diff --git a/go/engine/engine_test.go b/go/engine/engine_test.go
index c625db1..d518f85 100644
--- a/go/engine/engine_test.go
+++ b/go/engine/engine_test.go
@@ -32,11 +32,11 @@ func NewFsWrapper(path string, st *state.State) FsWrapper {
 	}
 }
 
-func(fs FsWrapper) one(ctx context.Context) (string, error) {
+func(fs FsWrapper) one(sym string, ctx context.Context) (string, error) {
 	return "one", nil
 }
 
-func(fs FsWrapper) inky(ctx context.Context) (string, error) {
+func(fs FsWrapper) inky(sym string, ctx context.Context) (string, error) {
 	return "tinkywinky", nil
 }
 
diff --git a/go/render/page.go b/go/render/page.go
index 544bf09..500e196 100644
--- a/go/render/page.go
+++ b/go/render/page.go
@@ -156,6 +156,11 @@ func(pg *Page) RenderTemplate(sym string, values map[string]string, idx uint16)
 // render menu and all syms except sink, split sink into display chunks
 func(pg *Page) prepare(sym string, values map[string]string, idx uint16) (map[string]string, error) {
 	var sink string
+
+	if pg.sizer == nil {
+		return values, nil
+	}
+
 	var sinkValues []string
 	noSinkValues := make(map[string]string)
 	for k, v := range values {
diff --git a/go/render/size_test.go b/go/render/size_test.go
index 705da79..206294e 100644
--- a/go/render/size_test.go
+++ b/go/render/size_test.go
@@ -41,19 +41,19 @@ func funcFor(sym string) (resource.EntryFunc, error) {
 	return nil, fmt.Errorf("unknown func: %s", sym)
 }
 
-func getFoo(ctx context.Context) (string, error) {
+func getFoo(sym string, ctx context.Context) (string, error) {
 	return "inky", nil
 }
 
-func getBar(ctx context.Context) (string, error) {
+func getBar(sym string, ctx context.Context) (string, error) {
 	return "pinky", nil
 }
 
-func getBaz(ctx context.Context) (string, error) {
+func getBaz(sym string, ctx context.Context) (string, error) {
 	return "blinky", nil
 }
 
-func getXyzzy(ctx context.Context) (string, error) {
+func getXyzzy(sym string, ctx context.Context) (string, error) {
 	return "inky pinky\nblinky clyde sue\ntinkywinky dipsy\nlala poo\none two three four five six seven\neight nine ten\neleven twelve", nil
 }
 
diff --git a/go/resource/fs.go b/go/resource/fs.go
index 5e88ca3..8d91039 100644
--- a/go/resource/fs.go
+++ b/go/resource/fs.go
@@ -1,6 +1,7 @@
 package resource
 
 import (
+	"context"
 	"fmt"
 	"io/ioutil"
 	"path"
@@ -11,6 +12,7 @@ import (
 type FsResource struct {
 	MenuResource
 	Path string
+	fns map[string]EntryFunc
 }
 
 func NewFsResource(path string) (FsResource) {
@@ -37,9 +39,32 @@ func(fs FsResource) GetCode(sym string) ([]byte, error) {
 }
 
 func(fs FsResource) FuncFor(sym string) (EntryFunc, error) {
-	return nil, fmt.Errorf("not implemented")
+	fn, ok := fs.fns[sym]
+	if ok {
+		return fn, nil
+	}
+	_, err := fs.getFuncNoCtx(sym)
+	if err != nil {
+		return nil, fmt.Errorf("unknown sym: %s", sym)
+	}
+	return fs.getFunc, nil
 }
 
