feat: add Static and StaticFS helpers for serving static files

One-liner static file serving: v.Static("/assets/", "./public") for
filesystem directories and v.StaticFS("/assets/", fsys) for embed.FS.
Both auto-normalize the URL prefix and disable directory listings.

README.md

@@ -1,30 +1,33 @@
-# ⚡Via
+# Via
+
 Real-time engine for building reactive web applications in pure Go.
 
-
 ## Why Via?
-Somewhere along the way, the web became tangled in layers of JavaScript, build chains, and frameworks stacked on frameworks.
 
-Via takes a radical stance:
+The web became tangled in layers of JavaScript, build chains, and frameworks stacked on frameworks. Via takes a different path.
 
-- No templates.
+**Philosophy**
-- No JavaScript.
+- No templates. No JavaScript. No transpilation. No hydration.
-- No transpilation.
+- Views are pure Go functions. HTML is composed with a type-safe DSL.
-- No hydration.
+- A single SSE stream carries all reactivity — no WebSocket juggling, no polling.
-- No front-end fatigue.
-- Single SSE stream.
-- Full reactivity.
-- Built-in Brotli compression.
-- Pure Go.
 
+**Batteries included**
+- Automatic CSRF protection on every action call
+- Token-bucket rate limiting (global defaults + per-action overrides)
+- Cookie-based sessions backed by SQLite
+- Pub/sub messaging with an embedded NATS backend
+- Structured logging via zerolog
+- Graceful shutdown with context draining
+- Brotli compression out of the box
 
 ## Example
+
 ```go
 package main
 
 import (
-	"github.com/go-via/via"
+	"github.com/ryanhamamura/via"
-	"github.com/go-via/via/h"
+	"github.com/ryanhamamura/via/h"
 )
 
 type Counter struct{ Count int }
@@ -57,25 +60,43 @@ func main() {
 }
 ```
 
+## What's built in
 
-## 🚧 Experimental
+- **Reactive views + signals** — bind state to the DOM; changes push over SSE automatically
-<s>Via is still a newborn.</s> Via is taking its first steps!
+- **Components** — self-contained subcontexts with their own data, actions, and signals
-- Version `0.1.0` released.
+- **Sessions** — cookie-based, backed by SQLite via `scs`
-- Expect a little less chaos.
+- **Pub/sub** — embedded NATS server with JetStream; generic `Publish[T]` / `Subscribe[T]` helpers
+- **CSRF protection** — automatic token generation and validation on every action
+- **Rate limiting** — token-bucket algorithm, configurable globally and per-action
+- **Event handling** — `OnClick`, `OnChange`, `OnSubmit`, `OnInput`, `OnFocus`, `OnBlur`, `OnMouseEnter`, `OnMouseLeave`, `OnScroll`, `OnDblClick`, `OnKeyDown`, and `OnKeyDownMap` for multi-key bindings
+- **Timed routines** — `OnInterval` with start/stop/update controls, tied to context lifecycle
+- **Redirects** — `Redirect`, `ReplaceURL`, and format-string variants
+- **Plugin system** — `func(v *V)` hooks for integrating CSS/JS libraries
+- **Structured logging** — zerolog with configurable levels; console output in dev, JSON in production
+- **Graceful shutdown** — listens for SIGINT/SIGTERM, drains contexts, closes pub/sub
+- **Context lifecycle** — background reaper cleans up disconnected contexts; configurable TTL
+- **HTML DSL** — the `h` package provides type-safe Go-native HTML composition
+
+## Examples
+
+The `internal/examples/` directory contains 14 runnable examples:
+
+`chatroom` · `counter` · `countercomp` · `greeter` · `keyboard` · `livereload` · `nats-chatroom` · `pathparams` · `picocss` · `plugins` · `pubsub-crud` · `realtimechart` · `session` · `shakespeare`
+
+## Experimental
+
+Via is maturing — sessions, CSRF, rate limiting, pub/sub, and graceful shutdown are in place — but the API is still evolving. Expect breaking changes before `v1`.
 
 ## Contributing
+
 - Via is intentionally minimal and opinionated — and so is contributing.
-- If you love Go, simplicity, and meaningful abstractions — Come along for the ride!
+- Fork, branch, build, tinker, submit a pull request.
-- Fork, branch, build, tinker with things, submit a pull request.
 - Keep every line purposeful.
 - Share feedback: open an issue or start a discussion.
 
