fix: update log to ensure consistent debug message

Update fsnotify comparison to check for WRITE events using the built-in
`Event.Has()` method instead of `==` comparison (used in older
versions).

This is because fsnotify's `Op` type is a bit mask, and some systems may
send multiple operations at once, which could be rejected by a standard
`==` check. Previously this was causing the `TestSingleEdit` unit test
to be flaky on Mac os.

README.md

@@ -151,6 +151,8 @@ execute `toolbox` to start the server:
 ```sh
 ./toolbox --tools-file "tools.yaml"
 ```
+> [!NOTE]
+> Toolbox enables dynamic reloading by default. To disable, use the `--disable-reload` flag.
 
 You can use `toolbox help` for a full list of flags! To stop the server, send a
 terminate signal (`ctrl+c` on most platforms).

cmd/root.go

@@ -19,20 +19,26 @@ import (
 	_ "embed"
 	"fmt"
 	"io"
+	"maps"
 	"os"
 	"os/signal"
 	"path/filepath"
 	"regexp"
 	"runtime"
+	"slices"
 	"strings"
 	"syscall"
 	"time"
 
+	"github.com/fsnotify/fsnotify"
 	yaml "github.com/goccy/go-yaml"
+	"github.com/googleapis/genai-toolbox/internal/auth"
 	"github.com/googleapis/genai-toolbox/internal/log"
 	"github.com/googleapis/genai-toolbox/internal/prebuiltconfigs"
 	"github.com/googleapis/genai-toolbox/internal/server"
+	"github.com/googleapis/genai-toolbox/internal/sources"
 	"github.com/googleapis/genai-toolbox/internal/telemetry"
+	"github.com/googleapis/genai-toolbox/internal/tools"
 	"github.com/googleapis/genai-toolbox/internal/util"
 
 	// Import tool packages for side effect of registration
@@ -178,6 +184,7 @@ func NewCommand(opts ...Option) *Command {
 	flags.StringVar(&cmd.cfg.TelemetryServiceName, "telemetry-service-name", "toolbox", "Sets the value of the service.name resource attribute for telemetry data.")
 	flags.StringVar(&cmd.prebuiltConfig, "prebuilt", "", "Use a prebuilt tool configuration by source type. Cannot be used with --tools-file. Allowed: 'alloydb-postgres', 'bigquery', 'cloud-sql-mysql', 'cloud-sql-postgres', 'cloud-sql-mssql', 'postgres', 'spanner', 'spanner-postgres'.")
 	flags.BoolVar(&cmd.cfg.Stdio, "stdio", false, "Listens via MCP STDIO instead of acting as a remote HTTP server.")
+	flags.BoolVar(&cmd.cfg.DisableReload, "disable-reload", false, "Disables dynamic reloading of tools file.")
 
 	// wrap RunE command so that we have access to original Command object
 	cmd.RunE = func(*cobra.Command, []string) error { return run(cmd) }
@@ -347,7 +354,7 @@ func loadAndMergeToolsFolder(ctx context.Context, folderPath string) (ToolsFile,
 
 	// Combine both file lists
 	allFiles := append(yamlFiles, ymlFiles...)
-	
+
 	if len(allFiles) == 0 {
 		return ToolsFile{}, fmt.Errorf("no YAML files found in directory %q", folderPath)
 	}
@@ -356,6 +363,177 @@ func loadAndMergeToolsFolder(ctx context.Context, folderPath string) (ToolsFile,
 	return loadAndMergeToolsFiles(ctx, allFiles)
 }
 
+func handleDynamicReload(ctx context.Context, toolsFile ToolsFile, s *server.Server) error {
+	logger, err := util.LoggerFromContext(ctx)
+	if err != nil {
+		panic(err)
+	}
+
+	sourcesMap, authServicesMap, toolsMap, toolsetsMap, err := validateReloadEdits(ctx, toolsFile)
+	if err != nil {
+		errMsg := fmt.Errorf("unable to validate reloaded edits: %w", err)
+		logger.WarnContext(ctx, errMsg.Error())
+		return err
+	}
+
+	s.ResourceMgr.SetResources(sourcesMap, authServicesMap, toolsMap, toolsetsMap)
+
+	return nil
+}
+
+// validateReloadEdits checks that the reloaded tools file configs can initialized without failing
+func validateReloadEdits(
+	ctx context.Context, toolsFile ToolsFile,
+) (map[string]sources.Source, map[string]auth.AuthService, map[string]tools.Tool, map[string]tools.Toolset, error,
+) {
+	logger, err := util.LoggerFromContext(ctx)
+	if err != nil {
+		panic(err)
+	}
+
+	instrumentation, err := util.InstrumentationFromContext(ctx)
+	if err != nil {
+		panic(err)
+	}
+
+	logger.DebugContext(ctx, "Attempting to parse and validate reloaded tools file.")
+
+	ctx, span := instrumentation.Tracer.Start(ctx, "toolbox/server/reload")
+	defer span.End()
+
+	reloadedConfig := server.ServerConfig{
+		Version:            versionString,
+		SourceConfigs:      toolsFile.Sources,
+		AuthServiceConfigs: toolsFile.AuthServices,
+		ToolConfigs:        toolsFile.Tools,
+		ToolsetConfigs:     toolsFile.Toolsets,
+	}
+
+	sourcesMap, authServicesMap, toolsMap, toolsetsMap, err := server.InitializeConfigs(ctx, reloadedConfig)
+	if err != nil {
+		errMsg := fmt.Errorf("unable to initialize reloaded configs: %w", err)
+		logger.WarnContext(ctx, errMsg.Error())
+		return nil, nil, nil, nil, err
+	}
+
+	return sourcesMap, authServicesMap, toolsMap, toolsetsMap, nil
+}
+
+// watchChanges checks for changes in the provided yaml tools file(s) or folder.
+func watchChanges(ctx context.Context, watchDirs map[string]bool, watchedFiles map[string]bool, s *server.Server) {
+	logger, err := util.LoggerFromContext(ctx)
+	if err != nil {
+		panic(err)
+	}
+
+	w, err := fsnotify.NewWatcher()
+	if err != nil {
+		logger.WarnContext(ctx, "error setting up new watcher %s", err)
+		return
+	}
+
+	defer w.Close()
+
+	watchingFolder := false
+	var folderToWatch string
+
+	// if watchedFiles is empty, indicates that user passed entire folder instead
+	if len(watchedFiles) == 0 {
+		watchingFolder = true
+
+		// validate that watchDirs only has single element
+		if len(watchDirs) > 1 {
+			logger.WarnContext(ctx, "error setting watcher, expected single tools folder if no file(s) are defined.")
+			return
+		}
+
+		for onlyKey := range watchDirs {
+			folderToWatch = onlyKey
+			break
+		}
+	}
+
+	for dir := range watchDirs {
+		err := w.Add(dir)
+		if err != nil {
+			logger.WarnContext(ctx, fmt.Sprintf("Error adding path %s to watcher: %s", dir, err))
+			break
+		}
+		logger.DebugContext(ctx, fmt.Sprintf("Added directory %s to watcher.", dir))
+	}
+
+	// debounce timer is used to prevent multiple writes triggering multiple reloads
+	debounceDelay := 100 * time.Millisecond
+	debounce := time.NewTimer(1 * time.Minute)
+	debounce.Stop()
+
+	for {
+		select {
+		case <-ctx.Done():
+			logger.DebugContext(ctx, "file watcher context cancelled")
+			return
+		case err, ok := <-w.Errors:
+			if !ok {
+				logger.WarnContext(ctx, "file watcher was closed unexpectedly")
+				return
+			}
+			if err != nil {
+				logger.WarnContext(ctx, "file watcher error %s", err)
+				return
+			}
+
+		case e, ok := <-w.Events:
+			if !ok {
+				logger.WarnContext(ctx, "file watcher already closed")
+				return
+			}
+
+			// only check for write events which indicate user saved a new tools file
+			if !e.Has(fsnotify.Write) {
+				continue
+			}
+
+			cleanedFilename := filepath.Clean(e.Name)
+			logger.DebugContext(ctx, fmt.Sprintf("WRITE event detected in %s", cleanedFilename))
+
+			folderChanged := watchingFolder &&
+				(strings.HasSuffix(cleanedFilename, ".yaml") || strings.HasSuffix(cleanedFilename, ".yml"))
+
+			if folderChanged || watchedFiles[cleanedFilename] {
+				// indicates the write event is on a relevant file
+				debounce.Reset(debounceDelay)
+			}
+
+		case <-debounce.C:
+			debounce.Stop()
+			var reloadedToolsFile ToolsFile
+
+			if watchingFolder {
+				logger.DebugContext(ctx, "Reloading tools folder.")
+				reloadedToolsFile, err = loadAndMergeToolsFolder(ctx, folderToWatch)
+				if err != nil {
+					logger.WarnContext(ctx, "error loading tools folder %s", err)
+					continue
+				}
+			} else {
+				logger.DebugContext(ctx, "Reloading tools file(s).")
+				reloadedToolsFile, err = loadAndMergeToolsFiles(ctx, slices.Collect(maps.Keys(watchedFiles)))
+				if err != nil {
+					logger.WarnContext(ctx, "error loading tools files %s", err)
+					continue
+				}
+			}
+
+			err = handleDynamicReload(ctx, reloadedToolsFile, s)
+			if err != nil {
+				errMsg := fmt.Errorf("unable to parse reloaded tools file at %q: %w", reloadedToolsFile, err)
+				logger.WarnContext(ctx, errMsg.Error())
+				continue
+			}
+		}
+	}
+}
+
 // updateLogLevel checks if Toolbox have to update the existing log level set by users.
 // stdio doesn't support "debug" and "info" logs.
 func updateLogLevel(stdio bool, logLevel string) bool {
@@ -370,6 +548,33 @@ func updateLogLevel(stdio bool, logLevel string) bool {
 	return false
 }
 
