diff --git a/boomer_test.go b/boomer_test.go
index 5d2e18a2..bc587297 100644
--- a/boomer_test.go
+++ b/boomer_test.go
@@ -12,17 +12,17 @@ func TestBoomerStandaloneRun(t *testing.T) {
 			BaseURL: "http://httpbin.org",
 		},
 		TestSteps: []IStep{
-			Step("headers").
+			NewStep("headers").
 				GET("/headers").
 				Validate().
 				AssertEqual("status_code", 200, "check status code").
 				AssertEqual("headers.\"Content-Type\"", "application/json", "check http response Content-Type"),
-			Step("user-agent").
+			NewStep("user-agent").
 				GET("/user-agent").
 				Validate().
 				AssertEqual("status_code", 200, "check status code").
 				AssertEqual("headers.\"Content-Type\"", "application/json", "check http response Content-Type"),
-			Step("TestCase3").CallRefCase(&TestCase{Config: TConfig{Name: "TestCase3"}}),
+			NewStep("TestCase3").CallRefCase(&TestCase{Config: TConfig{Name: "TestCase3"}}),
 		},
 	}
 	testcase2 := &TestCasePath{demoTestCaseJSONPath}
diff --git a/examples/demo_test.go b/examples/demo_test.go
index 22fd2f77..768ed470 100644
--- a/examples/demo_test.go
+++ b/examples/demo_test.go
@@ -20,7 +20,7 @@ var demoTestCase = &hrp.TestCase{
 		},
 	},
 	TestSteps: []hrp.IStep{
-		hrp.Step("get with params").
+		hrp.NewStep("get with params").
 			WithVariables(map[string]interface{}{ // step level variables
 				"n":       3,                // inherit config level variables if not set in step level, a/varFoo1
 				"b":       34.5,             // override config level variable if existed, n/b/varFoo2
@@ -37,7 +37,7 @@ var demoTestCase = &hrp.TestCase{
 			AssertLengthEqual("body.args.foo1", 5, "check args foo1").            // validate response body with jmespath
 			AssertLengthEqual("$varFoo1", 5, "check args foo1").                  // assert with extracted variable from current step
 			AssertEqual("body.args.foo2", "34.5", "check args foo2"),             // notice: request params value will be converted to string
-		hrp.Step("post json data").
+		hrp.NewStep("post json data").
 			POST("/post").
 			WithBody(map[string]interface{}{
 				"foo1": "$varFoo1",       // reference former extracted variable
@@ -47,7 +47,7 @@ var demoTestCase = &hrp.TestCase{
 			AssertEqual("status_code", 200, "check status code").
 			AssertLengthEqual("body.json.foo1", 5, "check args foo1").
 			AssertEqual("body.json.foo2", 12.3, "check args foo2"),
-		hrp.Step("post form data").
+		hrp.NewStep("post form data").
 			POST("/post").
 			WithHeaders(map[string]string{"Content-Type": "application/x-www-form-urlencoded; charset=UTF-8"}).
 			WithBody(map[string]interface{}{
diff --git a/examples/extract_test.go b/examples/extract_test.go
index 7f3891bf..b5555663 100644
--- a/examples/extract_test.go
+++ b/examples/extract_test.go
@@ -15,7 +15,7 @@ func TestCaseExtractStepSingle(t *testing.T) {
 			Verify:  false,
 		},
 		TestSteps: []hrp.IStep{
-			hrp.Step("get with params").
+			hrp.NewStep("get with params").
 				WithVariables(map[string]interface{}{
 					"var1":               "bar1",
 					"agent":              "HttpRunnerPlus",
@@ -52,7 +52,7 @@ func TestCaseExtractStepAssociation(t *testing.T) {
 			Verify:  false,
 		},
 		TestSteps: []hrp.IStep{
-			hrp.Step("get with params").
+			hrp.NewStep("get with params").
 				WithVariables(map[string]interface{}{
 					"var1":  "bar1",
 					"agent": "HttpRunnerPlus",
@@ -71,7 +71,7 @@ func TestCaseExtractStepAssociation(t *testing.T) {
