@@ -27,44 +27,35 @@ func main() {
 	cli.BuildDate = buildDate
 	cli.Version = version
 
-	// Parse command line arguments
 	args, err := cli.ParseArgs()
 	if err != nil {
 		fmt.Fprintln(os.Stderr, style.Errorf("parsing arguments: %v", err))
 		os.Exit(1)
 	}
 
-	// Set up signal handling before any blocking call.
-	// SIGINT, SIGTERM, and SIGHUP are all treated the same — clean shutdown.
 	sh := signals.New()
 	sh.Watch()
 
-
-	// Get viper instance with config file + environment variables + defaults
 	v := config.GetViper()
 
-	// Bind CLI args to viper (highest precedence)
 	config.BindCLIArgs(v, args.ToViperMap())
 
-	// Create runtime directly from viper configuration
+	// FeedsFile and Prompt come from positional CLI args; everything else from viper
 	rt := config.ViperToRuntime(v, args.FeedsFile, args.Prompt)
 
 
-	// Run dry-run mode if requested (validates config, shows statistics, no LLM calls)
 	if args.DryRun {
 		sh.Stop()
 		runDryRun(rt, args.Verbose)
 		os.Exit(0)
 	}
 
-	// Validate API key (required for actual execution)
 	if v.GetString("api_key") == "" {
 		sh.Stop()
 		fmt.Fprintln(os.Stderr, style.Errorf("OpenAI-compatible API key is required. Set via --api-key, %s environment variable, or config file.", "LLM_AGGREGATOR_API_KEY"))
 		os.Exit(1)
 	}
 
-	// Run with TUI if requested
 	if args.TUI {
 		sh.Stop()
 		runWithTUI(rt)
@@ -74,20 +65,13 @@ }
 }
 
 func runWithTUI(rt *runtime.Runtime) {
-	// 1. Create the model and pass the runtime to it.
+	// Build the model and inject progress bridge so runtime can send messages into the TUI
 	model := tui.New(rt)
-
-	// 2. Create the tea.Program.
 	p := tea.NewProgram(model, tea.WithAltScreen())
-
-	// 3. Create the TUIProgress handler and give it the program instance.
-	//    This is the bridge that allows the runtime to send messages to the TUI.
 	tp := tui.NewTUIProgress(p)
-
-	// 4. Inject the progress handler into the runtime.
 	rt.Progress = tp
 
-	// 5. Run the program. This is a blocking call.
+	// Blocking call; returns on quit
 	if _, err := p.Run(); err != nil {
 		fmt.Fprintln(os.Stderr, style.Errorf("TUI error: %v", err))
 		os.Exit(1)
@@ -95,7 +79,7 @@ }
 }
 
 func runWithoutTUI(rt *runtime.Runtime, verbose bool, sh *signals.SignalHandler) {
-	// Setup logger based on verbose flag and inject it into the runtime
+	// SimpleLogger outputs to stdout; nil uses NoopLogger
 	if verbose {
 		rt.Progress = progress.NewSimpleLogger(os.Stdout, true)
 	} else {

@@ -27,7 +27,8 @@ userAgent          string
 	progressCtx        *progress.Context
 }
 
-// NewFeedAggregatorWithProgress creates a new FeedAggregator with progress context.
+// NewFeedAggregatorWithProgress creates a FeedAggregator with progress reporting.
+// progressCtx may be nil (e.g. in dry-run mode with verbose disabled).
 func NewFeedAggregatorWithProgress(maxArticlesPerFeed, maxDaysOld, maxContentLength int, progressCtx *progress.Context) *FeedAggregator {
 	return &FeedAggregator{
 		maxArticlesPerFeed: maxArticlesPerFeed,
@@ -94,8 +95,8 @@
 	return articles, nil
 }
 
-// parseFeedsFromReader reads feed URLs from an io.Reader and fetches each one.
-// Used by both file-based and stdin-based feed loading.
+// parseFeedsFromReader reads feed URLs line-by-line from any io.Reader,
+// then fetches each feed concurrently. Used by both file and stdin paths.
 func (fa *FeedAggregator) parseFeedsFromReader(reader io.Reader, sourceName string) ([]*Article, error) {
 	content, err := io.ReadAll(reader)
 	if err != nil {
@@ -277,13 +278,9 @@ return time.Time{}
 }
 
 func (fa *FeedAggregator) extractContent(item *gofeed.Item, link string) string {
-	// Priority: Content -> Description -> Fetch webpage
-	// NOTE: Webpage scraping is only attempted when content is empty or <100
-	// chars. This balances content quality against latency (webpage fetch adds
-	// ~1-2s per article).
 	content := ""
 