-
 ## Credits
 
-Via builds upon the work of these amazing projects:
+Via builds upon the work of these projects:
 
-- 🚀 [Datastar](https://data-star.dev) - The hypermedia powerhouse at the core of Via. It powers browser reactivity through Signals and enables real-time HTML/Signal patches over an always-on SSE event stream.
+- [Datastar](https://data-star.dev) — the hypermedia framework powering browser reactivity through signals and real-time HTML patches over SSE.
-- 🧩 [Gomponents](https://maragu.dev/gomponents) - The awesome project that gifts Via with Go-native HTML composition superpowers through the `via/h` package.
+- [Gomponents](https://maragu.dev/gomponents) — Go-native HTML composition that powers the `via/h` package.
-
-> Thank you for building something that doesn’t just function — it inspires. 🫶

actiontrigger.go

@@ -107,6 +107,54 @@ func (a *actionTrigger) OnChange(options ...ActionTriggerOption) h.H {
 	return h.Data("on:change__debounce.200ms", buildOnExpr(actionURL(a.id), &opts))
 }
 
+// OnSubmit returns a via.h DOM attribute that triggers on form submit.
+func (a *actionTrigger) OnSubmit(options ...ActionTriggerOption) h.H {
+	opts := applyOptions(options...)
+	return h.Data("on:submit", buildOnExpr(actionURL(a.id), &opts))
+}
+
+// OnInput returns a via.h DOM attribute that triggers on input (without debounce).
+func (a *actionTrigger) OnInput(options ...ActionTriggerOption) h.H {
+	opts := applyOptions(options...)
+	return h.Data("on:input", buildOnExpr(actionURL(a.id), &opts))
+}
+
+// OnFocus returns a via.h DOM attribute that triggers when the element gains focus.
+func (a *actionTrigger) OnFocus(options ...ActionTriggerOption) h.H {
+	opts := applyOptions(options...)
+	return h.Data("on:focus", buildOnExpr(actionURL(a.id), &opts))
+}
+
+// OnBlur returns a via.h DOM attribute that triggers when the element loses focus.
+func (a *actionTrigger) OnBlur(options ...ActionTriggerOption) h.H {
+	opts := applyOptions(options...)
+	return h.Data("on:blur", buildOnExpr(actionURL(a.id), &opts))
+}
+
+// OnMouseEnter returns a via.h DOM attribute that triggers when the mouse enters the element.
+func (a *actionTrigger) OnMouseEnter(options ...ActionTriggerOption) h.H {
+	opts := applyOptions(options...)
+	return h.Data("on:mouseenter", buildOnExpr(actionURL(a.id), &opts))
+}
+
+// OnMouseLeave returns a via.h DOM attribute that triggers when the mouse leaves the element.
+func (a *actionTrigger) OnMouseLeave(options ...ActionTriggerOption) h.H {
+	opts := applyOptions(options...)
+	return h.Data("on:mouseleave", buildOnExpr(actionURL(a.id), &opts))
+}
+
+// OnScroll returns a via.h DOM attribute that triggers on scroll.
+func (a *actionTrigger) OnScroll(options ...ActionTriggerOption) h.H {
+	opts := applyOptions(options...)
+	return h.Data("on:scroll", buildOnExpr(actionURL(a.id), &opts))
+}
+
+// OnDblClick returns a via.h DOM attribute that triggers on double click.
+func (a *actionTrigger) OnDblClick(options ...ActionTriggerOption) h.H {
+	opts := applyOptions(options...)
+	return h.Data("on:dblclick", buildOnExpr(actionURL(a.id), &opts))
+}
+
 // OnKeyDown returns a via.h DOM attribute that triggers when a key is pressed.
 // key: optional, see https://developer.mozilla.org/en-US/docs/Web/API/KeyboardEvent/key
 // Example: OnKeyDown("Enter")

configuration.go

@@ -1,6 +1,8 @@
 package via
 
 import (
+	"time"
+
 	"github.com/alexedwards/scs/v2"
 	"github.com/rs/zerolog"
 )
@@ -54,4 +56,14 @@ type Options struct {
 	// PubSub enables publish/subscribe messaging. Use vianats.New() for an
 	// embedded NATS backend, or supply any PubSub implementation.
 	PubSub PubSub
+
+	// ContextTTL is the maximum time a context may exist without an SSE
+	// connection before the background reaper disposes it.
+	// Default: 30s. Negative value disables the reaper.
+	ContextTTL time.Duration
+
+	// ActionRateLimit configures the default token-bucket rate limiter for
+	// action endpoints. Zero values use built-in defaults (10 req/s, burst 20).
+	// Set Rate to -1 to disable rate limiting entirely.
+	ActionRateLimit RateLimitConfig
 }

context.go

@@ -8,9 +8,11 @@ import (
 	"maps"
 	"reflect"
 	"sync"
+	"sync/atomic"
 	"time"
 
 	"github.com/ryanhamamura/via/h"
+	"golang.org/x/time/rate"
 )
 
 // Context is the living bridge between Go and the browser.
@@ -19,13 +21,15 @@ import (
 type Context struct {
 	id                string
 	route             string
+	csrfToken         string
 	app               *V
 	view              func() h.H
 	routeParams       map[string]string
 	componentRegistry map[string]*Context
 	parentPageCtx     *Context
 	patchChan         chan patch
-	actionRegistry    map[string]func()
+	actionLimiter     *rate.Limiter
+	actionRegistry    map[string]actionEntry
 	signals           *sync.Map
 	mu                sync.RWMutex
 	ctxDisposedChan   chan struct{}
@@ -33,6 +37,8 @@ type Context struct {
 	subscriptions     []Subscription
 	subsMu            sync.Mutex
 	disposeOnce       sync.Once
+	createdAt         time.Time
+	sseConnected      atomic.Bool
 }
 
