diff --git a/acl/acl.go b/acl/acl.go
new file mode 100644
index 000000000..442837340
--- /dev/null
+++ b/acl/acl.go
@@ -0,0 +1,216 @@
+package acl
+
+import (
+	"github.com/armon/go-radix"
+)
+
+var (
+	// allowAll is a singleton policy which allows all
+	// non-management actions
+	allowAll ACL
+
+	// denyAll is a singleton policy which denies all actions
+	denyAll ACL
+
+	// manageAll is a singleton policy which allows all
+	// actions, including management
+	manageAll ACL
+)
+
+func init() {
+	// Setup the singletons
+	allowAll = &StaticACL{
+		allowManage:  false,
+		defaultAllow: true,
+	}
+	denyAll = &StaticACL{
+		allowManage:  false,
+		defaultAllow: false,
+	}
+	manageAll = &StaticACL{
+		allowManage:  true,
+		defaultAllow: true,
+	}
+}
+
+// ACL is the interface for policy enforcement.
+type ACL interface {
+	// KeyRead checks for permission to read a given key
+	KeyRead(string) bool
+
+	// KeyWrite checks for permission to write a given key
+	KeyWrite(string) bool
+
+	// KeyWritePrefix checks for permission to write to an
+	// entire key prefix. This means there must be no sub-policies
+	// that deny a write.
+	KeyWritePrefix(string) bool
+
+	// ACLList checks for permission to list all the ACLs
+	ACLList() bool
+
+	// ACLModify checks for permission to manipulate ACLs
+	ACLModify() bool
+}
+
+// StaticACL is used to implement a base ACL policy. It either
+// allows or denies all requests. This can be used as a parent
+// ACL to act in a blacklist or whitelist mode.
+type StaticACL struct {
+	allowManage  bool
+	defaultAllow bool
+}
+
+func (s *StaticACL) KeyRead(string) bool {
+	return s.defaultAllow
+}
+
+func (s *StaticACL) KeyWrite(string) bool {
+	return s.defaultAllow
+}
+
+func (s *StaticACL) KeyWritePrefix(string) bool {
+	return s.defaultAllow
+}
+
+func (s *StaticACL) ACLList() bool {
+	return s.allowManage
+}
+
+func (s *StaticACL) ACLModify() bool {
+	return s.allowManage
+}
+
+// AllowAll returns an ACL rule that allows all operations
+func AllowAll() ACL {
+	return allowAll
+}
+
+// DenyAll returns an ACL rule that denies all operations
+func DenyAll() ACL {
+	return denyAll
+}
+
+// ManageAll returns an ACL rule that can manage all resources
+func ManageAll() ACL {
+	return manageAll
+}
+
+// RootACL returns a possible ACL if the ID matches a root policy
+func RootACL(id string) ACL {
+	switch id {
+	case "allow":
+		return allowAll
+	case "deny":
+		return denyAll
+	case "manage":
+		return manageAll
+	default:
+		return nil
+	}
+}
+
+// PolicyACL is used to wrap a set of ACL policies to provide
+// the ACL interface.
+type PolicyACL struct {
+	// parent is used to resolve policy if we have
+	// no matching rule.
+	parent ACL
+
+	// keyRules contains the key policies
+	keyRules *radix.Tree
+}
+
+// New is used to construct a policy based ACL from a set of policies
+// and a parent policy to resolve missing cases.
+func New(parent ACL, policy *Policy) (*PolicyACL, error) {
+	p := &PolicyACL{
+		parent:   parent,
+		keyRules: radix.New(),
+	}
+
+	// Load the key policy
+	for _, kp := range policy.Keys {
+		p.keyRules.Insert(kp.Prefix, kp.Policy)
+	}
+	return p, nil
+}
+
+// KeyRead returns if a key is allowed to be read
+func (p *PolicyACL) KeyRead(key string) bool {
+	// Look for a matching rule
+	_, rule, ok := p.keyRules.LongestPrefix(key)
+	if ok {
+		switch rule.(string) {
+		case KeyPolicyRead:
+			return true
+		case KeyPolicyWrite:
+			return true
+		default:
+			return false
+		}
+	}
+
+	// No matching rule, use the parent.
+	return p.parent.KeyRead(key)
+}
+
+// KeyWrite returns if a key is allowed to be written
+func (p *PolicyACL) KeyWrite(key string) bool {
+	// Look for a matching rule
+	_, rule, ok := p.keyRules.LongestPrefix(key)
+	if ok {
+		switch rule.(string) {
+		case KeyPolicyWrite:
+			return true
+		default:
+			return false
+		}
+	}
+
+	// No matching rule, use the parent.
