diff --git a/examples/jsonplaceholder.graphql b/examples/jsonplaceholder.graphql
index 028bc1b047..3c3f040128 100644
--- a/examples/jsonplaceholder.graphql
+++ b/examples/jsonplaceholder.graphql
@@ -1,13 +1,12 @@
 schema
-  @server(port: 8000, headers: {cors: {allowOrigins: ["*"], allowHeaders: ["*"], allowMethods: [POST, GET, OPTIONS]}})
-  @upstream(baseURL: "http://jsonplaceholder.typicode.com", httpCache: true, batch: {delay: 100}) {
+  @server(port: 8000)
+  @link(src: "scripts/echo.js", type: Script)
+  @upstream(baseURL: "http://jsonplaceholder.typicode.com", httpCache: true) {
   query: Query
 }
 
 type Query {
   posts: [Post] @http(path: "/posts")
-  users: [User] @http(path: "/users")
-  user(id: Int!): User @http(path: "/users/{{.args.id}}")
 }
 
 type User {
@@ -24,5 +23,6 @@ type Post {
   userId: Int!
   title: String!
   body: String!
-  user: User @call(steps: [{query: "user", args: {id: "{{.value.userId}}"}}])
+  curId: Int! @js(name: "hello")
+  #  user: User @call(steps: [{query: "user", args: {id: "{{.value.userId}}"}}])
 }
diff --git a/examples/scripts/echo.js b/examples/scripts/echo.js
index d09ec8d429..77cdcfdb38 100644
--- a/examples/scripts/echo.js
+++ b/examples/scripts/echo.js
@@ -1,3 +1,8 @@
 function onRequest({request}) {
   return {request}
 }
+
+function hello(val) {
+  let json = JSON.parse(val)
+  return JSON.stringify(json.id)
+}
diff --git a/generated/.tailcallrc.graphql b/generated/.tailcallrc.graphql
index 9b6705faeb..383e95ca5c 100644
--- a/generated/.tailcallrc.graphql
+++ b/generated/.tailcallrc.graphql
@@ -179,7 +179,7 @@ directive @http(
 ) on FIELD_DEFINITION
 
 directive @js(
-  script: String!
+  name: String!
 ) on FIELD_DEFINITION
 
 """
@@ -667,7 +667,7 @@ enum HttpVersion {
   HTTP2
 }
 input JS {
-  script: String!
+  name: String!
 }
 input KeyValue {
   key: String!
diff --git a/generated/.tailcallrc.schema.json b/generated/.tailcallrc.schema.json
index a39e72e028..8e117c015c 100644
--- a/generated/.tailcallrc.schema.json
+++ b/generated/.tailcallrc.schema.json
@@ -749,10 +749,10 @@
     "JS": {
       "type": "object",
       "required": [
-        "script"
+        "name"
       ],
       "properties": {
-        "script": {
+        "name": {
           "type": "string"
         }
       }
diff --git a/src/blueprint/definitions.rs b/src/blueprint/definitions.rs
index 7a7fdb1991..19e5665add 100644
--- a/src/blueprint/definitions.rs
+++ b/src/blueprint/definitions.rs
@@ -500,6 +500,7 @@ pub fn to_field_definition(
         .and(update_http().trace(config::Http::trace_name().as_str()))
         .and(update_grpc(operation_type).trace(config::Grpc::trace_name().as_str()))
         .and(update_const_field().trace(config::Expr::trace_name().as_str()))
+        .and(update_js_field().trace(config::JS::trace_name().as_str()))
         .and(update_graphql(operation_type).trace(config::GraphQL::trace_name().as_str()))
         .and(update_modify().trace(config::Modify::trace_name().as_str()))
         .and(update_call(operation_type, object_name).trace(config::Call::trace_name().as_str()))
diff --git a/src/blueprint/operators/js.rs b/src/blueprint/operators/js.rs
new file mode 100644
index 0000000000..449b843fd2
--- /dev/null
+++ b/src/blueprint/operators/js.rs
@@ -0,0 +1,53 @@
+use std::sync::Arc;
+
+use crate::blueprint::*;
+use crate::config;
+use crate::config::Field;
+use crate::javascript::Runtime;
+use crate::lambda::Expression;
+use crate::try_fold::TryFold;
+use crate::valid::{Valid, ValidationError, Validator};
+
+pub struct CompileJs<'a> {
+    pub name: &'a str,
+    pub script: &'a Option<String>,
+}
+
+pub fn compile_js(inputs: CompileJs) -> Valid<Expression, String> {
+    let name = inputs.name;
+    let quickjs = rquickjs::Runtime::new().unwrap();
+    let ctx = rquickjs::Context::full(&quickjs).unwrap();
+
+    Valid::from_option(inputs.script.as_ref(), "script is required".to_string()).and_then(
+        |script| {
+            Valid::from(
+                ctx.with(|ctx| {
+                    ctx.eval::<(), &str>(script)?;
+                    Ok::<_, anyhow::Error>(())
+                })
+                .map_err(|e| ValidationError::new(e.to_string())),
+            )
+            .map(|_| {
+                Expression::Js(Arc::new(Runtime::new(
+                    name.to_string(),
+                    Script { source: script.clone(), timeout: None },
+                )))
+            })
+        },
+    )
+}
+
+pub fn update_js_field<'a>(
+) -> TryFold<'a, (&'a ConfigModule, &'a Field, &'a config::Type, &'a str), FieldDefinition, String>
+{
+    TryFold::<(&ConfigModule, &Field, &config::Type, &str), FieldDefinition, String>::new(
+        |(module, field, _, _), b_field| {
+            let Some(js) = &field.script else {
+                return Valid::succeed(b_field);
+            };
+
+            compile_js(CompileJs { script: &module.extensions.script, name: &js.name })
+                .map(|resolver| b_field.resolver(Some(resolver)))
+        },
+    )
+}
diff --git a/src/blueprint/operators/mod.rs b/src/blueprint/operators/mod.rs
index f12e64780e..166d71f219 100644
--- a/src/blueprint/operators/mod.rs
+++ b/src/blueprint/operators/mod.rs
@@ -3,6 +3,7 @@ mod expr;
 mod graphql;
 mod grpc;
 mod http;
+mod js;
 mod modify;
 mod protected;
 
