diff --git a/pkg/auth/auth.go b/pkg/auth/auth.go
new file mode 100644
index 00000000..8f8d4544
--- /dev/null
+++ b/pkg/auth/auth.go
@@ -0,0 +1,64 @@
+package auth
+
+import (
+	"fmt"
+	"path/filepath"
+	"strings"
+
+	"github.com/AlecAivazis/survey/v2"
+	"github.com/gptscript-ai/gptscript/pkg/builtin"
+	"github.com/gptscript-ai/gptscript/pkg/context"
+	"github.com/gptscript-ai/gptscript/pkg/engine"
+	"github.com/gptscript-ai/gptscript/pkg/runner"
+)
+
+func Authorize(ctx engine.Context, input string) (runner.AuthorizerResponse, error) {
+	defer context.GetPauseFuncFromCtx(ctx.Ctx)()()
+
+	if !ctx.Tool.IsCommand() {
+		return runner.AuthorizerResponse{
+			Accept: true,
+		}, nil
+	}
+
+	var (
+		result      bool
+		loc         = ctx.Tool.Source.Location
+		interpreter = strings.Split(ctx.Tool.Instructions, "\n")[0][2:]
+	)
+
+	if _, ok := builtin.SafeTools[interpreter]; ok {
+		return runner.AuthorizerResponse{
+			Accept: true,
+		}, nil
+	}
+
+	if ctx.Tool.Source.Repo != nil {
+		loc = ctx.Tool.Source.Repo.Root
+		loc = strings.TrimPrefix(loc, "https://")
+		loc = strings.TrimSuffix(loc, ".git")
+		loc = filepath.Join(loc, ctx.Tool.Source.Repo.Path, ctx.Tool.Source.Repo.Name)
+	}
+
+	if ctx.Tool.BuiltinFunc != nil {
+		loc = "Builtin"
+	}
+
+	err := survey.AskOne(&survey.Confirm{
+		Help:    fmt.Sprintf("The full source of the tools is as follows:\n\n%s", ctx.Tool.String()),
+		Default: true,
+		Message: fmt.Sprintf(`Description: %s
+  Interpreter: %s
+  Source: %s
+  Input: %s
+Allow the above tool to execute?`, ctx.Tool.Description, interpreter, loc, strings.TrimSpace(input)),
+	}, &result)
+	if err != nil {
+		return runner.AuthorizerResponse{}, err
+	}
+
+	return runner.AuthorizerResponse{
+		Accept:  result,
+		Message: "Request denied, blocking execution.",
+	}, nil
+}
diff --git a/pkg/builtin/builtin.go b/pkg/builtin/builtin.go
index 592f873f..5eb7be3c 100644
--- a/pkg/builtin/builtin.go
+++ b/pkg/builtin/builtin.go
@@ -20,11 +20,17 @@ import (
 	"github.com/AlecAivazis/survey/v2"
 	"github.com/BurntSushi/locker"
 	"github.com/google/shlex"
-	"github.com/gptscript-ai/gptscript/pkg/confirm"
 	"github.com/gptscript-ai/gptscript/pkg/types"
 	"github.com/jaytaylor/html2text"
 )
 
+var SafeTools = map[string]struct{}{
+	"sys.echo":        {},
+	"sys.time.now":    {},
+	"sys.prompt":      {},
+	"sys.chat.finish": {},
+}
+
 var tools = map[string]types.Tool{
 	"sys.time.now": {
 		Parameters: types.Parameters{
@@ -278,10 +284,6 @@ func SysExec(ctx context.Context, env []string, input string) (string, error) {
 
 	log.Debugf("Running %s in %s", params.Command, params.Directory)
 
-	if err := confirm.Promptf(ctx, "Run command: %s", params.Command); err != nil {
-		return "", err
-	}
-
 	var cmd *exec.Cmd
 
 	if runtime.GOOS == "windows" {
@@ -404,12 +406,6 @@ func SysWrite(ctx context.Context, _ []string, input string) (string, error) {
 		}
 	}
 
-	if _, err := os.Stat(file); err == nil {
-		if err := confirm.Promptf(ctx, "Overwrite: %s", params.Filename); err != nil {
-			return "", err
-		}
-	}
-
 	data := []byte(params.Content)
 	log.Debugf("Wrote %d bytes to file %s", len(data), file)
 
@@ -429,12 +425,6 @@ func SysAppend(ctx context.Context, env []string, input string) (string, error)
 	locker.Lock(params.Filename)
 	defer locker.Unlock(params.Filename)
 
-	if _, err := os.Stat(params.Filename); err == nil {
-		if err := confirm.Promptf(ctx, "Write to existing file: %s.", params.Filename); err != nil {
-			return "", err
-		}
-	}
-
 	f, err := os.OpenFile(params.Filename, os.O_APPEND|os.O_WRONLY|os.O_CREATE, 0644)
 	if err != nil {
 		return "", err
@@ -609,10 +599,6 @@ func SysRemove(ctx context.Context, env []string, input string) (string, error)
 		return "", err
 	}
 