+func resolveWatcherInputs(toolsFile string, toolsFiles []string, toolsFolder string) (map[string]bool, map[string]bool) {
+	var relevantFiles []string
+
+	// map for efficiently checking if a file is relevant
+	watchedFiles := make(map[string]bool)
+
+	// dirs that will be added to watcher (fsnotify prefers watching directory then filtering for file)
+	watchDirs := make(map[string]bool)
+
+	if len(toolsFiles) > 0 {
+		relevantFiles = toolsFiles
+	} else if toolsFolder != "" {
+		watchDirs[filepath.Clean(toolsFolder)] = true
+	} else {
+		relevantFiles = []string{toolsFile}
+	}
+
+	// extract parent dir for relevant files and dedup
+	for _, f := range relevantFiles {
+		cleanFile := filepath.Clean(f)
+		watchedFiles[cleanFile] = true
+		watchDirs[filepath.Dir(cleanFile)] = true
+	}
+
+	return watchDirs, watchedFiles
+}
+
 func run(cmd *Command) error {
 	if updateLogLevel(cmd.cfg.Stdio, cmd.cfg.LogLevel.String()) {
 		cmd.cfg.LogLevel = server.StringLevel(log.Warn)
@@ -466,6 +671,7 @@ func run(cmd *Command) error {
 			cmd.logger.ErrorContext(ctx, errMsg.Error())
 			return errMsg
 		}
+
 		// Use multiple tools files
 		cmd.logger.InfoContext(ctx, fmt.Sprintf("Loading and merging %d tool configuration files", len(cmd.tools_files)))
 		var err error
@@ -481,6 +687,7 @@ func run(cmd *Command) error {
 			cmd.logger.ErrorContext(ctx, errMsg.Error())
 			return errMsg
 		}
+
 		// Use tools folder
 		cmd.logger.InfoContext(ctx, fmt.Sprintf("Loading and merging all YAML files from directory: %s", cmd.tools_folder))
 		var err error
@@ -494,6 +701,7 @@ func run(cmd *Command) error {
 		if cmd.tools_file == "" {
 			cmd.tools_file = "tools.yaml"
 		}
+
 		// Read single tool file contents
 		buf, err := os.ReadFile(cmd.tools_file)
 		if err != nil {
@@ -516,9 +724,23 @@ func run(cmd *Command) error {
 		cmd.logger.WarnContext(ctx, "`authSources` is deprecated, use `authServices` instead")
 		cmd.cfg.AuthServiceConfigs = authSourceConfigs
 	}
+	if err != nil {
+		errMsg := fmt.Errorf("unable to parse tool file at %q: %w", cmd.tools_file, err)
+		cmd.logger.ErrorContext(ctx, errMsg.Error())
+		return errMsg
+	}
+
+	instrumentation, err := telemetry.CreateTelemetryInstrumentation(versionString)
+	if err != nil {
+		errMsg := fmt.Errorf("unable to create telemetry instrumentation: %w", err)
+		cmd.logger.ErrorContext(ctx, errMsg.Error())
+		return errMsg
+	}
+
+	ctx = util.WithInstrumentation(ctx, instrumentation)
 
 	// start server
-	s, err := server.NewServer(ctx, cmd.cfg, cmd.logger)
+	s, err := server.NewServer(ctx, cmd.cfg)
 	if err != nil {
 		errMsg := fmt.Errorf("toolbox failed to initialize: %w", err)
 		cmd.logger.ErrorContext(ctx, errMsg.Error())
@@ -553,6 +775,13 @@ func run(cmd *Command) error {
 		}()
 	}
 
+	watchDirs, watchedFiles := resolveWatcherInputs(cmd.tools_file, cmd.tools_files, cmd.tools_folder)
+
+	if !cmd.cfg.DisableReload {
+		// start watching the file(s) or folder for changes to trigger dynamic reloading
+		go watchChanges(ctx, watchDirs, watchedFiles, s)
+	}
+
 	// wait for either the server to error out or the command's context to be canceled
 	select {
 	case err := <-srvErr:

cmd/root_test.go

@@ -16,23 +16,33 @@ package cmd
 
 import (
 	"bytes"
+	"context"
 	_ "embed"
+	"fmt"
+	"io"
 	"os"
+	"path"
+	"path/filepath"
+	"regexp"
 	"runtime"
 	"strings"
 	"testing"
+	"time"
 
 	"github.com/google/go-cmp/cmp"
 
 	"github.com/googleapis/genai-toolbox/internal/auth/google"
+	"github.com/googleapis/genai-toolbox/internal/log"
 	"github.com/googleapis/genai-toolbox/internal/prebuiltconfigs"
 	"github.com/googleapis/genai-toolbox/internal/server"
 	cloudsqlpgsrc "github.com/googleapis/genai-toolbox/internal/sources/cloudsqlpg"
 	httpsrc "github.com/googleapis/genai-toolbox/internal/sources/http"
+	"github.com/googleapis/genai-toolbox/internal/telemetry"
 	"github.com/googleapis/genai-toolbox/internal/testutils"
 	"github.com/googleapis/genai-toolbox/internal/tools"
 	"github.com/googleapis/genai-toolbox/internal/tools/http"
 	"github.com/googleapis/genai-toolbox/internal/tools/postgres/postgressql"
+	"github.com/googleapis/genai-toolbox/internal/util"
 	"github.com/spf13/cobra"
 )
 
@@ -174,6 +184,13 @@ func TestServerConfigFlags(t *testing.T) {
 				Stdio: true,
 			}),
 		},
+		{
+			desc: "disable reload",
+			args: []string{"--disable-reload"},
+			want: withDefaults(server.ServerConfig{
+				DisableReload: true,
+			}),
+		},
 	}
 	for _, tc := range tcs {
 		t.Run(tc.desc, func(t *testing.T) {
@@ -965,6 +982,185 @@ func TestEnvVarReplacement(t *testing.T) {
 
