diff --git a/entc/entc.go b/entc/entc.go
index d90995e29..68bfbb0b4 100644
--- a/entc/entc.go
+++ b/entc/entc.go
@@ -17,6 +17,7 @@ import (
 
 	"github.com/facebook/ent/entc/gen"
 	"github.com/facebook/ent/entc/load"
+	"github.com/facebook/ent/schema/field"
 )
 
 // LoadGraph loads the schema package from the given schema path,
@@ -57,6 +58,9 @@ func Generate(schemaPath string, cfg *gen.Config, options ...Option) (err error)
 		// the schema.
 		cfg.Target = filepath.Dir(abs)
 	}
+	if cfg.IDType == nil {
+		cfg.IDType = &field.TypeInfo{Type: field.TypeInt}
+	}
 	for _, opt := range options {
 		if err := opt(cfg); err != nil {
 			return err
diff --git a/entc/gen/graph.go b/entc/gen/graph.go
index 3464807fd..c9bbaa9ff 100644
--- a/entc/gen/graph.go
+++ b/entc/gen/graph.go
@@ -85,9 +85,10 @@ func NewGraph(c *Config, schemas ...*load.Schema) (g *Graph, err error) {
 func (g *Graph) Gen() (err error) {
 	defer catch(&err)
 	var (
-		written             []string
-		templates, external = g.templates()
+		written  []string
+		external []GraphTemplate
 	)
+	templates, external = g.templates()
 	for _, n := range g.Nodes {
 		path := filepath.Join(g.Config.Target, n.Package())
 		check(os.MkdirAll(path, os.ModePerm), "create dir %q", path)
@@ -402,24 +403,25 @@ func (g *Graph) typ(name string) (*Type, bool) {
 // templates returns the template.Template for the code and external templates
 // to execute on the Graph object if provided.
 func (g *Graph) templates() (*template.Template, []GraphTemplate) {
-	templates = template.Must(templates.Clone())
 	if g.Template == nil {
 		return templates, nil
 	}
-	external := make([]GraphTemplate, 0)
+	g.Template.Funcs(Funcs)
+	external := make([]GraphTemplate, 0, len(g.Template.Templates()))
 	for _, tmpl := range g.Template.Templates() {
 		name := tmpl.Name()
-		// Check that is not defined in the default templates
-		// if it's not the root.
+		// Check that the template is not defined in the default templates if it's not the root.
 		if templates.Lookup(name) == nil && !parse.IsEmptyTree(tmpl.Root) && !extendExisting(name) {
 			external = append(external, GraphTemplate{
 				Name:   name,
 				Format: snake(name) + ".go",
 			})
 		}
-		templates = template.Must(templates.AddParseTree(name, tmpl.Tree))
 	}
-	return templates, external
+	for _, tmpl := range templates.Templates() {
+		g.Template = template.Must(g.Template.AddParseTree(tmpl.Name(), tmpl.Tree))
+	}
+	return g.Template, external
 }
 
 // ModuleInfo returns the entc binary module version.
diff --git a/examples/entcpkg/ent/entc.go b/examples/entcpkg/ent/entc.go
index 50c1f1b23..c827f043f 100644
--- a/examples/entcpkg/ent/entc.go
+++ b/examples/entcpkg/ent/entc.go
@@ -8,10 +8,11 @@ package main
 
 import (
 	"log"
+	"strings"
+	"text/template"
 
 	"github.com/facebook/ent/entc"
 	"github.com/facebook/ent/entc/gen"
-	"github.com/facebook/ent/schema/field"
 )
 
 func main() {
@@ -23,7 +24,10 @@ func main() {
 
 			// Code generated by entc, DO NOT EDIT.
 		`,
-		IDType: &field.TypeInfo{Type: field.TypeInt},
+		// A usage for custom templates with external functions.
+		Template: template.Must(template.New("template").
+			Funcs(template.FuncMap{"title": strings.ToTitle}).
+			ParseFiles("template/static.tmpl")),
 	})
 	if err != nil {
 		log.Fatal("running ent codegen:", err)
diff --git a/examples/entcpkg/ent/template/static.tmpl b/examples/entcpkg/ent/template/static.tmpl
new file mode 100644
index 000000000..4c4cc86d0
--- /dev/null
+++ b/examples/entcpkg/ent/template/static.tmpl
@@ -0,0 +1,9 @@
+{{/* A template for adding additional static fields to specific types. */}}
+{{ define "model/fields/additional" }}
+	{{- /* Add static fields to the "Card" entity. */}}
+	{{- if eq $.Name "User" }}
+		{{- /* A usage of an external function. */ -}}
+		// StaticField defined by templates (titled {{ title "staticField" }}).
+		StaticField string `json:"static_field,omitempty"`
+	{{- end }}
+{{ end }}
\ No newline at end of file
diff --git a/examples/entcpkg/ent/user.go b/examples/entcpkg/ent/user.go
index edae26a80..8c57f1b39 100644
--- a/examples/entcpkg/ent/user.go
+++ b/examples/entcpkg/ent/user.go
@@ -19,6 +19,9 @@ type User struct {
 	config
 	// ID of the ent.
 	ID int `json:"id,omitempty"`
+
+	// StaticField defined by templates (titled STATICFIELD).
+	StaticField string `json:"static_field,omitempty"`
 }
 
