diff --git a/.release-please-manifest.json b/.release-please-manifest.json
index 3cf71e6..b386bef 100644
--- a/.release-please-manifest.json
+++ b/.release-please-manifest.json
@@ -1,3 +1,3 @@
 {
-  ".": "0.1.0-alpha.18"
+  ".": "0.1.0-alpha.19"
 }
\ No newline at end of file
diff --git a/.stats.yml b/.stats.yml
index 7bf07f7..f3dbd23 100644
--- a/.stats.yml
+++ b/.stats.yml
@@ -1,4 +1,4 @@
 configured_endpoints: 15
 openapi_spec_url: https://storage.googleapis.com/stainless-sdk-openapi-specs/stainless%2Fstainless-v0-ddcc03297d5649ca543ccff5be72ca1c148696cdddf63cb640e3f8a9b86ab59e.yml
 openapi_spec_hash: 2870606e51060e9080104b1089f28b83
-config_hash: 94d0bc0af5fa718b5ab095e1d934e834
+config_hash: 3390d0ac1f2bb2f8e759f7758d1312c7
diff --git a/CHANGELOG.md b/CHANGELOG.md
index ae166b5..b5e5064 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,14 @@
 # Changelog
 
+## 0.1.0-alpha.19 (2025-06-20)
+
+Full Changelog: [v0.1.0-alpha.18...v0.1.0-alpha.19](https://github.com/stainless-api/stainless-api-cli/compare/v0.1.0-alpha.18...v0.1.0-alpha.19)
+
+### Chores
+
+* bump go package version ([abc91cb](https://github.com/stainless-api/stainless-api-cli/commit/abc91cb66f1e668c1e55f867ef2fbe4e22d6b61c))
+* **internal:** codegen related update ([e84af71](https://github.com/stainless-api/stainless-api-cli/commit/e84af710aeaec0674afcef3d4eba4e5d3bbe5e71))
+
 ## 0.1.0-alpha.18 (2025-06-19)
 
 Full Changelog: [v0.1.0-alpha.17...v0.1.0-alpha.18](https://github.com/stainless-api/stainless-api-cli/compare/v0.1.0-alpha.17...v0.1.0-alpha.18)
diff --git a/go.mod b/go.mod
index c468549..81425e0 100644
--- a/go.mod
+++ b/go.mod
@@ -5,12 +5,12 @@ go 1.23.0
 toolchain go1.23.10
 
 require (
-	github.com/charmbracelet/bubbles v0.21.0
+  github.com/charmbracelet/bubbles v0.21.0
 	github.com/charmbracelet/huh v0.7.0
 	github.com/charmbracelet/lipgloss v1.1.0
 	github.com/logrusorgru/aurora/v4 v4.0.0
 	github.com/pkg/browser v0.0.0-20240102092130-5ac0b6a4141c
-	github.com/stainless-api/stainless-api-go v0.8.0
+  github.com/stainless-api/stainless-api-go v0.9.0
 	github.com/tidwall/gjson v1.17.0
 	github.com/tidwall/pretty v1.2.1
 	github.com/tidwall/sjson v1.2.5
diff --git a/go.sum b/go.sum
index a3b3f7a..82534dd 100644
--- a/go.sum
+++ b/go.sum
@@ -69,8 +69,8 @@ github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZN
 github.com/rivo/uniseg v0.2.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=
 github.com/rivo/uniseg v0.4.7 h1:WUdvkW8uEhrYfLC4ZzdpI2ztxP1I582+49Oc5Mq64VQ=
 github.com/rivo/uniseg v0.4.7/go.mod h1:FN3SvrM+Zdj16jyLfmOkMNblXMcoc8DfTHruCPUcx88=
-github.com/stainless-api/stainless-api-go v0.8.0 h1:GD3U3B20zG9FW/O2I//6zqiMJSpw6AterUn0x08QU5c=
-github.com/stainless-api/stainless-api-go v0.8.0/go.mod h1:9Q2t8xq6EFgw8HYOsVxqKEfSDVe9eqCoh1zC0HMRwTY=
+github.com/stainless-api/stainless-api-go v0.9.0 h1:HlPcGQT6FX1/oPhpJTo46uBAjgwmUdzW7S97fMD0Gp0=
+github.com/stainless-api/stainless-api-go v0.9.0/go.mod h1:9Q2t8xq6EFgw8HYOsVxqKEfSDVe9eqCoh1zC0HMRwTY=
 github.com/stretchr/testify v1.10.0 h1:Xv5erBjTwe/5IxqUQTdXv5kgmIvbHo3QQyRwhJsOfJA=
 github.com/stretchr/testify v1.10.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
 github.com/tidwall/gjson v1.14.2/go.mod h1:/wbyibRr2FHMks5tjHJ5F8dMZh3AcwJEMf5vlfC0lxk=
diff --git a/pkg/cmd/build.go b/pkg/cmd/build.go
index 25ff92d..fed7706 100644
--- a/pkg/cmd/build.go
+++ b/pkg/cmd/build.go
@@ -605,7 +605,7 @@ func getAPICommandContextWithWorkspaceDefaults(cmd *cli.Command) (*apiCommandCon
 			if err != nil {
 				return nil, fmt.Errorf("failed to load OpenAPI spec from workspace config: %v", err)
 			}
-			jsonflag.Register(jsonflag.Body, "revision.openapi\\.yml.content", string(content))
+			jsonflag.Mutate(jsonflag.Body, "revision.openapi\\.yml.content", string(content))
 		}
 