 // View defines the UI rendered by this context.
@@ -100,26 +106,31 @@ func (c *Context) isComponent() bool {
 //		 	 	h.Button(h.Text("Increment n"), increment.OnClick()),
 //		 )
 //	})
-func (c *Context) Action(f func()) *actionTrigger {
+func (c *Context) Action(f func(), opts ...ActionOption) *actionTrigger {
 	id := genRandID()
 	if f == nil {
 		c.app.logErr(c, "failed to bind action '%s' to context: nil func", id)
 		return nil
 	}
 
+	entry := actionEntry{fn: f}
+	for _, opt := range opts {
+		opt(&entry)
+	}
+
 	if c.isComponent() {
-		c.parentPageCtx.actionRegistry[id] = f
+		c.parentPageCtx.actionRegistry[id] = entry
 	} else {
-		c.actionRegistry[id] = f
+		c.actionRegistry[id] = entry
 	}
 	return &actionTrigger{id}
 }
 
-func (c *Context) getActionFn(id string) (func(), error) {
+func (c *Context) getAction(id string) (actionEntry, error) {
-	if f, ok := c.actionRegistry[id]; ok {
+	if e, ok := c.actionRegistry[id]; ok {
-		return f, nil
+		return e, nil
 	}
-	return nil, fmt.Errorf("action '%s' not found", id)
+	return actionEntry{}, fmt.Errorf("action '%s' not found", id)
 }
 
 // OnInterval starts a go routine that sets a time.Ticker with the given duration and executes
@@ -474,12 +485,15 @@ func newContext(id string, route string, v *V) *Context {
 	return &Context{
 		id:                id,
 		route:             route,
+		csrfToken:         genCSRFToken(),
 		routeParams:       make(map[string]string),
 		app:               v,
 		componentRegistry: make(map[string]*Context),
-		actionRegistry:    make(map[string]func()),
+		actionLimiter:     newLimiter(v.actionRateLimit, defaultActionRate, defaultActionBurst),
+		actionRegistry:    make(map[string]actionEntry),
 		signals:           new(sync.Map),
 		patchChan:         make(chan patch, 1),
 		ctxDisposedChan:   make(chan struct{}, 1),
+		createdAt:         time.Now(),
 	}
 }

go.mod

@@ -14,6 +14,7 @@ require (
 	github.com/rs/zerolog v1.34.0
 	github.com/starfederation/datastar-go v1.0.3
 	github.com/stretchr/testify v1.11.1
+	golang.org/x/time v0.14.0
 )
 
 require (
@@ -37,6 +38,6 @@ require (
 	github.com/valyala/bytebufferpool v1.0.0 // indirect
 	golang.org/x/crypto v0.45.0 // indirect
 	golang.org/x/sys v0.38.0 // indirect
-	golang.org/x/time v0.14.0 // indirect
+	golang.org/x/time v0.14.0
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

ratelimit.go

@@ -0,0 +1,48 @@
+package via
+
+import "golang.org/x/time/rate"
+
+const (
+	defaultActionRate  float64 = 10.0
+	defaultActionBurst int     = 20
+)
+
+// RateLimitConfig configures token-bucket rate limiting for actions.
+// Zero values fall back to defaults. Rate of -1 disables limiting entirely.
+type RateLimitConfig struct {
+	Rate  float64
+	Burst int
+}
+
+// ActionOption configures per-action behaviour when passed to Context.Action.
+type ActionOption func(*actionEntry)
+
+type actionEntry struct {
+	fn      func()
+	limiter *rate.Limiter // nil = use context default
+}
+
+// WithRateLimit returns an ActionOption that gives this action its own
+// token-bucket limiter, overriding the context-level default.
+func WithRateLimit(r float64, burst int) ActionOption {
+	return func(e *actionEntry) {
+		e.limiter = newLimiter(RateLimitConfig{Rate: r, Burst: burst}, defaultActionRate, defaultActionBurst)
+	}
+}
+
+// newLimiter creates a *rate.Limiter from cfg, substituting defaults for zero
+// values. A Rate of -1 disables limiting (returns nil).
+func newLimiter(cfg RateLimitConfig, defaultRate float64, defaultBurst int) *rate.Limiter {
+	r := cfg.Rate
+	b := cfg.Burst
+	if r == -1 {
+		return nil
+	}
+	if r == 0 {
+		r = defaultRate
+	}
+	if b == 0 {
+		b = defaultBurst
+	}
+	return rate.NewLimiter(rate.Limit(r), b)
+}

