diff --git a/src/runtime/javascript/index.ts b/src/runtime/javascript/index.ts
index 8fe50db96..702b666c3 100644
--- a/src/runtime/javascript/index.ts
+++ b/src/runtime/javascript/index.ts
@@ -138,12 +138,22 @@ function handleError (err: StructObject<PgfExnType>): void {
   }
 }
 
-function PgfText_AsString (txtPtr: Pointer<any>) {
+function PgfText_AsString (txtPtr: Pointer<any>): string {
   const txtSize = txtPtr.deref().size
   const charPtr = ref.reinterpret(txtPtr, txtSize, ref.types.size_t.size)
   return charPtr.toString('utf8')
 }
 
+function PgfText_FromString (str: string): Pointer<any> {
+  const strbuf = Buffer.from(str, 'utf8')
+  const size = strbuf.length // size in bytes, not chars
+  const sizebuf = ref.alloc(ref.types.size_t, size)
+  const txtbuf = Buffer.alloc(ref.types.size_t.size + size + 1)
+  sizebuf.copy(txtbuf, 0, 0)
+  strbuf.copy(txtbuf, ref.types.size_t.size, 0)
+  return txtbuf as Pointer<void>
+}
+
 // ----------------------------------------------------------------------------
 // PGF grammar object
 
@@ -215,20 +225,31 @@ function bootNGF (pgf_path: string, ngf_path: string): PGFGrammar {
   return new PGFGrammar(db, rev)
 }
 
+function readNGF (path: string): PGFGrammar {
+  const rev = ref.alloc(PgfRevisionPtr)
+  const err = new PgfExn
+  const db = runtime.pgf_read_ngf(path, rev, err.ref())
+  handleError(err)
+  return new PGFGrammar(db, rev)
+}
+
+function newNGF (abstract_name: string, path?: string): PGFGrammar {
+  const absname = PgfText_FromString(abstract_name)
+  const fpath = path != null ? path : null
+  const rev = ref.alloc(PgfRevisionPtr)
+  const err = new PgfExn
+  const db = runtime.pgf_new_ngf(absname, fpath, rev, err.ref())
+  handleError(err)
+  return new PGFGrammar(db, rev)
+}
+
 // ----------------------------------------------------------------------------
 // Exposed library API
 
 export default {
   PGFError,
   readPGF,
-  bootNGF
+  bootNGF,
+  readNGF,
+  newNGF
 }
-
-// ----------------------------------------------------------------------------
-// Quick testing
-
-// const gr = readPGF('../haskell/tests/basic.pgf')
-// console.log(gr)
-// console.log(gr.getAbstractName())
-// console.log(gr.getCategories())
-// console.log(gr.getFunctions())
diff --git a/src/runtime/javascript/tests/basic.test.ts b/src/runtime/javascript/tests/basic.test.ts
index 050b59036..f975b1d24 100644
--- a/src/runtime/javascript/tests/basic.test.ts
+++ b/src/runtime/javascript/tests/basic.test.ts
@@ -1,6 +1,8 @@
 import PGF, { PGFGrammar } from '../index'
 import fs from 'fs'
 
+// ----------------------------------------------------------------------------
+
 describe('readPGF', () => {
   test('valid', () => {
     PGF.readPGF('../haskell/tests/basic.pgf')
@@ -18,13 +20,21 @@ describe('readPGF', () => {
     }).toThrow(PGF.PGFError)
   })
 
-  // test('NGF', () => {
-  //   expect(() => {
-  //     PGF.readPGF('basic.ngf')
-  //   }).toThrow(PGF.PGFError)
-  // })
+  test('NGF', () => {
+    try {
+      fs.unlinkSync('./basic.ngf')
+    } catch {
+      // empty
+    }
+    PGF.bootNGF('../haskell/tests/basic.pgf', './basic.ngf')
+    expect(() => {
+      PGF.readPGF('./basic.ngf')
+    }).toThrow(PGF.PGFError)
+  })
 })
 
+// ----------------------------------------------------------------------------
+
 describe('bootNGF', () => {
   beforeAll(() => {
     try {
@@ -63,6 +73,71 @@ describe('bootNGF', () => {
   })
 })
 
+// ----------------------------------------------------------------------------
+
+describe('readNGF', () => {
+  // beforeAll(() => {
+  //   try {
+  //     fs.unlinkSync('./basic.ngf')
+  //   } catch {
+  //     // empty
+  //   }
+  // })
+
+  test('valid', () => {
+    const gr = PGF.readNGF('./basic.ngf')
+    expect(gr.getCategories().length).toBeGreaterThan(0)
+  })
+
+  test('non-existent', () => {
+    expect(() => {
+      PGF.readNGF('./abc.ngf')
+    }).toThrow(Error)
+  })
+
+  test('GF', () => {
+    expect(() => {
+      PGF.readNGF('../haskell/tests/basic.gf')
+    }).toThrow(PGF.PGFError)
+  })
+
+  test('PGF', () => {
+    expect(() => {
+      PGF.readNGF('../haskell/tests/basic.pgf')
+    }).toThrow(PGF.PGFError)
+  })
+})
+
+// ----------------------------------------------------------------------------
+
+describe('newNGF', () => {
+  beforeAll(() => {
+    try {
+      fs.unlinkSync('./empty.ngf')
+    } catch {
+      // empty
+    }
+  })
+
+  test('file', () => {
+    const gr = PGF.newNGF('empty', './empty.ngf')
+    expect(gr.getCategories().length).toBe(0)
+  })
+
+  test('memory', () => {
+    const gr = PGF.newNGF('empty')
+    expect(gr.getCategories().length).toBe(0)
+  })
+
+  test('existing', () => {
+    expect(() => {
+      PGF.newNGF('empty', './basic.ngf')
+    }).toThrow(Error)
+  })
+})
+
+// ----------------------------------------------------------------------------
+
 describe('abstract syntax', () => {
   let gr: PGFGrammar