diff --git a/Cargo.lock b/Cargo.lock
index 5853fb3b..260da48c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -607,7 +607,9 @@ name = "cozo-node"
 version = "0.5.0"
 dependencies = [
  "cozo",
+ "crossbeam",
  "lazy_static",
+ "miette",
  "neon",
 ]
 
diff --git a/cozo-lib-nodejs/Cargo.toml b/cozo-lib-nodejs/Cargo.toml
index afb789ce..017593a4 100644
--- a/cozo-lib-nodejs/Cargo.toml
+++ b/cozo-lib-nodejs/Cargo.toml
@@ -42,6 +42,8 @@ io-uring = ["cozo/io-uring"]
 [dependencies]
 cozo = { version = "0.5.0", path = "../cozo-core", default-features = false }
 lazy_static = "1.4.0"
+crossbeam = "0.8.2"
+miette = "5.5.0"
 
 [dependencies.neon]
 version = "0.10"
diff --git a/cozo-lib-nodejs/build_linux.sh b/cozo-lib-nodejs/build_linux.sh
deleted file mode 100755
index 30f7183d..00000000
--- a/cozo-lib-nodejs/build_linux.sh
+++ /dev/null
@@ -1,7 +0,0 @@
-#!/usr/bin/env bash
-
-rm -fr native
-mkdir -p native/6
-cross build --target=x86_64-unknown-linux-gnu --release
-mv target/x86_64-unknown-linux-gnu/release/libcozo_node.so native/6/index.node
-npm run package
diff --git a/cozo-lib-nodejs/build_mac.sh b/cozo-lib-nodejs/build_mac.sh
deleted file mode 100755
index 63a0b4c9..00000000
--- a/cozo-lib-nodejs/build_mac.sh
+++ /dev/null
@@ -1,7 +0,0 @@
-#!/usr/bin/env bash
-
-rm -fr native
-mkdir -p native/6
-cargo build --release
-mv target/release/libcozo_node.dylib native/6/index.node
-yarn package
diff --git a/cozo-lib-nodejs/build_win.ps1 b/cozo-lib-nodejs/build_win.ps1
deleted file mode 100644
index 223109dd..00000000
--- a/cozo-lib-nodejs/build_win.ps1
+++ /dev/null
@@ -1,9 +0,0 @@
-$ErrorActionPreference="Stop"
-
-if (test-path native/6/index.node) {
-    Remove-Item native/6/index.node
-}
-
-cargo build --release
-cp target/release/cozo_node.dll native/6/index.node
-yarn package
diff --git a/cozo-lib-nodejs/example.js b/cozo-lib-nodejs/example.js
index d12d1511..e021117c 100644
--- a/cozo-lib-nodejs/example.js
+++ b/cozo-lib-nodejs/example.js
@@ -6,14 +6,47 @@
  * You can obtain one at https://mozilla.org/MPL/2.0/.
  */
 
+const {Buffer} = require('node:buffer')
 const {CozoDb} = require('.');
 
 (async () => {
     const db = new CozoDb()
     try {
-        const result = await db.run('?[a] <- [["hello"], ["world"]]');
+        const result = await db.run('?[a] <- [["hello"], ["world"], [$b]]', {b: Buffer.alloc(8, 255)});
         console.log(result.rows)
     } catch (e) {
         console.error(e)
     }
-})()
\ No newline at end of file
+    const cb_id = db.register_callback('test', (op, new_rows, old_rows) => {
+        console.log(`${op} ${JSON.stringify(new_rows)} ${JSON.stringify(old_rows)}`)
+    })
+
+    await db.run(`?[a] <- [[1],[2],[3]] :create test {a}`);
+
+    db.register_named_rule('Pipipy', 1, async (inputs, options) => {
+        console.log(`rule inputs: ${JSON.stringify(inputs)} ${JSON.stringify(options)}`)
+        await sleep(1000);
+        return inputs[0].map((row) => [row[0] * options.mul])
+    })
+
+    try {
+        let r = await db.run(`
+        rel[] <- [[1],[2]]
+        
+        ?[a] <~ Pipipy(rel[], mul: 3)
+        `);
+        console.log(r);
+    } catch (e) {
+        console.error(e.display);
+    }
+    db.unregister_callback(cb_id)
+    db.unregister_named_rule('Pipipy')
+})()
+
+function sleep(ms) {
+    return new Promise((resolve, reject) => {
+        setTimeout(() => {
+            resolve()
+        }, ms);
+    })
+}
\ No newline at end of file
diff --git a/cozo-lib-nodejs/index.js b/cozo-lib-nodejs/index.js
index 9feb8a89..4eb97d77 100644
--- a/cozo-lib-nodejs/index.js
+++ b/cozo-lib-nodejs/index.js
@@ -22,13 +22,12 @@ class CozoDb {
 