+	return p.parent.KeyWrite(key)
+}
+
+// KeyWritePrefix returns if a prefix is allowed to be written
+func (p *PolicyACL) KeyWritePrefix(prefix string) bool {
+	// Look for a matching rule that denies
+	_, rule, ok := p.keyRules.LongestPrefix(prefix)
+	if ok && rule.(string) != KeyPolicyWrite {
+		return false
+	}
+
+	// Look if any of our children have a deny policy
+	deny := false
+	p.keyRules.WalkPrefix(prefix, func(path string, rule interface{}) bool {
+		// We have a rule to prevent a write in a sub-directory!
+		if rule.(string) != KeyPolicyWrite {
+			deny = true
+			return true
+		}
+		return false
+	})
+
+	// Deny the write if any sub-rules may be violated
+	if deny {
+		return false
+	}
+
+	// If we had a matching rule, done
+	if ok {
+		return true
+	}
+
+	// No matching rule, use the parent.
+	return p.parent.KeyWritePrefix(prefix)
+}
+
+// ACLList checks if listing of ACLs is allowed
+func (p *PolicyACL) ACLList() bool {
+	return p.parent.ACLList()
+}
+
+// ACLModify checks if modification of ACLs is allowed
+func (p *PolicyACL) ACLModify() bool {
+	return p.parent.ACLModify()
+}
diff --git a/acl/acl_test.go b/acl/acl_test.go
new file mode 100644
index 000000000..9be0388db
--- /dev/null
+++ b/acl/acl_test.go
@@ -0,0 +1,197 @@
+package acl
+
+import (
+	"testing"
+)
+
+func TestRootACL(t *testing.T) {
+	if RootACL("allow") != AllowAll() {
+		t.Fatalf("Bad root")
+	}
+	if RootACL("deny") != DenyAll() {
+		t.Fatalf("Bad root")
+	}
+	if RootACL("manage") != ManageAll() {
+		t.Fatalf("Bad root")
+	}
+	if RootACL("foo") != nil {
+		t.Fatalf("bad root")
+	}
+}
+
+func TestStaticACL(t *testing.T) {
+	all := AllowAll()
+	if _, ok := all.(*StaticACL); !ok {
+		t.Fatalf("expected static")
+	}
+
+	none := DenyAll()
+	if _, ok := none.(*StaticACL); !ok {
+		t.Fatalf("expected static")
+	}
+
+	manage := ManageAll()
+	if _, ok := none.(*StaticACL); !ok {
+		t.Fatalf("expected static")
+	}
+
+	if !all.KeyRead("foobar") {
+		t.Fatalf("should allow")
+	}
+	if !all.KeyWrite("foobar") {
+		t.Fatalf("should allow")
+	}
+	if all.ACLList() {
+		t.Fatalf("should not allow")
+	}
+	if all.ACLModify() {
+		t.Fatalf("should not allow")
+	}
+
+	if none.KeyRead("foobar") {
+		t.Fatalf("should not allow")
+	}
+	if none.KeyWrite("foobar") {
+		t.Fatalf("should not allow")
+	}
+	if none.ACLList() {
+		t.Fatalf("should not noneow")
+	}
+	if none.ACLModify() {
+		t.Fatalf("should not noneow")
+	}
+
+	if !manage.KeyRead("foobar") {
+		t.Fatalf("should allow")
+	}
+	if !manage.KeyWrite("foobar") {
+		t.Fatalf("should allow")
+	}
+	if !manage.ACLList() {
+		t.Fatalf("should allow")
+	}
+	if !manage.ACLModify() {
+		t.Fatalf("should allow")
+	}
+}
+
+func TestPolicyACL(t *testing.T) {
+	all := AllowAll()
+	policy := &Policy{
+		Keys: []*KeyPolicy{
+			&KeyPolicy{
+				Prefix: "foo/",
+				Policy: KeyPolicyWrite,
+			},
+			&KeyPolicy{
+				Prefix: "foo/priv/",
+				Policy: KeyPolicyDeny,
+			},
+			&KeyPolicy{
+				Prefix: "bar/",
+				Policy: KeyPolicyDeny,
+			},
+			&KeyPolicy{
+				Prefix: "zip/",
+				Policy: KeyPolicyRead,
+			},
+		},
+	}
+	acl, err := New(all, policy)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	type tcase struct {
+		inp         string
+		read        bool
+		write       bool
+		writePrefix bool
+	}
+	cases := []tcase{
+		{"other", true, true, true},
+		{"foo/test", true, true, true},
+		{"foo/priv/test", false, false, false},
+		{"bar/any", false, false, false},
+		{"zip/test", true, false, false},
+		{"foo/", true, true, false},
+		{"", true, true, false},
+	}
+	for _, c := range cases {
+		if c.read != acl.KeyRead(c.inp) {
+			t.Fatalf("Read fail: %#v", c)
+		}
+		if c.write != acl.KeyWrite(c.inp) {