-	// Try to get content from item
+	// Feed item content fields are tried in order; gofeed unifies atom Content/Description
 	if item.Content != "" {
 		content = item.Content
 	} else if item.Description != "" {
@@ -323,10 +320,10 @@ if err != nil {
 		return "", err
 	}
 
-	// Remove script and style elements
+	// Remove noise elements before extracting text
 	doc.Find("script, style, nav, footer, header").Remove()
 
-	// Try to find article content
+	// Try article-shaped selectors first, then fall back to paragraphs, then body
 	articleSelectors := []string{
 		"article",
 		"main",
@@ -348,7 +345,7 @@ }
 		}
 	}
 
-	// Fallback: get all paragraphs
+	// Fallback: collect all paragraphs
 	paragraphs := doc.Find("p")
 	if paragraphs.Length() > 0 {
 		var texts []string
@@ -361,7 +358,7 @@ return text, nil
 		}
 	}
 
-	// Last resort: get all text
+	// Last resort: raw body text
 	text := doc.Text()
 	text = strings.Join(strings.Fields(text), " ")
 	if len(text) > 200 {

@@ -2,7 +2,7 @@ package aggregator
 
 import "time"
 
-// Article represents an article extracted from an RSS feed.
+// Article represents an item extracted from an RSS feed.
 type Article struct {
 	Title      string    `json:"title"`
 	Link       string    `json:"link"`
@@ -13,7 +13,8 @@ SourceFeed string    `json:"source_feed,omitempty"`
 	Summary    string    `json:"summary,omitempty"`
 }
 
-// ToMap converts article to a map for serialisation.
+// ToMap serialises the article to a map for LLM input or JSON output.
+// Content is truncated to 500 chars to avoid oversized prompts.
 func (a *Article) ToMap() map[string]any {
 	content := a.Content
 	if len(content) > 500 {

@@ -13,7 +13,7 @@ Version   string
 	BuildDate string
 )
 
-// Args represents command-line arguments.
+// Args defines all command-line flags supported by the program.
 type Args struct {
 	// Feed input
 	FeedsFile string `arg:"-f,--feeds-file" help:"Path to file containing RSS feed URLs (one per line)"`
@@ -51,7 +51,7 @@ ShowVersion  bool   `arg:"--version" help:"Show version"`
 	DryRun       bool   `arg:"-D,--dry-run" help:"Validate config, show article statistics, and exit without making LLM API calls"`
 }
 
-// Version returns the version string.
+// Version returns the version string (e.g. "llm_aggregator v0.1.0 (built 2025-01-01)").
 func (a *Args) Version() string {
 	return fmt.Sprintf("llm_aggregator v%s (built %s)", Version, BuildDate)
 }
@@ -61,7 +61,8 @@ func (a *Args) Description() string {
 	return "LLM Aggregator - Aggregate RSS feeds and summarise with LLM API"
 }
 
-// ParseKeywords parses comma-separated keywords string into list.
+// ParseKeywords splits a comma-separated keyword string into a trimmed list.
+// Empty tokens resulting from malformed input are discarded.
 func ParseKeywords(keywordString string) []string {
 	if keywordString == "" {
 		return nil
@@ -106,13 +107,13 @@
 	return &args, nil
 }
 
-// ToViperMap converts Args to a map for binding to Viper.
-// Only non-nil values (explicitly provided CLI flags) are included.
+// ToViperMap serialises Args to a viper key-value map.
+// Only fields with non-nil/non-empty values are included, giving CLI args the
+// highest precedence over config file and environment variables.
 //
-// NOTE: FeedsFile and Prompt are strings (not pointers), so they're ALWAYS
-// included if non-empty. This differs from optional fields which use pointer
-// types to detect explicit provision vs. default zero values. See isZero() in
-// config package.
+// NOTE: FeedsFile and Prompt are plain strings — they are always included when
+// non-empty, unlike optional pointer-typed fields where nil means "not provided".
+// This difference is intentional; see isZero in the config package.
 func (a *Args) ToViperMap() map[string]any {
 	m := map[string]any{}
 	if a.FeedsFile != "" {

