transformer to push the same directive multiple times
+                                if !ty.directives.iter().any(|d| {
+                                    d.name == directive.name && d.arguments == directive.arguments
+                                }) {
+                                    ty.directives.push(directive);
+                                }
                             })
                         }
                         None => Valid::succeed(()),
diff --git a/tests/core/parse.rs b/tests/core/parse.rs
index 6246c40008..f7af845d81 100644
--- a/tests/core/parse.rs
+++ b/tests/core/parse.rs
@@ -15,7 +15,8 @@ use tailcall::cli::javascript;
 use tailcall::core::app_context::AppContext;
 use tailcall::core::blueprint::Blueprint;
 use tailcall::core::cache::InMemoryCache;
-use tailcall::core::config::{ConfigModule, Source};
+use tailcall::core::config::{ConfigModule, Link, RuntimeConfig, Source};
+use tailcall::core::merge_right::MergeRight;
 use tailcall::core::runtime::TargetRuntime;
 use tailcall::core::worker::{Command, Event};
 use tailcall::core::{EnvIO, WorkerIO};
@@ -51,7 +52,7 @@ impl ExecutionSpec {
             .peekable();
 
         let mut name: Option<String> = None;
-        let mut server: Vec<(Source, String)> = Vec::with_capacity(2);
+        let mut config = RuntimeConfig::default();
         let mut mock: Option<Vec<Mock>> = None;
         let mut env: Option<HashMap<String, String>> = None;
         let mut files: BTreeMap<String, String> = BTreeMap::new();
@@ -59,6 +60,7 @@ impl ExecutionSpec {
         let mut runner: Option<Annotation> = None;
         let mut check_identity = false;
         let mut sdl_error = false;
+        let mut links_counter = 0;
 
         while let Some(node) = children.next() {
             match node {
@@ -172,8 +174,16 @@ impl ExecutionSpec {
 
                             match name {
                                 "config" => {
-                                    // Server configs are only parsed if the test isn't skipped.
-                                    server.push((source, content));
+                                    config = config.merge_right(
+                                        RuntimeConfig::from_source(source, &content).unwrap(),
+                                    );
+                                }
+                                "schema" => {
+                                    // Schemas configs are only parsed if the test isn't skipped.
+                                    let name = format!("schema_{}.graphql", links_counter);
+                                    files.insert(name.clone(), content);
+                                    config.links.push(Link { src: name, ..Default::default() });
+                                    links_counter += 1;
                                 }
                                 "mock" => {
                                     if mock.is_none() {
@@ -240,9 +250,9 @@ impl ExecutionSpec {
             }
         }
 
-        if server.is_empty() {
+        if links_counter == 0 {
             return Err(anyhow!(
-                "Unexpected blocks in {:?}: You must define a GraphQL Config in an execution test.",
+                "Unexpected blocks in {:?}: You must define a GraphQL Schema in an execution test.",
                 path,
             ));
         }
@@ -252,7 +262,7 @@ impl ExecutionSpec {
             name: name.unwrap_or_else(|| path.file_name().unwrap().to_str().unwrap().to_string()),
             safe_name: path.file_name().unwrap().to_str().unwrap().to_string(),
 
-            server,
+            config,
             mock,
             env,
             test,
diff --git a/tests/core/runtime.rs b/tests/core/runtime.rs
index 0961593cc3..22ad9748af 100644
--- a/tests/core/runtime.rs
+++ b/tests/core/runtime.rs
@@ -10,7 +10,7 @@ use derive_setters::Setters;
 use tailcall::cli::javascript::init_worker_io;
 use tailcall::core::blueprint::Script;
 use tailcall::core::cache::InMemoryCache;
-use tailcall::core::config::Source;
+use tailcall::core::config::RuntimeConfig;
 use tailcall::core::runtime::TargetRuntime;
 use tailcall::core::worker::{Command, Event};
 
@@ -25,7 +25,7 @@ pub struct ExecutionSpec {
     pub name: String,
     pub safe_name: String,
 