 }
 
+// normalizeFilepaths is a helper function to allow same filepath formats for Mac and Windows.
+// this prevents needing multiple "want" cases for TestResolveWatcherInputs
+func normalizeFilepaths(m map[string]bool) map[string]bool {
+	newMap := make(map[string]bool)
+	for k, v := range m {
+		newMap[filepath.ToSlash(k)] = v
+	}
+	return newMap
+}
+
+func TestResolveWatcherInputs(t *testing.T) {
+	tcs := []struct {
+		description      string
+		toolsFile        string
+		toolsFiles       []string
+		toolsFolder      string
+		wantWatchDirs    map[string]bool
+		wantWatchedFiles map[string]bool
+	}{
+		{
+			description:      "single tools file",
+			toolsFile:        "tools_folder/example_tools.yaml",
+			toolsFiles:       []string{},
+			toolsFolder:      "",
+			wantWatchDirs:    map[string]bool{"tools_folder": true},
+			wantWatchedFiles: map[string]bool{"tools_folder/example_tools.yaml": true},
+		},
+		{
+			description:      "default tools file (root dir)",
+			toolsFile:        "tools.yaml",
+			toolsFiles:       []string{},
+			toolsFolder:      "",
+			wantWatchDirs:    map[string]bool{".": true},
+			wantWatchedFiles: map[string]bool{"tools.yaml": true},
+		},
+		{
+			description:   "multiple files in different folders",
+			toolsFile:     "",
+			toolsFiles:    []string{"tools_folder/example_tools.yaml", "tools_folder2/example_tools.yaml"},
+			toolsFolder:   "",
+			wantWatchDirs: map[string]bool{"tools_folder": true, "tools_folder2": true},
+			wantWatchedFiles: map[string]bool{
+				"tools_folder/example_tools.yaml":  true,
+				"tools_folder2/example_tools.yaml": true,
+			},
+		},
+		{
+			description:   "multiple files in same folder",
+			toolsFile:     "",
+			toolsFiles:    []string{"tools_folder/example_tools.yaml", "tools_folder/example_tools2.yaml"},
+			toolsFolder:   "",
+			wantWatchDirs: map[string]bool{"tools_folder": true},
+			wantWatchedFiles: map[string]bool{
+				"tools_folder/example_tools.yaml":  true,
+				"tools_folder/example_tools2.yaml": true,
+			},
+		},
+		{
+			description: "multiple files in different levels",
+			toolsFile:   "",
+			toolsFiles: []string{
+				"tools_folder/example_tools.yaml",
+				"tools_folder/special_tools/example_tools2.yaml"},
+			toolsFolder:   "",
+			wantWatchDirs: map[string]bool{"tools_folder": true, "tools_folder/special_tools": true},
+			wantWatchedFiles: map[string]bool{
+				"tools_folder/example_tools.yaml":                true,
+				"tools_folder/special_tools/example_tools2.yaml": true,
+			},
+		},
+		{
+			description:      "tools folder",
+			toolsFile:        "",
+			toolsFiles:       []string{},
+			toolsFolder:      "tools_folder",
+			wantWatchDirs:    map[string]bool{"tools_folder": true},
+			wantWatchedFiles: map[string]bool{},
+		},
+	}
+	for _, tc := range tcs {
+		t.Run(tc.description, func(t *testing.T) {
+			gotWatchDirs, gotWatchedFiles := resolveWatcherInputs(tc.toolsFile, tc.toolsFiles, tc.toolsFolder)
+
+			normalizedGotWatchDirs := normalizeFilepaths(gotWatchDirs)
+			normalizedGotWatchedFiles := normalizeFilepaths(gotWatchedFiles)
+
+			if diff := cmp.Diff(tc.wantWatchDirs, normalizedGotWatchDirs); diff != "" {
+				t.Errorf("incorrect watchDirs: diff %v", diff)
+			}
+			if diff := cmp.Diff(tc.wantWatchedFiles, normalizedGotWatchedFiles); diff != "" {
+				t.Errorf("incorrect watchedFiles: diff %v", diff)
+			}
+
+		})
+	}
+}
+
+// helper function for testing file detection in dynamic reloading
+func tmpFileWithCleanup(content []byte) (string, func(), error) {
+	f, err := os.CreateTemp("", "*")
+	if err != nil {
+		return "", nil, err
+	}
+	cleanup := func() { os.Remove(f.Name()) }
+
+	if _, err := f.Write(content); err != nil {
+		cleanup()
+		return "", nil, err
+	}
+	if err := f.Close(); err != nil {
+		cleanup()
+		return "", nil, err
+	}
+	return f.Name(), cleanup, err
+}
+
+func TestSingleEdit(t *testing.T) {
+	ctx, cancelCtx := context.WithTimeout(context.Background(), time.Minute)
+	defer cancelCtx()
+
+	pr, pw := io.Pipe()
+	defer pw.Close()
+	defer pr.Close()
+
+	fileToWatch, cleanup, err := tmpFileWithCleanup([]byte("initial content"))
+	if err != nil {
+		t.Fatalf("error editing tools file %s", err)
+	}
+	defer cleanup()
+
+	logger, err := log.NewStdLogger(pw, pw, "DEBUG")
+	if err != nil {
+		t.Fatalf("failed to setup logger %s", err)
+	}
+	ctx = util.WithLogger(ctx, logger)
+
+	instrumentation, err := telemetry.CreateTelemetryInstrumentation(versionString)
+	if err != nil {
+		t.Fatalf("failed to setup instrumentation %s", err)
+	}
+	ctx = util.WithInstrumentation(ctx, instrumentation)
+
+	mockServer := &server.Server{}
+
+	cleanFileToWatch := filepath.Clean(fileToWatch)
+	watchDir := filepath.Dir(cleanFileToWatch)
+
+	watchedFiles := map[string]bool{cleanFileToWatch: true}
+	watchDirs := map[string]bool{watchDir: true}
+
+	go watchChanges(ctx, watchDirs, watchedFiles, mockServer)
+
+	// escape backslash so regex doesn't fail on windows filepaths
+	regexEscapedPathFile := strings.ReplaceAll(cleanFileToWatch, `\`, `\\\\*\\`)
+	regexEscapedPathFile = path.Clean(regexEscapedPathFile)
+
+	regexEscapedPathDir := strings.ReplaceAll(watchDir, `\`, `\\\\*\\`)
+	regexEscapedPathDir = path.Clean(regexEscapedPathDir)
+
+	begunWatchingDir := regexp.MustCompile(fmt.Sprintf(`DEBUG "Added directory %s to watcher."`, regexEscapedPathDir))
+	res, err := testutils.WaitForString(ctx, begunWatchingDir, pr)
+	t.Log("log result: ", res)
+	if err != nil {
+		t.Fatalf("timeout or error waiting for watcher to start: %s, actually got: ", err)
+	}
+
+	err = os.WriteFile(fileToWatch, []byte("modification"), 0777)
+	if err != nil {
+		t.Fatalf("error writing to file: %v", err)
+	}
+
+	detectedFileChange := regexp.MustCompile(fmt.Sprintf(`DEBUG "WRITE event detected in %s"`, regexEscapedPathFile))
+	res, err = testutils.WaitForString(ctx, detectedFileChange, pr)
+	t.Log("log result: ", res)
+	if err != nil {
+		t.Fatalf("timeout or error waiting for file to detect write: %s", err)
+	}
+}
+
 func TestPrebuiltTools(t *testing.T) {
 	alloydb_config, _ := prebuiltconfigs.Get("alloydb-postgres")
 	bigquery_config, _ := prebuiltconfigs.Get("bigquery")

docs/en/getting-started/introduction/_index.md

@@ -123,6 +123,9 @@ execute `toolbox` to start the server:
 ```sh
 ./toolbox --tools-file "tools.yaml"
 ```
+{{< notice note >}}
+Toolbox enables dynamic reloading by default. To disable, use the `--disable-reload` flag.
+{{< /notice >}}
 
 You can use `toolbox help` for a full list of flags! To stop the server, send a
 terminate signal (`ctrl+c` on most platforms).

docs/en/getting-started/local_quickstart.md

@@ -257,6 +257,9 @@ In this section, we will download Toolbox, configure our tools in a
     ```bash
     ./toolbox --tools-file "tools.yaml"
     ```
+    {{< notice note >}}
+    Toolbox enables dynamic reloading by default. To disable, use the `--disable-reload` flag.
+    {{< /notice >}}
 
 ## Step 3: Connect your agent to Toolbox
 

docs/en/how-to/connect_via_mcp.md

@@ -63,6 +63,10 @@ When running with stdio, Toolbox will listen via stdio instead of acting as a
 remote HTTP server. Logs will be set to the `warn` level by default. `debug` and
 `info` logs are not supported with stdio.
 
+{{< notice note >}}
+Toolbox enables dynamic reloading by default. To disable, use the `--disable-reload` flag.
+{{< /notice >}}
+
 ### Connecting via HTTP
 
 Toolbox supports the HTTP transport protocol with and without SSE.

docs/en/samples/bigquery/local_quickstart.md

@@ -292,6 +292,9 @@ to use BigQuery, and then run the Toolbox server.
     ```bash
     ./toolbox --tools-file "tools.yaml"
     ```
+    {{< notice note >}}
+    Toolbox enables dynamic reloading by default. To disable, use the `--disable-reload` flag.
+    {{< /notice >}}
 
 ## Step 3: Connect your agent to Toolbox
 

go.mod

@@ -14,6 +14,7 @@ require (
 	github.com/GoogleCloudPlatform/opentelemetry-operations-go/exporter/trace v1.29.0
 	github.com/couchbase/gocb/v2 v2.10.0
 	github.com/couchbase/tools-common/http v1.0.9
+	github.com/fsnotify/fsnotify v1.9.0
 	github.com/go-chi/chi/v5 v5.2.2
 	github.com/go-chi/httplog/v2 v2.1.1
 	github.com/go-chi/render v1.0.3

go.sum

@@ -765,6 +765,8 @@ github.com/felixge/httpsnoop v1.0.4 h1:NFTV2Zj1bL4mc9sqWACXbQFVBBg2W3GPvqp8/ESS2
 github.com/felixge/httpsnoop v1.0.4/go.mod h1:m8KPJKqk1gH5J9DgRY2ASl2lWCfGKXixSwevea8zH2U=
 github.com/fogleman/gg v1.2.1-0.20190220221249-0403632d5b90/go.mod h1:R/bRT+9gY/C5z7JzPU0zXsXHKM4/ayA+zqcVNZzPa1k=
 github.com/fogleman/gg v1.3.0/go.mod h1:R/bRT+9gY/C5z7JzPU0zXsXHKM4/ayA+zqcVNZzPa1k=
+github.com/fsnotify/fsnotify v1.9.0 h1:2Ml+OJNzbYCTzsxtv8vKSFD9PbJjmhYF14k/jKC7S9k=
+github.com/fsnotify/fsnotify v1.9.0/go.mod h1:8jBTzvmWwFyi3Pb8djgCCO5IBqzKJ/Jwo8TRcHyHii0=
 github.com/gabriel-vasile/mimetype v1.4.8 h1:FfZ3gj38NjllZIeJAmMhr+qKL8Wu+nOoI3GqacKw1NM=
 github.com/gabriel-vasile/mimetype v1.4.8/go.mod h1:ByKUIKGjh1ODkGM1asKUbQZOLGrPjydw3hYPU2YU9t8=
 github.com/ghodss/yaml v1.0.0/go.mod h1:4dBDuWmgqj2HViK6kFavaiC9ZROes6MMH2rRYeMEF04=

internal/server/api.go

@@ -75,7 +75,7 @@ func toolsetHandler(s *Server, w http.ResponseWriter, r *http.Request) {
 		)
 	}()
 
-	toolset, ok := s.toolsets[toolsetName]
+	toolset, ok := s.ResourceMgr.GetToolset(toolsetName)
 	if !ok {
 		err = fmt.Errorf("toolset %q does not exist", toolsetName)
 		s.logger.DebugContext(ctx, err.Error())
@@ -111,7 +111,7 @@ func toolGetHandler(s *Server, w http.ResponseWriter, r *http.Request) {
 			metric.WithAttributes(attribute.String("toolbox.operation.status", status)),
 		)
 	}()
-	tool, ok := s.tools[toolName]
+	tool, ok := s.ResourceMgr.GetTool(toolName)
 	if !ok {
 		err = fmt.Errorf("invalid tool name: tool with name %q does not exist", toolName)
 		s.logger.DebugContext(ctx, err.Error())
@@ -156,7 +156,7 @@ func toolInvokeHandler(s *Server, w http.ResponseWriter, r *http.Request) {
 		)
 	}()
 