@@ -15,7 +15,8 @@ "llm_aggregator/internal/runtime"
 	"llm_aggregator/internal/style"
 )
 
-// Config holds the application configuration loaded from TOML file, environment variables, and CLI arguments.
+// Config holds application configuration sourced from TOML, environment variables, and CLI arguments.
+// See config.GetViper for precedence and singleton behaviour.
 type Config struct {
 	// Feed aggregation options
 	MaxArticlesPerFeed int    `mapstructure:"max_articles_per_feed"`
@@ -45,13 +46,12 @@ IncludeArticles bool   `mapstructure:"include_articles"`
 	Plain           bool   `mapstructure:"plain"`
 }
 
-// GetViper returns the global viper instance with all configuration sources set up.
-// The precedence order is: CLI flags > Environment variables > Config file > Defaults.
+// GetViper returns the global viper instance.
+// Precedence (highest first): CLI flags → environment variables → config file → defaults.
 //
-// NOTE: Viper uses a singleton pattern. Subsequent calls to GetViper() return the SAME
-// instance with all previously set values. This means defaults are only set once,
-// environment vars are bound once, and the config file is read once. Do NOT call this
-// expecting a fresh state — if you need a fresh instance for testing, use viper.New() directly.
+// NOTE: Viper is a singleton. Subsequent calls return the SAME instance with all
+// previously set values. Defaults, env bindings, and config-file reads are idempotent
+// but the instance is NOT reset between calls. Use viper.New() directly for testing.
 func GetViper() *viper.Viper {
 	// Set defaults first (lowest priority)
 	setDefaults()
@@ -117,13 +117,12 @@ }
 	}
 }
 
-// isZero checks if a value is the zero value for its type.
+// isZero reports whether v is the zero value for its type.
 //
-// NOTE: This function is critical for CLI argument handling. Pointer types
-// (*string, *int, etc.) return true only when nil (not provided), NOT when
-// pointing to a zero value. This allows distinguishing between "flag not
-// provided" (nil) vs "flag explicitly set to zero" (e.g., --temperature 0
-// should override default, but no flag means preserve default).
+// This is critical for CLI handling: pointer types (*string, *int, …) return true
+// when nil (flag not provided), not when dereferencing to zero. This distinguishes
+// "--temperature 0" (explicit zero, overrides default) from no flag at all (nil,
+// preserves default from config/env).
 func isZero(v any) bool {
 	// Handle nil interface values first (before type switch)
 	if v == nil {
@@ -171,7 +170,8 @@ return false
 	}
 }
 
-// ViperToRuntime converts viper configuration directly to runtime.Runtime.
+// ViperToRuntime converts viper configuration into a Runtime value.
+// FeedsFile and Prompt are passed separately as they come from positional CLI args.
 func ViperToRuntime(v *viper.Viper, feedsFile, prompt string) *runtime.Runtime {
 	rt := &runtime.Runtime{
 		FeedsFile: feedsFile,

@@ -1,10 +1,7 @@
 package defaults
 
-// Default values for the llm_aggregator application.
-//
-// These constants are used throughout the codebase to ensure
-// consistent default values across CLI arguments, configuration,
-// and runtime settings.
+// Default values used throughout the application.
+// Kept in one place so they are consistent across CLI, config, and runtime.
 
 const (
 	// DefaultModel is the default LLM model.

@@ -25,13 +25,8 @@ llmTimeout int // seconds; 0 means no timeout
 	logger    *progress.Context
 }
 
-// NewLLMClient creates a new LLM client.
-// apiKey: LLM API key (or read from LLM_AGGREGATOR_API_KEY env var)
-// baseURL: API base URL (defaults to "https://api.deepseek.com")
-// model: Model to use (defaults to "deepseek-chat")
-// maxTokens: Maximum tokens in response (defaults to 4000)
-// temperature: Sampling temperature (0.0 to 1.0, defaults to 0.7)
-// timeoutSeconds: Request timeout in seconds (defaults to 300)
+// NewLLMClient creates an LLM API client.
+// Set apiKey to "" to read from LLM_AGGREGATOR_API_KEY.
 func NewLLMClient(apiKey, baseURL, model string, maxTokens int, temperature float64, timeoutSeconds int) (*LLMClient, error) {
 	// Get API key from parameter or environment variable
 	if apiKey == "" {
@@ -83,17 +78,15 @@ func (dc *LLMClient) SetLogger(logger *progress.Context) {
 	dc.logger = logger
 }
 