     run(script, params) {
         return new Promise((resolve, reject) => {
-            const params_str = JSON.stringify(params || {})
-            native.query_db(this.db_id, script, params_str, (result_str) => {
-                const result = JSON.parse(result_str);
-                if (result.ok) {
-                    resolve(result)
+            params = params || {};
+            native.query_db(this.db_id, script, params, (err, result) => {
+                if (err) {
+                    reject(JSON.parse(err))
                 } else {
-                    reject(result)
+                    resolve(result)
                 }
             })
         })
@@ -100,6 +99,36 @@ class CozoDb {
             })
         })
     }
+
+    register_callback(relation, cb, capacity = -1) {
+        return native.register_callback(this.db_id, relation, cb, capacity)
+    }
+
+    unregister_callback(cb_id) {
+        return native.unregister_callback(this.db_id, cb_id)
+    }
+
+    register_named_rule(name, arity, cb) {
+        return native.register_named_rule(this.db_id, name, arity, async (ret_id, inputs, options) => {
+            let ret = undefined;
+            try {
+                ret = await cb(inputs, options);
+            } catch (e) {
+                console.error(e);
+                native.respond_to_named_rule_invocation(ret_id, '' + e);
+                return;
+            }
+            try {
+                native.respond_to_named_rule_invocation(ret_id, ret);
+            } catch (e) {
+                console.error(e);
+            }
+        })
+    }
+
+    unregister_named_rule(name) {
+        return native.unregister_named_rule(this.db_id, name)
+    }
 }
 
 module.exports = {CozoDb: CozoDb}
diff --git a/cozo-lib-nodejs/src/lib.rs b/cozo-lib-nodejs/src/lib.rs
index ddc2e81d..b2ed97fb 100644
--- a/cozo-lib-nodejs/src/lib.rs
+++ b/cozo-lib-nodejs/src/lib.rs
@@ -8,16 +8,185 @@
 use std::collections::BTreeMap;
 use std::sync::atomic::{AtomicU32, Ordering};
 use std::sync::{Arc, Mutex};
+use std::thread;
 
+use crossbeam::channel::Sender;
 use lazy_static::lazy_static;
+use miette::{miette, Result};
 use neon::prelude::*;
+use neon::types::buffer::TypedArray;
 
 use cozo::*;
 