-	if err := confirm.Promptf(ctx, "Remove: %s", params.Location); err != nil {
-		return "", err
-	}
-
 	// Lock the file to prevent concurrent writes from other tool calls.
 	locker.Lock(params.Location)
 	defer locker.Unlock(params.Location)
diff --git a/pkg/cli/eval.go b/pkg/cli/eval.go
index a51b7f3b..addab89d 100644
--- a/pkg/cli/eval.go
+++ b/pkg/cli/eval.go
@@ -72,12 +72,12 @@ func (e *Eval) Run(cmd *cobra.Command, args []string) error {
 	}
 
 	if e.Chat {
-		return chat.Start(e.gptscript.NewRunContext(cmd), nil, runner, func() (types.Program, error) {
+		return chat.Start(cmd.Context(), nil, runner, func() (types.Program, error) {
 			return prg, nil
 		}, os.Environ(), toolInput)
 	}
 
-	toolOutput, err := runner.Run(e.gptscript.NewRunContext(cmd), prg, os.Environ(), toolInput)
+	toolOutput, err := runner.Run(cmd.Context(), prg, os.Environ(), toolInput)
 	if err != nil {
 		return err
 	}
diff --git a/pkg/cli/gptscript.go b/pkg/cli/gptscript.go
index 6fbc0bc2..38502ceb 100644
--- a/pkg/cli/gptscript.go
+++ b/pkg/cli/gptscript.go
@@ -13,10 +13,10 @@ import (
 	"github.com/acorn-io/cmd"
 	"github.com/fatih/color"
 	"github.com/gptscript-ai/gptscript/pkg/assemble"
+	"github.com/gptscript-ai/gptscript/pkg/auth"
 	"github.com/gptscript-ai/gptscript/pkg/builtin"
 	"github.com/gptscript-ai/gptscript/pkg/cache"
 	"github.com/gptscript-ai/gptscript/pkg/chat"
-	"github.com/gptscript-ai/gptscript/pkg/confirm"
 	"github.com/gptscript-ai/gptscript/pkg/gptscript"
 	"github.com/gptscript-ai/gptscript/pkg/input"
 	"github.com/gptscript-ai/gptscript/pkg/loader"
@@ -117,14 +117,6 @@ func New() *cobra.Command {
 	return command
 }
 
-func (r *GPTScript) NewRunContext(cmd *cobra.Command) context.Context {
-	ctx := cmd.Context()
-	if r.Confirm {
-		ctx = confirm.WithConfirm(ctx, confirm.TextPrompt{})
-	}
-	return ctx
-}
-
 func (r *GPTScript) NewGPTScriptOpts() (gptscript.Options, error) {
 	opts := gptscript.Options{
 		Cache:   cache.Options(r.CacheOptions),
@@ -140,6 +132,10 @@ func (r *GPTScript) NewGPTScriptOpts() (gptscript.Options, error) {
 		Workspace:         r.Workspace,
 	}
 
+	if r.Confirm {
+		opts.Runner.Authorizer = auth.Authorize
+	}
+
 	if r.Ports != "" {
 		start, end, _ := strings.Cut(r.Ports, "-")
 		startNum, err := strconv.ParseInt(strings.TrimSpace(start), 10, 64)
@@ -388,7 +384,7 @@ func (r *GPTScript) Run(cmd *cobra.Command, args []string) (retErr error) {
 	}
 
 	if r.ChatState != "" {
-		resp, err := gptScript.Chat(r.NewRunContext(cmd), r.ChatState, prg, os.Environ(), toolInput)
+		resp, err := gptScript.Chat(cmd.Context(), r.ChatState, prg, os.Environ(), toolInput)
 		if err != nil {
 			return err
 		}
@@ -400,12 +396,12 @@ func (r *GPTScript) Run(cmd *cobra.Command, args []string) (retErr error) {
 	}
 
 	if prg.IsChat() || r.ForceChat {
-		return chat.Start(r.NewRunContext(cmd), nil, gptScript, func() (types.Program, error) {
+		return chat.Start(cmd.Context(), nil, gptScript, func() (types.Program, error) {
 			return r.readProgram(ctx, gptScript, args)
 		}, os.Environ(), toolInput)
 	}
 