-// TokenUsage holds token usage information from the API
+// TokenUsage holds token usage information from the API response.
 type TokenUsage struct {
 	PromptTokens     int
 	CompletionTokens int
 }
 
-// SummariseArticles summarises a list of articles based on user prompt.
-// articles: List of article maps
-// userPrompt: User's query/summarisation request
-// systemPrompt: Optional system prompt (defaults to helpful assistant)
-// ctx: Context for cancellation. If cancelled, the LLM API call aborts.
+// SummariseArticles sends articles to the LLM for summarisation.
+// Returns the LLM response text, token usage, and any error.
+// ctx must carry signal cancellation so that SIGINT/SIGTERM aborts the call.
 func (dc *LLMClient) SummariseArticles(
 	articles []map[string]any,
 	userPrompt string,

@@ -19,7 +19,8 @@ excludeKeywords      []string
 	logger               *progress.Context
 }
 
-// NewContentProcessor creates a new ContentProcessor with the specified options.
+// NewContentProcessor creates a processor that filters and truncates articles.
+// Keyword comparison is case-insensitive.
 func NewContentProcessor(maxTotalArticles, maxContentPerArticle int, filterKeywords, excludeKeywords []string) *ContentProcessor {
 	// Convert keywords to lowercase for case-insensitive matching
 	filterLower := make([]string, len(filterKeywords))
@@ -45,7 +46,8 @@ func (cp *ContentProcessor) SetLogger(logger *progress.Context) {
 	cp.logger = logger
 }
 
-// ProcessArticles processes articles: filter, sort, and prepare for LLM.
+// ProcessArticles applies keyword filtering, sorting, and a ceiling on total count,
+// then converts each article to a map for the LLM.
 func (cp *ContentProcessor) ProcessArticles(articles []*aggregator.Article, sortBy string, reverse bool) []map[string]any {
 	if len(articles) == 0 {
 		if cp.logger != nil {
@@ -78,6 +80,8 @@
 	return processed
 }
 
+// filterArticles applies include/exclude keyword filters to the article list.
+// Exclusions take priority over inclusions. If no filters are set, all articles pass.
 func (cp *ContentProcessor) filterArticles(articles []*aggregator.Article) []*aggregator.Article {
 	if len(cp.filterKeywords) == 0 && len(cp.excludeKeywords) == 0 {
 		return articles
@@ -88,7 +92,6 @@
 	for _, article := range articles {
 		include := true
 
-		// Check if article should be excluded
 		if len(cp.excludeKeywords) > 0 {
 			articleText := strings.ToLower(article.Title + " " + article.Content)
 			for _, keyword := range cp.excludeKeywords {
@@ -102,7 +105,6 @@ }
 			}
 		}
 
-		// Check if article should be included (only if we have inclusion filters)
 		if include && len(cp.filterKeywords) > 0 {
 			articleText := strings.ToLower(article.Title + " " + article.Content)
 			include = false
@@ -134,13 +136,12 @@ if len(articles) == 0 {
 		return articles
 	}
 
-	// Create a copy to avoid modifying the original slice
 	sortedArticles := make([]*aggregator.Article, len(articles))
 	copy(sortedArticles, articles)
 
-	// Define sort functions
 	switch strings.ToLower(sortBy) {
 	case "date":
+		// Zero times sort to the end when reverse=false (oldest last)
 		sort.Slice(sortedArticles, func(i, j int) bool {
 			iTime := sortedArticles[i].Published
 			jTime := sortedArticles[j].Published
@@ -174,7 +175,7 @@ }
 			return iSource < jSource
 		})
 	default:
-		// Default to date sorting
+		// Unknown sort key: fall back to date order
 		sort.Slice(sortedArticles, func(i, j int) bool {
 			iTime := sortedArticles[i].Published
 			jTime := sortedArticles[j].Published
@@ -224,8 +225,8 @@
 	return processed
 }
 
