diff --git a/go.mod b/go.mod
index af6d842..426549c 100644
--- a/go.mod
+++ b/go.mod
@@ -4,6 +4,7 @@ go 1.19
 
 require (
 	github.com/go-playground/validator/v10 v10.11.1
+	github.com/pkg/errors v0.9.1
 	github.com/senseyeio/duration v0.0.0-20180430131211-7c2a214ada46
 	github.com/stretchr/testify v1.7.0
 	k8s.io/apimachinery v0.25.1
diff --git a/go.sum b/go.sum
index a82bf18..9657239 100644
--- a/go.sum
+++ b/go.sum
@@ -30,6 +30,8 @@ github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
 github.com/leodido/go-urn v1.2.1 h1:BqpAaACuzVSgi/VLzGZIobT2z4v53pjosyNd9Yv6n/w=
 github.com/leodido/go-urn v1.2.1/go.mod h1:zt4jvISO2HfUBqxjfIshjdMTYS56ZS/qv49ictyFfxY=
 github.com/pkg/diff v0.0.0-20210226163009-20ebb0f2a09e/go.mod h1:pJLUxLENpZxwdsKMEsNbx1VGcRFpLqf3715MtcvvzbA=
+github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
+github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/rogpeppe/go-internal v1.6.1/go.mod h1:xXDCJY+GAPziupqXw64V24skbSoqbTEfhy4qGm1nDQc=
diff --git a/hack/conv/main.go b/hack/conv/main.go
new file mode 100644
index 0000000..e70e738
--- /dev/null
+++ b/hack/conv/main.go
@@ -0,0 +1,128 @@
+// Copyright 2022 The Serverless Workflow Specification 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 main
+
+import (
+	"encoding/json"
+	"errors"
+	"log"
+	"os"
+	"path"
+	"path/filepath"
+	"strings"
+
+	"gopkg.in/yaml.v3"
+
+	"github.com/serverlessworkflow/sdk-go/v2/test"
+)
+
+func convert(i interface{}) interface{} {
+	switch x := i.(type) {
+	case map[interface{}]interface{}:
+		m2 := map[string]interface{}{}
+		for k, v := range x {
+			m2[k.(string)] = convert(v)
+		}
+		return m2
+	case []interface{}:
+		for i, v := range x {
+			x[i] = convert(v)
+		}
+	}
+	return i
+}
+
+func transform(
+	files []string,
+	srcFormat string,
+	destFormat string,
+	unmarshal func(data []byte, out interface{}) error,
+	marshal func(in interface{}) ([]byte, error),
+) {
+	for _, srcFile := range files {
+		if !strings.HasSuffix(srcFile, srcFormat) {
+			log.Printf("%s is not %s format, skip it", srcFile, srcFormat)
+			continue
+		}
+
+		destFile := srcFile[0:len(srcFile)-len(srcFormat)] + destFormat
+		if _, err := os.Stat(destFile); err == nil {
+			log.Printf("ERR: the target file %v exists, skip it", destFile)
+			continue
+		} else if !errors.Is(err, os.ErrNotExist) {
+			log.Printf("ERR: stat target file %v, %v, skip it", destFile, err)
+			continue
+		}
+
+		srcData, err := os.ReadFile(filepath.Clean(srcFile))
+		if err != nil {
+			log.Printf("ERR: cannot read file %v, %v, skip it", srcFile, err)
+			continue
+		}
+
+		var srcObj interface{}
+		err = unmarshal(srcData, &srcObj)
+		if err != nil {
+			log.Printf("ERR: cannot unmarshal file %v to %s, %v, skip it", srcFile, srcFormat, err)
+			continue
+		}
+
+		destObj := convert(srcObj)
+		destData, err := marshal(destObj)
+		if err != nil {
+			log.Printf("ERR: cannot marshal fild %v data to %v, %v, skip it", srcFile, destFormat, err)
+			continue
+		}
+
+		err = os.WriteFile(destFile, destData, 0600)
+		if err != nil {
+			log.Printf("ERR: cannot write to file %v, %v, skip it", destFile, err)
+			continue
+		}
+
+		log.Printf("convert %v to %v done", srcFile, destFile)
+	}
+}
+
+func main() {
+	// TODO: make this as argument
+	dir := path.Join(test.CurrentProjectPath(), "parser", "testdata", "workflows", "urifiles")
+	dirEntries, err := os.ReadDir(dir)
+	if err != nil {
+		panic(err)
+	}
+
+	files := make([]string, 0, len(dirEntries))
+	for _, entry := range dirEntries {
+		if entry.IsDir() {
+			log.Printf("%s is directory, skip it", entry.Name())
+			continue
+		}
+
+		files = append(files, path.Join(dir, entry.Name()))
+	}
+
+	log.Printf("found %v files", len(files))
+
+	// First, convert all json format files to yaml
+	log.Printf("start to convert all json format files to yaml format")
+	transform(files, ".json", ".yaml", json.Unmarshal, yaml.Marshal)
+
+	// Second, convert all yaml format files to json
+	log.Printf("start to convert all yaml format files to json format")
+	transform(files, ".yaml", ".json", yaml.Unmarshal, func(in interface{}) ([]byte, error) {
+		return json.MarshalIndent(in, "", "    ")
+	})
+}
diff --git a/model/util.go b/model/util.go
index 1cfd08b..31f711b 100644
--- a/model/util.go
+++ b/model/util.go
@@ -21,6 +21,8 @@ import (
 	"os"
 	"path/filepath"
 	"strings"
+
+	"sigs.k8s.io/yaml"
 )
 
