diff --git a/docs/examples.md b/docs/examples.md
index eeb75b2..71e7707 100644
--- a/docs/examples.md
+++ b/docs/examples.md
@@ -824,19 +824,19 @@ quiet: true
 **Basic Docker usage:**
 
 ```sh
-docker run --rm aykhans/sarin -U http://example.com -r 1000 -c 10
+docker run -it --rm aykhans/sarin -U http://example.com -r 1000 -c 10
 ```
 
 **With local config file:**
 
 ```sh
-docker run --rm -v $(pwd)/config.yaml:/config.yaml aykhans/sarin -f /config.yaml
+docker run -it --rm -v $(pwd)/config.yaml:/config.yaml aykhans/sarin -f /config.yaml
 ```
 
 **With remote config file:**
 
 ```sh
-docker run --rm aykhans/sarin -f https://example.com/config.yaml
+docker run -it --rm aykhans/sarin -f https://example.com/config.yaml
 ```
 
 **Interactive mode with TTY:**
diff --git a/docs/templating.md b/docs/templating.md
index 4ff3e49..8b2173e 100644
--- a/docs/templating.md
+++ b/docs/templating.md
@@ -98,16 +98,16 @@ sarin -U http://example.com/users \
 | `strings_Truncate(s string, n int)`                        | Truncate to `n` characters with ellipsis                            | `{{ strings_Truncate "hello world" 5 }}` → `hello...`     |
 | `strings_TrimPrefix(s string, prefix string)`              | Remove prefix from string                                           | `{{ strings_TrimPrefix "hello" "he" }}` → `llo`           |
 | `strings_TrimSuffix(s string, suffix string)`              | Remove suffix from string                                           | `{{ strings_TrimSuffix "hello" "lo" }}` → `hel`           |
-| `strings_Join(sep string, values ...string)`               | Join strings with separator                                         | `{{ strings_Join "-" "a" "b" "c" }}` → `a-b-c`            |
 
 ### Collection Functions
 
-| Function                      | Description                                   | Example                                      |
-| ----------------------------- | --------------------------------------------- | -------------------------------------------- |
-| `dict_Str(pairs ...string)`   | Create string dictionary from key-value pairs | `{{ dict_Str "key1" "val1" "key2" "val2" }}` |
-| `slice_Str(values ...string)` | Create string slice                           | `{{ slice_Str "a" "b" "c" }}`                |
-| `slice_Int(values ...int)`    | Create int slice                              | `{{ slice_Int 1 2 3 }}`                      |
-| `slice_Uint(values ...uint)`  | Create uint slice                             | `{{ slice_Uint 1 2 3 }}`                     |
+| Function                                 | Description                                   | Example                                                  |
+| ---------------------------------------- | --------------------------------------------- | -------------------------------------------------------- |
+| `dict_Str(pairs ...string)`              | Create string dictionary from key-value pairs | `{{ dict_Str "key1" "val1" "key2" "val2" }}`             |
+| `slice_Str(values ...string)`            | Create string slice                           | `{{ slice_Str "a" "b" "c" }}`                            |
+| `slice_Join(slice []string, sep string)` | Join string slice with separator              | `{{ slice_Join (slice_Str "a" "b" "c") "-" }}` → `a-b-c` |
+| `slice_Int(values ...int)`               | Create int slice                              | `{{ slice_Int 1 2 3 }}`                                  |
+| `slice_Uint(values ...uint)`             | Create uint slice                             | `{{ slice_Uint 1 2 3 }}`                                 |
 
 ### Body Functions
 
diff --git a/internal/config/cli.go b/internal/config/cli.go
index 47aa8e6..0dd5895 100644
--- a/internal/config/cli.go
+++ b/internal/config/cli.go
@@ -71,7 +71,6 @@ func (arg *stringSliceArg) Set(value string) error {
 
 // Parse parses command-line arguments into a Config object.
 // It can return the following errors:
-// - types.ErrCLINoArgs
 // - types.CLIUnexpectedArgsError
 // - types.FieldParseErrors
 func (parser ConfigCLIParser) Parse() (*Config, error) {
@@ -178,12 +177,6 @@ func (parser ConfigCLIParser) Parse() (*Config, error) {
 		panic(err)
 	}
 
-	// Check if no flags were set and no non-flag arguments were provided.
-	// This covers cases where `sarin` is run without any meaningful arguments.
-	if flagSet.NFlag() == 0 && len(flagSet.Args()) == 0 {
-		return nil, types.ErrCLINoArgs
-	}
-
 	// Check for any unexpected non-flag arguments remaining after parsing.
 	if args := flagSet.Args(); len(args) > 0 {
 		return nil, types.NewCLIUnexpectedArgsError(args)
diff --git a/internal/config/config.go b/internal/config/config.go
index a70bfb5..f96c902 100644
--- a/internal/config/config.go
+++ b/internal/config/config.go
@@ -536,12 +536,6 @@ func ReadAllConfigs() *Config {
 	cliParser := NewConfigCLIParser(os.Args)
 	cliConf, err := cliParser.Parse()
 	_ = utilsErr.MustHandle(err,
-		utilsErr.OnSentinel(types.ErrCLINoArgs, func(err error) error {
-			cliParser.PrintHelp()
-			fmt.Fprintln(os.Stderr, StyleYellow.Render("\nNo arguments provided."))
-			os.Exit(1)
-			return nil
-		}),
 		utilsErr.OnType(func(err types.CLIUnexpectedArgsError) error {
 			cliParser.PrintHelp()
 			fmt.Fprintln(os.Stderr,
diff --git a/internal/sarin/sarin.go b/internal/sarin/sarin.go
index 437665a..b3e7780 100644
--- a/internal/sarin/sarin.go
+++ b/internal/sarin/sarin.go
@@ -3,6 +3,7 @@ package sarin
 import (
 	"context"
 	"net/url"
+	"os"
 	"strconv"
 	"strings"
 	"sync"
@@ -13,6 +14,7 @@ import (
 	"github.com/charmbracelet/bubbles/spinner"
 	tea "github.com/charmbracelet/bubbletea"
 	"github.com/charmbracelet/lipgloss"
+	"github.com/charmbracelet/x/term"
 	"github.com/valyala/fasthttp"
 	"go.aykhans.me/sarin/internal/script"
 	"go.aykhans.me/sarin/internal/types"
@@ -155,6 +157,10 @@ func (q sarin) Start(ctx context.Context) {
 	var messageChannel chan runtimeMessage
 	var sendMessage messageSender
 
