diff --git a/pkg/engine/engine.go b/pkg/engine/engine.go
index ebc83454..24ee9302 100644
--- a/pkg/engine/engine.go
+++ b/pkg/engine/engine.go
@@ -7,21 +7,12 @@ import (
 	"sync"
 	"sync/atomic"
 
-	"github.com/gptscript-ai/gptscript/pkg/system"
 	"github.com/gptscript-ai/gptscript/pkg/types"
 	"github.com/gptscript-ai/gptscript/pkg/version"
 )
 
 var completionID int64
 
-type ErrToolNotFound struct {
-	ToolName string
-}
-
-func (e *ErrToolNotFound) Error() string {
-	return fmt.Sprintf("tool not found: %s", e.ToolName)
-}
-
 type Model interface {
 	Call(ctx context.Context, messageRequest types.CompletionRequest, status chan<- types.CompletionStatus) (*types.CompletionMessage, error)
 }
@@ -62,12 +53,11 @@ type CallResult struct {
 }
 
 type Context struct {
-	ID        string
-	Ctx       context.Context
-	Parent    *Context
-	Program   *types.Program
-	Tool      types.Tool
-	toolNames map[string]struct{}
+	ID      string
+	Ctx     context.Context
+	Parent  *Context
+	Program *types.Program
+	Tool    types.Tool
 }
 
 func (c *Context) ParentID() string {
@@ -119,65 +109,6 @@ func (c *Context) SubCall(ctx context.Context, toolID, callID string) (Context,
 	}, nil
 }
 
-func (c *Context) getTool(parent types.Tool, name string) (types.Tool, error) {
-	toolID, ok := parent.ToolMapping[name]
-	if !ok {
-		return types.Tool{}, &ErrToolNotFound{
-			ToolName: name,
-		}
-	}
-	tool, ok := c.Program.ToolSet[toolID]
-	if !ok {
-		return types.Tool{}, &ErrToolNotFound{
-			ToolName: name,
-		}
-	}
-	return tool, nil
-}
-
-func (c *Context) appendTool(completion *types.CompletionRequest, parentTool types.Tool, subToolName string) error {
-	subTool, err := c.getTool(parentTool, subToolName)
-	if err != nil {
-		return err
-	}
-
-	args := subTool.Parameters.Arguments
-	if args == nil && !subTool.IsCommand() {
-		args = &system.DefaultToolSchema
-	}
-
-	for _, existingTool := range completion.Tools {
-		if existingTool.Function.ToolID == subTool.ID {
-			return nil
-		}
-	}
-
-	if c.toolNames == nil {
-		c.toolNames = map[string]struct{}{}
-	}
-
-	if subTool.Instructions == "" {
-		log.Debugf("Skipping zero instruction tool %s (%s)", subToolName, subTool.ID)
-	} else {
-		completion.Tools = append(completion.Tools, types.CompletionTool{
-			Function: types.CompletionFunctionDefinition{
-				ToolID:      subTool.ID,
-				Name:        PickToolName(subToolName, c.toolNames),
-				Description: subTool.Parameters.Description,
-				Parameters:  args,
-			},
-		})
-	}
-
-	for _, export := range subTool.Export {
-		if err := c.appendTool(completion, subTool, export); err != nil {
-			return err
-		}
-	}
-
-	return nil
-}
-
 func (e *Engine) Start(ctx Context, input string) (*Return, error) {
 	tool := ctx.Tool
 
@@ -207,10 +138,10 @@ func (e *Engine) Start(ctx Context, input string) (*Return, error) {
 		InternalSystemPrompt: tool.Parameters.InternalPrompt,
 	}
 
-	for _, subToolName := range tool.Parameters.Tools {
-		if err := ctx.appendTool(&completion, ctx.Tool, subToolName); err != nil {
-			return nil, err
-		}
+	var err error
+	completion.Tools, err = tool.GetCompletionTools(*ctx.Program)
+	if err != nil {
+		return nil, err
 	}
 
 	if tool.Instructions != "" {
diff --git a/pkg/loader/loader.go b/pkg/loader/loader.go
index 41248957..57d1866e 100644
--- a/pkg/loader/loader.go
+++ b/pkg/loader/loader.go
@@ -17,7 +17,6 @@ import (
 	"github.com/getkin/kin-openapi/openapi3"
 	"github.com/gptscript-ai/gptscript/pkg/assemble"
 	"github.com/gptscript-ai/gptscript/pkg/builtin"
-	"github.com/gptscript-ai/gptscript/pkg/engine"
 	"github.com/gptscript-ai/gptscript/pkg/parser"
 	"github.com/gptscript-ai/gptscript/pkg/types"
 	"gopkg.in/yaml.v3"
@@ -109,7 +108,7 @@ func loadProgram(data []byte, into *types.Program, targetToolName string) (types
 
 	tool, ok := into.ToolSet[tool.LocalTools[targetToolName]]
 	if !ok {
-		return tool, &engine.ErrToolNotFound{
+		return tool, &types.ErrToolNotFound{
 			ToolName: targetToolName,
 		}
 	}
diff --git a/pkg/tests/runner_test.go b/pkg/tests/runner_test.go
index 6e911977..539d0c76 100644
--- a/pkg/tests/runner_test.go
+++ b/pkg/tests/runner_test.go
@@ -3,7 +3,6 @@ package tests
 import (
 	"testing"
 