-	s, err := gptScript.Run(r.NewRunContext(cmd), prg, os.Environ(), toolInput)
+	s, err := gptScript.Run(cmd.Context(), prg, os.Environ(), toolInput)
 	if err != nil {
 		return err
 	}
diff --git a/pkg/confirm/confirm.go b/pkg/confirm/confirm.go
deleted file mode 100644
index a494aded..00000000
--- a/pkg/confirm/confirm.go
+++ /dev/null
@@ -1,45 +0,0 @@
-package confirm
-
-import (
-	"context"
-	"errors"
-	"fmt"
-
-	"github.com/AlecAivazis/survey/v2"
-)
-
-type Confirm interface {
-	Confirm(ctx context.Context, prompt string) error
-}
-
-type confirmer struct{}
-
-func WithConfirm(ctx context.Context, c Confirm) context.Context {
-	return context.WithValue(ctx, confirmer{}, c)
-}
-
-func Promptf(ctx context.Context, fmtString string, args ...any) error {
-	c, ok := ctx.Value(confirmer{}).(Confirm)
-	if !ok {
-		return nil
-	}
-	return c.Confirm(ctx, fmt.Sprintf(fmtString, args...))
-}
-
-type TextPrompt struct {
-}
-
-func (t TextPrompt) Confirm(_ context.Context, prompt string) error {
-	var result bool
-	err := survey.AskOne(&survey.Confirm{
-		Message: prompt,
-		Default: false,
-	}, &result)
-	if err != nil {
-		return err
-	}
-	if !result {
-		return errors.New("abort")
-	}
-	return nil
-}
diff --git a/pkg/mvl/log.go b/pkg/mvl/log.go
index f35e023e..1523982f 100644
--- a/pkg/mvl/log.go
+++ b/pkg/mvl/log.go
@@ -43,7 +43,7 @@ func (f formatter) Format(entry *logrus.Entry) ([]byte, error) {
 			}
 			d, _ := json.Marshal(i)
 			i = string(d)
-			i = strings.TrimSpace(i[1 : len(i)-2])
+			i = strings.TrimSpace(i[1 : len(i)-1])
 			if addDot {
 				i += "..."
 			}
diff --git a/pkg/openai/client.go b/pkg/openai/client.go
index c1787497..486d58c3 100644
--- a/pkg/openai/client.go
+++ b/pkg/openai/client.go
@@ -435,7 +435,9 @@ func appendMessage(msg types.CompletionMessage, response openai.ChatCompletionSt
 			tc.ToolCall.Index = tool.Index
 		}
 		tc.ToolCall.ID = override(tc.ToolCall.ID, tool.ID)
-		tc.ToolCall.Function.Name += tool.Function.Name
+		if tc.ToolCall.Function.Name != tool.Function.Name {
+			tc.ToolCall.Function.Name += tool.Function.Name
+		}
 		tc.ToolCall.Function.Arguments += tool.Function.Arguments
 
 		msg.Content[idx] = tc
diff --git a/pkg/runner/runner.go b/pkg/runner/runner.go
index d4a5516b..42966493 100644
--- a/pkg/runner/runner.go
+++ b/pkg/runner/runner.go
@@ -36,6 +36,20 @@ type Options struct {
 	EndPort            int64                 `usage:"-"`
 	CredentialOverride string                `usage:"-"`
 	Sequential         bool                  `usage:"-"`
+	Authorizer         AuthorizerFunc        `usage:"-"`
+}
+
+type AuthorizerResponse struct {
+	Accept  bool
+	Message string
+}
+
+type AuthorizerFunc func(ctx engine.Context, input string) (AuthorizerResponse, error)
+
+func DefaultAuthorizer(_ engine.Context, _ string) (AuthorizerResponse, error) {
+	return AuthorizerResponse{
+		Accept: true,
+	}, nil
 }
 
 func complete(opts ...Options) (result Options) {
@@ -46,6 +60,9 @@ func complete(opts ...Options) (result Options) {
 		result.EndPort = types.FirstSet(opt.EndPort, result.EndPort)
 		result.CredentialOverride = types.FirstSet(opt.CredentialOverride, result.CredentialOverride)
 		result.Sequential = types.FirstSet(opt.Sequential, result.Sequential)
+		if opt.Authorizer != nil {
+			result.Authorizer = opt.Authorizer
+		}
 	}
 	if result.MonitorFactory == nil {
 		result.MonitorFactory = noopFactory{}
@@ -56,11 +73,15 @@ func complete(opts ...Options) (result Options) {
 	if result.StartPort == 0 {
 		result.StartPort = result.EndPort
 	}
+	if result.Authorizer == nil {
+		result.Authorizer = DefaultAuthorizer
+	}
 	return
 }
 
 type Runner struct {
 	c              engine.Model
+	auth           AuthorizerFunc
 	factory        MonitorFactory
 	runtimeManager engine.RuntimeManager
 	ports          engine.Ports
@@ -81,6 +102,7 @@ func New(client engine.Model, credCtx string, opts ...Options) (*Runner, error)
 		credMutex:      sync.Mutex{},
 		credOverrides:  opt.CredentialOverride,
 		sequential:     opt.Sequential,
+		auth:           opt.Authorizer,
 	}
 
 	if opt.StartPort != 0 {
@@ -405,6 +427,20 @@ func (r *Runner) start(callCtx engine.Context, state *State, monitor Monitor, en
 
 	callCtx.Ctx = context2.AddPauseFuncToCtx(callCtx.Ctx, monitor.Pause)
 
+	authResp, err := r.auth(callCtx, input)
+	if err != nil {
+		return nil, err
+	}
+
+	if !authResp.Accept {
+		msg := fmt.Sprintf("[AUTHORIZATION ERROR]: %s", authResp.Message)
+		return &State{
+			Continuation: &engine.Return{
+				Result: &msg,
+			},
+		}, nil
+	}
+
 	ret, err := e.Start(callCtx, input)
 	if err != nil {
 		return nil, err