-// EstimateTokenCount estimates token count for articles using tiktoken.
-// This is the accurate method using OpenAI's tokenisation.
+// EstimateTokenCount uses tiktoken to estimate total token count across all articles.
+// Falls back to char÷4 on encoding errors (logged as warnings).
 func (cp *ContentProcessor) EstimateTokenCount(articles []map[string]any, model string) int {
 	totalTokens := 0
 

@@ -7,14 +7,15 @@
 	"llm_aggregator/internal/style"
 )
 
-// Logger provides logging interface for the aggregator
+// Logger is the minimal interface for progress and verbose logging implementations.
 type Logger interface {
 	Logf(format string, args ...any)
 	Warningf(format string, args ...any)
 	Debugf(format string, args ...any)
 }
 
-// Progress provides progress reporting interface for TUI
+// Progress extends Logger with stage/count/timing reporting.
+// Implementations: NoopLogger (no output), SimpleLogger (stdout), TUIProgress (tea messages).
 type Progress interface {
 	Logger
 	SetStage(stage string)
@@ -24,13 +25,13 @@ SetTokenEstimate(total, used int)
 	StartWaiting()
 }
 
-// SimpleLogger implements Logger with io.Writer output
+// SimpleLogger writes formatted output to an io.Writer.
 type SimpleLogger struct {
 	writer io.Writer
 	debug  bool
 }
 
-// NewSimpleLogger creates a new SimpleLogger
+// NewSimpleLogger creates a SimpleLogger; set debug=true to enable Debugf output.
 func NewSimpleLogger(writer io.Writer, debug bool) *SimpleLogger {
 	return &SimpleLogger{
 		writer: writer,
@@ -60,7 +61,7 @@ func (sl *SimpleLogger) SetArticleCount(total, processed int)       {}
 func (sl *SimpleLogger) SetTokenEstimate(total, used int)           {}
 func (sl *SimpleLogger) StartWaiting()                            {}
 
-// NoopLogger implements Logger with no output
+// NoopLogger discards all output. Used as the default when no progress is desired.
 type NoopLogger struct{}
 
 func (nl *NoopLogger) Logf(format string, args ...any)      {}
@@ -72,12 +73,12 @@ func (nl *NoopLogger) SetArticleCount(total, processed int)        {}
 func (nl *NoopLogger) SetTokenEstimate(total, used int)           {}
 func (nl *NoopLogger) StartWaiting()                            {}
 
-// Context provides progress context for components
+// Context wraps a Logger and guards against nil receiver.
 type Context struct {
 	logger Logger
 }
 
-// NewContext creates a new progress context
+// NewContext wraps a Logger. Passing nil produces a no-op context.
 func NewContext(logger Logger) *Context {
 	return &Context{
 		logger: logger,

@@ -16,7 +16,8 @@ "llm_aggregator/internal/processor"
 	"llm_aggregator/internal/progress"
 )
 
-// Runtime holds the execution context for the aggregator
+// Runtime holds the full execution context for the pipeline.
+// It is constructed once in main() and passed through each stage.
 type Runtime struct {
 	// Configuration
 	FeedsFile          string
@@ -46,11 +47,13 @@ Summary     string
 	Error       error
 	Interrupted bool // Set to true when a termination signal is received
 
-	// Logger for verbose output
+	// Progress is the logger/progress handler injected by the caller.
+	// nil means no output (NoopLogger). SimpleLogger outputs to stdout.
+	// TUIProgress bridges into the Bubbletea program for live updates.
 	Progress progress.Progress
 }
 
-// Execute runs the full aggregation pipeline
+// Execute runs the four-stage pipeline: aggregate → process → LLM → (output is separate).
 func (r *Runtime) Execute(ctx context.Context) error {
 	// The logger/progress handler is injected, so we don't create it here.
 	// We wrap it in a context to pass to sub-modules that expect a *progress.Context.
@@ -154,9 +157,8 @@ r.Progress.SetStage("Getting summary")
 	r.Progress.SetSubStage(fmt.Sprintf("Sending %d articles to LLM", len(processedArticles)))
 	r.Progress.StartWaiting()
 
-	// Derive a timeout context for the LLM call from the parent context.
-	// The parent context carries signal cancellation, so both signal interrupts
-	// and timeouts will abort the call.
+	// callCtx wraps the parent context with a timeout derived from LLMTimeout.
+	// Both signal cancellation and timeout will abort the LLM call.
 	callCtx := ctx
 	if r.LLMTimeout > 0 {
 		var cancel context.CancelFunc
@@ -181,7 +183,7 @@ }
 	return nil
 }
 