-	tool, ok := s.tools[toolName]
+	tool, ok := s.ResourceMgr.GetTool(toolName)
 	if !ok {
 		err = fmt.Errorf("invalid tool name: tool with name %q does not exist", toolName)
 		s.logger.DebugContext(ctx, err.Error())
@@ -167,7 +167,7 @@ func toolInvokeHandler(s *Server, w http.ResponseWriter, r *http.Request) {
 	// Tool authentication
 	// claimsFromAuth maps the name of the authservice to the claims retrieved from it.
 	claimsFromAuth := make(map[string]map[string]any)
-	for _, aS := range s.authServices {
+	for _, aS := range s.ResourceMgr.GetAuthServiceMap() {
 		claims, err := aS.GetClaimsFromHeader(ctx, r.Header)
 		if err != nil {
 			s.logger.DebugContext(ctx, err.Error())

internal/server/common_test.go

@@ -147,14 +147,23 @@ func setUpServer(t *testing.T, router string, tools map[string]tools.Tool, tools
 		t.Fatalf("unable to setup otel: %s", err)
 	}
 
-	instrumentation, err := CreateTelemetryInstrumentation(fakeVersionString)
+	instrumentation, err := telemetry.CreateTelemetryInstrumentation(fakeVersionString)
 	if err != nil {
 		t.Fatalf("unable to create custom metrics: %s", err)
 	}
 
 	sseManager := newSseManager(ctx)
 
-	server := Server{version: fakeVersionString, logger: testLogger, instrumentation: instrumentation, sseManager: sseManager, tools: tools, toolsets: toolsets}
+	resourceManager := NewResourceManager(nil, nil, tools, toolsets)
+
+	server := Server{
+		version:         fakeVersionString,
+		logger:          testLogger,
+		instrumentation: instrumentation,
+		sseManager:      sseManager,
+		ResourceMgr:     resourceManager,
+	}
+
 	var r chi.Router
 	switch router {
 	case "api":

internal/server/config.go

@@ -53,6 +53,8 @@ type ServerConfig struct {
 	TelemetryServiceName string
 	// Stdio indicates if Toolbox is listening via MCP stdio.
 	Stdio bool
+	// DisableReload indicates if the user has disabled dynamic reloading for Toolbox.
+	DisableReload bool
 }
 
 type logFormat string

internal/server/mcp.go

@@ -479,12 +479,12 @@ func processMcpMessage(ctx context.Context, body []byte, s *Server, protocolVers
 		}
 		return v, res, err
 	default:
-		toolset, ok := s.toolsets[toolsetName]
+		toolset, ok := s.ResourceMgr.GetToolset(toolsetName)
 		if !ok {
 			err = fmt.Errorf("toolset does not exist")
 			return "", jsonrpc.NewError(baseMessage.Id, jsonrpc.INVALID_REQUEST, err.Error(), nil), err
 		}
-		res, err := mcp.ProcessMethod(ctx, protocolVersion, baseMessage.Id, baseMessage.Method, toolset, s.tools, body)
+		res, err := mcp.ProcessMethod(ctx, protocolVersion, baseMessage.Id, baseMessage.Method, toolset, s.ResourceMgr.GetToolsMap(), body)
 		return "", res, err
 	}
 }

internal/server/mcp_test.go

@@ -693,14 +693,22 @@ func TestStdioSession(t *testing.T) {
 		}
 	}()
 
-	instrumentation, err := CreateTelemetryInstrumentation(fakeVersionString)
+	instrumentation, err := telemetry.CreateTelemetryInstrumentation(fakeVersionString)
 	if err != nil {
 		t.Fatalf("unable to create custom metrics: %s", err)
 	}
 
 	sseManager := newSseManager(ctx)
 
-	server := &Server{version: fakeVersionString, logger: testLogger, instrumentation: instrumentation, sseManager: sseManager, tools: toolsMap, toolsets: toolsets}
+	resourceManager := NewResourceManager(nil, nil, toolsMap, toolsets)
+
+	server := &Server{
+		version:         fakeVersionString,
+		logger:          testLogger,
+		instrumentation: instrumentation,
+		sseManager:      sseManager,
+		ResourceMgr:     resourceManager,
+	}
 
 	in := bufio.NewReader(pr)
 	stdioSession := NewStdioSession(server, in, pw)

internal/server/server.go

@@ -21,6 +21,7 @@ import (
 	"net"
 	"net/http"
 	"strconv"
+	"sync"
 	"time"
 
 	"github.com/go-chi/chi/v5"
@@ -29,6 +30,7 @@ import (
 	"github.com/googleapis/genai-toolbox/internal/auth"
 	"github.com/googleapis/genai-toolbox/internal/log"
 	"github.com/googleapis/genai-toolbox/internal/sources"
+	"github.com/googleapis/genai-toolbox/internal/telemetry"
 	"github.com/googleapis/genai-toolbox/internal/tools"
 	"github.com/googleapis/genai-toolbox/internal/util"
 	"go.opentelemetry.io/otel/attribute"
@@ -42,26 +44,225 @@ type Server struct {
 	listener        net.Listener
 	root            chi.Router
 	logger          log.Logger
-	instrumentation *Instrumentation
+	instrumentation *telemetry.Instrumentation
 	sseManager      *sseManager
+	ResourceMgr     *ResourceManager
+}
 
+// ResourceManager contains available resources for the server. Should be initialized with NewResourceManager().
+type ResourceManager struct {
+	mu           sync.RWMutex
 	sources      map[string]sources.Source
 	authServices map[string]auth.AuthService
 	tools        map[string]tools.Tool
 	toolsets     map[string]tools.Toolset
 }
 