 // scanValues returns the types for scanning values from sql.Rows.
diff --git a/go.mod b/go.mod
index 4f56c4774..0262fcb0d 100644
--- a/go.mod
+++ b/go.mod
@@ -26,6 +26,6 @@ require (
 	github.com/stretchr/testify v1.6.1
 	go.opencensus.io v0.22.4
 	golang.org/x/mod v0.3.0 // indirect
-	golang.org/x/sync v0.0.0-20200317015054-43a5402ce75a
-	golang.org/x/tools v0.0.0-20200615222825-6aa8f57aacd9
+	golang.org/x/sync v0.0.0-20200625203802-6e8e738ad208
+	golang.org/x/tools v0.0.0-20200904185747-39188db58858
 )
diff --git a/go.sum b/go.sum
index c8eb8168f..1a8eb9fe9 100644
--- a/go.sum
+++ b/go.sum
@@ -173,6 +173,7 @@ github.com/ugorji/go v1.1.4/go.mod h1:uQMGLiO92mf5W77hV/PUCpI3pbzQx3CRekS0kk+RGr
 github.com/xiang90/probing v0.0.0-20190116061207-43a291ad63a2/go.mod h1:UETIi67q53MR2AWcXfiuqkDkRtnGDLqkBTpCHuJHxtU=
 github.com/xordataexchange/crypt v0.0.3-0.20170626215501-b2862e3d0a77/go.mod h1:aYKd//L2LvnjZzWKhF00oedf4jCCReLcmhLdhm1A27Q=
 github.com/yuin/goldmark v1.1.27/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
+github.com/yuin/goldmark v1.2.1/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 go.etcd.io/bbolt v1.3.2/go.mod h1:IbVyRI1SCnLcuJnV2u8VeU0CEYM7e686BmAb1XKL+uU=
 go.opencensus.io v0.22.3 h1:8sGtKOrtQqkN1bp2AtX+misvLIlOmsEsNd+9NIcPEm8=
 go.opencensus.io v0.22.3/go.mod h1:yxeiOL68Rb0Xd1ddK5vPZ/oVn4vY4Ynel7k9FzqtOIw=
@@ -184,6 +185,7 @@ go.uber.org/zap v1.10.0/go.mod h1:vwi/ZaCAaUcBkycHslxD9B2zi4UTXhF60s6SWpuDF0Q=
 golang.org/x/crypto v0.0.0-20180904163835-0709b304e793/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
+golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/exp v0.0.0-20190121172915-509febef88a4/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
 golang.org/x/lint v0.0.0-20181026193005-c67002cb31c3/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=
 golang.org/x/lint v0.0.0-20190227174305-5b3e6a55c961/go.mod h1:wehouNa3lNwaWXcvxsM5YxQ5yQlVC4a0KAMCusXpPoU=
@@ -206,6 +208,7 @@ golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLL
 golang.org/x/net v0.0.0-20200202094626-16171245cfb2/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/net v0.0.0-20200226121028-0de0cce0169b/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/net v0.0.0-20200324143707-d3edc9973b7e/go.mod h1:qpuaurCH72eLCgpAm/N6yyVIVM9cpaDIP3A8BGJEC5A=
+golang.org/x/net v0.0.0-20200822124328-c89045814202/go.mod h1:/O7V0waA8r7cgGh81Ro3o1hOxt32SMVPicZroKQ2sZA=
 golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
 golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20181108010431-42b317875d0f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
@@ -216,6 +219,8 @@ golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJ
 golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20200317015054-43a5402ce75a h1:WXEvlFVvvGxCJLG6REjsT03iWnKLEWinaScsxF2Vm2o=
 golang.org/x/sync v0.0.0-20200317015054-43a5402ce75a/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20200625203802-6e8e738ad208 h1:qwRHBd0NqMbJxfbotnDhm2ByMI1Shq4Y6oRJo21SGJA=
+golang.org/x/sync v0.0.0-20200625203802-6e8e738ad208/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20180830151530-49385e6e1522/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20180905080454-ebe1bf3edb33/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20181107165924-66b7b1311ac8/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
@@ -236,12 +241,16 @@ golang.org/x/tools v0.0.0-20190311212946-11955173bddd/go.mod h1:LCzVGOaR6xXOjkQ3
 golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/tools v0.0.0-20200615222825-6aa8f57aacd9 h1:cwgUY+1ja2qxWb2dyaCoixaA66WGWmrijSlxaM+JM/g=
 golang.org/x/tools v0.0.0-20200615222825-6aa8f57aacd9/go.mod h1:EkVYQZoAsY45+roYkvgYkIh4xh/qjgUK9TdY2XT94GE=
+golang.org/x/tools v0.0.0-20200904185747-39188db58858 h1:xLt+iB5ksWcZVxqc+g9K41ZHy+6MKWfXCDsjSThnsPA=
+golang.org/x/tools v0.0.0-20200904185747-39188db58858/go.mod h1:Cj7w3i3Rnn0Xh82ur9kSqwfTHTeVxaDqrfMjpcNT6bE=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7 h1:9zdDQZ7Thm29KFXgAX/+yaf3eVbP7djjWp/dXAppNCc=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898 h1:/atklqdjdhuosWIl6AIbOeHJjicWYPqR9bpxqxYG2pA=
 golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543 h1:E7g+9GITq07hpfrRu66IVDexMakfv52eLZ2CXBWiKr4=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 h1:go1bK/D/BFZV2I8cIQd1NKEZ+0owSTG1fDTci4IqFcE=
+golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 google.golang.org/appengine v1.1.0/go.mod h1:EbEs0AVv82hx2wNQdGPgUI5lhzA/G0D9YwlJXL52JkM=
 google.golang.org/appengine v1.4.0 h1:/wp5JvzpHIxhs/dumFmF7BXTf3Z+dd4uXta4kVyO508=
 google.golang.org/appengine v1.4.0/go.mod h1:xpcJRLb0r/rnEns0DIKYYv+WjYCduHsrkT7/EB5XEv4=