 		if !cmd.IsSet("stainless-config") && !cmd.IsSet("config") && config.StainlessConfig != "" {
@@ -615,7 +615,7 @@ func getAPICommandContextWithWorkspaceDefaults(cmd *cli.Command) (*apiCommandCon
 			if err != nil {
 				return nil, fmt.Errorf("failed to load Stainless config from workspace config: %v", err)
 			}
-			jsonflag.Register(jsonflag.Body, "revision.openapi\\.stainless\\.yml.content", string(content))
+			jsonflag.Mutate(jsonflag.Body, "revision.openapi\\.stainless\\.yml.content", string(content))
 		}
 	}
 	return cc, err
diff --git a/pkg/cmd/cmd.go b/pkg/cmd/cmd.go
index 818e942..6d5c1eb 100644
--- a/pkg/cmd/cmd.go
+++ b/pkg/cmd/cmd.go
@@ -15,6 +15,10 @@ var Command = cli.Command{
 			Name:  "debug",
 			Usage: "Enable debug logging",
 		},
+		&cli.StringFlag{
+			Name:  "base-url",
+			Usage: "Override the base URL for API requests",
+		},
 	},
 	Commands: []*cli.Command{
 		{
diff --git a/pkg/cmd/project.go b/pkg/cmd/project.go
index 17938af..43ec011 100644
--- a/pkg/cmd/project.go
+++ b/pkg/cmd/project.go
@@ -136,6 +136,8 @@ var projectsList = cli.Command{
 }
 
 func handleProjectsCreate(ctx context.Context, cmd *cli.Command) error {
+	cc := getAPICommandContext(cmd)
+
 	// Define available target languages
 	availableTargets := []huh.Option[string]{
 		huh.NewOption("TypeScript", "typescript").Selected(true),
@@ -184,7 +186,7 @@ func handleProjectsCreate(ctx context.Context, cmd *cli.Command) error {
 		Info("Creating a new project...")
 
 		// Fetch available organizations for suggestions
-		orgs := fetchUserOrgs(ctx)
+		orgs := fetchUserOrgs(cc.client, ctx)
 
 		// Auto-fill with first organization if org is empty and orgs are available
 		if org == "" && len(orgs) > 0 {
@@ -294,7 +296,7 @@ func handleProjectsCreate(ctx context.Context, cmd *cli.Command) error {
 		content, err := os.ReadFile(openAPISpec)
 		if err == nil {
 			// Inject the actual file content into the project creation payload
-			jsonflag.Register(jsonflag.Body, "revision.openapi\\.yml.content", string(content))
+			jsonflag.Mutate(jsonflag.Body, "revision.openapi\\.yml.content", string(content))
 		}
 	}
 