-// NewServer returns a Server object based on provided Config.
-func NewServer(ctx context.Context, cfg ServerConfig, l log.Logger) (*Server, error) {
-	instrumentation, err := CreateTelemetryInstrumentation(cfg.Version)
+func NewResourceManager(
+	sourcesMap map[string]sources.Source,
+	authServicesMap map[string]auth.AuthService,
+	toolsMap map[string]tools.Tool, toolsetsMap map[string]tools.Toolset,
+) *ResourceManager {
+	resourceMgr := &ResourceManager{
+		mu:           sync.RWMutex{},
+		sources:      sourcesMap,
+		authServices: authServicesMap,
+		tools:        toolsMap,
+		toolsets:     toolsetsMap,
+	}
+
+	return resourceMgr
+}
+
+func (r *ResourceManager) GetSource(sourceName string) (sources.Source, bool) {
+	r.mu.RLock()
+	defer r.mu.RUnlock()
+	source, ok := r.sources[sourceName]
+	return source, ok
+}
+
+func (r *ResourceManager) GetAuthService(authServiceName string) (auth.AuthService, bool) {
+	r.mu.RLock()
+	defer r.mu.RUnlock()
+	authService, ok := r.authServices[authServiceName]
+	return authService, ok
+}
+
+func (r *ResourceManager) GetTool(toolName string) (tools.Tool, bool) {
+	r.mu.RLock()
+	defer r.mu.RUnlock()
+	tool, ok := r.tools[toolName]
+	return tool, ok
+}
+
+func (r *ResourceManager) GetToolset(toolsetName string) (tools.Toolset, bool) {
+	r.mu.RLock()
+	defer r.mu.RUnlock()
+	toolset, ok := r.toolsets[toolsetName]
+	return toolset, ok
+}
+
+func (r *ResourceManager) SetResources(sourcesMap map[string]sources.Source, authServicesMap map[string]auth.AuthService, toolsMap map[string]tools.Tool, toolsetsMap map[string]tools.Toolset) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	r.sources = sourcesMap
+	r.authServices = authServicesMap
+	r.tools = toolsMap
+	r.toolsets = toolsetsMap
+}
+
+func (r *ResourceManager) GetAuthServiceMap() map[string]auth.AuthService {
+	r.mu.RLock()
+	defer r.mu.RUnlock()
+	return r.authServices
+}
+
+func (r *ResourceManager) GetToolsMap() map[string]tools.Tool {
+	r.mu.RLock()
+	defer r.mu.RUnlock()
+	return r.tools
+}
+
+func InitializeConfigs(ctx context.Context, cfg ServerConfig) (
+	map[string]sources.Source,
+	map[string]auth.AuthService,
+	map[string]tools.Tool,
+	map[string]tools.Toolset,
+	error,
+) {
+	ctx = util.WithUserAgent(ctx, cfg.Version)
+	instrumentation, err := util.InstrumentationFromContext(ctx)
 	if err != nil {
-		return nil, fmt.Errorf("unable to create telemetry instrumentation: %w", err)
+		panic(err)
+	}
+
+	l, err := util.LoggerFromContext(ctx)
+	if err != nil {
+		panic(err)
+	}
+
+	// initialize and validate the sources from configs
+	sourcesMap := make(map[string]sources.Source)
+	for name, sc := range cfg.SourceConfigs {
+		s, err := func() (sources.Source, error) {
+			childCtx, span := instrumentation.Tracer.Start(
+				ctx,
+				"toolbox/server/source/init",
+				trace.WithAttributes(attribute.String("source_kind", sc.SourceConfigKind())),
+				trace.WithAttributes(attribute.String("source_name", name)),
+			)
+			defer span.End()
+			s, err := sc.Initialize(childCtx, instrumentation.Tracer)
+			if err != nil {
+				return nil, fmt.Errorf("unable to initialize source %q: %w", name, err)
+			}
+			return s, nil
+		}()
+		if err != nil {
+			return nil, nil, nil, nil, err
+		}
+		sourcesMap[name] = s
+	}
+	l.InfoContext(ctx, fmt.Sprintf("Initialized %d sources.", len(sourcesMap)))
+
+	// initialize and validate the auth services from configs
+	authServicesMap := make(map[string]auth.AuthService)
+	for name, sc := range cfg.AuthServiceConfigs {
+		a, err := func() (auth.AuthService, error) {
+			_, span := instrumentation.Tracer.Start(
+				ctx,
+				"toolbox/server/auth/init",
+				trace.WithAttributes(attribute.String("auth_kind", sc.AuthServiceConfigKind())),
+				trace.WithAttributes(attribute.String("auth_name", name)),
+			)
+			defer span.End()
+			a, err := sc.Initialize()
+			if err != nil {
+				return nil, fmt.Errorf("unable to initialize auth service %q: %w", name, err)
+			}
+			return a, nil
+		}()
+		if err != nil {
+			return nil, nil, nil, nil, err
+		}
+		authServicesMap[name] = a
+	}
+	l.InfoContext(ctx, fmt.Sprintf("Initialized %d authServices.", len(authServicesMap)))
+
+	// initialize and validate the tools from configs
+	toolsMap := make(map[string]tools.Tool)
+	for name, tc := range cfg.ToolConfigs {
+		t, err := func() (tools.Tool, error) {
+			_, span := instrumentation.Tracer.Start(
+				ctx,
+				"toolbox/server/tool/init",
+				trace.WithAttributes(attribute.String("tool_kind", tc.ToolConfigKind())),
+				trace.WithAttributes(attribute.String("tool_name", name)),
+			)
+			defer span.End()
+			t, err := tc.Initialize(sourcesMap)
+			if err != nil {
+				return nil, fmt.Errorf("unable to initialize tool %q: %w", name, err)
+			}
+			return t, nil
+		}()
+		if err != nil {
+			return nil, nil, nil, nil, err
+		}
+		toolsMap[name] = t
+	}
+	l.InfoContext(ctx, fmt.Sprintf("Initialized %d tools.", len(toolsMap)))
+
+	// create a default toolset that contains all tools
+	allToolNames := make([]string, 0, len(toolsMap))
+	for name := range toolsMap {
+		allToolNames = append(allToolNames, name)
+	}
+	if cfg.ToolsetConfigs == nil {
+		cfg.ToolsetConfigs = make(ToolsetConfigs)
+	}
+	cfg.ToolsetConfigs[""] = tools.ToolsetConfig{Name: "", ToolNames: allToolNames}
+
+	// initialize and validate the toolsets from configs
+	toolsetsMap := make(map[string]tools.Toolset)
+	for name, tc := range cfg.ToolsetConfigs {
+		t, err := func() (tools.Toolset, error) {
+			_, span := instrumentation.Tracer.Start(
+				ctx,
+				"toolbox/server/toolset/init",
+				trace.WithAttributes(attribute.String("toolset_name", name)),
+			)
+			defer span.End()
+			t, err := tc.Initialize(cfg.Version, toolsMap)
+			if err != nil {
+				return tools.Toolset{}, fmt.Errorf("unable to initialize toolset %q: %w", name, err)
+			}
+			return t, err
+		}()
+		if err != nil {
+			return nil, nil, nil, nil, err
+		}
+		toolsetsMap[name] = t
+	}
+	l.InfoContext(ctx, fmt.Sprintf("Initialized %d toolsets.", len(toolsetsMap)))
+
+	return sourcesMap, authServicesMap, toolsMap, toolsetsMap, nil
+}
+
+// NewServer returns a Server object based on provided Config.
+func NewServer(ctx context.Context, cfg ServerConfig) (*Server, error) {
+	instrumentation, err := util.InstrumentationFromContext(ctx)
+	if err != nil {
+		return nil, err
 	}
 
 	ctx, span := instrumentation.Tracer.Start(ctx, "toolbox/server/init")
 	defer span.End()
 
-	ctx = util.WithUserAgent(ctx, cfg.Version)
+	l, err := util.LoggerFromContext(ctx)
+	if err != nil {
+		return nil, err
+	}
 
 	// set up http serving
 	r := chi.NewRouter()
@@ -97,116 +298,18 @@ func NewServer(ctx context.Context, cfg ServerConfig, l log.Logger) (*Server, er
 	httpLogger := httplog.NewLogger("httplog", httpOpts)
 	r.Use(httplog.RequestLogger(httpLogger))
 
-	// initialize and validate the sources from configs
-	sourcesMap := make(map[string]sources.Source)
-	for name, sc := range cfg.SourceConfigs {
-		s, err := func() (sources.Source, error) {
-			childCtx, span := instrumentation.Tracer.Start(
-				ctx,
-				"toolbox/server/source/init",
-				trace.WithAttributes(attribute.String("source_kind", sc.SourceConfigKind())),
-				trace.WithAttributes(attribute.String("source_name", name)),
-			)
-			defer span.End()
-			s, err := sc.Initialize(childCtx, instrumentation.Tracer)
-			if err != nil {
-				return nil, fmt.Errorf("unable to initialize source %q: %w", name, err)
-			}
-			return s, nil
-		}()
-		if err != nil {
-			return nil, err
-		}
-		sourcesMap[name] = s
+	sourcesMap, authServicesMap, toolsMap, toolsetsMap, err := InitializeConfigs(ctx, cfg)
+	if err != nil {
+		return nil, fmt.Errorf("unable to initialize configs: %w", err)
 	}
-	l.InfoContext(ctx, fmt.Sprintf("Initialized %d sources.", len(sourcesMap)))
-
-	// initialize and validate the auth services from configs
-	authServicesMap := make(map[string]auth.AuthService)
-	for name, sc := range cfg.AuthServiceConfigs {
-		a, err := func() (auth.AuthService, error) {
-			_, span := instrumentation.Tracer.Start(
-				ctx,
-				"toolbox/server/auth/init",
-				trace.WithAttributes(attribute.String("auth_kind", sc.AuthServiceConfigKind())),
-				trace.WithAttributes(attribute.String("auth_name", name)),
-			)
-			defer span.End()
-			a, err := sc.Initialize()
-			if err != nil {
-				return nil, fmt.Errorf("unable to initialize auth service %q: %w", name, err)
-			}
-			return a, nil
-		}()
-		if err != nil {
-			return nil, err
-		}
-		authServicesMap[name] = a
-	}
-	l.InfoContext(ctx, fmt.Sprintf("Initialized %d authServices.", len(authServicesMap)))
-
-	// initialize and validate the tools from configs
-	toolsMap := make(map[string]tools.Tool)
-	for name, tc := range cfg.ToolConfigs {
-		t, err := func() (tools.Tool, error) {
-			_, span := instrumentation.Tracer.Start(
-				ctx,
-				"toolbox/server/tool/init",
-				trace.WithAttributes(attribute.String("tool_kind", tc.ToolConfigKind())),
-				trace.WithAttributes(attribute.String("tool_name", name)),
-			)
-			defer span.End()
-			t, err := tc.Initialize(sourcesMap)
-			if err != nil {
-				return nil, fmt.Errorf("unable to initialize tool %q: %w", name, err)
-			}
-			return t, nil
-		}()
-		if err != nil {
-			return nil, err
-		}
-		toolsMap[name] = t
-	}
-	l.InfoContext(ctx, fmt.Sprintf("Initialized %d tools.", len(toolsMap)))
-
-	// create a default toolset that contains all tools
-	allToolNames := make([]string, 0, len(toolsMap))
-	for name := range toolsMap {
-		allToolNames = append(allToolNames, name)
-	}
-	if cfg.ToolsetConfigs == nil {
-		cfg.ToolsetConfigs = make(ToolsetConfigs)
-	}
-	cfg.ToolsetConfigs[""] = tools.ToolsetConfig{Name: "", ToolNames: allToolNames}
-
-	// initialize and validate the toolsets from configs
-	toolsetsMap := make(map[string]tools.Toolset)
-	for name, tc := range cfg.ToolsetConfigs {
-		t, err := func() (tools.Toolset, error) {
-			_, span := instrumentation.Tracer.Start(
-				ctx,
-				"toolbox/server/toolset/init",
-				trace.WithAttributes(attribute.String("toolset_name", name)),
-			)
-			defer span.End()
-			t, err := tc.Initialize(cfg.Version, toolsMap)
-			if err != nil {
-				return tools.Toolset{}, fmt.Errorf("unable to initialize toolset %q: %w", name, err)
-			}
-			return t, err
-		}()
-		if err != nil {
-			return nil, err
-		}
-		toolsetsMap[name] = t
-	}
-	l.InfoContext(ctx, fmt.Sprintf("Initialized %d toolsets.", len(toolsetsMap)))
 
 	addr := net.JoinHostPort(cfg.Address, strconv.Itoa(cfg.Port))
 	srv := &http.Server{Addr: addr, Handler: r}
 
 	sseManager := newSseManager(ctx)
 