+			t.Fatalf("Write fail: %#v", c)
+		}
+		if c.writePrefix != acl.KeyWritePrefix(c.inp) {
+			t.Fatalf("Write prefix fail: %#v", c)
+		}
+	}
+}
+
+func TestPolicyACL_Parent(t *testing.T) {
+	deny := DenyAll()
+	policyRoot := &Policy{
+		Keys: []*KeyPolicy{
+			&KeyPolicy{
+				Prefix: "foo/",
+				Policy: KeyPolicyWrite,
+			},
+			&KeyPolicy{
+				Prefix: "bar/",
+				Policy: KeyPolicyRead,
+			},
+		},
+	}
+	root, err := New(deny, policyRoot)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	policy := &Policy{
+		Keys: []*KeyPolicy{
+			&KeyPolicy{
+				Prefix: "foo/priv/",
+				Policy: KeyPolicyRead,
+			},
+			&KeyPolicy{
+				Prefix: "bar/",
+				Policy: KeyPolicyDeny,
+			},
+			&KeyPolicy{
+				Prefix: "zip/",
+				Policy: KeyPolicyRead,
+			},
+		},
+	}
+	acl, err := New(root, policy)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	type tcase struct {
+		inp         string
+		read        bool
+		write       bool
+		writePrefix bool
+	}
+	cases := []tcase{
+		{"other", false, false, false},
+		{"foo/test", true, true, true},
+		{"foo/priv/test", true, false, false},
+		{"bar/any", false, false, false},
+		{"zip/test", true, false, false},
+	}
+	for _, c := range cases {
+		if c.read != acl.KeyRead(c.inp) {
+			t.Fatalf("Read fail: %#v", c)
+		}
+		if c.write != acl.KeyWrite(c.inp) {
+			t.Fatalf("Write fail: %#v", c)
+		}
+		if c.writePrefix != acl.KeyWritePrefix(c.inp) {
+			t.Fatalf("Write prefix fail: %#v", c)
+		}
+	}
+}
diff --git a/acl/cache.go b/acl/cache.go
new file mode 100644
index 000000000..6e7295562
--- /dev/null
+++ b/acl/cache.go
@@ -0,0 +1,164 @@
+package acl
+
+import (
+	"crypto/md5"
+	"fmt"
+
+	"github.com/hashicorp/golang-lru"
+)
+
+// FaultFunc is a function used to fault in the parent,
+// rules for an  ACL given it's ID
+type FaultFunc func(id string) (string, string, error)
+
+// aclEntry allows us to store the ACL with it's policy ID
+type aclEntry struct {
+	ACL    ACL
+	Parent string
+	RuleID string
+}
+
+// Cache is used to implement policy and ACL caching
+type Cache struct {
+	faultfn     FaultFunc
+	aclCache    *lru.Cache // Cache id -> acl
+	policyCache *lru.Cache // Cache policy -> acl
+	ruleCache   *lru.Cache // Cache rules -> policy
+}
+
+// NewCache contructs a new policy and ACL cache of a given size
+func NewCache(size int, faultfn FaultFunc) (*Cache, error) {
+	if size <= 0 {
+		return nil, fmt.Errorf("Must provide positive cache size")
+	}
+	rc, _ := lru.New(size)
+	pc, _ := lru.New(size)
+	ac, _ := lru.New(size)
+	c := &Cache{
+		faultfn:     faultfn,
+		aclCache:    ac,
+		policyCache: pc,
+		ruleCache:   rc,
+	}
+	return c, nil
+}
+
+// GetPolicy is used to get a potentially cached policy set.
+// If not cached, it will be parsed, and then cached.
+func (c *Cache) GetPolicy(rules string) (*Policy, error) {
+	return c.getPolicy(c.ruleID(rules), rules)
+}
+
+// getPolicy is an internal method to get a cached policy,
+// but it assumes a pre-computed ID
+func (c *Cache) getPolicy(id, rules string) (*Policy, error) {
+	raw, ok := c.ruleCache.Get(id)
+	if ok {
+		return raw.(*Policy), nil
+	}
+	policy, err := Parse(rules)
+	if err != nil {
+		return nil, err
+	}
+	policy.ID = id
+	c.ruleCache.Add(id, policy)
+	return policy, nil
+
+}
+
+// ruleID is used to generate an ID for a rule
+func (c *Cache) ruleID(rules string) string {
+	return fmt.Sprintf("%x", md5.Sum([]byte(rules)))
+}
+
+// policyID returns the cache ID for a policy
+func (c *Cache) policyID(parent, ruleID string) string {
+	return parent + ":" + ruleID
+}
+
+// GetACLPolicy is used to get the potentially cached ACL
+// policy. If not cached, it will be generated and then cached.