+	if !q.quiet && !term.IsTerminal(os.Stdout.Fd()) {
+		q.quiet = true
+	}
+
 	if q.quiet {
 		sendMessage = func(level runtimeMessageLevel, text string) {}
 	} else {
diff --git a/internal/sarin/template.go b/internal/sarin/template.go
index 754bcfd..c91a49a 100644
--- a/internal/sarin/template.go
+++ b/internal/sarin/template.go
@@ -62,10 +62,6 @@ func NewDefaultTemplateFuncMap(randSource rand.Source, fileCache *FileCache) tem
 		},
 		"strings_TrimPrefix": strings.TrimPrefix,
 		"strings_TrimSuffix": strings.TrimSuffix,
-		"strings_Join": func(sep string, values ...string) string {
-			return strings.Join(values, sep)
-		},
-
 		// Dict
 		"dict_Str": func(values ...string) map[string]string {
 			dict := make(map[string]string)
@@ -83,6 +79,7 @@ func NewDefaultTemplateFuncMap(randSource rand.Source, fileCache *FileCache) tem
 		"slice_Str":  func(values ...string) []string { return values },
 		"slice_Int":  func(values ...int) []int { return values },
 		"slice_Uint": func(values ...uint) []uint { return values },
+		"slice_Join": strings.Join,
 
 		// File
 		// file_Base64 reads a file (local or remote URL) and returns its Base64 encoded content.
diff --git a/internal/types/cookie.go b/internal/types/cookie.go
index 927f900..e0d4969 100644
--- a/internal/types/cookie.go
+++ b/internal/types/cookie.go
@@ -15,7 +15,7 @@ func (cookies Cookies) GetValue(key string) *[]string {
 	return nil
 }
 
-func (cookies *Cookies) Append(cookie ...Cookie) {
+func (cookies *Cookies) Merge(cookie ...Cookie) {
 	for _, c := range cookie {
 		if item := cookies.GetValue(c.Key); item != nil {
 			*item = append(*item, c.Value...)
@@ -27,7 +27,7 @@ func (cookies *Cookies) Append(cookie ...Cookie) {
 
 func (cookies *Cookies) Parse(rawValues ...string) {
 	for _, rawValue := range rawValues {
-		cookies.Append(*ParseCookie(rawValue))
+		*cookies = append(*cookies, *ParseCookie(rawValue))
 	}
 }
 
diff --git a/internal/types/errors.go b/internal/types/errors.go
index a8a2332..6bc6a76 100644
--- a/internal/types/errors.go
+++ b/internal/types/errors.go
@@ -250,10 +250,6 @@ func (e TemplateRenderError) Unwrap() error {
 
 // ======================================== CLI ========================================
 
-var (
-	ErrCLINoArgs = errors.New("CLI expects arguments but received none")
-)
-
 type CLIUnexpectedArgsError struct {
 	Args []string
 }
diff --git a/internal/types/header.go b/internal/types/header.go
index 9215218..5695689 100644
--- a/internal/types/header.go
+++ b/internal/types/header.go
@@ -24,7 +24,7 @@ func (headers Headers) GetValue(key string) *[]string {
 	return nil
 }
 
-func (headers *Headers) Append(header ...Header) {
+func (headers *Headers) Merge(header ...Header) {
 	for _, h := range header {
 		if item := headers.GetValue(h.Key); item != nil {
 			*item = append(*item, h.Value...)
@@ -36,7 +36,7 @@ func (headers *Headers) Append(header ...Header) {
 
 func (headers *Headers) Parse(rawValues ...string) {
 	for _, rawValue := range rawValues {
-		headers.Append(*ParseHeader(rawValue))
+		*headers = append(*headers, *ParseHeader(rawValue))
 	}
 }
 
diff --git a/internal/types/param.go b/internal/types/param.go
index d043396..4e6621b 100644
--- a/internal/types/param.go
+++ b/internal/types/param.go
@@ -15,7 +15,7 @@ func (params Params) GetValue(key string) *[]string {
 	return nil
 }
 
-func (params *Params) Append(param ...Param) {
+func (params *Params) Merge(param ...Param) {
 	for _, p := range param {
 		if item := params.GetValue(p.Key); item != nil {
 			*item = append(*item, p.Value...)
@@ -27,7 +27,7 @@ func (params *Params) Append(param ...Param) {
 
 func (params *Params) Parse(rawValues ...string) {
 	for _, rawValue := range rawValues {
-		params.Append(*ParseParam(rawValue))
+		*params = append(*params, *ParseParam(rawValue))
 	}
 }