ratelimit_test.go

@@ -0,0 +1,101 @@
+package via
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestNewLimiter_Defaults(t *testing.T) {
+	l := newLimiter(RateLimitConfig{}, defaultActionRate, defaultActionBurst)
+	require.NotNil(t, l)
+	assert.InDelta(t, defaultActionRate, float64(l.Limit()), 0.001)
+	assert.Equal(t, defaultActionBurst, l.Burst())
+}
+
+func TestNewLimiter_CustomValues(t *testing.T) {
+	l := newLimiter(RateLimitConfig{Rate: 5, Burst: 10}, defaultActionRate, defaultActionBurst)
+	require.NotNil(t, l)
+	assert.InDelta(t, 5.0, float64(l.Limit()), 0.001)
+	assert.Equal(t, 10, l.Burst())
+}
+
+func TestNewLimiter_DisabledWithNegativeRate(t *testing.T) {
+	l := newLimiter(RateLimitConfig{Rate: -1}, defaultActionRate, defaultActionBurst)
+	assert.Nil(t, l)
+}
+
+func TestTokenBucket_AllowsBurstThenRejects(t *testing.T) {
+	l := newLimiter(RateLimitConfig{Rate: 1, Burst: 3}, 1, 3)
+	require.NotNil(t, l)
+
+	for i := 0; i < 3; i++ {
+		assert.True(t, l.Allow(), "request %d should be allowed within burst", i)
+	}
+	assert.False(t, l.Allow(), "request beyond burst should be rejected")
+}
+
+func TestWithRateLimit_CreatesLimiter(t *testing.T) {
+	entry := actionEntry{fn: func() {}}
+	opt := WithRateLimit(2, 4)
+	opt(&entry)
+
+	require.NotNil(t, entry.limiter)
+	assert.InDelta(t, 2.0, float64(entry.limiter.Limit()), 0.001)
+	assert.Equal(t, 4, entry.limiter.Burst())
+}
+
+func TestContextAction_WithRateLimit(t *testing.T) {
+	v := New()
+	c := newContext("test-rl", "/", v)
+
+	called := false
+	c.Action(func() { called = true }, WithRateLimit(1, 2))
+
+	// Verify the entry has its own limiter
+	for _, entry := range c.actionRegistry {
+		require.NotNil(t, entry.limiter)
+		assert.InDelta(t, 1.0, float64(entry.limiter.Limit()), 0.001)
+		assert.Equal(t, 2, entry.limiter.Burst())
+	}
+	assert.False(t, called)
+}
+
+func TestContextAction_DefaultNoPerActionLimiter(t *testing.T) {
+	v := New()
+	c := newContext("test-no-rl", "/", v)
+
+	c.Action(func() {})
+
+	for _, entry := range c.actionRegistry {
+		assert.Nil(t, entry.limiter, "entry without WithRateLimit should have nil limiter")
+	}
+}
+
+func TestContextLimiter_DefaultsApplied(t *testing.T) {
+	v := New()
+	c := newContext("test-ctx-limiter", "/", v)
+
+	require.NotNil(t, c.actionLimiter)
+	assert.InDelta(t, defaultActionRate, float64(c.actionLimiter.Limit()), 0.001)
+	assert.Equal(t, defaultActionBurst, c.actionLimiter.Burst())
+}
+
+func TestContextLimiter_DisabledViaConfig(t *testing.T) {
+	v := New()
+	v.actionRateLimit = RateLimitConfig{Rate: -1}
+	c := newContext("test-disabled", "/", v)
+
+	assert.Nil(t, c.actionLimiter)
+}
+
+func TestContextLimiter_CustomConfig(t *testing.T) {
+	v := New()
+	v.Config(Options{ActionRateLimit: RateLimitConfig{Rate: 50, Burst: 100}})
+	c := newContext("test-custom", "/", v)
+
+	require.NotNil(t, c.actionLimiter)
+	assert.InDelta(t, 50.0, float64(c.actionLimiter.Limit()), 0.001)
+	assert.Equal(t, 100, c.actionLimiter.Burst())
+}