 const prefix = "file:/"
@@ -49,6 +51,17 @@ func getBytesFromFile(s string) (b []byte, err error) {
 	if b, err = os.ReadFile(filepath.Clean(s)); err != nil {
 		return nil, err
 	}
+
+	// TODO: optimize this
+	// NOTE: In specification, we can declared independently definitions with another file format, so
+	// we must convert independently yaml source to json format data before unmarshal.
+	if strings.HasSuffix(s, ".yaml") || strings.HasSuffix(s, ".yml") {
+		b, err = yaml.YAMLToJSON(b)
+		if err != nil {
+			return nil, err
+		}
+	}
+
 	return b, nil
 }
 
diff --git a/parser/testdata/workflows/applicationrequest-issue103.json b/parser/testdata/workflows/applicationrequest-issue103.json
new file mode 100644
index 0000000..9b8c0a2
--- /dev/null
+++ b/parser/testdata/workflows/applicationrequest-issue103.json
@@ -0,0 +1,79 @@
+{
+  "id": "applicantrequest",
+  "version": "1.0",
+  "name": "Applicant Request Decision Workflow",
+  "description": "Determine if applicant request is valid",
+  "start": "CheckApplication",
+  "specVersion": "0.7",
+  "auth": "./testdata/workflows/urifiles/auth.yaml",
+  "functions": [
+    {
+      "name": "sendRejectionEmailFunction",
+      "operation": "http://myapis.org/applicationapi.json#emailRejection"
+    }
+  ],
+  "retries": [
+    {
+      "name": "TimeoutRetryStrategy",
+      "delay": "PT1M",
+      "maxAttempts": "5"
+    }
+  ],
+  "states": [
+    {
+      "name": "CheckApplication",
+      "type": "switch",
+      "dataConditions": [
+        {
+          "condition": "${ .applicants | .age >= 18 }",
+          "transition": {
+            "nextState": "StartApplication"
+          }
+        },
+        {
+          "condition": "${ .applicants | .age < 18 }",
+          "transition": {
+            "nextState": "RejectApplication"
+          }
+        }
+      ],
+      "default": {
+        "transition": {
+          "nextState": "RejectApplication"
+        }
+      }
+    },
+    {
+      "name": "StartApplication",
+      "type": "operation",
+      "actions": [
+        {
+          "subFlowRef": {
+            "workflowId": "startApplicationWorkflowId"
+          }
+        }
+      ],
+      "end": {
+        "terminate": true
+      }
+    },
+    {
+      "name": "RejectApplication",
+      "type": "operation",
+      "actionMode": "sequential",
+      "actions": [
+        {
+          "functionRef": {
+            "refName": "sendRejectionEmailFunction",
+            "parameters": {
+              "applicant": "${ .applicant }"
+            }
+          }
+        }
+      ],
+      "end": {
+        "terminate": true
+      }
+    }
+  ]
+}
\ No newline at end of file
diff --git a/parser/testdata/workflows/urifiles/auth.yaml b/parser/testdata/workflows/urifiles/auth.yaml
new file mode 100644
index 0000000..14ba4e2
--- /dev/null
+++ b/parser/testdata/workflows/urifiles/auth.yaml
@@ -0,0 +1,23 @@
+# Copyright 2022 The Serverless Workflow Specification 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.
+
+- name: testAuth
+  properties:
+    token: test_token
+  scheme: bearer
+- name: testAuth2
+  properties:
+    password: test_pwd
+    username: test_user
+  scheme: basic
diff --git a/test/path.go b/test/path.go
new file mode 100644
index 0000000..e9ff5e4
--- /dev/null
+++ b/test/path.go
@@ -0,0 +1,53 @@
+// Copyright 2022 The Serverless Workflow Specification 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 test
+
+import (
+	"os"
+	"path/filepath"
+	"runtime"
+
+	"github.com/pkg/errors"
+)
+
+// CurrentProjectPath get the project root path
+func CurrentProjectPath() string {
+	path := currentFilePath()
+
+	ppath, err := filepath.Abs(filepath.Join(filepath.Dir(path), "../"))
+	if err != nil {
+		panic(errors.Wrapf(err, "Get current project path with %s failed", path))
+	}
+
+	f, err := os.Stat(ppath)
+	if err != nil {
+		panic(errors.Wrapf(err, "Stat project path %v failed", ppath))
+	}
+
+	if f.Mode()&os.ModeSymlink != 0 {
+		fpath, err := os.Readlink(ppath)
+		if err != nil {
+			panic(errors.Wrapf(err, "Readlink from path %v failed", fpath))
+		}
+		ppath = fpath
+	}
+
+	return ppath
+}
+
+func currentFilePath() string {
+	_, file, _, _ := runtime.Caller(1)
+	return file
+}
diff --git a/test/path_test.go b/test/path_test.go
new file mode 100644
index 0000000..4ccb672
--- /dev/null
+++ b/test/path_test.go
@@ -0,0 +1,31 @@
+// Copyright 2022 The Serverless Workflow Specification 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 test
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestCurrentProjectPath(t *testing.T) {
+	t.Run("normal test", func(t *testing.T) {
+		path := CurrentProjectPath()
+
+		// NOTE: the '/code' path is used with code pipeline.
+		// When code running in the pipeline, the codebase will copy to /home/code directory.
+		assert.Regexp(t, "(/sdk-go$)|(/code$)", path)
+	})
+}