feat: add two-way manifest sync between project and app settings

cmd/manifest/manifest.go

@@ -82,6 +82,7 @@ func NewCommand(clients *shared.ClientFactory) *cobra.Command {
 	// Add child commands
 	cmd.AddCommand(NewDiffCommand(clients))
 	cmd.AddCommand(NewInfoCommand(clients))
+	cmd.AddCommand(NewSyncCommand(clients))
 	cmd.AddCommand(NewValidateCommand(clients))
 
 	cmd.Flags().StringVar(

cmd/manifest/sync.go

@@ -0,0 +1,69 @@
+// Copyright 2022-2026 Salesforce, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package manifest
+
+import (
+	"github.com/opentracing/opentracing-go"
+	"github.com/slackapi/slack-cli/internal/app"
+	"github.com/slackapi/slack-cli/internal/cmdutil"
+	"github.com/slackapi/slack-cli/internal/experiment"
+	"github.com/slackapi/slack-cli/internal/manifest"
+	"github.com/slackapi/slack-cli/internal/prompts"
+	"github.com/slackapi/slack-cli/internal/shared"
+	"github.com/slackapi/slack-cli/internal/slackerror"
+	"github.com/slackapi/slack-cli/internal/style"
+	"github.com/spf13/cobra"
+)
+
+var manifestSyncFunc = manifest.Sync
+
+func NewSyncCommand(clients *shared.ClientFactory) *cobra.Command {
+	cmd := &cobra.Command{
+		Use:    "sync",
+		Short:  "Sync the app manifest between project and app settings",
+		Long:   "Compare the local project manifest with app settings, resolve differences, and sync both to the same state.",
+		Hidden: true,
+		Example: style.ExampleCommandsf([]style.ExampleCommand{
+			{Command: "manifest sync", Meaning: "Sync project manifest with app settings"},
+		}),
+		Args: cobra.NoArgs,
+		PreRunE: func(cmd *cobra.Command, args []string) error {
+			if !clients.Config.WithExperimentOn(experiment.ManifestSync) {
+				return slackerror.New(slackerror.ErrExperimentRequired).
+					WithRemediation("Enable the %s experiment with %s",
+						style.Highlight(string(experiment.ManifestSync)),
+						style.CommandText("--experiment manifest-sync"),
+					)
+			}
+			return cmdutil.IsValidProjectDirectory(clients)
+		},
+		RunE: func(cmd *cobra.Command, args []string) error {
+			ctx := cmd.Context()
+			span, ctx := opentracing.StartSpanFromContext(ctx, "cmd.manifest.sync")
+			defer span.Finish()
+
+			selection, err := appSelectPromptFunc(ctx, clients, prompts.ShowAllEnvironments, prompts.ShowInstalledAppsOnly)
+			if err != nil {
+				return err
+			}
+
+			clients.Config.ManifestEnv = app.SetManifestEnvTeamVars(clients.Config.ManifestEnv, selection.App.TeamDomain, selection.App.IsDev)
+
+			_, err = manifestSyncFunc(ctx, clients, selection.App, selection.Auth)
+			return err
+		},
+	}
+	return cmd
+}