+	resourceManager := NewResourceManager(sourcesMap, authServicesMap, toolsMap, toolsetsMap)
+
 	s := &Server{
 		version:         cfg.Version,
 		srv:             srv,
@@ -214,11 +317,7 @@ func NewServer(ctx context.Context, cfg ServerConfig, l log.Logger) (*Server, er
 		logger:          l,
 		instrumentation: instrumentation,
 		sseManager:      sseManager,
-
-		sources:      sourcesMap,
-		authServices: authServicesMap,
-		tools:        toolsMap,
-		toolsets:     toolsetsMap,
+		ResourceMgr:     resourceManager,
 	}
 	// control plane
 	apiR, err := apiRouter(s)

internal/server/server_test.go

@@ -23,9 +23,16 @@ import (
 	"strings"
 	"testing"
 
+	"github.com/google/go-cmp/cmp"
+	"github.com/googleapis/genai-toolbox/internal/auth"
 	"github.com/googleapis/genai-toolbox/internal/log"
 	"github.com/googleapis/genai-toolbox/internal/server"
+	"github.com/googleapis/genai-toolbox/internal/sources"
+	"github.com/googleapis/genai-toolbox/internal/sources/alloydbpg"
 	"github.com/googleapis/genai-toolbox/internal/telemetry"
+	"github.com/googleapis/genai-toolbox/internal/testutils"
+	"github.com/googleapis/genai-toolbox/internal/tools"
+	"github.com/googleapis/genai-toolbox/internal/util"
 )
 
 func TestServe(t *testing.T) {
@@ -54,8 +61,16 @@ func TestServe(t *testing.T) {
 	if err != nil {
 		t.Fatalf("unexpected error: %s", err)
 	}
+	ctx = util.WithLogger(ctx, testLogger)
 
-	s, err := server.NewServer(ctx, cfg, testLogger)
+	instrumentation, err := telemetry.CreateTelemetryInstrumentation(cfg.Version)
+	if err != nil {
+		t.Fatalf("unexpected error: %s", err)
+	}
+
+	ctx = util.WithInstrumentation(ctx, instrumentation)
+
+	s, err := server.NewServer(ctx, cfg)
 	if err != nil {
 		t.Fatalf("unable to initialize server: %v", err)
 	}
@@ -93,3 +108,67 @@ func TestServe(t *testing.T) {
 		t.Fatalf("version missing from output: %q", got)
 	}
 }
+
+func TestUpdateServer(t *testing.T) {
+	ctx, err := testutils.ContextWithNewLogger()
+	if err != nil {
+		t.Fatalf("error setting up logger: %s", err)
+	}
+
+	addr, port := "127.0.0.1", 5000
+	cfg := server.ServerConfig{
+		Version: "0.0.0",
+		Address: addr,
+		Port:    port,
+	}
+
+	instrumentation, err := telemetry.CreateTelemetryInstrumentation(cfg.Version)
+	if err != nil {
+		t.Fatalf("unexpected error: %s", err)
+	}
+
+	ctx = util.WithInstrumentation(ctx, instrumentation)
+
+	s, err := server.NewServer(ctx, cfg)
+	if err != nil {
+		t.Fatalf("error setting up server: %s", err)
+	}
+
+	newSources := map[string]sources.Source{
+		"example-source": &alloydbpg.Source{
+			Name: "example-alloydb-source",
+			Kind: "alloydb-postgres",
+		},
+	}
+	newAuth := map[string]auth.AuthService{"example-auth": nil}
+	newTools := map[string]tools.Tool{"example-tool": nil}
+	newToolsets := map[string]tools.Toolset{
+		"example-toolset": {
+			Name: "example-toolset", Tools: []*tools.Tool{},
+		},
+	}
+	s.ResourceMgr.SetResources(newSources, newAuth, newTools, newToolsets)
+	if err != nil {
+		t.Errorf("error updating server: %s", err)
+	}
+
+	gotSource, _ := s.ResourceMgr.GetSource("example-source")
+	if diff := cmp.Diff(gotSource, newSources["example-source"]); diff != "" {
+		t.Errorf("error updating server, sources (-want +got):\n%s", diff)
+	}
+
+	gotAuthService, _ := s.ResourceMgr.GetAuthService("example-auth")
+	if diff := cmp.Diff(gotAuthService, newAuth["example-auth"]); diff != "" {
+		t.Errorf("error updating server, authServices (-want +got):\n%s", diff)
+	}
+
+	gotTool, _ := s.ResourceMgr.GetTool("example-tool")
+	if diff := cmp.Diff(gotTool, newTools["example-tool"]); diff != "" {
+		t.Errorf("error updating server, tools (-want +got):\n%s", diff)
+	}
+
+	gotToolset, _ := s.ResourceMgr.GetToolset("example-toolset")
+	if diff := cmp.Diff(gotToolset, newToolsets["example-toolset"]); diff != "" {
+		t.Errorf("error updating server, toolset (-want +got):\n%s", diff)
+	}
+}

internal/telemetry/instrumentation.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package server
+package telemetry
 
 import (
 	"fmt"

internal/testutils/testutils.go

@@ -15,9 +15,12 @@
 package testutils
 
 import (
+	"bufio"
 	"context"
 	"fmt"
+	"io"
 	"os"
+	"regexp"
 	"strings"
 
 	"github.com/googleapis/genai-toolbox/internal/log"
@@ -42,3 +45,63 @@ func ContextWithNewLogger() (context.Context, error) {
 	}
 	return util.WithLogger(ctx, logger), nil
 }
+
+// WaitForString waits until the server logs a single line that matches the provided regex.
+// returns the output of whatever the server sent so far.
+func WaitForString(ctx context.Context, re *regexp.Regexp, pr io.ReadCloser) (string, error) {
+	in := bufio.NewReader(pr)
+	ctx, cancel := context.WithCancel(ctx)
+	defer cancel()
+
+	// read lines in background, sending result of each read over a channel
+	// this allows us to use in.ReadString without blocking
+	type result struct {
+		s   string
+		err error
+	}
+	output := make(chan result)
+	go func() {
+		defer close(output)
+		for {
+			select {
+			case <-ctx.Done():
+				// if the context is canceled, the orig thread will send back the error
+				// so we can just exit the goroutine here
+				return
+			default:
+				// otherwise read a line from the output
+				s, err := in.ReadString('\n')
+				if err != nil {
+					output <- result{err: err}
+					return
+				}
+				output <- result{s: s}
+				// if that last string matched, exit the goroutine
+				if re.MatchString(s) {
+					return
+				}
+			}
+		}
+	}()
+
+	// collect the output until the ctx is canceled, an error was hit,
+	// or match was found (which is indicated the channel is closed)
+	var sb strings.Builder
+	for {
+		select {
+		case <-ctx.Done():
+			// if ctx is done, return that error
+			return sb.String(), ctx.Err()
+		case o, ok := <-output:
+			if !ok {
+				// match was found!
+				return sb.String(), nil
+			}
+			if o.err != nil {
+				// error was found!
+				return sb.String(), o.err
+			}
+			sb.WriteString(o.s)
+		}
+	}
+}

internal/util/util.go

@@ -23,6 +23,7 @@ import (
 	"github.com/go-playground/validator/v10"
 	yaml "github.com/goccy/go-yaml"
 	"github.com/googleapis/genai-toolbox/internal/log"
+	"github.com/googleapis/genai-toolbox/internal/telemetry"
 )
 
 // DecodeJSON decodes a given reader into an interface using the json decoder.
@@ -98,10 +99,25 @@ func WithLogger(ctx context.Context, logger log.Logger) context.Context {
 	return context.WithValue(ctx, loggerKey, logger)
 }
 
-// LoggerFromContext retreives the logger or return an error
+// LoggerFromContext retrieves the logger or return an error
 func LoggerFromContext(ctx context.Context) (log.Logger, error) {
 	if logger, ok := ctx.Value(loggerKey).(log.Logger); ok {
 		return logger, nil
 	}
 	return nil, fmt.Errorf("unable to retrieve logger")
 }
+
+const instrumentationKey contextKey = "instrumentation"
+
+// WithInstrumentation adds an instrumentation into the context as a value
+func WithInstrumentation(ctx context.Context, instrumentation *telemetry.Instrumentation) context.Context {
+	return context.WithValue(ctx, instrumentationKey, instrumentation)
+}
+
+// InstrumentationFromContext retrieves the instrumentation or return an error
+func InstrumentationFromContext(ctx context.Context) (*telemetry.Instrumentation, error) {
+	if instrumentation, ok := ctx.Value(instrumentationKey).(*telemetry.Instrumentation); ok {
+		return instrumentation, nil
+	}
+	return nil, fmt.Errorf("unable to retrieve instrumentation")
+}

tests/alloydbainl/alloydb_ai_nl_integration_test.go

@@ -28,6 +28,7 @@ import (
 	"time"
 
 	"github.com/googleapis/genai-toolbox/internal/server/mcp/jsonrpc"
+	"github.com/googleapis/genai-toolbox/internal/testutils"
 	"github.com/googleapis/genai-toolbox/tests"
 )
 
