diff --git a/encoding/yaml/yaml.go b/encoding/yaml/yaml.go
new file mode 100644
index 0000000..3db8b08
--- /dev/null
+++ b/encoding/yaml/yaml.go
@@ -0,0 +1,100 @@
+// Copyright 2019 The CUE Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package yaml converts YAML encodings to and from CUE. When converting to CUE,
+// comments and position information are retained.
+package yaml
+
+import (
+	"bytes"
+	"io"
+
+	"cuelang.org/go/cue"
+	"cuelang.org/go/cue/ast"
+	"cuelang.org/go/internal/third_party/yaml"
+	goyaml "github.com/ghodss/yaml"
+)
+
+// TODO: replace the ghodss YAML encoder. It has a few major issues:
+//   - it does not expose the underlying error, which means we lose valuable
+//     information.
+//   - comments and other meta data are lost.
+
+// Extract parses the YAML to a CUE expression. Streams are returned as a list
+// of the streamed values.
+func Extract(filename string, src interface{}) (*ast.File, error) {
+	a := []ast.Expr{}
+	d, err := yaml.NewDecoder(filename, src)
+	if err != nil {
+		return nil, err
+	}
+	for {
+		expr, err := d.Decode()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return nil, err
+		}
+		a = append(a, expr)
+	}
+	f := &ast.File{Filename: filename}
+	switch len(a) {
+	case 0:
+	case 1:
+		switch x := a[0].(type) {
+		case *ast.StructLit:
+			f.Decls = x.Elts
+		default:
+			f.Decls = []ast.Decl{&ast.EmitDecl{Expr: x}}
+		}
+	default:
+		f.Decls = []ast.Decl{&ast.EmitDecl{Expr: &ast.ListLit{Elts: a}}}
+	}
+	return f, nil
+}
+
+// Decode converts a YAML file to a CUE value. Streams are returned as a list
+// of the streamed values.
+func Decode(r *cue.Runtime, filename string, src interface{}) (*cue.Instance, error) {
+	file, err := Extract(filename, src)
+	if err != nil {
+		return nil, err
+	}
+	return r.CompileFile(file)
+}
+
+// Encode returns the YAML encoding of v.
+func Encode(v cue.Value) ([]byte, error) {
+	b, err := goyaml.Marshal(v)
+	return b, err
+}
+
+// EncodeStream returns the YAML encoding of iter, where consecutive values
+// of iter are separated with a `---`.
+func EncodeStream(iter cue.Iterator) ([]byte, error) {
+	// TODO: return an io.Reader and allow asynchronous processing.
+	buf := &bytes.Buffer{}
+	for i := 0; iter.Next(); i++ {
+		if i > 0 {
+			buf.WriteString("---\n")
+		}
+		b, err := goyaml.Marshal(iter.Value())
+		if err != nil {
+			return nil, err
+		}
+		buf.Write(b)
+	}
+	return buf.Bytes(), nil
+}