cmd/manifest/sync_test.go

@@ -0,0 +1,51 @@
+// Copyright 2022-2026 Salesforce, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package manifest
+
+import (
+	"context"
+	"testing"
+
+	"github.com/slackapi/slack-cli/internal/experiment"
+	"github.com/slackapi/slack-cli/internal/shared"
+	"github.com/slackapi/slack-cli/internal/slackerror"
+	"github.com/slackapi/slack-cli/test/testutil"
+	"github.com/spf13/cobra"
+)
+
+func TestSyncCommand(t *testing.T) {
+	testutil.TableTestCommand(t, testutil.CommandTests{
+		"errors when the manifest-sync experiment is off": {
+			Setup: func(t *testing.T, ctx context.Context, cm *shared.ClientsMock, cf *shared.ClientFactory) {
+				cm.AddDefaultMocks()
+				cf.Config.LoadExperiments(ctx, cf.IO.PrintDebug)
+			},
+			ExpectedError: slackerror.New(slackerror.ErrExperimentRequired),
+		},
+		"passes the experiment gate when manifest-sync is enabled via flag": {
+			Setup: func(t *testing.T, ctx context.Context, cm *shared.ClientsMock, cf *shared.ClientFactory) {
+				cm.AddDefaultMocks()
+				cf.Config.ExperimentsFlag = []string{string(experiment.ManifestSync)}
+				cf.Config.LoadExperiments(ctx, cf.IO.PrintDebug)
+			},
+			// We expect the command to fail downstream of the gate (no app
+			// selected, no SDK config), but NOT with ErrCommandUnavailable —
+			// the gate itself should pass.
+			ExpectedErrorStrings: []string{},
+		},
+	}, func(clients *shared.ClientFactory) *cobra.Command {
+		return NewSyncCommand(clients)
+	})
+}

cmd/root.go

@@ -81,6 +81,7 @@ var AliasMap = map[string]*AliasInfo{
 	"logout":    {CommandFactory: auth.NewLogoutCommand, CanonicalName: "auth logout", ParentName: "auth"},
 	"run":       {CommandFactory: platform.NewRunCommand, CanonicalName: "platform run", ParentName: "platform"},
 	"samples":   {CommandFactory: project.NewSamplesCommand, CanonicalName: "project samples", ParentName: "project"},
+	"sync":      {CommandFactory: manifest.NewSyncCommand, CanonicalName: "manifest sync", ParentName: "manifest"},
 	"uninstall": {CommandFactory: app.NewUninstallCommand, CanonicalName: "app uninstall", ParentName: "app"},
 }
 var processName = cmdutil.GetProcessName()

internal/experiment/experiment.go

@@ -33,6 +33,9 @@ const (
 	// Lipgloss experiment shows pretty styles.
 	Lipgloss Experiment = "lipgloss"
 
+	// ManifestSync experiment enables two-way manifest sync between local and remote.
+	ManifestSync Experiment = "manifest-sync"
+
 	// Placeholder experiment is a placeholder for testing and does nothing... or does it?
 	Placeholder Experiment = "placeholder"
 
@@ -44,6 +47,7 @@ const (
 // Please also add here 👇
 var AllExperiments = []Experiment{
 	Lipgloss,
+	ManifestSync,
 	Placeholder,
 	SetIcon,
 }