@@ -11,5 +12,6 @@ pub use expr::*;
 pub use graphql::*;
 pub use grpc::*;
 pub use http::*;
+pub use js::*;
 pub use modify::*;
 pub use protected::*;
diff --git a/src/cli/mod.rs b/src/cli/mod.rs
index 497016fab9..bc3c987b93 100644
--- a/src/cli/mod.rs
+++ b/src/cli/mod.rs
@@ -1,8 +1,6 @@
 mod command;
 mod error;
 mod fmt;
-#[cfg(feature = "js")]
-pub mod javascript;
 pub mod metrics;
 pub mod server;
 mod tc;
diff --git a/src/cli/runtime/mod.rs b/src/cli/runtime/mod.rs
index b0499c6f35..6852d5ce39 100644
--- a/src/cli/runtime/mod.rs
+++ b/src/cli/runtime/mod.rs
@@ -23,7 +23,7 @@ fn init_file() -> Arc<dyn FileIO> {
 fn init_hook_http(http: Arc<impl HttpIO>, script: Option<blueprint::Script>) -> Arc<dyn HttpIO> {
     #[cfg(feature = "js")]
     if let Some(script) = script {
-        return crate::cli::javascript::init_http(http, script);
+        return crate::javascript::init_http(http, script);
     }
 
     #[cfg(not(feature = "js"))]
diff --git a/src/config/config.rs b/src/config/config.rs
index a2478f37e7..d863224f06 100644
--- a/src/config/config.rs
+++ b/src/config/config.rs
@@ -355,7 +355,7 @@ impl Field {
 
 #[derive(Serialize, Deserialize, Clone, Debug, PartialEq, Eq, schemars::JsonSchema)]
 pub struct JS {
-    pub script: String,
+    pub name: String,
 }
 
 #[derive(Serialize, Deserialize, Clone, Debug, PartialEq, Eq, schemars::JsonSchema)]
diff --git a/src/cli/javascript/js_request.rs b/src/javascript/js_request.rs
similarity index 100%
rename from src/cli/javascript/js_request.rs
rename to src/javascript/js_request.rs
diff --git a/src/cli/javascript/js_response.rs b/src/javascript/js_response.rs
similarity index 100%
rename from src/cli/javascript/js_response.rs
rename to src/javascript/js_response.rs
diff --git a/src/cli/javascript/mod.rs b/src/javascript/mod.rs
similarity index 92%
rename from src/cli/javascript/mod.rs
rename to src/javascript/mod.rs
index 8ecbb6aa40..90859b5f13 100644
--- a/src/cli/javascript/mod.rs
+++ b/src/javascript/mod.rs
@@ -20,7 +20,7 @@ pub fn init_http(
     script: blueprint::Script,
 ) -> Arc<dyn HttpIO + Sync + Send> {
     tracing::debug!("Initializing JavaScript HTTP filter: {}", script.source);
-    let script_io = Arc::new(Runtime::new(script));
+    let script_io = Arc::new(Runtime::new("onRequest".to_string(), script));
     Arc::new(RequestFilter::new(http, script_io))
 }
 