static_test.go

@@ -0,0 +1,143 @@
+package via
+
+import (
+	"io/fs"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"testing"
+	"testing/fstest"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestStatic(t *testing.T) {
+	dir := t.TempDir()
+	os.MkdirAll(filepath.Join(dir, "sub"), 0755)
+	os.WriteFile(filepath.Join(dir, "hello.txt"), []byte("hello world"), 0644)
+	os.WriteFile(filepath.Join(dir, "sub", "nested.txt"), []byte("nested"), 0644)
+
+	v := New()
+	v.Static("/assets/", dir)
+
+	t.Run("serves file", func(t *testing.T) {
+		w := httptest.NewRecorder()
+		r := httptest.NewRequest("GET", "/assets/hello.txt", nil)
+		v.mux.ServeHTTP(w, r)
+
+		assert.Equal(t, http.StatusOK, w.Code)
+		assert.Equal(t, "hello world", w.Body.String())
+	})
+
+	t.Run("serves nested file", func(t *testing.T) {
+		w := httptest.NewRecorder()
+		r := httptest.NewRequest("GET", "/assets/sub/nested.txt", nil)
+		v.mux.ServeHTTP(w, r)
+
+		assert.Equal(t, http.StatusOK, w.Code)
+		assert.Equal(t, "nested", w.Body.String())
+	})
+
+	t.Run("directory listing returns 404", func(t *testing.T) {
+		w := httptest.NewRecorder()
+		r := httptest.NewRequest("GET", "/assets/", nil)
+		v.mux.ServeHTTP(w, r)
+
+		assert.Equal(t, http.StatusNotFound, w.Code)
+	})
+
+	t.Run("subdirectory listing returns 404", func(t *testing.T) {
+		w := httptest.NewRecorder()
+		r := httptest.NewRequest("GET", "/assets/sub/", nil)
+		v.mux.ServeHTTP(w, r)
+
+		assert.Equal(t, http.StatusNotFound, w.Code)
+	})
+
+	t.Run("missing file returns 404", func(t *testing.T) {
+		w := httptest.NewRecorder()
+		r := httptest.NewRequest("GET", "/assets/nope.txt", nil)
+		v.mux.ServeHTTP(w, r)
+
+		assert.Equal(t, http.StatusNotFound, w.Code)
+	})
+}
+
+func TestStaticAutoSlash(t *testing.T) {
+	dir := t.TempDir()
+	os.WriteFile(filepath.Join(dir, "ok.txt"), []byte("ok"), 0644)
+
+	v := New()
+	v.Static("/files", dir) // no trailing slash
+
+	w := httptest.NewRecorder()
+	r := httptest.NewRequest("GET", "/files/ok.txt", nil)
+	v.mux.ServeHTTP(w, r)
+
+	assert.Equal(t, http.StatusOK, w.Code)
+	assert.Equal(t, "ok", w.Body.String())
+}
+
+func TestStaticFS(t *testing.T) {
+	fsys := fstest.MapFS{
+		"style.css":        {Data: []byte("body{}")},
+		"js/app.js":        {Data: []byte("console.log('hi')")},
+	}
+
+	v := New()
+	v.StaticFS("/static/", fsys)
+
+	t.Run("serves file", func(t *testing.T) {
+		w := httptest.NewRecorder()
+		r := httptest.NewRequest("GET", "/static/style.css", nil)
+		v.mux.ServeHTTP(w, r)
+
+		assert.Equal(t, http.StatusOK, w.Code)
+		assert.Equal(t, "body{}", w.Body.String())
+	})
+
+	t.Run("serves nested file", func(t *testing.T) {
+		w := httptest.NewRecorder()
+		r := httptest.NewRequest("GET", "/static/js/app.js", nil)
+		v.mux.ServeHTTP(w, r)
+
+		assert.Equal(t, http.StatusOK, w.Code)
+		assert.Equal(t, "console.log('hi')", w.Body.String())
+	})
+
+	t.Run("directory listing returns 404", func(t *testing.T) {
+		w := httptest.NewRecorder()
+		r := httptest.NewRequest("GET", "/static/", nil)
+		v.mux.ServeHTTP(w, r)
+
+		assert.Equal(t, http.StatusNotFound, w.Code)
+	})
+
+	t.Run("missing file returns 404", func(t *testing.T) {
+		w := httptest.NewRecorder()
+		r := httptest.NewRequest("GET", "/static/nope.css", nil)
+		v.mux.ServeHTTP(w, r)
+
+		assert.Equal(t, http.StatusNotFound, w.Code)
+	})
+}
+
+func TestStaticFSAutoSlash(t *testing.T) {
+	fsys := fstest.MapFS{
+		"ok.txt": {Data: []byte("ok")},
+	}
+
+	v := New()
+	v.StaticFS("/embed", fsys) // no trailing slash
+
+	w := httptest.NewRecorder()
+	r := httptest.NewRequest("GET", "/embed/ok.txt", nil)
+	v.mux.ServeHTTP(w, r)
+
+	assert.Equal(t, http.StatusOK, w.Code)
+	assert.Equal(t, "ok", w.Body.String())
+}
+
+// Verify StaticFS accepts the fs.FS interface (compile-time check).
+var _ fs.FS = fstest.MapFS{}

via.go

@@ -9,11 +9,13 @@ package via
 import (
 	"context"
 	"crypto/rand"
+	"crypto/subtle"
 	_ "embed"
 	"encoding/hex"
 	"encoding/json"
 	"fmt"
 	"io"
+	"io/fs"
 	"net/http"
 	"net/url"
 	"os"
@@ -47,9 +49,11 @@ type V struct {
 	devModePageInitFnMap map[string]func(*Context)
 	sessionManager       *scs.SessionManager
 	pubsub               PubSub
+	actionRateLimit      RateLimitConfig
 	datastarPath         string
 	datastarContent      []byte
 	datastarOnce         sync.Once
+	reaperStop           chan struct{}
 }
 
 func (v *V) logEvent(evt *zerolog.Event, c *Context) *zerolog.Event {
@@ -127,6 +131,12 @@ func (v *V) Config(cfg Options) {
 	if cfg.PubSub != nil {
 		v.pubsub = cfg.PubSub
 	}
+	if cfg.ContextTTL != 0 {
+		v.cfg.ContextTTL = cfg.ContextTTL
+	}
+	if cfg.ActionRateLimit.Rate != 0 || cfg.ActionRateLimit.Burst != 0 {
+		v.actionRateLimit = cfg.ActionRateLimit
+	}
 }
 