+func (c *Cache) GetACLPolicy(id string) (string, *Policy, error) {
+	// Check for a cached acl
+	if raw, ok := c.aclCache.Get(id); ok {
+		cached := raw.(aclEntry)
+		if raw, ok := c.ruleCache.Get(cached.RuleID); ok {
+			return cached.Parent, raw.(*Policy), nil
+		}
+	}
+
+	// Fault in the rules
+	parent, rules, err := c.faultfn(id)
+	if err != nil {
+		return "", nil, err
+	}
+
+	// Get cached
+	policy, err := c.GetPolicy(rules)
+	return parent, policy, err
+}
+
+// GetACL is used to get a potentially cached ACL policy.
+// If not cached, it will be generated and then cached.
+func (c *Cache) GetACL(id string) (ACL, error) {
+	// Look for the ACL directly
+	raw, ok := c.aclCache.Get(id)
+	if ok {
+		return raw.(aclEntry).ACL, nil
+	}
+
+	// Get the rules
+	parentID, rules, err := c.faultfn(id)
+	if err != nil {
+		return nil, err
+	}
+	ruleID := c.ruleID(rules)
+
+	// Check for a compiled ACL
+	policyID := c.policyID(parentID, ruleID)
+	var compiled ACL
+	if raw, ok := c.policyCache.Get(policyID); ok {
+		compiled = raw.(ACL)
+	} else {
+		// Get the policy
+		policy, err := c.getPolicy(ruleID, rules)
+		if err != nil {
+			return nil, err
+		}
+
+		// Get the parent ACL
+		parent := RootACL(parentID)
+		if parent == nil {
+			parent, err = c.GetACL(parentID)
+			if err != nil {
+				return nil, err
+			}
+		}
+
+		// Compile the ACL
+		acl, err := New(parent, policy)
+		if err != nil {
+			return nil, err
+		}
+
+		// Cache the compiled ACL
+		c.policyCache.Add(policyID, acl)
+		compiled = acl
+	}
+
+	// Cache and return the ACL
+	c.aclCache.Add(id, aclEntry{compiled, parentID, ruleID})
+	return compiled, nil
+}
+
+// ClearACL is used to clear the ACL cache if any
+func (c *Cache) ClearACL(id string) {
+	c.aclCache.Remove(id)
+}
+
+// Purge is used to clear all the ACL caches. The
+// rule and policy caches are not purged, since they
+// are content-hashed anyways.
+func (c *Cache) Purge() {
+	c.aclCache.Purge()
+}
diff --git a/acl/cache_test.go b/acl/cache_test.go
new file mode 100644
index 000000000..f880bcaf4
--- /dev/null
+++ b/acl/cache_test.go
@@ -0,0 +1,298 @@
+package acl
+
+import (
+	"testing"
+)
+
+func TestCache_GetPolicy(t *testing.T) {
+	c, err := NewCache(1, nil)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	p, err := c.GetPolicy("")
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	// Should get the same policy
+	p1, err := c.GetPolicy("")
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if p != p1 {
+		t.Fatalf("should be cached")
+	}
+
+	// Cache a new policy
+	_, err = c.GetPolicy(testSimplePolicy)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	// Test invalidation of p
+	p3, err := c.GetPolicy("")
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if p == p3 {
+		t.Fatalf("should be not cached")
+	}
+}
+
+func TestCache_GetACL(t *testing.T) {
+	policies := map[string]string{
+		"foo": testSimplePolicy,
+		"bar": testSimplePolicy2,
+	}
+	faultfn := func(id string) (string, string, error) {
+		return "deny", policies[id], nil
+	}
+
+	c, err := NewCache(1, faultfn)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	acl, err := c.GetACL("foo")
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	if acl.KeyRead("bar/test") {
+		t.Fatalf("should deny")
+	}
+	if !acl.KeyRead("foo/test") {
+		t.Fatalf("should allow")
+	}
+
+	acl2, err := c.GetACL("foo")
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	if acl != acl2 {
+		t.Fatalf("should be cached")
+	}
+
+	// Invalidate cache
+	_, err = c.GetACL("bar")
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	acl3, err := c.GetACL("foo")
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	if acl == acl3 {
+		t.Fatalf("should not be cached")
+	}
+}
+
+func TestCache_ClearACL(t *testing.T) {
+	policies := map[string]string{
+		"foo": testSimplePolicy,
+		"bar": testSimplePolicy,
+	}
+	faultfn := func(id string) (string, string, error) {
+		return "deny", policies[id], nil
+	}
+