+fn rows2js<'a>(cx: &mut impl Context<'a>, rows: &[Vec<DataValue>]) -> JsResult<'a, JsArray> {
+    let coll = cx.empty_array();
+    for (j, row) in rows.iter().enumerate() {
+        let cur = cx.empty_array();
+        for (i, el) in row.iter().enumerate() {
+            let el = value2js(cx, el)?;
+            cur.set(cx, i as u32, el)?;
+        }
+        coll.set(cx, j as u32, cur)?;
+    }
+    Ok(coll)
+}
+
+fn named_rows2js<'a>(cx: &mut impl Context<'a>, nr: &NamedRows) -> JsResult<'a, JsObject> {
+    let ret = cx.empty_object();
+    if let Some(rows) = &nr.next {
+        let converted = named_rows2js(cx, rows)?;
+        ret.set(cx, "next", converted)?;
+    };
+    let headers = cx.empty_array();
+    for (i, header) in nr.headers.iter().enumerate() {
+        let converted = cx.string(header);
+        headers.set(cx, i as u32, converted)?;
+    }
+    ret.set(cx, "headers", headers)?;
+    let rows = rows2js(cx, &nr.rows)?;
+    ret.set(cx, "rows", rows)?;
+    Ok(ret)
+}
+
+fn js2value<'a>(
+    cx: &mut impl Context<'a>,
+    val: Handle<'a, JsValue>,
+    coll: &mut DataValue,
+) -> JsResult<'a, JsUndefined> {
+    if let Ok(_) = val.downcast::<JsNull, _>(cx) {
+        *coll = DataValue::Null;
+    } else if let Ok(n) = val.downcast::<JsNumber, _>(cx) {
+        let n = n.value(cx);
+        *coll = DataValue::from(n);
+    } else if let Ok(b) = val.downcast::<JsBoolean, _>(cx) {
+        let b = b.value(cx);
+        *coll = DataValue::from(b);
+    } else if let Ok(_) = val.downcast::<JsUndefined, _>(cx) {
+        *coll = DataValue::Null;
+    } else if let Ok(s) = val.downcast::<JsString, _>(cx) {
+        let s = s.value(cx);
+        *coll = DataValue::Str(s.into());
+    } else if let Ok(l) = val.downcast::<JsArray, _>(cx) {
+        let n = l.len(cx);
+        let mut ret = Vec::with_capacity(n as usize);
+        for i in 0..n {
+            let v: Handle<JsValue> = l.get(cx, i)?;
+            let mut target = DataValue::Bot;
+            js2value(cx, v, &mut target)?;
+            ret.push(target);
+        }
+        *coll = DataValue::List(ret);
+    } else if let Ok(b) = val.downcast::<JsBuffer, _>(cx) {
+        let d = b.as_slice(cx);
+        *coll = DataValue::Bytes(d.to_vec());
+    } else {
+        let err = cx.string("Javascript value cannot be converted.");
+        return cx.throw(err);
+    }
+    Ok(cx.undefined())
+}
+
+fn value2js<'a>(cx: &mut impl Context<'a>, val: &DataValue) -> JsResult<'a, JsValue> {
+    Ok(match val {
+        DataValue::Null => cx.null().as_value(cx),
+        DataValue::Bool(b) => cx.boolean(*b).as_value(cx),
+        DataValue::Num(n) => match n {
+            Num::Int(i) => cx.number(*i as f64).as_value(cx),
+            Num::Float(f) => cx.number(*f).as_value(cx),
+        },
+        DataValue::Str(s) => cx.string(s).as_value(cx),
+        DataValue::Bytes(b) => {
+            let b = b.clone();
+            JsBuffer::external(cx, b).as_value(cx)
+        }
+        DataValue::Uuid(uuid) => cx.string(uuid.0.to_string()).as_value(cx),
+        DataValue::Regex(rx) => cx.string(rx.0.to_string()).as_value(cx),
+        DataValue::List(l) => {
+            let target_l = cx.empty_array();
+            for (i, el) in l.iter().enumerate() {
+                let el = value2js(cx, el)?;
+                target_l.set(cx, i as u32, el)?;
+            }
+            target_l.as_value(cx)
+        }
+        DataValue::Set(l) => {
+            let target_l = cx.empty_array();
+            for (i, el) in l.iter().enumerate() {
+                let el = value2js(cx, el)?;
+                target_l.set(cx, i as u32, el)?;
+            }
+            target_l.as_value(cx)
+        }
+        DataValue::Validity(vld) => {
+            let target_l = cx.empty_array();
+            let ts = cx.number(vld.timestamp.0 .0 as f64);
+            target_l.set(cx, 0, ts)?;
+            let a = cx.boolean(vld.is_assert.0);
+            target_l.set(cx, 1, a)?;
+            target_l.as_value(cx)
+        }
+        DataValue::Bot => cx.undefined().as_value(cx),
+    })
+}
+
+fn js2params<'a>(
+    cx: &mut impl Context<'a>,
+    js_params: Handle<'a, JsObject>,
+    collector: &mut BTreeMap<String, DataValue>,
+) -> JsResult<'a, JsUndefined> {
+    let keys = js_params.get_own_property_names(cx)?;
+    let n_keys = keys.len(cx);
+    for i in 0..n_keys {
+        let key: Handle<JsString> = keys.get(cx, i)?;
+        let key_str = key.value(cx);
+        let val: Handle<JsValue> = js_params.get(cx, key)?;
+        let mut value = DataValue::Bot;
+        js2value(cx, val, &mut value)?;
+        collector.insert(key_str, value);
+    }
+    Ok(cx.undefined())
+}
+
+fn js2rows<'a>(
+    cx: &mut impl Context<'a>,
+    rows: Handle<'a, JsArray>,
+    collector: &mut Vec<Vec<DataValue>>,
+) -> JsResult<'a, JsUndefined> {
+    let n_rows = rows.len(cx);
+    collector.reserve(n_rows as usize);
+    for i in 0..n_rows {
+        let row = rows.get::<JsArray, _, _>(cx, i)?;
+        let n_cols = row.len(cx);
+        let mut ret_row = Vec::with_capacity(n_cols as usize);
+        for j in 0..n_cols {
+            let col = row.get::<JsValue, _, _>(cx, j)?;
+            let mut val = DataValue::Bot;
+            js2value(cx, col, &mut val)?;
+            ret_row.push(val);
+        }
+        collector.push(ret_row);
+    }
+    Ok(cx.undefined())
+}
+
+fn params2js<'a>(
+    cx: &mut impl Context<'a>,
+    params: &BTreeMap<String, DataValue>,
+) -> JsResult<'a, JsObject> {
+    let obj = cx.empty_object();
+    for (k, v) in params {
+        let val = value2js(cx, v)?;
+        obj.set(cx, k as &str, val)?;
+    }
+    Ok(obj)
+}
+
 #[derive(Default)]
 struct Handles {
     current: AtomicU32,
     dbs: Mutex<BTreeMap<u32, Arc<DbInstance>>>,
+    cb_idx: AtomicU32,
+    current_cbs: Mutex<BTreeMap<u32, Sender<Result<NamedRows>>>>,
 }
 