@@ -302,12 +304,10 @@ func handleProjectsCreate(ctx context.Context, cmd *cli.Command) error {
 		content, err := os.ReadFile(stainlessConfig)
 		if err == nil {
 			// Inject the actual file content into the project creation payload
-			jsonflag.Register(jsonflag.Body, "revision.openapi\\.stainless\\.yml.content", string(content))
+			jsonflag.Mutate(jsonflag.Body, "revision.openapi\\.stainless\\.yml.content", string(content))
 		}
 	}
 
-	// Use the original logic - let the JSONFlag middleware handle parameter construction
-	cc := getAPICommandContext(cmd)
 	params := stainlessv0.ProjectNewParams{}
 	res, err := cc.client.Projects.New(
 		context.TODO(),
@@ -402,9 +402,7 @@ func handleProjectsList(ctx context.Context, cmd *cli.Command) error {
 }
 
 // fetchUserOrgs retrieves the list of organizations the user has access to
-func fetchUserOrgs(ctx context.Context) []string {
-	client := stainlessv0.NewClient(getClientOptions()...)
-
+func fetchUserOrgs(client stainlessv0.Client, ctx context.Context) []string {
 	res, err := client.Orgs.List(ctx)
 	if err != nil {
 		// Return empty slice if we can't fetch orgs
diff --git a/pkg/cmd/util.go b/pkg/cmd/util.go
index 63224d0..a305694 100644
--- a/pkg/cmd/util.go
+++ b/pkg/cmd/util.go
@@ -23,14 +23,20 @@ import (
 	"golang.org/x/term"
 )
 
-func getDefaultRequestOptions() []option.RequestOption {
-	return append(
-		[]option.RequestOption{
-			option.WithHeader("X-Stainless-Lang", "cli"),
-			option.WithHeader("X-Stainless-Runtime", "cli"),
-		},
-		getClientOptions()...,
-	)
+func getDefaultRequestOptions(cmd *cli.Command) []option.RequestOption {
+	opts := []option.RequestOption{
+		option.WithHeader("X-Stainless-Lang", "cli"),
+		option.WithHeader("X-Stainless-Runtime", "cli"),
+	}
+
+	// Override base URL if the --base-url flag is provided
+	if baseURL := cmd.String("base-url"); baseURL != "" {
+		opts = append(opts, option.WithBaseURL(baseURL))
+	}
+
+	opts = append(opts, getClientOptions()...)
+
+	return opts
 }
 
 type apiCommandContext struct {
@@ -47,7 +53,7 @@ func (c apiCommandContext) AsMiddleware() option.Middleware {
 	var header = []byte("{}")
 
 	// Apply JSON flag mutations
-	body, query, header, err := jsonflag.Apply(body, query, header)
+	body, query, header, err := jsonflag.ApplyMutations(body, query, header)
 	if err != nil {
 		log.Fatal(err)
 	}
@@ -130,7 +136,7 @@ func (c apiCommandContext) AsMiddleware() option.Middleware {
 }
 
 func getAPICommandContext(cmd *cli.Command) *apiCommandContext {
-	client := stainlessv0.NewClient(getDefaultRequestOptions()...)
+	client := stainlessv0.NewClient(getDefaultRequestOptions(cmd)...)
 	return &apiCommandContext{client, cmd}
 }
 
diff --git a/pkg/jsonflag/json_flag.go b/pkg/jsonflag/json_flag.go
index b5fdbce..4314124 100644
--- a/pkg/jsonflag/json_flag.go
+++ b/pkg/jsonflag/json_flag.go
@@ -16,9 +16,9 @@ type JSONConfig struct {
 	SetValue interface{}
 }
 
-type JsonValueCreator[T any] struct{}
+type JSONValueCreator[T any] struct{}
 
-func (c JsonValueCreator[T]) Create(val T, dest *T, config JSONConfig) cli.Value {
+func (c JSONValueCreator[T]) Create(val T, dest *T, config JSONConfig) cli.Value {
 	*dest = val
 	return &jsonValue[T]{
 		destination: dest,
@@ -26,7 +26,7 @@ func (c JsonValueCreator[T]) Create(val T, dest *T, config JSONConfig) cli.Value
 	}
 }
 