diff --git a/src/cli/javascript/request_filter.rs b/src/javascript/request_filter.rs
similarity index 96%
rename from src/cli/javascript/request_filter.rs
rename to src/javascript/request_filter.rs
index 5cb6b653d1..1bc7c04b51 100644
--- a/src/cli/javascript/request_filter.rs
+++ b/src/javascript/request_filter.rs
@@ -63,7 +63,7 @@ impl RequestFilter {
     async fn on_request(&self, mut request: reqwest::Request) -> anyhow::Result<Response<Bytes>> {
         let js_request = JsRequest::try_from(&request)?;
         let event = Event::Request(js_request);
-        let command = self.worker.call("onRequest".to_string(), event).await?;
+        let command = self.worker.call(event).await?;
         match command {
             Some(command) => match command {
                 Command::Request(js_request) => {
@@ -104,9 +104,9 @@ mod tests {
     use hyper::body::Bytes;
     use rquickjs::{Context, FromJs, IntoJs, Object, Runtime, String as JsString};
 
-    use crate::cli::javascript::request_filter::Command;
-    use crate::cli::javascript::{JsRequest, JsResponse};
     use crate::http::Response;
+    use crate::javascript::request_filter::Command;
+    use crate::javascript::{JsRequest, JsResponse};
 
     #[test]
     fn test_command_from_invalid_object() {
diff --git a/src/cli/javascript/runtime.rs b/src/javascript/runtime.rs
similarity index 55%
rename from src/cli/javascript/runtime.rs
rename to src/javascript/runtime.rs
index 3f2c5cf7b0..a5f9339371 100644
--- a/src/cli/javascript/runtime.rs
+++ b/src/javascript/runtime.rs
@@ -1,6 +1,8 @@
 use std::cell::{OnceCell, RefCell};
+use std::fmt::{Debug, Formatter};
 use std::thread;
 
+use async_graphql_value::ConstValue;
 use rquickjs::{Context, Ctx, FromJs, Function, IntoJs, Value};
 
 use super::request_filter::{Command, Event};
@@ -25,7 +27,7 @@ fn qjs_print(msg: String, is_err: bool) {
 
 fn setup_builtins(ctx: &Ctx<'_>) -> rquickjs::Result<()> {
     ctx.globals().set("__qjs_print", js_qjs_print)?;
-    let _: Value = ctx.eval_file("src/cli/javascript/shim/console.js")?;
+    let _: Value = ctx.eval_file("src/javascript/shim/console.js")?;
 
     Ok(())
 }
@@ -47,18 +49,33 @@ impl LocalRuntime {
 
 pub struct Runtime {
     script: blueprint::Script,
+    function_name: String,
     // Single threaded JS runtime, that's shared across all tokio workers.
     tokio_runtime: Option<tokio::runtime::Runtime>,
 }
 
+impl Debug for Runtime {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        write!(
+            f,
+            "Runtime {{ script: {:?}, function_name: {} }}",
+            self.script, self.function_name
+        )
+    }
+}
+
 impl Runtime {
-    pub fn new(script: blueprint::Script) -> Self {
+    pub fn new(name: String, script: blueprint::Script) -> Self {
         let tokio_runtime = tokio::runtime::Builder::new_multi_thread()
             .worker_threads(1)
             .build()
             .expect("JS runtime not initialized");
 
-        Self { script, tokio_runtime: Some(tokio_runtime) }
+        Self {
+            script,
+            function_name: name,
+            tokio_runtime: Some(tokio_runtime),
+        }
     }
 }
 
@@ -75,27 +92,13 @@ impl Drop for Runtime {
 
 #[async_trait::async_trait]
 impl WorkerIO<Event, Command> for Runtime {
-    async fn call(&self, name: String, event: Event) -> anyhow::Result<Option<Command>> {
+    async fn call(&self, event: Event) -> anyhow::Result<Option<Command>> {
         let script = self.script.clone();
+        let name = self.function_name.clone();
         if let Some(runtime) = &self.tokio_runtime {
             runtime
                 .spawn(async move {
-                    // initialize runtime if this is the first call
-                    // exit if failed to initialize
-                    LOCAL_RUNTIME.with(move |cell| {
-                        if cell.borrow().get().is_none() {
-                            LocalRuntime::try_new(script).and_then(|runtime| {
-                                cell.borrow().set(runtime).map_err(|_| {
-                                    anyhow::anyhow!(
-                                    "trying to reinitialize an already initialized QuickJS runtime"
-                                )
-                                })
-                            })
-                        } else {
-                            Ok(())
-                        }
-                    })?;
-
+                    init_rt(script)?;
                     call(name, event)
                 })
                 .await?
@@ -105,6 +108,40 @@ impl WorkerIO<Event, Command> for Runtime {
     }
 }
 