 lazy_static! {
@@ -51,37 +220,54 @@ fn close_db(mut cx: FunctionContext) -> JsResult<JsBoolean> {
     Ok(cx.boolean(db.is_some()))
 }
 
-fn query_db(mut cx: FunctionContext) -> JsResult<JsUndefined> {
-    let id = cx.argument::<JsNumber>(0)?.value(&mut cx) as u32;
-    let db = {
-        let db_ref = {
-            let dbs = HANDLES.dbs.lock().unwrap();
-            dbs.get(&id).cloned()
-        };
-        match db_ref {
-            None => {
-                let s = cx.string("database already closed");
-                cx.throw(s)?
+macro_rules! get_db {
+    ($cx:expr) => {{
+        let id = $cx.argument::<JsNumber>(0)?.value(&mut $cx) as u32;
+        let db = {
+            let db_ref = {
+                let dbs = HANDLES.dbs.lock().unwrap();
+                dbs.get(&id).cloned()
+            };
+            match db_ref {
+                None => {
+                    let s = $cx.string("database already closed");
+                    $cx.throw(s)?
+                }
+                Some(db) => db,
             }
-            Some(db) => db,
-        }
-    };
+        };
+        db
+    }};
+}
 
+fn query_db(mut cx: FunctionContext) -> JsResult<JsUndefined> {
+    let db = get_db!(cx);
     let query = cx.argument::<JsString>(1)?.value(&mut cx);
-    let params = cx.argument::<JsString>(2)?.value(&mut cx);
+    let params_js = cx.argument::<JsObject>(2)?;
+    let mut params = BTreeMap::new();
+    js2params(&mut cx, params_js, &mut params)?;
 
     let callback = cx.argument::<JsFunction>(3)?.root(&mut cx);
 
     let channel = cx.channel();
 
-    std::thread::spawn(move || {
-        let result = db.run_script_str(&query, &params);
+    thread::spawn(move || {
+        let result = db.run_script(&query, params);
         channel.send(move |mut cx| {
             let callback = callback.into_inner(&mut cx);
             let this = cx.undefined();
-            let json_str = cx.string(result);
-            callback.call(&mut cx, this, vec![json_str.upcast()])?;
-
+            match result {
+                Ok(nr) => {
+                    let js_vals = named_rows2js(&mut cx, &nr)?.as_value(&mut cx);
+                    let err = cx.undefined().as_value(&mut cx);
+                    callback.call(&mut cx, this, vec![err, js_vals])?;
+                }
+                Err(err) => {
+                    let reports = format_error_as_json(err, Some(&query)).to_string();
+                    let err = cx.string(&reports).as_value(&mut cx);
+                    callback.call(&mut cx, this, vec![err])?;
+                }
+            }
             Ok(())
         });
     });
@@ -90,28 +276,12 @@ fn query_db(mut cx: FunctionContext) -> JsResult<JsUndefined> {
 }
 