-func (c JsonValueCreator[T]) ToString(val T) string {
+func (c JSONValueCreator[T]) ToString(val T) string {
 	switch v := any(val).(type) {
 	case string:
 		if v == "" {
@@ -59,13 +59,13 @@ func (v *jsonValue[T]) Set(val string) error {
 	if v.config.SetValue != nil {
 		// For boolean flags with SetValue, register the configured value
 		if _, isBool := any(parsed).(bool); isBool {
-			globalRegistry.Register(v.config.Kind, v.config.Path, v.config.SetValue)
+			globalRegistry.Mutate(v.config.Kind, v.config.Path, v.config.SetValue)
 			*v.destination = any(true).(T) // Set the flag itself to true
 			return nil
 		}
 		// For any flags with SetValue, register the configured value
 		if _, isAny := any(parsed).(interface{}); isAny {
-			globalRegistry.Register(v.config.Kind, v.config.Path, v.config.SetValue)
+			globalRegistry.Mutate(v.config.Kind, v.config.Path, v.config.SetValue)
 			*v.destination = any(v.config.SetValue).(T)
 			return nil
 		}
@@ -123,7 +123,7 @@ func (v *jsonValue[T]) Set(val string) error {
 	}
 
 	*v.destination = parsed
-	globalRegistry.Register(v.config.Kind, v.config.Path, parsed)
+	globalRegistry.Mutate(v.config.Kind, v.config.Path, parsed)
 	return err
 }
 
@@ -173,10 +173,10 @@ func (v *jsonValue[T]) IsBoolFlag() bool {
 	return v.config.SetValue != nil
 }
 
-// JsonDateValueCreator is a specialized creator for date-only values
-type JsonDateValueCreator struct{}
+// JSONDateValueCreator is a specialized creator for date-only values
+type JSONDateValueCreator struct{}
 
-func (c JsonDateValueCreator) Create(val time.Time, dest *time.Time, config JSONConfig) cli.Value {
+func (c JSONDateValueCreator) Create(val time.Time, dest *time.Time, config JSONConfig) cli.Value {
 	*dest = val
 	return &jsonDateValue{
 		destination: dest,
@@ -184,7 +184,7 @@ func (c JsonDateValueCreator) Create(val time.Time, dest *time.Time, config JSON
 	}
 }
 
-func (c JsonDateValueCreator) ToString(val time.Time) string {
+func (c JSONDateValueCreator) ToString(val time.Time) string {
 	return val.Format("2006-01-02")
 }
 
@@ -220,7 +220,7 @@ func (v *jsonDateValue) Set(val string) error {
 	}
 
 	*v.destination = timeVal
-	globalRegistry.Register(v.config.Kind, v.config.Path, timeVal.Format("2006-01-02"))
+	globalRegistry.Mutate(v.config.Kind, v.config.Path, timeVal.Format("2006-01-02"))
 	return nil
 }
 
@@ -242,14 +242,6 @@ func (v *jsonDateValue) IsBoolFlag() bool {
 	return false
 }
 
-type JSONStringFlag = cli.FlagBase[string, JSONConfig, JsonValueCreator[string]]
-type JSONBoolFlag = cli.FlagBase[bool, JSONConfig, JsonValueCreator[bool]]
-type JSONIntFlag = cli.FlagBase[int, JSONConfig, JsonValueCreator[int]]
-type JSONFloatFlag = cli.FlagBase[float64, JSONConfig, JsonValueCreator[float64]]
-type JSONDatetimeFlag = cli.FlagBase[time.Time, JSONConfig, JsonValueCreator[time.Time]]
-type JSONDateFlag = cli.FlagBase[time.Time, JSONConfig, JsonDateValueCreator]
-type JSONAnyFlag = cli.FlagBase[interface{}, JSONConfig, JsonValueCreator[interface{}]]
-
 // JsonFileValueCreator handles file-based flags that read content and register with mutations
 type JsonFileValueCreator struct{}
 
@@ -281,7 +273,7 @@ func (v *jsonFileValue) Set(filePath string) error {
 	*v.destination = filePath
 	
 	// Register the file content with the global registry
-	globalRegistry.Register(v.config.Kind, v.config.Path, string(content))
+	globalRegistry.Mutate(v.config.Kind, v.config.Path, string(content))
 	return nil
 }
 