+#[async_trait::async_trait]
+impl WorkerIO<Option<ConstValue>, ConstValue> for Runtime {
+    async fn call(&self, input: Option<ConstValue>) -> anyhow::Result<Option<ConstValue>> {
+        let script = self.script.clone();
+        let name = self.function_name.clone();
+        if let Some(runtime) = &self.tokio_runtime {
+            runtime
+                .spawn(async move {
+                    init_rt(script)?;
+                    execute_inner(name, input).map(Some)
+                })
+                .await?
+        } else {
+            anyhow::bail!("JS Runtime is stopped")
+        }
+    }
+}
+
+fn init_rt(script: blueprint::Script) -> anyhow::Result<()> {
+    // initialize runtime if this is the first call
+    // exit if failed to initialize
+    LOCAL_RUNTIME.with(move |cell| {
+        if cell.borrow().get().is_none() {
+            LocalRuntime::try_new(script).and_then(|runtime| {
+                cell.borrow().set(runtime).map_err(|_| {
+                    anyhow::anyhow!("trying to reinitialize an already initialized QuickJS runtime")
+                })
+            })
+        } else {
+            Ok(())
+        }
+    })
+}
+
 fn prepare_args<'js>(ctx: &Ctx<'js>, req: JsRequest) -> rquickjs::Result<(Value<'js>,)> {
     let object = rquickjs::Object::new(ctx.clone())?;
     object.set("request", req.into_js(ctx)?)?;
@@ -137,3 +174,28 @@ fn call(name: String, event: Event) -> anyhow::Result<Option<Command>> {
         })
     })
 }
+
+fn execute_inner(name: String, value: Option<ConstValue>) -> anyhow::Result<ConstValue> {
+    let value = value
+        .map(|v| serde_json::to_string(&v))
+        .ok_or(anyhow::anyhow!("No graphql value found"))??;
+
+    LOCAL_RUNTIME.with_borrow_mut(|cell| {
+        let runtime = cell
+            .get_mut()
+            .ok_or(anyhow::anyhow!("JS runtime not initialized"))?;
+        runtime.0.with(|ctx| {
+            let fn_as_value = ctx
+                .globals()
+                .get::<_, rquickjs::Function>(&name)
+                .map_err(|_| anyhow::anyhow!("globalThis not initialized"))?;
+
+            let function = fn_as_value
+                .as_function()
+                .ok_or(anyhow::anyhow!("`hello` is not a function"))?;
+            let val: String = function.call((value, ))
+                .map_err(|_| anyhow::anyhow!("unable to parse value from js function: {} maybe because it's not returning a string?", name,))?;
+            Ok::<_, anyhow::Error>(serde_json::from_str(&val)?)
+        })
+    })
+}
diff --git a/src/cli/javascript/shim/console.js b/src/javascript/shim/console.js
similarity index 100%
rename from src/cli/javascript/shim/console.js
rename to src/javascript/shim/console.js
diff --git a/src/lambda/expression.rs b/src/lambda/expression.rs
index 1b050d247b..e1bb59d7ae 100644
--- a/src/lambda/expression.rs
+++ b/src/lambda/expression.rs
@@ -8,11 +8,12 @@ use async_graphql_value::ConstValue;
 use thiserror::Error;
 
 use super::{Eval, EvaluationContext, ResolverContextLike, IO};
-use crate::auth;
 use crate::blueprint::DynamicValue;
+use crate::javascript::Runtime;
 use crate::json::JsonLike;
 use crate::lambda::cache::Cache;
 use crate::serde_value_ext::ValueExt;
+use crate::{auth, WorkerIO};
 