 fn backup_db(mut cx: FunctionContext) -> JsResult<JsUndefined> {
-    let id = cx.argument::<JsNumber>(0)?.value(&mut cx) as u32;
-    let db = {
-        let db_ref = {
-            let dbs = HANDLES.dbs.lock().unwrap();
-            dbs.get(&id).cloned()
-        };
-        match db_ref {
-            None => {
-                let s = cx.string("database already closed");
-                cx.throw(s)?
-            }
-            Some(db) => db,
-        }
-    };
-
+    let db = get_db!(cx);
     let path = cx.argument::<JsString>(1)?.value(&mut cx);
-
     let callback = cx.argument::<JsFunction>(2)?.root(&mut cx);
-
     let channel = cx.channel();
 
-    std::thread::spawn(move || {
+    thread::spawn(move || {
         let result = db.backup_db_str(&path);
         channel.send(move |mut cx| {
             let callback = callback.into_inner(&mut cx);
@@ -127,28 +297,12 @@ fn backup_db(mut cx: FunctionContext) -> JsResult<JsUndefined> {
 }
 
 fn restore_db(mut cx: FunctionContext) -> JsResult<JsUndefined> {
-    let id = cx.argument::<JsNumber>(0)?.value(&mut cx) as u32;
-    let db = {
-        let db_ref = {
-            let dbs = HANDLES.dbs.lock().unwrap();
-            dbs.get(&id).cloned()
-        };
-        match db_ref {
-            None => {
-                let s = cx.string("database already closed");
-                cx.throw(s)?
-            }
-            Some(db) => db,
-        }
-    };
-
+    let db = get_db!(cx);
     let path = cx.argument::<JsString>(1)?.value(&mut cx);
-
     let callback = cx.argument::<JsFunction>(2)?.root(&mut cx);
-
     let channel = cx.channel();
 
-    std::thread::spawn(move || {
+    thread::spawn(move || {
         let result = db.restore_backup_str(&path);
         channel.send(move |mut cx| {
             let callback = callback.into_inner(&mut cx);
@@ -164,28 +318,12 @@ fn restore_db(mut cx: FunctionContext) -> JsResult<JsUndefined> {
 }
 
 fn export_relations(mut cx: FunctionContext) -> JsResult<JsUndefined> {
-    let id = cx.argument::<JsNumber>(0)?.value(&mut cx) as u32;
-    let db = {
-        let db_ref = {
-            let dbs = HANDLES.dbs.lock().unwrap();
-            dbs.get(&id).cloned()
-        };
-        match db_ref {
-            None => {
-                let s = cx.string("database already closed");
-                cx.throw(s)?
-            }
-            Some(db) => db,
-        }
-    };
-
+    let db = get_db!(cx);
     let rels = cx.argument::<JsString>(1)?.value(&mut cx);
-
     let callback = cx.argument::<JsFunction>(2)?.root(&mut cx);
-
     let channel = cx.channel();
 
-    std::thread::spawn(move || {
+    thread::spawn(move || {
         let result = db.export_relations_str(&rels);
         channel.send(move |mut cx| {
             let callback = callback.into_inner(&mut cx);
@@ -201,28 +339,12 @@ fn export_relations(mut cx: FunctionContext) -> JsResult<JsUndefined> {
 }
 
 fn import_relations(mut cx: FunctionContext) -> JsResult<JsUndefined> {
-    let id = cx.argument::<JsNumber>(0)?.value(&mut cx) as u32;
-    let db = {
-        let db_ref = {
-            let dbs = HANDLES.dbs.lock().unwrap();
-            dbs.get(&id).cloned()
-        };
-        match db_ref {
-            None => {
-                let s = cx.string("database already closed");
-                cx.throw(s)?
-            }
-            Some(db) => db,
-        }
-    };
-
+    let db = get_db!(cx);
     let data = cx.argument::<JsString>(1)?.value(&mut cx);
-
     let callback = cx.argument::<JsFunction>(2)?.root(&mut cx);
-
     let channel = cx.channel();
 