 // AppendToHead appends the given h.H nodes to the head of the base HTML document.
@@ -199,7 +209,7 @@ func (v *V) Page(route string, initContextFn func(c *Context)) {
 		headElements := []h.H{h.Script(h.Type("module"), h.Src(v.datastarPath))}
 		headElements = append(headElements, v.documentHeadIncludes...)
 		headElements = append(headElements,
-			h.Meta(h.Data("signals", fmt.Sprintf("{'via-ctx':'%s'}", id))),
+			h.Meta(h.Data("signals", fmt.Sprintf("{'via-ctx':'%s','via-csrf':'%s'}", id, c.csrfToken))),
 			h.Meta(h.Data("init", "@get('/_sse')")),
 			h.Meta(h.Data("init", fmt.Sprintf(`window.addEventListener('beforeunload', (evt) => {
 			navigator.sendBeacon('/_session/close', '%s');});`, c.id))),
@@ -238,6 +248,14 @@ func (v *V) currSessionNum() int {
 	return len(v.contextRegistry)
 }
 
+func (v *V) cleanupCtx(c *Context) {
+	c.dispose()
+	if v.cfg.DevMode {
+		v.devModeRemovePersisted(c)
+	}
+	v.unregisterCtx(c)
+}
+
 func (v *V) unregisterCtx(c *Context) {
 	if c.id == "" {
 		v.logErr(c, "unregister ctx failed: ctx contains empty id")
@@ -259,6 +277,50 @@ func (v *V) getCtx(id string) (*Context, error) {
 	return nil, fmt.Errorf("ctx '%s' not found", id)
 }
 
+func (v *V) startReaper() {
+	ttl := v.cfg.ContextTTL
+	if ttl < 0 {
+		return
+	}
+	if ttl == 0 {
+		ttl = 30 * time.Second
+	}
+	interval := ttl / 3
+	if interval < 5*time.Second {
+		interval = 5 * time.Second
+	}
+	v.reaperStop = make(chan struct{})
+	go func() {
+		ticker := time.NewTicker(interval)
+		defer ticker.Stop()
+		for {
+			select {
+			case <-v.reaperStop:
+				return
+			case <-ticker.C:
+				v.reapOrphanedContexts(ttl)
+			}
+		}
+	}()
+}
+
+func (v *V) reapOrphanedContexts(ttl time.Duration) {
+	now := time.Now()
+	v.contextRegistryMutex.RLock()
+	var orphans []*Context
+	for _, c := range v.contextRegistry {
+		if !c.sseConnected.Load() && now.Sub(c.createdAt) > ttl {
+			orphans = append(orphans, c)
+		}
+	}
+	v.contextRegistryMutex.RUnlock()
+
+	for _, c := range orphans {
+		v.logInfo(c, "reaping orphaned context (no SSE connection after %s)", ttl)
+		v.cleanupCtx(c)
+	}
+}
+
 // Start starts the Via HTTP server and blocks until a SIGINT or SIGTERM
 // signal is received, then performs a graceful shutdown.
 func (v *V) Start() {
@@ -271,6 +333,8 @@ func (v *V) Start() {
 		Handler: handler,
 	}
 
+	v.startReaper()
+
 	errCh := make(chan error, 1)
 	go func() {
 		errCh <- v.server.ListenAndServe()
@@ -301,6 +365,9 @@ func (v *V) Shutdown() {
 }
 
 func (v *V) shutdown() {
+	if v.reaperStop != nil {
+		close(v.reaperStop)
+	}
 	v.logInfo(nil, "draining all contexts")
 	v.drainAllContexts()
 
@@ -346,6 +413,46 @@ func (v *V) HTTPServeMux() *http.ServeMux {
 	return v.mux
 }
 
+// Static serves files from a filesystem directory at the given URL prefix.
+//
+// Example:
+//
+//	v.Static("/assets/", "./public")
+func (v *V) Static(urlPrefix, dir string) {
+	if !strings.HasSuffix(urlPrefix, "/") {
+		urlPrefix += "/"
+	}
+	fileServer := http.StripPrefix(urlPrefix, http.FileServer(http.Dir(dir)))
+	v.mux.Handle("GET "+urlPrefix, noDirListing(fileServer))
+}
+
+// StaticFS serves files from an [fs.FS] at the given URL prefix.
+// This is useful with //go:embed filesystems.
+//
+// Example:
+//
+//	//go:embed static
+//	var staticFiles embed.FS
+//	v.StaticFS("/assets/", staticFiles)
+func (v *V) StaticFS(urlPrefix string, fsys fs.FS) {
+	if !strings.HasSuffix(urlPrefix, "/") {
+		urlPrefix += "/"
+	}
+	fileServer := http.StripPrefix(urlPrefix, http.FileServerFS(fsys))
+	v.mux.Handle("GET "+urlPrefix, noDirListing(fileServer))
+}
+
+// noDirListing wraps a file server handler to return 404 for directory requests.
+func noDirListing(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if strings.HasSuffix(r.URL.Path, "/") {
+			http.NotFound(w, r)
+			return
+		}
+		next.ServeHTTP(w, r)
+	})
+}
+
 func (v *V) ensureDatastarHandler() {
 	v.datastarOnce.Do(func() {
 		v.mux.HandleFunc("GET "+v.datastarPath, func(w http.ResponseWriter, r *http.Request) {
@@ -400,10 +507,7 @@ func (v *V) devModeRemovePersisted(c *Context) {
 	}
 	file.Close()
 