+	c, err := NewCache(1, faultfn)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	acl, err := c.GetACL("foo")
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	// Nuke the cache
+	c.ClearACL("foo")
+
+	// Clear the policy cache
+	c.policyCache.Purge()
+
+	acl2, err := c.GetACL("foo")
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	if acl == acl2 {
+		t.Fatalf("should not be cached")
+	}
+}
+
+func TestCache_Purge(t *testing.T) {
+	policies := map[string]string{
+		"foo": testSimplePolicy,
+		"bar": testSimplePolicy,
+	}
+	faultfn := func(id string) (string, string, error) {
+		return "deny", policies[id], nil
+	}
+
+	c, err := NewCache(1, faultfn)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	acl, err := c.GetACL("foo")
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	// Nuke the cache
+	c.Purge()
+	c.policyCache.Purge()
+
+	acl2, err := c.GetACL("foo")
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	if acl == acl2 {
+		t.Fatalf("should not be cached")
+	}
+}
+
+func TestCache_GetACLPolicy(t *testing.T) {
+	policies := map[string]string{
+		"foo": testSimplePolicy,
+		"bar": testSimplePolicy,
+	}
+	faultfn := func(id string) (string, string, error) {
+		return "deny", policies[id], nil
+	}
+	c, err := NewCache(1, faultfn)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	p, err := c.GetPolicy(testSimplePolicy)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	_, err = c.GetACL("foo")
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	parent, p2, err := c.GetACLPolicy("foo")
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if parent != "deny" {
+		t.Fatalf("bad: %v", parent)
+	}
+
+	if p2 != p {
+		t.Fatalf("expected cached policy")
+	}
+
+	parent, p3, err := c.GetACLPolicy("bar")
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if parent != "deny" {
+		t.Fatalf("bad: %v", parent)
+	}
+
+	if p3 != p {
+		t.Fatalf("expected cached policy")
+	}
+}
+
+func TestCache_GetACL_Parent(t *testing.T) {
+	faultfn := func(id string) (string, string, error) {
+		switch id {
+		case "foo":
+			// Foo inherits from bar
+			return "bar", testSimplePolicy, nil
+		case "bar":
+			return "deny", testSimplePolicy2, nil
+		}
+		t.Fatalf("bad case")
+		return "", "", nil
+	}
+
+	c, err := NewCache(1, faultfn)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	acl, err := c.GetACL("foo")
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	if !acl.KeyRead("bar/test") {
+		t.Fatalf("should allow")
+	}
+	if !acl.KeyRead("foo/test") {
+		t.Fatalf("should allow")
+	}
+}
+
+func TestCache_GetACL_ParentCache(t *testing.T) {
+	// Same rules, different parent
+	faultfn := func(id string) (string, string, error) {
+		switch id {
+		case "foo":
+			return "allow", testSimplePolicy, nil
+		case "bar":
+			return "deny", testSimplePolicy, nil
+		}
+		t.Fatalf("bad case")
+		return "", "", nil
+	}
+
+	c, err := NewCache(16, faultfn)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	acl, err := c.GetACL("foo")
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	if !acl.KeyRead("bar/test") {
+		t.Fatalf("should allow")
+	}
+	if !acl.KeyRead("foo/test") {
+		t.Fatalf("should allow")
+	}
+
+	acl2, err := c.GetACL("bar")
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	if acl == acl2 {
+		t.Fatalf("should not match")
+	}
+
+	if acl2.KeyRead("bar/test") {
+		t.Fatalf("should not allow")
+	}
+	if !acl2.KeyRead("foo/test") {
+		t.Fatalf("should allow")
+	}
+}
+
+var testSimplePolicy = `
+key "foo/" {
+	policy = "read"
+}
+`
+
+var testSimplePolicy2 = `
+key "bar/" {
+	policy = "read"
+}
+`
diff --git a/acl/policy.go b/acl/policy.go
new file mode 100644
index 000000000..014ef51ac
--- /dev/null
+++ b/acl/policy.go
@@ -0,0 +1,57 @@
+package acl
+
+import (
+	"fmt"
+	"github.com/hashicorp/hcl"
+)
+
+const (
+	KeyPolicyDeny  = "deny"
+	KeyPolicyRead  = "read"
+	KeyPolicyWrite = "write"
+)
+
+// Policy is used to represent the policy specified by
+// an ACL configuration.