@@ -90,7 +91,7 @@ func TestAlloyDBAINLToolEndpoints(t *testing.T) {
 
 	waitCtx, cancel := context.WithTimeout(ctx, 10*time.Second)
 	defer cancel()
-	out, err := cmd.WaitForString(waitCtx, regexp.MustCompile(`Server ready to serve`))
+	out, err := testutils.WaitForString(waitCtx, regexp.MustCompile(`Server ready to serve`), cmd.Out)
 	if err != nil {
 		t.Logf("toolbox command logs: \n%s", out)
 		t.Fatalf("toolbox didn't start successfully: %s", err)

tests/alloydbpg/alloydb_pg_integration_test.go

@@ -26,6 +26,7 @@ import (
 
 	"cloud.google.com/go/alloydbconn"
 	"github.com/google/uuid"
+	"github.com/googleapis/genai-toolbox/internal/testutils"
 	"github.com/googleapis/genai-toolbox/tests"
 	"github.com/jackc/pgx/v5/pgxpool"
 )
@@ -157,7 +158,7 @@ func TestAlloyDBPgToolEndpoints(t *testing.T) {
 
 	waitCtx, cancel := context.WithTimeout(ctx, 10*time.Second)
 	defer cancel()
-	out, err := cmd.WaitForString(waitCtx, regexp.MustCompile(`Server ready to serve`))
+	out, err := testutils.WaitForString(waitCtx, regexp.MustCompile(`Server ready to serve`), cmd.Out)
 	if err != nil {
 		t.Logf("toolbox command logs: \n%s", out)
 		t.Fatalf("toolbox didn't start successfully: %s", err)

tests/bigquery/bigquery_integration_test.go

@@ -29,6 +29,7 @@ import (
 
 	bigqueryapi "cloud.google.com/go/bigquery"
 	"github.com/google/uuid"
+	"github.com/googleapis/genai-toolbox/internal/testutils"
 	"github.com/googleapis/genai-toolbox/tests"
 	"golang.org/x/oauth2/google"
 	"google.golang.org/api/googleapi"
@@ -124,7 +125,7 @@ func TestBigQueryToolEndpoints(t *testing.T) {
 
 	waitCtx, cancel := context.WithTimeout(ctx, 10*time.Second)
 	defer cancel()
-	out, err := cmd.WaitForString(waitCtx, regexp.MustCompile(`Server ready to serve`))
+	out, err := testutils.WaitForString(waitCtx, regexp.MustCompile(`Server ready to serve`), cmd.Out)
 	if err != nil {
 		t.Logf("toolbox command logs: \n%s", out)
 		t.Fatalf("toolbox didn't start successfully: %s", err)

tests/bigtable/bigtable_integration_test.go

@@ -29,6 +29,7 @@ import (
 
 	"cloud.google.com/go/bigtable"
 	"github.com/google/uuid"
+	"github.com/googleapis/genai-toolbox/internal/testutils"
 	"github.com/googleapis/genai-toolbox/internal/tools"
 	"github.com/googleapis/genai-toolbox/tests"
 )
@@ -103,7 +104,7 @@ func TestBigtableToolEndpoints(t *testing.T) {
 
 	waitCtx, cancel := context.WithTimeout(ctx, 10*time.Second)
 	defer cancel()
-	out, err := cmd.WaitForString(waitCtx, regexp.MustCompile(`Server ready to serve`))
+	out, err := testutils.WaitForString(waitCtx, regexp.MustCompile(`Server ready to serve`), cmd.Out)
 	if err != nil {
 		t.Logf("toolbox command logs: \n%s", out)
 		t.Fatalf("toolbox didn't start successfully: %s", err)

tests/cloudsqlmssql/cloud_sql_mssql_integration_test.go

@@ -29,6 +29,7 @@ import (
 	"cloud.google.com/go/cloudsqlconn"
 	"cloud.google.com/go/cloudsqlconn/sqlserver/mssql"
 	"github.com/google/uuid"
+	"github.com/googleapis/genai-toolbox/internal/testutils"
 	"github.com/googleapis/genai-toolbox/tests"
 )
 
@@ -151,7 +152,7 @@ func TestCloudSQLMSSQLToolEndpoints(t *testing.T) {
 
 	waitCtx, cancel := context.WithTimeout(ctx, 10*time.Second)
 	defer cancel()
-	out, err := cmd.WaitForString(waitCtx, regexp.MustCompile(`Server ready to serve`))
+	out, err := testutils.WaitForString(waitCtx, regexp.MustCompile(`Server ready to serve`), cmd.Out)
 	if err != nil {
 		t.Logf("toolbox command logs: \n%s", out)
 		t.Fatalf("toolbox didn't start successfully: %s", err)

tests/cloudsqlmysql/cloud_sql_mysql_integration_test.go

@@ -28,6 +28,7 @@ import (
 	"cloud.google.com/go/cloudsqlconn"
 	"cloud.google.com/go/cloudsqlconn/mysql/mysql"
 	"github.com/google/uuid"
+	"github.com/googleapis/genai-toolbox/internal/testutils"
 	"github.com/googleapis/genai-toolbox/tests"
 )
 
@@ -138,7 +139,7 @@ func TestCloudSQLMySQLToolEndpoints(t *testing.T) {
 
 	waitCtx, cancel := context.WithTimeout(ctx, 10*time.Second)
 	defer cancel()
-	out, err := cmd.WaitForString(waitCtx, regexp.MustCompile(`Server ready to serve`))
+	out, err := testutils.WaitForString(waitCtx, regexp.MustCompile(`Server ready to serve`), cmd.Out)
 	if err != nil {
 		t.Logf("toolbox command logs: \n%s", out)
 		t.Fatalf("toolbox didn't start successfully: %s", err)

tests/cloudsqlpg/cloud_sql_pg_integration_test.go

@@ -26,6 +26,7 @@ import (
 
 	"cloud.google.com/go/cloudsqlconn"
 	"github.com/google/uuid"
+	"github.com/googleapis/genai-toolbox/internal/testutils"
 	"github.com/googleapis/genai-toolbox/tests"
 	"github.com/jackc/pgx/v5/pgxpool"
 )
@@ -142,7 +143,7 @@ func TestCloudSQLPgSimpleToolEndpoints(t *testing.T) {
 
 	waitCtx, cancel := context.WithTimeout(ctx, 10*time.Second)
 	defer cancel()
-	out, err := cmd.WaitForString(waitCtx, regexp.MustCompile(`Server ready to serve`))
+	out, err := testutils.WaitForString(waitCtx, regexp.MustCompile(`Server ready to serve`), cmd.Out)
 	if err != nil {
 		t.Logf("toolbox command logs: \n%s", out)
 		t.Fatalf("toolbox didn't start successfully: %s", err)

tests/couchbase/couchbase_integration_test.go

@@ -25,6 +25,7 @@ import (
 
 	"github.com/couchbase/gocb/v2"
 	"github.com/google/uuid"
+	"github.com/googleapis/genai-toolbox/internal/testutils"
 	"github.com/googleapis/genai-toolbox/tests"
 )
 
@@ -128,7 +129,7 @@ func TestCouchbaseToolEndpoints(t *testing.T) {
 
 	waitCtx, cancel := context.WithTimeout(ctx, 10*time.Second)
 	defer cancel()
-	out, err := cmd.WaitForString(waitCtx, regexp.MustCompile(`Server ready to serve`))
+	out, err := testutils.WaitForString(waitCtx, regexp.MustCompile(`Server ready to serve`), cmd.Out)
 	if err != nil {
 		t.Logf("toolbox command logs: \n%s", out)
 		t.Fatalf("toolbox didn't start successfully: %s", err)

tests/dgraph/dgraph_integration_test.go

@@ -26,6 +26,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/googleapis/genai-toolbox/internal/testutils"
 	"github.com/googleapis/genai-toolbox/tests"
 )
 
@@ -78,7 +79,7 @@ func TestDgraphToolEndpoints(t *testing.T) {
 
 	waitCtx, cancel := context.WithTimeout(ctx, 10*time.Second)
 	defer cancel()
-	out, err := cmd.WaitForString(waitCtx, regexp.MustCompile(`Server ready to serve`))
+	out, err := testutils.WaitForString(waitCtx, regexp.MustCompile(`Server ready to serve`), cmd.Out)
 	if err != nil {
 		t.Logf("toolbox command logs: \n%s", out)
 		t.Fatalf("toolbox didn't start successfully: %s", err)

tests/http/http_integration_test.go

@@ -28,6 +28,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/googleapis/genai-toolbox/internal/testutils"
 	"github.com/googleapis/genai-toolbox/internal/tools"
 	"github.com/googleapis/genai-toolbox/tests"
 )
@@ -254,7 +255,7 @@ func TestHttpToolEndpoints(t *testing.T) {
 
 	waitCtx, cancel := context.WithTimeout(ctx, 10*time.Second)
 	defer cancel()
-	out, err := cmd.WaitForString(waitCtx, regexp.MustCompile(`Server ready to serve`))
+	out, err := testutils.WaitForString(waitCtx, regexp.MustCompile(`Server ready to serve`), cmd.Out)
 	if err != nil {
 		t.Logf("toolbox command logs: \n%s", out)
 		t.Fatalf("toolbox didn't start successfully: %s", err)

tests/mssql/mssql_integration_test.go

@@ -26,6 +26,7 @@ import (
 	"time"
 
 	"github.com/google/uuid"
+	"github.com/googleapis/genai-toolbox/internal/testutils"
 	"github.com/googleapis/genai-toolbox/tests"
 )
 