-// WasInterrupted returns true if a termination signal was received during execution.
+// was interrupted by a signal during execution.
 func (r *Runtime) WasInterrupted() bool {
 	return r.Interrupted
 }

@@ -8,7 +8,7 @@
 	"github.com/pkoukk/tiktoken-go"
 )
 
-// Encoding names for different model families
+// Encoding names accepted by tiktoken for common model families.
 const (
 	EncodingCl100kBase = "cl100k_base" // GPT-4, GPT-3.5-turbo, embeddings
 	EncodingO200kBase  = "o200k_base"  // GPT-4o, GPT-4.1, GPT-4.5
@@ -24,7 +24,7 @@ }
 
 var cache = &tokenizerCache{encodings: make(map[string]*tiktoken.Tiktoken)}
 
-// GetEncoding returns a Tiktoken encoding for the given encoding name.
+// GetEncoding returns a cached Tiktoken encoding, initialising it if necessary.
 func GetEncoding(encodingName string) (*tiktoken.Tiktoken, error) {
 	// Check cache first
 	cache.mu.RLock()
@@ -48,7 +48,8 @@
 	return enc, nil
 }
 
-// EncodingForModel returns the appropriate encoding name for a given model.
+// EncodingForModel maps a model name to the nearest tiktoken encoding.
+// Unknown model families fall back to cl100k_base.
 func EncodingForModel(model string) (string, error) {
 	model = strings.ToLower(model)
 
@@ -87,7 +88,7 @@ // Default to cl100k_base (most common for modern models)
 	return EncodingCl100kBase, nil
 }
 
-// CountTokens counts the tokens in a text string using the appropriate encoding.
+// CountTokens returns the number of tokens in text for the given model.
 func CountTokens(text string, model string) (int, error) {
 	encodingName, err := EncodingForModel(model)
 	if err != nil {

@@ -159,9 +159,8 @@
 	return tea.Batch(m.spinner.Tick, m.startProcessing)
 }
 
-// This is now the standard bubbletea command pattern.
-// The bubbletea runtime will execute this function in a goroutine.
-// We no longer need to manage the goroutine or use program.Send().
+// startProcessing is the standard bubbletea command pattern.
+// The runtime executes in a goroutine managed by the bubbletea runtime.
 func (m *Model) startProcessing() tea.Msg {
 	err := m.runtime.Execute(context.Background())
 	return processingDoneMsg{err: err}
@@ -226,7 +225,7 @@ }
 			m.viewport.SetContent(summaryContent)
 		}
 	case progressMsg:
-		// This message type seems unused, but leaving it in case.
+		// progressMsg drives the progress bar; sent by the runtime via program.Send.
 		progress := float64(msg)
 		if progress >= 1.0 {
 			m.done = true
@@ -235,7 +234,7 @@ }
 		cmd := m.progress.SetPercent(float64(progress))
 		return m, cmd
 	case spinner.TickMsg:
-		// MODIFIED: Stop updating the spinner once we're done.
+		// Stop the spinner once processing completes
 		if m.done {
 			return m, nil
 		}

@@ -8,13 +8,12 @@
 	tea "github.com/charmbracelet/bubbletea"
 )
 
-// TUIProgress implements the progress.Progress interface for TUI
+// TUIProgress bridges progress.Progress calls into a running Bubbletea tea.Program.
 type TUIProgress struct {
 	program *tea.Program
 }
 
-// NewTUIProgress creates a new TUIProgress.
-// It now accepts the program instance instead of creating one.
+// NewTUIProgress wraps an existing tea.Program instance (created by the caller).
 func NewTUIProgress(p *tea.Program) *TUIProgress {
 	return &TUIProgress{
 		program: p,
@@ -56,7 +55,7 @@ func (tp *TUIProgress) Warningf(format string, args ...any) {
 	tp.Logf("⚠️ Warning: "+format, args...)
 }
 
-// Debugf does nothing in the TUI.
+// Debugf is a no-op in the TUI; debug output is handled via the progress bar.
 func (tp *TUIProgress) Debugf(format string, args ...any) {}
 
 // Run runs the TUI