 				AssertEqual("$varFoo1", "bar1", "check args foo1").
 				AssertEqual("body.args.foo2", "bar2", "check args foo2").
 				AssertEqual("body.headers.\"user-agent\"", "HttpRunnerPlus", "check header user agent"),
-			hrp.Step("post json data").
+			hrp.NewStep("post json data").
 				POST("/post").
 				WithHeaders(map[string]string{"User-Agent": "HttpRunnerPlus"}).
 				WithBody(map[string]interface{}{"foo1": "bar1", "foo2": "bar2"}).
diff --git a/examples/function_test.go b/examples/function_test.go
index 2ae4d642..946c8a1b 100644
--- a/examples/function_test.go
+++ b/examples/function_test.go
@@ -19,7 +19,7 @@ func TestCaseCallFunction(t *testing.T) {
 			},
 		},
 		TestSteps: []hrp.IStep{
-			hrp.Step("get with params").
+			hrp.NewStep("get with params").
 				GET("/get").
 				WithParams(map[string]interface{}{"foo1": "${gen_random_string($n)}", "foo2": "${max($a, $b)}"}).
 				WithHeaders(map[string]string{"User-Agent": "HttpRunnerPlus"}).
@@ -29,7 +29,7 @@ func TestCaseCallFunction(t *testing.T) {
 				AssertEqual("status_code", 200, "check status code").
 				AssertLengthEqual("body.args.foo1", 5, "check args foo1").
 				AssertEqual("body.args.foo2", "12.3", "check args foo2"), // notice: request params value will be converted to string
-			hrp.Step("post json data with functions").
+			hrp.NewStep("post json data with functions").
 				POST("/post").
 				WithHeaders(map[string]string{"User-Agent": "HttpRunnerPlus"}).
 				WithBody(map[string]interface{}{"foo1": "${gen_random_string($n)}", "foo2": "${max($a, $b)}"}).
diff --git a/examples/request_test.go b/examples/request_test.go
index a17047a5..43a8f417 100644
--- a/examples/request_test.go
+++ b/examples/request_test.go
@@ -14,7 +14,7 @@ func TestCaseBasicRequest(t *testing.T) {
 			Verify:  false,
 		},
 		TestSteps: []hrp.IStep{
-			hrp.Step("get with params").
+			hrp.NewStep("get with params").
 				GET("/get").
 				WithParams(map[string]interface{}{"foo1": "bar1", "foo2": "bar2"}).
 				WithHeaders(map[string]string{
@@ -26,7 +26,7 @@ func TestCaseBasicRequest(t *testing.T) {
 				AssertEqual("headers.\"Content-Type\"", "application/json; charset=utf-8", "check header Content-Type").
 				AssertEqual("body.args.foo1", "bar1", "check args foo1").
 				AssertEqual("body.args.foo2", "bar2", "check args foo2"),
-			hrp.Step("post raw text").
+			hrp.NewStep("post raw text").
 				POST("/post").
 				WithHeaders(map[string]string{
 					"User-Agent":   "HttpRunnerPlus",
@@ -36,7 +36,7 @@ func TestCaseBasicRequest(t *testing.T) {
 				Validate().
 				AssertEqual("status_code", 200, "check status code").
 				AssertEqual("body.data", "This is expected to be sent back as part of response body.", "check data"),
-			hrp.Step("post form data").
+			hrp.NewStep("post form data").
 				POST("/post").
 				WithHeaders(map[string]string{
 					"User-Agent":   "HttpRunnerPlus",
@@ -47,7 +47,7 @@ func TestCaseBasicRequest(t *testing.T) {
 				AssertEqual("status_code", 200, "check status code").
 				AssertEqual("body.form.foo1", "bar1", "check form foo1").
 				AssertEqual("body.form.foo2", "bar2", "check form foo2"),
-			hrp.Step("post json data").
+			hrp.NewStep("post json data").
 				POST("/post").
 				WithHeaders(map[string]string{
 					"User-Agent": "HttpRunnerPlus",
@@ -57,7 +57,7 @@ func TestCaseBasicRequest(t *testing.T) {
 				AssertEqual("status_code", 200, "check status code").