-    pub server: Vec<(Source, String)>,
+    pub config: RuntimeConfig,
     pub mock: Option<Vec<Mock>>,
     pub env: Option<HashMap<String, String>>,
     pub test: Option<Vec<APIRequest>>,
diff --git a/tests/core/spec.rs b/tests/core/spec.rs
index 56a569da2b..1892aaf959 100644
--- a/tests/core/spec.rs
+++ b/tests/core/spec.rs
@@ -16,11 +16,10 @@ use tailcall::core::async_graphql_hyper::{GraphQLBatchRequest, GraphQLRequest};
 use tailcall::core::blueprint::{Blueprint, BlueprintError};
 use tailcall::core::config::reader::ConfigReader;
 use tailcall::core::config::transformer::Required;
-use tailcall::core::config::{Config, ConfigModule, ConfigReaderContext, Source};
+use tailcall::core::config::{Config, ConfigModule, ConfigReaderContext, LinkType, Source};
 use tailcall::core::http::handle_request;
 use tailcall::core::mustache::PathStringEval;
 use tailcall::core::print_schema::print_schema;
-use tailcall::core::variance::Invariant;
 use tailcall::core::Mustache;
 use tailcall_prettier::Parser;
 use tailcall_valid::{Cause, Valid, ValidationError, Validator};
@@ -97,54 +96,53 @@ async fn check_identity(spec: &ExecutionSpec, reader_ctx: &ConfigReaderContext<'
     // enabled for either new tests that request it or old graphql_spec
     // tests that were explicitly written with it in mind
     if spec.check_identity {
-        for (source, content) in spec.server.iter() {
-            if matches!(source, Source::GraphQL) {
-                let mustache = Mustache::parse(content);
-                let content = PathStringEval::new().eval_partial(&mustache, reader_ctx);
-                let config = Config::from_source(source.to_owned(), &content).unwrap();
-                let actual = config.to_sdl();
-
-                // \r is added automatically in windows, it's safe to replace it with \n
-                let content = content.replace("\r\n", "\n");
-
-                let path_str = spec.path.display().to_string();
-                let context = format!("path: {}", path_str);
-
-                let actual = tailcall_prettier::format(actual, &tailcall_prettier::Parser::Gql)
-                    .await
-                    .map_err(|e| e.with_context(context.clone()))
-                    .unwrap();
-
-                let expected = tailcall_prettier::format(content, &tailcall_prettier::Parser::Gql)
-                    .await
-                    .map_err(|e| e.with_context(context.clone()))
-                    .unwrap();
-
-                pretty_assertions::assert_eq!(
-                    actual,
-                    expected,
-                    "Identity check failed for {:#?}",
-                    spec.path,
-                );
-            } else {
-                panic!(
-                    "Spec {:#?} has \"check identity\" enabled, but its config isn't in GraphQL.",
-                    spec.path
-                );
-            }
+        for link in spec
+            .config
+            .links
+            .iter()
+            .filter(|link| link.type_of == LinkType::Config)
+        {
+            let content = reader_ctx.runtime.file.read(&link.src).await.unwrap();
+            let mustache = Mustache::parse(&content);
+            let content = PathStringEval::new().eval_partial(&mustache, reader_ctx);
+            let config = Config::from_source(Source::GraphQL, &content).unwrap();
+            let actual = config.to_sdl();
+
+            // \r is added automatically in windows, it's safe to replace it with \n
+            let content = content.replace("\r\n", "\n");
+
+            let path_str = spec.path.display().to_string();
+            let context = format!("path: {}", path_str);
+
+            let actual = tailcall_prettier::format(actual, &tailcall_prettier::Parser::Gql)
+                .await
+                .map_err(|e| e.with_context(context.clone()))
+                .unwrap();
+
+            let expected = tailcall_prettier::format(content, &tailcall_prettier::Parser::Gql)
+                .await
+                .map_err(|e| e.with_context(context.clone()))
+                .unwrap();
+
+            pretty_assertions::assert_eq!(
+                actual,
+                expected,
+                "Identity check failed for {:#?}",
+                spec.path,
+            );
         }
     }
 }
 
 async fn run_query_tests_on_spec(
     spec: ExecutionSpec,
-    server: Vec<ConfigModule>,
+    config_module: &ConfigModule,
     mock_http_client: Arc<Http>,
 ) {
     if let Some(tests) = spec.test.as_ref() {
         let app_ctx = spec
             .app_context(
-                server.first().unwrap(),
+                config_module,
                 spec.env.clone().unwrap_or_default(),
                 mock_http_client.clone(),
             )
@@ -200,42 +198,27 @@ async fn test_spec(spec: ExecutionSpec) {
 
     let reader = ConfigReader::init(runtime);
 