+type Policy struct {
+	ID   string       `hcl:"-"`
+	Keys []*KeyPolicy `hcl:"key,expand"`
+}
+
+// KeyPolicy represents a policy for a key
+type KeyPolicy struct {
+	Prefix string `hcl:",key"`
+	Policy string
+}
+
+func (k *KeyPolicy) GoString() string {
+	return fmt.Sprintf("%#v", *k)
+}
+
+// Parse is used to parse the specified ACL rules into an
+// intermediary set of policies, before being compiled into
+// the ACL
+func Parse(rules string) (*Policy, error) {
+	// Decode the rules
+	p := &Policy{}
+	if rules == "" {
+		// Hot path for empty rules
+		return p, nil
+	}
+
+	if err := hcl.Decode(p, rules); err != nil {
+		return nil, fmt.Errorf("Failed to parse ACL rules: %v", err)
+	}
+
+	// Validate the key policy
+	for _, kp := range p.Keys {
+		switch kp.Policy {
+		case KeyPolicyDeny:
+		case KeyPolicyRead:
+		case KeyPolicyWrite:
+		default:
+			return nil, fmt.Errorf("Invalid key policy: %#v", kp)
+		}
+	}
+	return p, nil
+}
diff --git a/acl/policy_test.go b/acl/policy_test.go
new file mode 100644
index 000000000..0fc75e0fa
--- /dev/null
+++ b/acl/policy_test.go
@@ -0,0 +1,100 @@
+package acl
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestParse(t *testing.T) {
+	inp := `
+key "" {
+	policy = "read"
+}
+key "foo/" {
+	policy = "write"
+}
+key "foo/bar/" {
+	policy = "read"
+}
+key "foo/bar/baz" {
+	policy = "deny"
+}
+	`
+	exp := &Policy{
+		Keys: []*KeyPolicy{
+			&KeyPolicy{
+				Prefix: "",
+				Policy: KeyPolicyRead,
+			},
+			&KeyPolicy{
+				Prefix: "foo/",
+				Policy: KeyPolicyWrite,
+			},
+			&KeyPolicy{
+				Prefix: "foo/bar/",
+				Policy: KeyPolicyRead,
+			},
+			&KeyPolicy{
+				Prefix: "foo/bar/baz",
+				Policy: KeyPolicyDeny,
+			},
+		},
+	}
+
+	out, err := Parse(inp)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	if !reflect.DeepEqual(out, exp) {
+		t.Fatalf("bad: %#v %#v", out, exp)
+	}
+}
+
+func TestParse_JSON(t *testing.T) {
+	inp := `{
+	"key": {
+		"": {
+			"policy": "read"
+		},
+		"foo/": {
+			"policy": "write"
+		},
+		"foo/bar/": {
+			"policy": "read"
+		},
+		"foo/bar/baz": {
+			"policy": "deny"
+		}
+	}
+}`
+	exp := &Policy{
+		Keys: []*KeyPolicy{
+			&KeyPolicy{
+				Prefix: "",
+				Policy: KeyPolicyRead,
+			},
+			&KeyPolicy{
+				Prefix: "foo/",
+				Policy: KeyPolicyWrite,
+			},
+			&KeyPolicy{
+				Prefix: "foo/bar/",
+				Policy: KeyPolicyRead,
+			},
+			&KeyPolicy{
+				Prefix: "foo/bar/baz",
+				Policy: KeyPolicyDeny,
+			},
+		},
+	}
+
+	out, err := Parse(inp)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	if !reflect.DeepEqual(out, exp) {
+		t.Fatalf("bad: %#v %#v", out, exp)
+	}
+}
diff --git a/command/agent/acl_endpoint.go b/command/agent/acl_endpoint.go
new file mode 100644
index 000000000..52db96fec
--- /dev/null
+++ b/command/agent/acl_endpoint.go
@@ -0,0 +1,190 @@
+package agent
+
+import (
+	"fmt"
+	"github.com/hashicorp/consul/consul/structs"
+	"net/http"
+	"strings"
+)
+
+// aclCreateResponse is used to wrap the ACL ID
+type aclCreateResponse struct {
+	ID string
+}
+
+// aclDisabled handles if ACL datacenter is not configured
+func aclDisabled(resp http.ResponseWriter, req *http.Request) (interface{}, error) {
+	resp.WriteHeader(401)
+	resp.Write([]byte("ACL support disabled"))
+	return nil, nil
+}
+
+func (s *HTTPServer) ACLDestroy(resp http.ResponseWriter, req *http.Request) (interface{}, error) {
+	args := structs.ACLRequest{
+		Datacenter: s.agent.config.ACLDatacenter,
+		Op:         structs.ACLDelete,
+	}
+	s.parseToken(req, &args.Token)
+
+	// Pull out the acl id
+	args.ACL.ID = strings.TrimPrefix(req.URL.Path, "/v1/acl/destroy/")
+	if args.ACL.ID == "" {
+		resp.WriteHeader(400)
+		resp.Write([]byte("Missing ACL"))