 				AssertEqual("body.json.foo1", "bar1", "check json foo1").
 				AssertEqual("body.json.foo2", "bar2", "check json foo2"),
-			hrp.Step("put request").
+			hrp.NewStep("put request").
 				PUT("/put").
 				WithHeaders(map[string]string{
 					"User-Agent":   "HttpRunnerPlus",
diff --git a/examples/validate_test.go b/examples/validate_test.go
index 17f768ca..e1ddb45e 100644
--- a/examples/validate_test.go
+++ b/examples/validate_test.go
@@ -14,7 +14,7 @@ func TestCaseValidateStep(t *testing.T) {
 			Verify:  false,
 		},
 		TestSteps: []hrp.IStep{
-			hrp.Step("get with params").
+			hrp.NewStep("get with params").
 				WithVariables(map[string]interface{}{
 					"var1":               "bar1",
 					"agent":              "HttpRunnerPlus",
@@ -32,7 +32,7 @@ func TestCaseValidateStep(t *testing.T) {
 				AssertEqual("body.args.foo1", "bar1", "check args foo1").                                                // assert response json body with jmespath
 				AssertEqual("body.args.foo2", "bar2", "check args foo2").
 				AssertEqual("body.headers.\"user-agent\"", "HttpRunnerPlus", "check header user agent"),
-			hrp.Step("get with params").
+			hrp.NewStep("get with params").
 				WithVariables(map[string]interface{}{
 					"var1":  "bar1",
 					"agent": "HttpRunnerPlus",
diff --git a/examples/variables_test.go b/examples/variables_test.go
index 2d4f4c55..7fc70bac 100644
--- a/examples/variables_test.go
+++ b/examples/variables_test.go
@@ -19,7 +19,7 @@ func TestCaseConfigVariables(t *testing.T) {
 			Verify: false,
 		},
 		TestSteps: []hrp.IStep{
-			hrp.Step("get with params").
+			hrp.NewStep("get with params").
 				GET("/get").
 				WithParams(map[string]interface{}{"foo1": "$var1", "foo2": "bar2"}).
 				WithHeaders(map[string]string{"User-Agent": "$agent"}).
@@ -47,7 +47,7 @@ func TestCaseStepVariables(t *testing.T) {
 			Verify:  false,
 		},
 		TestSteps: []hrp.IStep{
-			hrp.Step("get with params").
+			hrp.NewStep("get with params").
 				WithVariables(map[string]interface{}{
 					"var1":               "bar1",
 					"agent":              "HttpRunnerPlus",
@@ -85,7 +85,7 @@ func TestCaseOverrideConfigVariables(t *testing.T) {
 			Verify: false,
 		},
 		TestSteps: []hrp.IStep{
-			hrp.Step("get with params").
+			hrp.NewStep("get with params").
 				WithVariables(map[string]interface{}{
 					"var1":  "bar1",   // override config variable
 					"agent": "$agent", // reference config variable
@@ -125,7 +125,7 @@ func TestCaseParseVariables(t *testing.T) {
 			},
 		},
 		TestSteps: []hrp.IStep{
-			hrp.Step("get with params").
+			hrp.NewStep("get with params").
 				WithVariables(map[string]interface{}{
 					"n":       3,
 					"b":       34.5,
@@ -140,7 +140,7 @@ func TestCaseParseVariables(t *testing.T) {
 				AssertEqual("status_code", 200, "check status code").
 				AssertLengthEqual("body.args.foo1", 5, "check args foo1").
 				AssertEqual("body.args.foo2", "34.5", "check args foo2"), // notice: request params value will be converted to string
-			hrp.Step("post json data with functions").
+			hrp.NewStep("post json data with functions").
 				POST("/post").
 				WithHeaders(map[string]string{"User-Agent": "HttpRunnerPlus"}).
 				WithBody(map[string]interface{}{"foo1": "${gen_random_string($n)}", "foo2": "${max($a, $b)}"}).
diff --git a/runner.go b/runner.go
index e143b6d8..dc9206ff 100644
--- a/runner.go
+++ b/runner.go
@@ -20,17 +20,18 @@ import (
 	"github.com/httprunner/hrp/internal/ga"
 )
 