-func(rs FsResource) String() string {
-	return fmt.Sprintf("fs resource at path: %s", rs.Path)
+func(fs FsResource) String() string {
+	return fmt.Sprintf("fs resource at path: %s", fs.Path)
+}
+
+func(fs FsResource) getFunc(sym string, ctx context.Context) (string, error) {
+	return fs.getFuncNoCtx(sym)
+}
+
+func(fs FsResource) getFuncNoCtx(sym string) (string, error) {
+	fb := sym + ".txt"
+	fp := path.Join(fs.Path, fb)
+	r, err := ioutil.ReadFile(fp)
+	if err != nil {
+		return "", fmt.Errorf("failed getting data for sym '%s': %v", sym, err)
+	}
+	s := string(r)
+	return strings.TrimSpace(s), err
 }
diff --git a/go/resource/render.go b/go/resource/render.go
deleted file mode 100644
index 9ff9923..0000000
--- a/go/resource/render.go
+++ /dev/null
@@ -1,40 +0,0 @@
-package resource
-
-//import (
-//	"bytes"
-//	"fmt"
-//	"log"
-//	"text/template"
-//)
-
-
-//// DefaultRenderTemplate is an adapter to implement the builtin golang text template renderer as resource.RenderTemplate.
-//func DefaultRenderTemplate(r Resource, sym string, values map[string]string, idx uint16, sizer *Sizer) (string, error) {
-//	v, err := r.GetTemplate(sym, nil)
-//	if err != nil {
-//		return "", err
-//	}
-//
-//	if sizer != nil {
-//		values, err = sizer.GetAt(values, idx)
-//	} else if idx > 0 {
-//		return "", fmt.Errorf("sizer needed for indexed render")
-//	}
-//	log.Printf("render for index: %v", idx)
-//
-//	if err != nil {
-//		return "", err
-//	}
-//	
-//	tp, err := template.New("tester").Option("missingkey=error").Parse(v)
-//	if err != nil {
-//		return "", err
-//	}
-//
-//	b := bytes.NewBuffer([]byte{})
-//	err = tp.Execute(b, values)
-//	if err != nil {
-//		return "", err
-//	}
-//	return b.String(), err
-//}
diff --git a/go/resource/resource.go b/go/resource/resource.go
index a739afa..3694e20 100644
--- a/go/resource/resource.go
+++ b/go/resource/resource.go
@@ -5,7 +5,7 @@ import (
 )
 
 // EntryFunc is a function signature for retrieving value for a key
-type EntryFunc func(ctx context.Context) (string, error)
+type EntryFunc func(sym string, ctx context.Context) (string, error)
 type CodeFunc func(sym string) ([]byte, error)
 type TemplateFunc func(sym string) (string, error)
 type FuncForFunc func(sym string) (EntryFunc, error)
diff --git a/go/resource/resource_test.go b/go/resource/resource_test.go
index 0a2ed92..1a100c2 100644
--- a/go/resource/resource_test.go
+++ b/go/resource/resource_test.go
@@ -26,29 +26,29 @@ func getTemplate(sym string) (string, error) {
 func funcFor(sym string) (EntryFunc, error) {
 	switch sym {
 	case "foo":
-		return getFoo, nil
+		return get, nil
 	case "bar":
-		return getBar, nil
+		return get, nil
 	case "baz":
-		return getBaz, nil
+		return get, nil
 	case "xyzzy":
 		return getXyzzy, nil
 	}
 	return nil, fmt.Errorf("unknown func: %s", sym)
 }
 
-func getFoo(ctx context.Context) (string, error) {
-	return "inky", nil
+func get(sym string, ctx context.Context) (string, error) {
+	switch sym {
+	case "foo":
+		return "inky", nil
+	case "bar":
+		return "pinky", nil
+	case "baz":
+		return "blinky", nil
+	}
+	return "", fmt.Errorf("unknown sym: %s", sym)
 }
 
-func getBar(ctx context.Context) (string, error) {
-	return "pinky", nil
-}
-
-func getBaz(ctx context.Context) (string, error) {
-	return "blinky", nil
-}
-
-func getXyzzy(ctx context.Context) (string, error) {
+func getXyzzy(sym string, ctx context.Context) (string, error) {
 	return "inky pinky\nblinky clyde sue\ntinkywinky dipsy\nlala poo\none two three four five six seven\neight nine ten\neleven twelve", nil
 }
diff --git a/go/testdata/testdata.go b/go/testdata/testdata.go
index a327407..2905572 100644
--- a/go/testdata/testdata.go
+++ b/go/testdata/testdata.go
@@ -19,7 +19,7 @@ var (
 	dirLock = false	
 )
 