 #[derive(Clone, Debug)]
 pub enum Expression {
@@ -22,6 +23,7 @@ pub enum Expression {
     Cache(Cache),
     Path(Box<Expression>, Vec<String>),
     Protect(Box<Expression>),
+    Js(Arc<Runtime>),
 }
 
 impl Display for Expression {
@@ -33,6 +35,7 @@ impl Display for Expression {
             Expression::Cache(_) => write!(f, "Cache"),
             Expression::Path(_, _) => write!(f, "Input"),
             Expression::Protect(expr) => write!(f, "Protected({expr})"),
+            Expression::Js(_) => write!(f, "Js"),
         }
     }
 }
@@ -190,6 +193,10 @@ impl Eval for Expression {
                 }
                 Expression::IO(operation) => operation.eval(ctx).await,
                 Expression::Cache(cached) => cached.eval(ctx).await,
+                Expression::Js(js) => {
+                    let val = js.call(ctx.value().cloned()).await?;
+                    Ok(val.unwrap_or(async_graphql::Value::Null))
+                }
             }
         })
     }
diff --git a/src/lambda/modify.rs b/src/lambda/modify.rs
index afd59a3443..2ce6b96329 100644
--- a/src/lambda/modify.rs
+++ b/src/lambda/modify.rs
@@ -37,6 +37,7 @@ impl Expression {
                             })
                         }
                     },
+                    Expression::Js(_) => expr,
                     Expression::Dynamic(_) => expr,
                     Expression::IO(_) => expr,
                     Expression::Cache(Cache { expr, max_age }) => {
diff --git a/src/lib.rs b/src/lib.rs
index 6ab74992b2..a54d731180 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -20,6 +20,8 @@ pub mod grpc;
 pub mod has_headers;
 pub mod helpers;
 pub mod http;
+#[cfg(feature = "js")]
+pub mod javascript;
 pub mod json;
 pub mod lambda;
 pub mod merge_right;
@@ -85,7 +87,7 @@ pub type EntityCache = dyn Cache<Key = u64, Value = ConstValue>;
 #[async_trait::async_trait]
 pub trait WorkerIO<In, Out>: Send + Sync + 'static {
     /// Calls a global JS function
-    async fn call(&self, name: String, input: In) -> anyhow::Result<Option<Out>>;
+    async fn call(&self, input: In) -> anyhow::Result<Option<Out>>;
 }
 
 pub fn is_default<T: Default + Eq>(val: &T) -> bool {
diff --git a/src/runtime.rs b/src/runtime.rs
index fae12cd71e..1a751fa8bf 100644
--- a/src/runtime.rs
+++ b/src/runtime.rs
@@ -50,10 +50,9 @@ pub mod test {
 
     use crate::blueprint::Upstream;
     use crate::cache::InMemoryCache;
-    use crate::cli::javascript;
     use crate::http::Response;
     use crate::runtime::TargetRuntime;
-    use crate::{blueprint, EnvIO, FileIO, HttpIO};
+    use crate::{blueprint, javascript, EnvIO, FileIO, HttpIO};
 
     #[derive(Clone)]
     struct TestHttp {
diff --git a/tests/core/parse.rs b/tests/core/parse.rs
index 303744f300..2076da9dc0 100644
--- a/tests/core/parse.rs
+++ b/tests/core/parse.rs
@@ -12,11 +12,10 @@ use markdown::mdast::Node;
 use markdown::ParseOptions;
 use tailcall::blueprint::Blueprint;
 use tailcall::cache::InMemoryCache;
-use tailcall::cli::javascript;
 use tailcall::config::{ConfigModule, Source};
 use tailcall::http::AppContext;
 use tailcall::runtime::TargetRuntime;
-use tailcall::EnvIO;
+use tailcall::{javascript, EnvIO};
 
 use super::file::File;
 use super::http::Http;
diff --git a/tests/core/runtime.rs b/tests/core/runtime.rs
index 0b198a4796..f9e6125b00 100644
--- a/tests/core/runtime.rs
+++ b/tests/core/runtime.rs
@@ -6,11 +6,10 @@ use std::sync::atomic::{AtomicUsize, Ordering};
 use std::sync::Arc;
 
 use derive_setters::Setters;
-use tailcall::blueprint;
 use tailcall::cache::InMemoryCache;
-use tailcall::cli::javascript;
 use tailcall::config::Source;
 use tailcall::runtime::TargetRuntime;
+use tailcall::{blueprint, javascript};
 
 use super::env::Env;
 use super::file::TestFileIO;
diff --git a/tests/server_spec.rs b/tests/server_spec.rs
index d24fbe3387..2b3ca62614 100644
--- a/tests/server_spec.rs
+++ b/tests/server_spec.rs
@@ -13,8 +13,8 @@ pub mod test {
     use reqwest::Client;
     use reqwest_middleware::{ClientBuilder, ClientWithMiddleware};
     use tailcall::cache::InMemoryCache;
-    use tailcall::cli::javascript;
     use tailcall::http::Response;
+    use tailcall::javascript;
     use tailcall::runtime::TargetRuntime;
     use tokio::io::{AsyncReadExt, AsyncWriteExt};