-// run API test with default configs
+// Run starts to run API test with default configs.
 func Run(testcases ...ITestCase) error {
 	t := &testing.T{}
 	return NewRunner(t).SetDebug(true).Run(testcases...)
 }
 
-func NewRunner(t *testing.T) *Runner {
+// NewRunner constructs a new runner instance.
+func NewRunner(t *testing.T) *runner {
 	if t == nil {
 		t = &testing.T{}
 	}
-	return &Runner{
+	return &runner{
 		t:     t,
 		debug: false, // default to turn off debug
 		client: &http.Client{
@@ -43,20 +44,22 @@ func NewRunner(t *testing.T) *Runner {
 	}
 }
 
-type Runner struct {
+type runner struct {
 	t                *testing.T
 	debug            bool
 	client           *http.Client
 	sessionVariables map[string]interface{}
 }
 
-func (r *Runner) SetDebug(debug bool) *Runner {
+// SetDebug configures whether to log HTTP request and response content.
+func (r *runner) SetDebug(debug bool) *runner {
 	log.Info().Bool("debug", debug).Msg("[init] SetDebug")
 	r.debug = debug
 	return r
 }
 
-func (r *Runner) SetProxyUrl(proxyUrl string) *Runner {
+// SetProxyUrl configures the proxy URL, which is usually used to capture HTTP packets for debugging.
+func (r *runner) SetProxyUrl(proxyUrl string) *runner {
 	log.Info().Str("proxyUrl", proxyUrl).Msg("[init] SetProxyUrl")
 	p, err := url.Parse(proxyUrl)
 	if err != nil {
@@ -70,7 +73,8 @@ func (r *Runner) SetProxyUrl(proxyUrl string) *Runner {
 	return r
 }
 
-func (r *Runner) Run(testcases ...ITestCase) error {
+// Run starts to execute one or multiple testcases.
+func (r *runner) Run(testcases ...ITestCase) error {
 	event := ga.EventTracking{
 		Category: "RunAPITests",
 		Action:   "hrp run",
@@ -94,7 +98,7 @@ func (r *Runner) Run(testcases ...ITestCase) error {
 	return nil
 }
 
-func (r *Runner) runCase(testcase *TestCase) error {
+func (r *runner) runCase(testcase *TestCase) error {
 	config := &testcase.Config
 	if err := r.parseConfig(config); err != nil {
 		return err
@@ -113,7 +117,7 @@ func (r *Runner) runCase(testcase *TestCase) error {
 	return nil
 }
 
-func (r *Runner) runStep(step IStep, config *TConfig) (stepResult *stepData, err error) {
+func (r *runner) runStep(step IStep, config *TConfig) (stepResult *stepData, err error) {
 	log.Info().Str("step", step.name()).Msg("run step start")
 
 	// copy step to avoid data racing
@@ -170,7 +174,7 @@ func (r *Runner) runStep(step IStep, config *TConfig) (stepResult *stepData, err
 	return
 }
 