@@ -304,3 +296,10 @@ func (v *jsonFileValue) IsBoolFlag() bool {
 }
 
 type JSONFileFlag = cli.FlagBase[string, JSONConfig, JsonFileValueCreator]
+type JSONStringFlag = cli.FlagBase[string, JSONConfig, JSONValueCreator[string]]
+type JSONBoolFlag = cli.FlagBase[bool, JSONConfig, JSONValueCreator[bool]]
+type JSONIntFlag = cli.FlagBase[int, JSONConfig, JSONValueCreator[int]]
+type JSONFloatFlag = cli.FlagBase[float64, JSONConfig, JSONValueCreator[float64]]
+type JSONDatetimeFlag = cli.FlagBase[time.Time, JSONConfig, JSONValueCreator[time.Time]]
+type JSONDateFlag = cli.FlagBase[time.Time, JSONConfig, JSONDateValueCreator]
+type JSONAnyFlag = cli.FlagBase[interface{}, JSONConfig, JSONValueCreator[interface{}]]
diff --git a/pkg/jsonflag/mutation.go b/pkg/jsonflag/mutation.go
index b5c525c..d0eb78e 100644
--- a/pkg/jsonflag/mutation.go
+++ b/pkg/jsonflag/mutation.go
@@ -29,7 +29,7 @@ type registry struct {
 
 var globalRegistry = &registry{}
 
-func (r *registry) Register(kind MutationKind, path string, value interface{}) {
+func (r *registry) Mutate(kind MutationKind, path string, value interface{}) {
 	r.mutations = append(r.mutations, Mutation{
 		Kind:  kind,
 		Path:  path,
@@ -37,7 +37,7 @@ func (r *registry) Register(kind MutationKind, path string, value interface{}) {
 	})
 }
 
-func (r *registry) ApplyMutations(body, query, header []byte) ([]byte, []byte, []byte, error) {
+func (r *registry) Apply(body, query, header []byte) ([]byte, []byte, []byte, error) {
 	var err error
 
 	for _, mutation := range r.mutations {
@@ -67,18 +67,24 @@ func (r *registry) List() []Mutation {
 	return result
 }
 
-func Apply(body, query, header []byte) ([]byte, []byte, []byte, error) {
-	body, query, header, err := globalRegistry.ApplyMutations(body, query, header)
-	globalRegistry.Clear()
-	return body, query, header, err
+// Mutate adds a mutation that will be applied to the specified kind of data
+func Mutate(kind MutationKind, path string, value interface{}) {
+	globalRegistry.Mutate(kind, path, value)
+}
+
+// ApplyMutations applies all registered mutations to the provided JSON data
+func ApplyMutations(body, query, header []byte) ([]byte, []byte, []byte, error) {
+	return globalRegistry.Apply(body, query, header)
 }
 
-func Clear() {
+// ClearMutations removes all registered mutations from the global registry
+func ClearMutations() {
 	globalRegistry.Clear()
 }
 
-func Register(kind MutationKind, path string, value interface{}) {
-	globalRegistry.Register(kind, path, value)
+// ListMutations returns a copy of all currently registered mutations
+func ListMutations() []Mutation {
+	return globalRegistry.List()
 }
 
 func jsonSet(json []byte, path string, value interface{}) ([]byte, error) {
diff --git a/pkg/jsonflag/mutation_test.go b/pkg/jsonflag/mutation_test.go
index 1ba78e1..e87e518 100644
--- a/pkg/jsonflag/mutation_test.go
+++ b/pkg/jsonflag/mutation_test.go
@@ -2,18 +2,16 @@ package jsonflag
 
 import (
 	"testing"
-
-	"github.com/urfave/cli/v3"
 )
 
 func TestApply(t *testing.T) {
-	Clear()
+	ClearMutations()
 
-	globalRegistry.Register(Body, "name", "test")
-	globalRegistry.Register(Query, "page", 1)
-	globalRegistry.Register(Header, "authorization", "Bearer token")
+	Mutate(Body, "name", "test")
+	Mutate(Query, "page", 1)
+	Mutate(Header, "authorization", "Bearer token")
 
-	body, query, header, err := globalRegistry.ApplyMutations(
+	body, query, header, err := ApplyMutations(
 		[]byte(`{}`),
 		[]byte(`{}`),
 		[]byte(`{}`),