-	// remove ctx to persisted list
-	if _, ok := ctxRegMap[c.id]; !ok {
 	delete(ctxRegMap, c.id)
-	}
 
 	// write persisted list to file
 	file, err = os.Create(p)
@@ -507,6 +611,7 @@ func New() *V {
 		// use last-event-id to tell if request is a sse reconnect
 		sse.Send(datastar.EventTypePatchElements, []string{}, datastar.WithSSEEventId("via"))
 
+		c.sseConnected.Store(true)
 		v.logDebug(c, "SSE connection established")
 
 		go func() {
@@ -517,6 +622,7 @@ func New() *V {
 			select {
 			case <-sse.Context().Done():
 				v.logDebug(c, "SSE connection ended")
+				v.cleanupCtx(c)
 				return
 			case <-c.ctxDisposedChan:
 				v.logDebug(c, "context disposed, closing SSE")
@@ -572,13 +678,29 @@ func New() *V {
 			v.logErr(nil, "action '%s' failed: %v", actionID, err)
 			return
 		}
+		csrfToken, _ := sigs["via-csrf"].(string)
+		if subtle.ConstantTimeCompare([]byte(csrfToken), []byte(c.csrfToken)) != 1 {
+			v.logWarn(c, "action '%s' rejected: invalid CSRF token", actionID)
+			http.Error(w, "invalid CSRF token", http.StatusForbidden)
+			return
+		}
+		if c.actionLimiter != nil && !c.actionLimiter.Allow() {
+			v.logWarn(c, "action '%s' rate limited", actionID)
+			http.Error(w, "rate limited", http.StatusTooManyRequests)
+			return
+		}
 		c.reqCtx = r.Context()
-		actionFn, err := c.getActionFn(actionID)
+		entry, err := c.getAction(actionID)
 		if err != nil {
 			v.logDebug(c, "action '%s' failed: %v", actionID, err)
 			return
 		}
-		// log err if actionFn panics
+		if entry.limiter != nil && !entry.limiter.Allow() {
+			v.logWarn(c, "action '%s' rate limited (per-action)", actionID)
+			http.Error(w, "rate limited", http.StatusTooManyRequests)
+			return
+		}
+		// log err if action panics
 		defer func() {
 			if r := recover(); r != nil {
 				v.logErr(c, "action '%s' failed: %v", actionID, r)
@@ -586,7 +708,7 @@ func New() *V {
 		}()
 
 		c.injectSignals(sigs)
-		actionFn()
+		entry.fn()
 	})
 
 	v.mux.HandleFunc("POST /_session/close", func(w http.ResponseWriter, r *http.Request) {
@@ -603,12 +725,8 @@ func New() *V {
 			v.logErr(c, "failed to handle session close: %v", err)
 			return
 		}
-		c.dispose()
 		v.logDebug(c, "session close event triggered")
-		if v.cfg.DevMode {
+		v.cleanupCtx(c)
-			v.devModeRemovePersisted(c)
-		}
-		v.unregisterCtx(c)
 	})
 	return v
 }
@@ -619,6 +737,12 @@ func genRandID() string {
 	return hex.EncodeToString(b)[:8]
 }
 
+func genCSRFToken() string {
+	b := make([]byte, 16)
+	rand.Read(b)
+	return hex.EncodeToString(b)
+}
+
 func extractParams(pattern, path string) map[string]string {
 	p := strings.Split(strings.Trim(pattern, "/"), "/")
 	u := strings.Split(strings.Trim(path, "/"), "/")

via_test.go

@@ -1,9 +1,13 @@
 package via
 
 import (
+	"encoding/json"
 	"net/http"
 	"net/http/httptest"
+	"os"
+	"path/filepath"
 	"testing"
+	"time"
 
 	"github.com/ryanhamamura/via/h"
 	"github.com/stretchr/testify/assert"
@@ -128,6 +132,60 @@ func TestAction(t *testing.T) {
 	assert.Contains(t, body, "/_action/")
 }
 