-    std::thread::spawn(move || {
+    thread::spawn(move || {
         let result = db.import_relations_str(&data);
         channel.send(move |mut cx| {
             let callback = callback.into_inner(&mut cx);
@@ -238,28 +360,12 @@ fn import_relations(mut cx: FunctionContext) -> JsResult<JsUndefined> {
 }
 
 fn import_from_backup(mut cx: FunctionContext) -> JsResult<JsUndefined> {
-    let id = cx.argument::<JsNumber>(0)?.value(&mut cx) as u32;
-    let db = {
-        let db_ref = {
-            let dbs = HANDLES.dbs.lock().unwrap();
-            dbs.get(&id).cloned()
-        };
-        match db_ref {
-            None => {
-                let s = cx.string("database already closed");
-                cx.throw(s)?
-            }
-            Some(db) => db,
-        }
-    };
-
+    let db = get_db!(cx);
     let data = cx.argument::<JsString>(1)?.value(&mut cx);
-
     let callback = cx.argument::<JsFunction>(2)?.root(&mut cx);
-
     let channel = cx.channel();
 
-    std::thread::spawn(move || {
+    thread::spawn(move || {
         let result = db.import_from_backup_str(&data);
         channel.send(move |mut cx| {
             let callback = callback.into_inner(&mut cx);
@@ -274,6 +380,131 @@ fn import_from_backup(mut cx: FunctionContext) -> JsResult<JsUndefined> {
     Ok(cx.undefined())
 }
 
