fix: use random available port by default

pkg/cli/gptscript.go

@@ -59,7 +59,7 @@ type GPTScript struct {
 	ListModels         bool   `usage:"List the models available and exit" local:"true"`
 	ListTools          bool   `usage:"List built-in tools and exit" local:"true"`
 	Server             bool   `usage:"Start server" local:"true"`
-	ListenAddress      string `usage:"Server listen address" default:"127.0.0.1:9090" local:"true"`
+	ListenAddress      string `usage:"Server listen address" default:"127.0.0.1:0" local:"true"`
 	Chdir              string `usage:"Change current working directory" short:"C"`
 	Daemon             bool   `usage:"Run tool as a daemon" local:"true" hidden:"true"`
 	Ports              string `usage:"The port range to use for ephemeral daemon ports (ex: 11000-12000)" hidden:"true"`

pkg/sdkserver/routes.go

@@ -7,7 +7,6 @@ import (
 	"io"
 	"net/http"
 	"os"
-	"slices"
 	"sort"
 	"strings"
 	"sync"
@@ -165,7 +164,14 @@ func (s *server) execHandler(w http.ResponseWriter, r *http.Request) {
 
 	reqObject.Env = append(os.Environ(), reqObject.Env...)
 	// Don't overwrite the PromptURLEnvVar if it is already set in the environment.
-	if !slices.ContainsFunc(reqObject.Env, func(s string) bool { return strings.HasPrefix(s, types.PromptTokenEnvVar+"=") }) {
+	var promptTokenAlreadySet bool
+	for _, env := range reqObject.Env {
+		if strings.HasPrefix(env, types.PromptTokenEnvVar+"=") {
+			promptTokenAlreadySet = true
+			break
+		}
+	}
+	if !promptTokenAlreadySet {
 		// Append a prompt URL for this run.
 		reqObject.Env = append(reqObject.Env, fmt.Sprintf("%s=http://%s/prompt/%s", types.PromptURLEnvVar, s.address, runID), fmt.Sprintf("%s=%s", types.PromptTokenEnvVar, s.token))
 	}

pkg/sdkserver/server.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"io"
 	"log/slog"
+	"net"
 	"net/http"
 	"os"
 	"os/signal"
@@ -17,6 +18,7 @@ import (
 	"github.com/gptscript-ai/gptscript/pkg/gptscript"
 	"github.com/gptscript-ai/gptscript/pkg/mvl"
 	"github.com/gptscript-ai/gptscript/pkg/runner"
+	"github.com/gptscript-ai/gptscript/pkg/types"
 	"github.com/rs/cors"
 )
 
@@ -46,14 +48,24 @@ func Start(ctx context.Context, opts Options) error {
 	opts.Options.Runner.MonitorFactory = NewSessionFactory(events)
 	go events.Start(ctx)
 
+	token := uuid.NewString()
+	// Add the prompt token env var so that gptscript doesn't start its own server. We never want this client to start the
+	// prompt server because it is only used for fmt, parse, etc.
+	opts.Env = append(opts.Env, fmt.Sprintf("%s=%s", types.PromptTokenEnvVar, token))
+
 	g, err := gptscript.New(&opts.Options)
 	if err != nil {
 		return err
 	}
 
+	listener, err := net.Listen("tcp", opts.ListenAddress)
+	if err != nil {
+		return fmt.Errorf("failed to listen on %s: %w", opts.ListenAddress, err)
+	}
+
 	s := &server{
-		address:          opts.ListenAddress,
-		token:            uuid.NewString(),
+		address:          listener.Addr().String(),
+		token:            token,
 		client:           g,
 		events:           events,
 		waitingToConfirm: make(map[string]chan runner.AuthorizerResponse),
@@ -64,7 +76,6 @@ func Start(ctx context.Context, opts Options) error {
 	s.addRoutes(http.DefaultServeMux)
 
 	server := http.Server{
-		Addr: opts.ListenAddress,
 		Handler: apply(http.DefaultServeMux,
 			contentType("application/json"),
 			addRequestID,
@@ -74,7 +85,7 @@ func Start(ctx context.Context, opts Options) error {
 		),
 	}
 
-	slog.Info("Starting server", "addr", server.Addr)
+	slog.Info("Starting server", "addr", s.address)
 
 	context.AfterFunc(sigCtx, func() {
 		ctx, cancel := context.WithTimeout(ctx, 15*time.Second)
@@ -85,7 +96,7 @@ func Start(ctx context.Context, opts Options) error {
 		slog.Info("Server stopped")
 	})
 
-	if err := server.ListenAndServe(); err != nil && !errors.Is(err, http.ErrServerClosed) {
+	if err := server.Serve(listener); err != nil && !errors.Is(err, http.ErrServerClosed) {
 		return fmt.Errorf("server error: %w", err)
 	}
 

pkg/server/server.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"io"
 	"io/fs"
+	"net"
 	"net/http"
 	"os"
 	"path/filepath"
@@ -212,10 +213,15 @@ func (s *Server) getContext(req *http.Request) (string, context.Context) {
 }
 
 func (s *Server) Start(ctx context.Context) error {
+	listener, err := net.Listen("tcp", s.listenAddress)
+	if err != nil {
+		return fmt.Errorf("could not listen on %s: %w", s.listenAddress, err)
+	}
+
 	s.ctx = ctx
 	s.melody.HandleConnect(s.Connect)
 	go s.events.Start(ctx)
-	log.Infof("Listening on http://%s", s.listenAddress)
+	log.Infof("Listening on http://%s", listener.Addr().String())
 	handler := cors.Default().Handler(s)
 	server := &http.Server{Addr: s.listenAddress, Handler: handler}
 	context.AfterFunc(ctx, func() {
@@ -224,7 +230,7 @@ func (s *Server) Start(ctx context.Context) error {
 		_ = server.Shutdown(ctx)
 	})
 
-	return server.ListenAndServe()
+	return server.Serve(listener)
 }
 
 func (s *Server) Connect(session *melody.Session) {