-func (r *Runner) runStepRequest(step *TStep) (stepResult *stepData, err error) {
+func (r *runner) runStepRequest(step *TStep) (stepResult *stepData, err error) {
 	stepResult = &stepData{
 		name:           step.Name,
 		success:        false,
@@ -335,7 +339,7 @@ func (r *Runner) runStepRequest(step *TStep) (stepResult *stepData, err error) {
 	return
 }
 
-func (r *Runner) runStepTestCase(step *TStep) (stepResult *stepData, err error) {
+func (r *runner) runStepTestCase(step *TStep) (stepResult *stepData, err error) {
 	stepResult = &stepData{
 		name:    step.Name,
 		success: false,
@@ -345,7 +349,7 @@ func (r *Runner) runStepTestCase(step *TStep) (stepResult *stepData, err error)
 	return
 }
 
-func (r *Runner) parseConfig(config *TConfig) error {
+func (r *runner) parseConfig(config *TConfig) error {
 	// parse config variables
 	parsedVariables, err := parseVariables(config.Variables)
 	if err != nil {
@@ -371,7 +375,7 @@ func (r *Runner) parseConfig(config *TConfig) error {
 	return nil
 }
 
-func (r *Runner) GetSummary() *testCaseSummary {
+func (r *runner) getSummary() *testCaseSummary {
 	return &testCaseSummary{}
 }
 
diff --git a/runner_test.go b/runner_test.go
index 72476dde..cd48eec4 100644
--- a/runner_test.go
+++ b/runner_test.go
@@ -11,17 +11,17 @@ func TestHttpRunner(t *testing.T) {
 			BaseURL: "http://httpbin.org",
 		},
 		TestSteps: []IStep{
-			Step("headers").
+			NewStep("headers").
 				GET("/headers").
 				Validate().
 				AssertEqual("status_code", 200, "check status code").
 				AssertEqual("headers.\"Content-Type\"", "application/json", "check http response Content-Type"),
-			Step("user-agent").
+			NewStep("user-agent").
 				GET("/user-agent").
 				Validate().
 				AssertEqual("status_code", 200, "check status code").
 				AssertEqual("headers.\"Content-Type\"", "application/json", "check http response Content-Type"),
-			Step("TestCase3").CallRefCase(&TestCase{Config: TConfig{Name: "TestCase3"}}),
+			NewStep("TestCase3").CallRefCase(&TestCase{Config: TConfig{Name: "TestCase3"}}),
 		},
 	}
 	testcase2 := &TestCase{
diff --git a/step.go b/step.go
index d86fa897..53d35c21 100644
--- a/step.go
+++ b/step.go
@@ -2,7 +2,8 @@ package hrp
 
 import "fmt"
 
-func Step(name string) *step {
+// NewStep returns a new constructed teststep with specified step name.
+func NewStep(name string) *step {
 	return &step{
 		TStep: &TStep{
 			Name:      name,
diff --git a/step_test.go b/step_test.go
index 40206391..fc7db698 100644
--- a/step_test.go
+++ b/step_test.go
@@ -5,7 +5,7 @@ import (
 )
 
 var (
-	stepGET = Step("get with params").
+	stepGET = NewStep("get with params").
 		GET("/get").
 		WithParams(map[string]interface{}{"foo1": "bar1", "foo2": "bar2"}).
 		WithHeaders(map[string]string{"User-Agent": "HttpRunnerPlus"}).
@@ -16,7 +16,7 @@ var (
 		AssertEqual("headers.\"Content-Type\"", "application/json; charset=utf-8", "check header Content-Type").
 		AssertEqual("body.args.foo1", "bar1", "check param foo1").
 		AssertEqual("body.args.foo2", "bar2", "check param foo2")
-	stepPOSTData = Step("post form data").
+	stepPOSTData = NewStep("post form data").
 			POST("/post").
 			WithParams(map[string]interface{}{"foo1": "bar1", "foo2": "bar2"}).
 			WithHeaders(map[string]string{"User-Agent": "HttpRunnerPlus", "Content-Type": "application/x-www-form-urlencoded"}).