internal/manifest/display.go

@@ -0,0 +1,169 @@
+// Copyright 2022-2026 Salesforce, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package manifest
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"sort"
+
+	"github.com/slackapi/slack-cli/internal/iostreams"
+	"github.com/slackapi/slack-cli/internal/style"
+)
+
+// DisplayDiffs prints the differences to the terminal.
+func DisplayDiffs(ctx context.Context, io iostreams.IOStreamer, diffs *DiffResult) {
+	if !diffs.HasDifferences() {
+		return
+	}
+
+	sorted := make([]FieldDiff, len(diffs.Diffs))
+	copy(sorted, diffs.Diffs)
+	sort.Slice(sorted, func(i, j int) bool {
+		return sorted[i].Path < sorted[j].Path
+	})
+
+	io.PrintInfo(ctx, false, "\n%s", style.Sectionf(style.TextSection{
+		Emoji: "books",
+		Text:  "App Manifest",
+		Secondary: []string{
+			fmt.Sprintf("Found %d difference(s) between project and app settings", len(sorted)),
+		},
+	}))
+
+	for _, d := range sorted {
+		io.PrintInfo(ctx, false, "")
+		switch d.Type {
+		case DiffModified:
+			io.PrintInfo(ctx, false, "  %s", style.Bold(d.Path))
+			io.PrintInfo(ctx, false, "    Project:      %s", formatValue(d.LocalValue))
+			io.PrintInfo(ctx, false, "    App settings: %s", formatValue(d.RemoteValue))
+		case DiffLocalOnly:
+			io.PrintInfo(ctx, false, "  %s %s", style.Bold(d.Path), "(only in project)")
+			io.PrintInfo(ctx, false, "    Value: %s", formatValue(d.LocalValue))
+		case DiffRemoteOnly:
+			io.PrintInfo(ctx, false, "  %s %s", style.Bold(d.Path), "(only in app settings)")
+			io.PrintInfo(ctx, false, "    Value: %s", formatValue(d.RemoteValue))
+		}
+	}
+	io.PrintInfo(ctx, false, "")
+}
+
+// PromptResolutionStrategy asks the user how they want to resolve differences.
+func PromptResolutionStrategy(ctx context.Context, io iostreams.IOStreamer) (MergeStrategy, error) {
+	options := []string{
+		"Use all project values",
+		"Use all app settings values",
+		"Choose for each difference",
+	}
+	resp, err := io.SelectPrompt(ctx, "How would you like to resolve these differences?", options, iostreams.SelectPromptConfig{
+		Required: true,
+	})
+	if err != nil {
+		return 0, err
+	}
+	switch resp.Index {
+	case 0:
+		return MergeAllLocal, nil
+	case 1:
+		return MergeAllRemote, nil
+	default:
+		return MergePerField, nil
+	}
+}
+
+// PromptFieldResolutions asks the user to resolve each difference individually.
+func PromptFieldResolutions(ctx context.Context, io iostreams.IOStreamer, diffs *DiffResult) ([]FieldResolution, error) {
+	sorted := make([]FieldDiff, len(diffs.Diffs))
+	copy(sorted, diffs.Diffs)
+	sort.Slice(sorted, func(i, j int) bool {
+		return sorted[i].Path < sorted[j].Path
+	})
+
+	resolutions := make([]FieldResolution, 0, len(sorted))
+	for _, d := range sorted {
+		var options []string
+		switch d.Type {
+		case DiffModified:
+			options = []string{
+				fmt.Sprintf("Use project: %s", formatValue(d.LocalValue)),
+				fmt.Sprintf("Use app settings: %s", formatValue(d.RemoteValue)),
+			}
+		case DiffLocalOnly:
+			options = []string{
+				"Keep (include in merged manifest)",
+				"Remove (exclude from merged manifest)",
+			}
+		case DiffRemoteOnly:
+			options = []string{
+				"Remove (exclude from merged manifest)",
+				"Keep (include in merged manifest)",
+			}
+		}
+
+		resp, err := io.SelectPrompt(ctx, d.Path, options, iostreams.SelectPromptConfig{
+			Required: true,
+		})
+		if err != nil {
+			return nil, err
+		}
+
+		var resolution Resolution
+		switch d.Type {
+		case DiffModified:
+			if resp.Index == 0 {
+				resolution = ResolveLocal
+			} else {
+				resolution = ResolveRemote
+			}
+		case DiffLocalOnly:
+			if resp.Index == 0 {
+				resolution = ResolveLocal
+			} else {
+				resolution = ResolveRemote
+			}
+		case DiffRemoteOnly:
+			if resp.Index == 0 {
+				resolution = ResolveLocal
+			} else {
+				resolution = ResolveRemote
+			}
+		}
+
+		resolutions = append(resolutions, FieldResolution{Path: d.Path, Resolution: resolution})
+	}
+	return resolutions, nil
+}
+
+func formatValue(v any) string {
+	if v == nil {
+		return "(not present)"
+	}
+	switch val := v.(type) {
+	case string:
+		return fmt.Sprintf("%q", val)
+	default:
+		data, err := json.Marshal(val)
+		if err != nil {
+			return fmt.Sprintf("%v", val)
+		}
+		s := string(data)
+		if len(s) > 80 {
+			return s[:77] + "..."
+		}
+		return s
+	}
+}