-    // Resolve all configs
-    let config_modules = join_all(spec.server.iter().map(|(source, content)| async {
-        let mustache = Mustache::parse(content);
-        let content = PathStringEval::new().eval_partial(&mustache, &reader_ctx);
+    let config = Config::from(spec.config.clone());
 
-        let config = Config::from_source(source.to_owned(), &content)?;
+    let config_module = reader.resolve(config, spec.path.parent()).await;
 
-        reader.resolve(config, spec.path.parent()).await
-    }))
-    .await;
-
-    let config_module = Valid::from_iter(config_modules.iter(), |config_module| {
-        Valid::from(config_module.as_ref().map_err(|e| {
-            match e.downcast_ref::<ValidationError<String>>() {
+    let config_module =
+        Valid::from(
+            config_module.map_err(|e| match e.downcast_ref::<ValidationError<String>>() {
                 Some(err) => err.clone(),
                 None => ValidationError::new(e.to_string()),
-            }
-        }))
-    })
-    .and_then(|cfgs| {
-        let mut cfgs = cfgs.into_iter();
-        let config_module = cfgs.next().expect("At least one config should be defined");
-
-        cfgs.fold(Valid::succeed(config_module.clone()), |acc, c| {
-            acc.and_then(|acc| acc.unify(c.clone()))
-        })
-    })
-    // Apply required transformers to the configuration
-    .and_then(|cfg| cfg.transform(Required));
+            }),
+        )
+        // Apply required transformers to the configuration
+        .and_then(|cfg| cfg.transform(Required));
 
     // check sdl error if any
     if is_sdl_error(&spec, config_module.clone()).await {
         return;
     }
 
-    let merged = config_module.to_result().unwrap().to_sdl();
+    let config_module = config_module.to_result().unwrap();
+    let merged = config_module.to_sdl();
 
     let formatter = tailcall_prettier::format(merged, &Parser::Gql)
         .await
@@ -245,34 +228,25 @@ async fn test_spec(spec: ExecutionSpec) {
 
     insta::assert_snapshot!(snapshot_name, formatter);
 
-    let config_modules = config_modules
-        .into_iter()
-        .collect::<Result<Vec<_>, _>>()
-        .unwrap();
-
     check_identity(&spec, &reader_ctx).await;
 
     // client: Check if client spec matches snapshot
-    if config_modules.len() == 1 {
-        let config = &config_modules[0];
-
-        let client = print_schema(
-            (Blueprint::try_from(config)
-                .context(format!("file: {}", spec.path.to_str().unwrap()))
-                .unwrap())
-            .to_schema(),
-        );
-
-        let formatted = tailcall_prettier::format(client, &Parser::Gql)
-            .await
-            .unwrap();
-        let snapshot_name = format!("{}_client", spec.safe_name);
-
-        insta::assert_snapshot!(snapshot_name, formatted);
-    }
+    let client = print_schema(
+        (Blueprint::try_from(&config_module)
+            .context(format!("file: {}", spec.path.to_str().unwrap()))
+            .unwrap())
+        .to_schema(),
+    );
+
+    let formatted = tailcall_prettier::format(client, &Parser::Gql)
+        .await
+        .unwrap();
+    let snapshot_name = format!("{}_client", spec.safe_name);
+
+    insta::assert_snapshot!(snapshot_name, formatted);
 
     // run query tests
-    run_query_tests_on_spec(spec, config_modules, mock_http_client).await;
+    run_query_tests_on_spec(spec, &config_module, mock_http_client).await;
 }
 
 pub async fn load_and_test_execution_spec(path: &Path) -> anyhow::Result<()> {