+		return nil, nil
+	}
+
+	var out string
+	if err := s.agent.RPC("ACL.Apply", &args, &out); err != nil {
+		return nil, err
+	}
+	return true, nil
+}
+
+func (s *HTTPServer) ACLCreate(resp http.ResponseWriter, req *http.Request) (interface{}, error) {
+	return s.aclSet(resp, req, false)
+}
+
+func (s *HTTPServer) ACLUpdate(resp http.ResponseWriter, req *http.Request) (interface{}, error) {
+	return s.aclSet(resp, req, true)
+}
+
+func (s *HTTPServer) aclSet(resp http.ResponseWriter, req *http.Request, update bool) (interface{}, error) {
+	// Mandate a PUT request
+	if req.Method != "PUT" {
+		resp.WriteHeader(405)
+		return nil, nil
+	}
+
+	args := structs.ACLRequest{
+		Datacenter: s.agent.config.ACLDatacenter,
+		Op:         structs.ACLSet,
+		ACL: structs.ACL{
+			Type: structs.ACLTypeClient,
+		},
+	}
+	s.parseToken(req, &args.Token)
+
+	// Handle optional request body
+	if req.ContentLength > 0 {
+		if err := decodeBody(req, &args.ACL, nil); err != nil {
+			resp.WriteHeader(400)
+			resp.Write([]byte(fmt.Sprintf("Request decode failed: %v", err)))
+			return nil, nil
+		}
+	}
+
+	// Ensure there is no ID set for create
+	if !update && args.ACL.ID != "" {
+		resp.WriteHeader(400)
+		resp.Write([]byte(fmt.Sprintf("ACL ID cannot be set")))
+		return nil, nil
+	}
+
+	// Ensure there is an ID set for update
+	if update && args.ACL.ID == "" {
+		resp.WriteHeader(400)
+		resp.Write([]byte(fmt.Sprintf("ACL ID must be set")))
+		return nil, nil
+	}
+
+	// Create the acl, get the ID
+	var out string
+	if err := s.agent.RPC("ACL.Apply", &args, &out); err != nil {
+		return nil, err
+	}
+
+	// Format the response as a JSON object
+	return aclCreateResponse{out}, nil
+}
+
+func (s *HTTPServer) ACLClone(resp http.ResponseWriter, req *http.Request) (interface{}, error) {
+	args := structs.ACLSpecificRequest{
+		Datacenter: s.agent.config.ACLDatacenter,
+	}
+	var dc string
+	if done := s.parse(resp, req, &dc, &args.QueryOptions); done {
+		return nil, nil
+	}
+
+	// Pull out the acl id
+	args.ACL = strings.TrimPrefix(req.URL.Path, "/v1/acl/clone/")
+	if args.ACL == "" {
+		resp.WriteHeader(400)
+		resp.Write([]byte("Missing ACL"))
+		return nil, nil
+	}
+
+	var out structs.IndexedACLs
+	defer setMeta(resp, &out.QueryMeta)
+	if err := s.agent.RPC("ACL.Get", &args, &out); err != nil {
+		return nil, err
+	}
+
+	// Bail if the ACL is not found
+	if len(out.ACLs) == 0 {
+		resp.WriteHeader(404)
+		resp.Write([]byte(fmt.Sprintf("Target ACL not found")))
+		return nil, nil
+	}
+
+	// Create a new ACL
+	createArgs := structs.ACLRequest{
+		Datacenter: args.Datacenter,
+		Op:         structs.ACLSet,
+		ACL:        *out.ACLs[0],
+	}
+	createArgs.ACL.ID = ""
+	createArgs.Token = args.Token
+
+	// Create the acl, get the ID
+	var outID string
+	if err := s.agent.RPC("ACL.Apply", &createArgs, &outID); err != nil {
+		return nil, err
+	}
+
+	// Format the response as a JSON object
+	return aclCreateResponse{outID}, nil
+}
+
+func (s *HTTPServer) ACLGet(resp http.ResponseWriter, req *http.Request) (interface{}, error) {
+	args := structs.ACLSpecificRequest{
+		Datacenter: s.agent.config.ACLDatacenter,
+	}
+	var dc string
+	if done := s.parse(resp, req, &dc, &args.QueryOptions); done {
+		return nil, nil
+	}
+
+	// Pull out the acl id
+	args.ACL = strings.TrimPrefix(req.URL.Path, "/v1/acl/info/")
+	if args.ACL == "" {
+		resp.WriteHeader(400)
+		resp.Write([]byte("Missing ACL"))
+		return nil, nil
+	}
+
+	var out structs.IndexedACLs
+	defer setMeta(resp, &out.QueryMeta)
+	if err := s.agent.RPC("ACL.Get", &args, &out); err != nil {
+		return nil, err
+	}
+	return out.ACLs, nil
+}
+
+func (s *HTTPServer) ACLList(resp http.ResponseWriter, req *http.Request) (interface{}, error) {