+func TestEventTypes(t *testing.T) {
+	tests := []struct {
+		name     string
+		attr     string
+		buildEl  func(trigger *actionTrigger) h.H
+	}{
+		{"OnSubmit", "data-on:submit", func(tr *actionTrigger) h.H { return h.Form(tr.OnSubmit()) }},
+		{"OnInput", "data-on:input", func(tr *actionTrigger) h.H { return h.Input(tr.OnInput()) }},
+		{"OnFocus", "data-on:focus", func(tr *actionTrigger) h.H { return h.Input(tr.OnFocus()) }},
+		{"OnBlur", "data-on:blur", func(tr *actionTrigger) h.H { return h.Input(tr.OnBlur()) }},
+		{"OnMouseEnter", "data-on:mouseenter", func(tr *actionTrigger) h.H { return h.Div(tr.OnMouseEnter()) }},
+		{"OnMouseLeave", "data-on:mouseleave", func(tr *actionTrigger) h.H { return h.Div(tr.OnMouseLeave()) }},
+		{"OnScroll", "data-on:scroll", func(tr *actionTrigger) h.H { return h.Div(tr.OnScroll()) }},
+		{"OnDblClick", "data-on:dblclick", func(tr *actionTrigger) h.H { return h.Div(tr.OnDblClick()) }},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			var trigger *actionTrigger
+			v := New()
+			v.Page("/", func(c *Context) {
+				trigger = c.Action(func() {})
+				c.View(func() h.H { return tt.buildEl(trigger) })
+			})
+
+			req := httptest.NewRequest("GET", "/", nil)
+			w := httptest.NewRecorder()
+			v.mux.ServeHTTP(w, req)
+			body := w.Body.String()
+			assert.Contains(t, body, tt.attr)
+			assert.Contains(t, body, "/_action/"+trigger.id)
+		})
+	}
+
+	t.Run("WithSignal", func(t *testing.T) {
+		var trigger *actionTrigger
+		var sig *signal
+		v := New()
+		v.Page("/", func(c *Context) {
+			trigger = c.Action(func() {})
+			sig = c.Signal("val")
+			c.View(func() h.H {
+				return h.Div(trigger.OnDblClick(WithSignal(sig, "x")))
+			})
+		})
+
+		req := httptest.NewRequest("GET", "/", nil)
+		w := httptest.NewRecorder()
+		v.mux.ServeHTTP(w, req)
+		body := w.Body.String()
+		assert.Contains(t, body, "data-on:dblclick")
+		assert.Contains(t, body, "$"+sig.ID()+"='x'")
+	})
+}
+
 func TestOnKeyDownWithWindow(t *testing.T) {
 	var trigger *actionTrigger
 	v := New()
@@ -235,3 +293,93 @@ func TestPage_PanicsOnNoView(t *testing.T) {
 		v.Page("/", func(c *Context) {})
 	})
 }
+
+func TestReaperCleansOrphanedContexts(t *testing.T) {
+	v := New()
+	c := newContext("orphan-1", "/", v)
+	c.createdAt = time.Now().Add(-time.Minute) // created 1 min ago
+	v.registerCtx(c)
+
+	_, err := v.getCtx("orphan-1")
+	assert.NoError(t, err)
+
+	v.reapOrphanedContexts(10 * time.Second)
+
+	_, err = v.getCtx("orphan-1")
+	assert.Error(t, err, "orphaned context should have been reaped")
+}
+
+func TestReaperIgnoresConnectedContexts(t *testing.T) {
+	v := New()
+	c := newContext("connected-1", "/", v)
+	c.createdAt = time.Now().Add(-time.Minute)
+	c.sseConnected.Store(true)
+	v.registerCtx(c)
+
+	v.reapOrphanedContexts(10 * time.Second)
+
+	_, err := v.getCtx("connected-1")
+	assert.NoError(t, err, "connected context should survive reaping")
+}
+
+func TestReaperDisabledWithNegativeTTL(t *testing.T) {
+	v := New()
+	v.cfg.ContextTTL = -1
+	v.startReaper()
+	assert.Nil(t, v.reaperStop, "reaper should not start with negative TTL")
+}
+
+func TestCleanupCtxIdempotent(t *testing.T) {
+	v := New()
+	c := newContext("idempotent-1", "/", v)
+	v.registerCtx(c)
+
+	assert.NotPanics(t, func() {
+		v.cleanupCtx(c)
+		v.cleanupCtx(c)
+	})
+
+	_, err := v.getCtx("idempotent-1")
+	assert.Error(t, err, "context should be removed after cleanup")
+}
+
+func TestDevModeRemovePersistedFix(t *testing.T) {
+	v := New()
+	v.cfg.DevMode = true
+
+	dir := filepath.Join(t.TempDir(), ".via", "devmode")
+	p := filepath.Join(dir, "ctx.json")
+	assert.NoError(t, os.MkdirAll(dir, 0755))
+
+	// Write a persisted context
+	ctxRegMap := map[string]string{"test-ctx-1": "/"}
+	f, err := os.Create(p)
+	assert.NoError(t, err)
+	assert.NoError(t, json.NewEncoder(f).Encode(ctxRegMap))
+	f.Close()
+
+	// Patch devModeRemovePersisted to use our temp path by calling it
+	// directly — we need to override the path. Instead, test via the
+	// actual function by temporarily changing the working dir.
+	origDir, _ := os.Getwd()
+	assert.NoError(t, os.Chdir(t.TempDir()))
+	defer os.Chdir(origDir)
+
+	// Re-create the structure in the temp dir
+	assert.NoError(t, os.MkdirAll(filepath.Join(".via", "devmode"), 0755))
+	p2 := filepath.Join(".via", "devmode", "ctx.json")
+	f2, _ := os.Create(p2)
+	json.NewEncoder(f2).Encode(map[string]string{"test-ctx-1": "/"})
+	f2.Close()
+
+	c := newContext("test-ctx-1", "/", v)
+	v.devModeRemovePersisted(c)
+
+	// Read back and verify
+	f3, err := os.Open(p2)
+	assert.NoError(t, err)
+	defer f3.Close()
+	var result map[string]string
+	assert.NoError(t, json.NewDecoder(f3).Decode(&result))
+	assert.Empty(t, result, "persisted context should be removed")
+}