-	"github.com/gptscript-ai/gptscript/pkg/engine"
 	"github.com/gptscript-ai/gptscript/pkg/tests/tester"
 	"github.com/gptscript-ai/gptscript/pkg/types"
 	"github.com/stretchr/testify/assert"
@@ -15,7 +14,7 @@ func TestCwd(t *testing.T) {
 
 	runner.RespondWith(tester.Result{
 		Func: types.CompletionFunctionCall{
-			Name: engine.ToolNormalizer("./subtool/test.gpt"),
+			Name: types.ToolNormalizer("./subtool/test.gpt"),
 		},
 	})
 	runner.RespondWith(tester.Result{
diff --git a/pkg/types/completion.go b/pkg/types/completion.go
index e370e9cb..e4bb92a5 100644
--- a/pkg/types/completion.go
+++ b/pkg/types/completion.go
@@ -28,7 +28,6 @@ type CompletionFunctionDefinition struct {
 	ToolID      string           `json:"toolID,omitempty"`
 	Name        string           `json:"name"`
 	Description string           `json:"description,omitempty"`
-	Domain      string           `json:"domain,omitempty"`
 	Parameters  *openapi3.Schema `json:"parameters"`
 }
 
diff --git a/pkg/types/log.go b/pkg/types/log.go
new file mode 100644
index 00000000..ba3ff8c5
--- /dev/null
+++ b/pkg/types/log.go
@@ -0,0 +1,5 @@
+package types
+
+import "github.com/gptscript-ai/gptscript/pkg/mvl"
+
+var log = mvl.Package()
diff --git a/pkg/types/tool.go b/pkg/types/tool.go
index 777e7953..ebd5812e 100644
--- a/pkg/types/tool.go
+++ b/pkg/types/tool.go
@@ -7,6 +7,7 @@ import (
 	"strings"
 
 	"github.com/getkin/kin-openapi/openapi3"
+	"github.com/gptscript-ai/gptscript/pkg/system"
 	"golang.org/x/exp/maps"
 )
 
@@ -16,6 +17,14 @@ const (
 	CommandPrefix = "#!"
 )
 
+type ErrToolNotFound struct {
+	ToolName string
+}
+
+func (e *ErrToolNotFound) Error() string {
+	return fmt.Sprintf("tool not found: %s", e.ToolName)
+}
+
 type ToolSet map[string]Tool
 
 type Program struct {
@@ -24,6 +33,17 @@ type Program struct {
 	ToolSet     ToolSet `json:"toolSet,omitempty"`
 }
 
+func (p Program) GetCompletionTools() (result []CompletionTool, err error) {
+	return Tool{
+		Parameters: Parameters{
+			Tools: []string{"main"},
+		},
+		ToolMapping: map[string]string{
+			"main": p.EntryToolID,
+		},
+	}.GetCompletionTools(p)
+}
+
 func (p Program) TopLevelTools() (result []Tool) {
 	for _, tool := range p.ToolSet[p.EntryToolID].LocalTools {
 		result = append(result, p.ToolSet[tool])
@@ -124,6 +144,75 @@ func (t Tool) String() string {
 	return buf.String()
 }
 
+func (t Tool) GetCompletionTools(prg Program) (result []CompletionTool, err error) {
+	toolNames := map[string]struct{}{}
+
+	for _, subToolName := range t.Parameters.Tools {
+		result, err = appendTool(result, prg, t, subToolName, toolNames)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return result, nil
+}
+
+func getTool(prg Program, parent Tool, name string) (Tool, error) {
+	toolID, ok := parent.ToolMapping[name]
+	if !ok {
+		return Tool{}, &ErrToolNotFound{
+			ToolName: name,
+		}
+	}
+	tool, ok := prg.ToolSet[toolID]
+	if !ok {
+		return Tool{}, &ErrToolNotFound{
+			ToolName: name,
+		}
+	}
+	return tool, nil
+}
+
+func appendTool(completionTools []CompletionTool, prg Program, parentTool Tool, subToolName string, toolNames map[string]struct{}) ([]CompletionTool, error) {
+	subTool, err := getTool(prg, parentTool, subToolName)
+	if err != nil {
+		return nil, err
+	}
+
+	args := subTool.Parameters.Arguments
+	if args == nil && !subTool.IsCommand() {
+		args = &system.DefaultToolSchema
+	}
+
+	for _, existingTool := range completionTools {
+		if existingTool.Function.ToolID == subTool.ID {
+			return completionTools, nil
+		}
+	}
+
+	if subTool.Instructions == "" {
+		log.Debugf("Skipping zero instruction tool %s (%s)", subToolName, subTool.ID)
+	} else {
+		completionTools = append(completionTools, CompletionTool{
+			Function: CompletionFunctionDefinition{
+				ToolID:      subTool.ID,
+				Name:        PickToolName(subToolName, toolNames),
+				Description: subTool.Parameters.Description,
+				Parameters:  args,
+			},
+		})
+	}
+
+	for _, export := range subTool.Export {
+		completionTools, err = appendTool(completionTools, prg, subTool, export, toolNames)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return completionTools, nil
+}
+
 type Repo struct {
 	// VCS The VCS type, such as "git"
 	VCS string
diff --git a/pkg/engine/toolname.go b/pkg/types/toolname.go
similarity index 98%
rename from pkg/engine/toolname.go
rename to pkg/types/toolname.go
index 69357c50..8f46dd19 100644
--- a/pkg/engine/toolname.go
+++ b/pkg/types/toolname.go
@@ -1,4 +1,4 @@
-package engine
+package types
 
 import (
 	"path/filepath"