@@ -124,7 +125,7 @@ func TestMSSQLToolEndpoints(t *testing.T) {
 
 	waitCtx, cancel := context.WithTimeout(ctx, 10*time.Second)
 	defer cancel()
-	out, err := cmd.WaitForString(waitCtx, regexp.MustCompile(`Server ready to serve`))
+	out, err := testutils.WaitForString(waitCtx, regexp.MustCompile(`Server ready to serve`), cmd.Out)
 	if err != nil {
 		t.Logf("toolbox command logs: \n%s", out)
 		t.Fatalf("toolbox didn't start successfully: %s", err)

tests/mysql/mysql_integration_test.go

@@ -25,6 +25,7 @@ import (
 	"time"
 
 	"github.com/google/uuid"
+	"github.com/googleapis/genai-toolbox/internal/testutils"
 	"github.com/googleapis/genai-toolbox/tests"
 )
 
@@ -115,7 +116,7 @@ func TestMySQLToolEndpoints(t *testing.T) {
 
 	waitCtx, cancel := context.WithTimeout(ctx, 10*time.Second)
 	defer cancel()
-	out, err := cmd.WaitForString(waitCtx, regexp.MustCompile(`Server ready to serve`))
+	out, err := testutils.WaitForString(waitCtx, regexp.MustCompile(`Server ready to serve`), cmd.Out)
 	if err != nil {
 		t.Logf("toolbox command logs: \n%s", out)
 		t.Fatalf("toolbox didn't start successfully: %s", err)

tests/neo4j/neo4j_integration_test.go

@@ -26,6 +26,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/googleapis/genai-toolbox/internal/testutils"
 	"github.com/googleapis/genai-toolbox/tests"
 )
 
@@ -87,7 +88,7 @@ func TestNeo4jToolEndpoints(t *testing.T) {
 
 	waitCtx, cancel := context.WithTimeout(ctx, 10*time.Second)
 	defer cancel()
-	out, err := cmd.WaitForString(waitCtx, regexp.MustCompile(`Server ready to serve`))
+	out, err := testutils.WaitForString(waitCtx, regexp.MustCompile(`Server ready to serve`), cmd.Out)
 	if err != nil {
 		t.Logf("toolbox command logs: \n%s", out)
 		t.Fatalf("toolbox didn't start successfully: %s", err)

tests/postgres/postgres_integration_test.go

@@ -25,6 +25,7 @@ import (
 	"time"
 
 	"github.com/google/uuid"
+	"github.com/googleapis/genai-toolbox/internal/testutils"
 	"github.com/googleapis/genai-toolbox/tests"
 	"github.com/jackc/pgx/v5/pgxpool"
 )
@@ -121,7 +122,7 @@ func TestPostgres(t *testing.T) {
 
 	waitCtx, cancel := context.WithTimeout(ctx, 10*time.Second)
 	defer cancel()
-	out, err := cmd.WaitForString(waitCtx, regexp.MustCompile(`Server ready to serve`))
+	out, err := testutils.WaitForString(waitCtx, regexp.MustCompile(`Server ready to serve`), cmd.Out)
 	if err != nil {
 		t.Logf("toolbox command logs: \n%s", out)
 		t.Fatalf("toolbox didn't start successfully: %s", err)

tests/redis/redis_test.go

@@ -22,6 +22,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/googleapis/genai-toolbox/internal/testutils"
 	"github.com/googleapis/genai-toolbox/tests"
 	"github.com/redis/go-redis/v9"
 )
@@ -90,7 +91,7 @@ func TestRedisToolEndpoints(t *testing.T) {
 
 	waitCtx, cancel := context.WithTimeout(ctx, 10*time.Second)
 	defer cancel()
-	out, err := cmd.WaitForString(waitCtx, regexp.MustCompile(`Server ready to serve`))
+	out, err := testutils.WaitForString(waitCtx, regexp.MustCompile(`Server ready to serve`), cmd.Out)
 	if err != nil {
 		t.Logf("toolbox command logs: \n%s", out)
 		t.Fatalf("toolbox didn't start successfully: %s", err)

tests/server.go

@@ -15,13 +15,10 @@
 package tests
 
 import (
-	"bufio"
 	"context"
 	"fmt"
 	"io"
 	"os"
-	"regexp"
-	"strings"
 
 	yaml "github.com/goccy/go-yaml"
 
@@ -133,63 +130,3 @@ func (c *CmdExec) Close() {
 		c.Close()
 	}
 }
-
-// WaitForString waits until the server logs a single line that matches the provided regex.
-// returns the output of whatever the server sent so far.
-func (c *CmdExec) WaitForString(ctx context.Context, re *regexp.Regexp) (string, error) {
-	ctx, cancel := context.WithCancel(ctx)
-	defer cancel()
-	in := bufio.NewReader(c.Out)
-
-	// read lines in background, sending result of each read over a channel
-	// this allows us to use in.ReadString without blocking
-	type result struct {
-		s   string
-		err error
-	}
-	output := make(chan result)
-	go func() {
-		defer close(output)
-		for {
-			select {
-			case <-ctx.Done():
-				// if the context is canceled, the orig thread will send back the error
-				// so we can just exit the goroutine here
-				return
-			default:
-				// otherwise read a line from the output
-				s, err := in.ReadString('\n')
-				if err != nil {
-					output <- result{err: err}
-					return
-				}
-				output <- result{s: s}
-				// if that last string matched, exit the goroutine
-				if re.MatchString(s) {
-					return
-				}
-			}
-		}
-	}()
-
-	// collect the output until the ctx is canceled, an error was hit,
-	// or match was found (which is indicated the channel is closed)
-	var sb strings.Builder
-	for {
-		select {
-		case <-ctx.Done():
-			// if ctx is done, return that error
-			return sb.String(), ctx.Err()
-		case o, ok := <-output:
-			if !ok {
-				// match was found!
-				return sb.String(), nil
-			}
-			if o.err != nil {
-				// error was found!
-				return sb.String(), o.err
-			}
-			sb.WriteString(o.s)
-		}
-	}
-}

tests/source.go

@@ -26,6 +26,7 @@ import (
 	"time"
 
 	"cloud.google.com/go/cloudsqlconn"
+	"github.com/googleapis/genai-toolbox/internal/testutils"
 )
 
 // RunSourceConnection test for source connection
@@ -57,7 +58,7 @@ func RunSourceConnectionTest(t *testing.T, sourceConfig map[string]any, toolKind
 
 	waitCtx, cancel := context.WithTimeout(ctx, 10*time.Second)
 	defer cancel()
-	out, err := cmd.WaitForString(waitCtx, regexp.MustCompile(`Server ready to serve`))
+	out, err := testutils.WaitForString(waitCtx, regexp.MustCompile(`Server ready to serve`), cmd.Out)
 	if err != nil {
 		t.Logf("toolbox command logs: \n%s", out)
 		return fmt.Errorf("toolbox didn't start successfully: %s", err)

tests/spanner/spanner_integration_test.go

@@ -31,6 +31,7 @@ import (
 	database "cloud.google.com/go/spanner/admin/database/apiv1"
 	"cloud.google.com/go/spanner/admin/database/apiv1/databasepb"
 	"github.com/google/uuid"
+	"github.com/googleapis/genai-toolbox/internal/testutils"
 	"github.com/googleapis/genai-toolbox/internal/tools"
 	"github.com/googleapis/genai-toolbox/tests"
 )
@@ -141,7 +142,7 @@ func TestSpannerToolEndpoints(t *testing.T) {
 
 	waitCtx, cancel := context.WithTimeout(ctx, 10*time.Second)
 	defer cancel()
-	out, err := cmd.WaitForString(waitCtx, regexp.MustCompile(`Server ready to serve`))
+	out, err := testutils.WaitForString(waitCtx, regexp.MustCompile(`Server ready to serve`), cmd.Out)
 	if err != nil {
 		t.Logf("toolbox command logs: \n%s", out)
 		t.Fatalf("toolbox didn't start successfully: %s", err)

tests/sqlite/sqlite_integration_test.go

@@ -25,6 +25,7 @@ import (
 	"time"
 
 	"github.com/google/uuid"
+	"github.com/googleapis/genai-toolbox/internal/testutils"
 	"github.com/googleapis/genai-toolbox/tests"
 )
 
@@ -143,7 +144,7 @@ func TestSQLiteToolEndpoint(t *testing.T) {
 
 	waitCtx, cancel := context.WithTimeout(ctx, 10*time.Second)
 	defer cancel()
-	out, err := cmd.WaitForString(waitCtx, regexp.MustCompile(`Server ready to serve`))
+	out, err := testutils.WaitForString(waitCtx, regexp.MustCompile(`Server ready to serve`), cmd.Out)
 	if err != nil {
 		t.Logf("toolbox command logs: \n%s", out)
 		t.Fatalf("toolbox didn't start successfully: %s", err)

tests/valkey/valkey_test.go

@@ -22,6 +22,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/googleapis/genai-toolbox/internal/testutils"
 	"github.com/googleapis/genai-toolbox/tests"
 	"github.com/valkey-io/valkey-go"
 )
@@ -93,7 +94,7 @@ func TestValkeyToolEndpoints(t *testing.T) {
 
 	waitCtx, cancel := context.WithTimeout(ctx, 10*time.Second)
 	defer cancel()
-	out, err := cmd.WaitForString(waitCtx, regexp.MustCompile(`Server ready to serve`))
+	out, err := testutils.WaitForString(waitCtx, regexp.MustCompile(`Server ready to serve`), cmd.Out)
 	if err != nil {
 		t.Logf("toolbox command logs: \n%s", out)
 		t.Fatalf("toolbox didn't start successfully: %s", err)