-func out(sym string, b []byte, tpl string) error {
+func out(sym string, b []byte, tpl string, data map[string]string) error {
 	fp := path.Join(DataDir, sym)
 	err := ioutil.WriteFile(fp, []byte(tpl), 0644)
 	if err != nil {
@@ -32,6 +32,20 @@ func out(sym string, b []byte, tpl string) error {
 	if err != nil {
 		return err
 	}
+
+	if data == nil {
+		return nil
+	}
+
+	for k, v := range data {
+		fb := k + ".txt"
+		fp = path.Join(DataDir, fb)
+		err = ioutil.WriteFile(fp, []byte(v), 0644)
+		if err != nil {
+			return err
+		}
+	}
+
 	return nil
 }
 
@@ -45,7 +59,7 @@ func root() error {
 
 	tpl := "hello world"
 
-	return out("root", b, tpl)
+	return out("root", b, tpl, nil)
 }
 
 func foo() error {
@@ -58,11 +72,14 @@ func foo() error {
 	b = vm.NewLine(b, vm.INCMP, []string{"1", "baz"}, nil, nil)
 	b = vm.NewLine(b, vm.CATCH, []string{"_catch"}, []byte{1}, []uint8{1})
 
+	data := make(map[string]string)
+	data["inky"] = "one"
+
 	tpl := `this is in foo
 
 it has more lines`
 
-	return out("foo", b, tpl)
+	return out("foo", b, tpl, data)
 }
 
 func bar() error {
@@ -73,7 +90,10 @@ func bar() error {
 
 	tpl := "this is bar - an end node"
 
-	return out("bar", b, tpl)
+	data := make(map[string]string)
+	data["pinky"] = "two"
+
+	return out("bar", b, tpl, data)
 }
 
 func baz() error {
@@ -83,7 +103,7 @@ func baz() error {
 
 	tpl := "this is baz which uses the var {{.inky}} in the template."
 
-	return out("baz", b, tpl)
+	return out("baz", b, tpl, nil)
 }
 
 func defaultCatch() error {
@@ -94,7 +114,7 @@ func defaultCatch() error {
 
 	tpl := "invalid input"
 
-	return out("_catch", b, tpl)
+	return out("_catch", b, tpl, nil)
 }
 
 func generate() error {
diff --git a/go/vm/runner.go b/go/vm/runner.go
index 0c6d7c7..89c44fc 100644
--- a/go/vm/runner.go
+++ b/go/vm/runner.go
@@ -345,6 +345,6 @@ func refresh(key string, rs resource.Resource, ctx context.Context) (string, err
 	if fn == nil {
 		return "", fmt.Errorf("no retrieve function for external symbol %v", key)
 	}
-	return fn(ctx)
+	return fn(key, ctx)
 }
 
diff --git a/go/vm/runner_test.go b/go/vm/runner_test.go
index 5378906..d509206 100644
--- a/go/vm/runner_test.go
+++ b/go/vm/runner_test.go
@@ -20,15 +20,15 @@ type TestResource struct {
 	state *state.State
 }
 
-func getOne(ctx context.Context) (string, error) {
+func getOne(sym string, ctx context.Context) (string, error) {
 	return "one", nil
 }
 
-func getTwo(ctx context.Context) (string, error) {
+func getTwo(sym string, ctx context.Context) (string, error) {
 	return "two", nil
 }
 
-func getDyn(ctx context.Context) (string, error) {
+func getDyn(sym string, ctx context.Context) (string, error) {
 	return dynVal, nil
 }
 
@@ -69,7 +69,7 @@ func (r TestResource) FuncFor(sym string) (resource.EntryFunc, error) {
 	return nil, fmt.Errorf("invalid function: '%s'", sym)
 }
 
-func(r TestResource) getInput(ctx context.Context) (string, error) {
+func(r TestResource) getInput(sym string, ctx context.Context) (string, error) {
 	v, err := r.state.GetInput()
 	return string(v), err
 }