+fn register_callback(mut cx: FunctionContext) -> JsResult<JsNumber> {
+    let db = get_db!(cx);
+    let name = cx.argument::<JsString>(1)?.value(&mut cx);
+    let capacity = cx.argument::<JsNumber>(3)?.value(&mut cx);
+    let capacity = if capacity < 0. {
+        None
+    } else {
+        Some(capacity as usize)
+    };
+    let callback = Arc::new(cx.argument::<JsFunction>(2)?.root(&mut cx));
+    let channel = cx.channel();
+
+    let (rid, recv) = db.register_callback(&name, capacity);
+    thread::spawn(move || {
+        for (op, new, old) in recv {
+            let cb = callback.clone();
+            channel.send(move |mut cx| {
+                let callback = cb.to_inner(&mut cx);
+                let op = cx.string(op.as_str()).as_value(&mut cx);
+                let new = rows2js(&mut cx, &new.rows)?.as_value(&mut cx);
+                let old = rows2js(&mut cx, &old.rows)?.as_value(&mut cx);
+                let this = cx.undefined();
+
+                callback.call(&mut cx, this, vec![op, new, old])?;
+                Ok(())
+            });
+        }
+    });
+    Ok(cx.number(rid))
+}
+
+fn unregister_callback(mut cx: FunctionContext) -> JsResult<JsBoolean> {
+    let db = get_db!(cx);
+    let id = cx.argument::<JsNumber>(1)?.value(&mut cx) as u32;
+    let removed = db.unregister_callback(id);
+    Ok(cx.boolean(removed))
+}
+
+fn register_named_rule(mut cx: FunctionContext) -> JsResult<JsUndefined> {
+    let db = get_db!(cx);
+    let name = cx.argument::<JsString>(1)?.value(&mut cx);
+    let arity = cx.argument::<JsNumber>(2)?.value(&mut cx) as usize;
+    let callback = Arc::new(cx.argument::<JsFunction>(3)?.root(&mut cx));
+    let channel = cx.channel();
+    let (rule_impl, recv) = SimpleFixedRule::rule_with_channel(arity);
+    if let Err(err) = db.register_fixed_rule(name, rule_impl) {
+        let msg = cx.string(err.to_string());
+        return cx.throw(msg);
+    }
+    thread::spawn(move || {
+        for (inputs, options, sender) in recv {
+            let id = HANDLES.cb_idx.fetch_add(1, Ordering::AcqRel);
+            {
+                HANDLES.current_cbs.lock().unwrap().insert(id, sender);
+            }
+            let cb = callback.clone();
+            channel.send(move |mut cx| {
+                let callback = cb.to_inner(&mut cx);
+                let inputs_js = cx.empty_array();
+                for (i, input) in inputs.into_iter().enumerate() {
+                    let input_js = rows2js(&mut cx, &input.rows)?;
+                    inputs_js.set(&mut cx, i as u32, input_js)?;
+                }
+                let inputs_js = inputs_js.as_value(&mut cx);
+                let options_js = params2js(&mut cx, &options)?.as_value(&mut cx);
+                let this = cx.undefined();
+                let ret_id = cx.number(id).as_value(&mut cx);
+                callback.call(&mut cx, this, vec![ret_id, inputs_js, options_js])?;
+
+                Ok(())
+            });
+        }
+    });
+
+    Ok(cx.undefined())
+}
+
+fn respond_to_named_rule_invocation(mut cx: FunctionContext) -> JsResult<JsUndefined> {
+    let ret_id = cx.argument::<JsNumber>(0)?.value(&mut cx) as u32;
+    let sender = {
+        match HANDLES.current_cbs.lock().unwrap().remove(&ret_id) {
+            None => {
+                let msg = cx.string("fixed rule invocation sender should only be used once");
+                return cx.throw(msg);
+            }
+            Some(s) => s,
+        }
+    };
+
+    let send_err = |err| {
+        let _ = sender.send(Err(miette!("Javascript fixed rule failed")));
+        err
+    };
+
+    let payload = cx.argument::<JsValue>(1)?;
+    if let Ok(msg) = payload.downcast::<JsString, _>(&mut cx) {
+        let _ = sender.send(Err(miette!(msg.value(&mut cx))));
+        return Ok(cx.undefined())
+    }
+
+    let data = payload.downcast_or_throw(&mut cx).map_err(send_err)?;
+    let mut rows = vec![];
+    js2rows(&mut cx, data, &mut rows).map_err(send_err)?;
+    let nr = NamedRows::new(vec![], rows);
+    if let Err(err) = sender.send(Ok(nr)) {
+        let msg = err.to_string();
+        let msg = cx.string(msg);
+        return cx.throw(msg);
+    }
+    Ok(cx.undefined())
+}
+
+fn unregister_named_rule(mut cx: FunctionContext) -> JsResult<JsBoolean> {
+    let db = get_db!(cx);
+    let name = cx.argument::<JsString>(1)?.value(&mut cx);
+    let removed = match db.unregister_fixed_rule(&name) {
+        Ok(b) => b,
+        Err(msg) => {
+            let msg = cx.string(msg.to_string());
+            return cx.throw(msg);
+        }
+    };
+    Ok(cx.boolean(removed))
+}
+
 #[neon::main]
 fn main(mut cx: ModuleContext) -> NeonResult<()> {
     cx.export_function("open_db", open_db)?;
@@ -284,5 +515,13 @@ fn main(mut cx: ModuleContext) -> NeonResult<()> {
     cx.export_function("export_relations", export_relations)?;
     cx.export_function("import_relations", import_relations)?;
     cx.export_function("import_from_backup", import_from_backup)?;
+    cx.export_function("register_callback", register_callback)?;
+    cx.export_function("unregister_callback", unregister_callback)?;
+    cx.export_function("register_named_rule", register_named_rule)?;
+    cx.export_function(
+        "respond_to_named_rule_invocation",
+        respond_to_named_rule_invocation,
+    )?;
+    cx.export_function("unregister_named_rule", unregister_named_rule)?;
     Ok(())
 }
diff --git a/cozo-lib-nodejs/test_build.sh b/cozo-lib-nodejs/test_build.sh
new file mode 100755
index 00000000..3236bb8d
--- /dev/null
+++ b/cozo-lib-nodejs/test_build.sh
@@ -0,0 +1,10 @@
+#
+# Copyright 2022, The Cozo Project Authors.
+#
+# This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0.
+# If a copy of the MPL was not distributed with this file,
+# You can obtain one at https://mozilla.org/MPL/2.0/.
+#
+
+cargo build -p cozo-node -F compact -F storage-rocksdb
+mv ../target/debug/libcozo_node.dylib native/6/cozo_node_prebuilt.node
\ No newline at end of file