+	args := structs.DCSpecificRequest{
+		Datacenter: s.agent.config.ACLDatacenter,
+	}
+	var dc string
+	if done := s.parse(resp, req, &dc, &args.QueryOptions); done {
+		return nil, nil
+	}
+
+	var out structs.IndexedACLs
+	defer setMeta(resp, &out.QueryMeta)
+	if err := s.agent.RPC("ACL.List", &args, &out); err != nil {
+		return nil, err
+	}
+	return out.ACLs, nil
+}
diff --git a/command/agent/acl_endpoint_test.go b/command/agent/acl_endpoint_test.go
new file mode 100644
index 000000000..9db7971b4
--- /dev/null
+++ b/command/agent/acl_endpoint_test.go
@@ -0,0 +1,160 @@
+package agent
+
+import (
+	"bytes"
+	"encoding/json"
+	"github.com/hashicorp/consul/consul/structs"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+func makeTestACL(t *testing.T, srv *HTTPServer) string {
+	body := bytes.NewBuffer(nil)
+	enc := json.NewEncoder(body)
+	raw := map[string]interface{}{
+		"Name":  "User Token",
+		"Type":  "client",
+		"Rules": "",
+	}
+	enc.Encode(raw)
+
+	req, err := http.NewRequest("PUT", "/v1/acl/create", body)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	resp := httptest.NewRecorder()
+	obj, err := srv.ACLCreate(resp, req)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	aclResp := obj.(aclCreateResponse)
+	return aclResp.ID
+}
+
+func TestACLUpdate(t *testing.T) {
+	httpTest(t, func(srv *HTTPServer) {
+		id := makeTestACL(t, srv)
+
+		body := bytes.NewBuffer(nil)
+		enc := json.NewEncoder(body)
+		raw := map[string]interface{}{
+			"ID":    id,
+			"Name":  "User Token 2",
+			"Type":  "client",
+			"Rules": "",
+		}
+		enc.Encode(raw)
+
+		req, err := http.NewRequest("PUT", "/v1/acl/update", body)
+		if err != nil {
+			t.Fatalf("err: %v", err)
+		}
+		resp := httptest.NewRecorder()
+		obj, err := srv.ACLUpdate(resp, req)
+		if err != nil {
+			t.Fatalf("err: %v", err)
+		}
+		aclResp := obj.(aclCreateResponse)
+		if aclResp.ID != id {
+			t.Fatalf("bad: %v", aclResp)
+		}
+	})
+}
+
+func TestACLDestroy(t *testing.T) {
+	httpTest(t, func(srv *HTTPServer) {
+		id := makeTestACL(t, srv)
+		req, err := http.NewRequest("PUT", "/v1/session/destroy/"+id, nil)
+		resp := httptest.NewRecorder()
+		obj, err := srv.ACLDestroy(resp, req)
+		if err != nil {
+			t.Fatalf("err: %v", err)
+		}
+		if resp := obj.(bool); !resp {
+			t.Fatalf("should work")
+		}
+	})
+}
+
+func TestACLClone(t *testing.T) {
+	httpTest(t, func(srv *HTTPServer) {
+		id := makeTestACL(t, srv)
+
+		req, err := http.NewRequest("GET",
+			"/v1/acl/clone/"+id, nil)
+		resp := httptest.NewRecorder()
+		obj, err := srv.ACLClone(resp, req)
+		if err != nil {
+			t.Fatalf("err: %v", err)
+		}
+		aclResp, ok := obj.(aclCreateResponse)
+		if !ok {
+			t.Fatalf("should work: %#v %#v", obj, resp)
+		}
+		if aclResp.ID == id {
+			t.Fatalf("bad id")
+		}
+
+		req, err = http.NewRequest("GET",
+			"/v1/acl/info/"+aclResp.ID, nil)
+		resp = httptest.NewRecorder()
+		obj, err = srv.ACLGet(resp, req)
+		if err != nil {
+			t.Fatalf("err: %v", err)
+		}
+		respObj, ok := obj.(structs.ACLs)
+		if !ok {
+			t.Fatalf("should work")
+		}
+		if len(respObj) != 1 {
+			t.Fatalf("bad: %v", respObj)
+		}
+	})
+}
+
+func TestACLGet(t *testing.T) {
+	httpTest(t, func(srv *HTTPServer) {
+		id := makeTestACL(t, srv)
+
+		req, err := http.NewRequest("GET",
+			"/v1/acl/info/"+id, nil)
+		resp := httptest.NewRecorder()
+		obj, err := srv.ACLGet(resp, req)
+		if err != nil {
+			t.Fatalf("err: %v", err)
+		}
+		respObj, ok := obj.(structs.ACLs)
+		if !ok {
+			t.Fatalf("should work")
+		}
+		if len(respObj) != 1 {
+			t.Fatalf("bad: %v", respObj)
+		}
+	})
+}
+
+func TestACLList(t *testing.T) {
+	httpTest(t, func(srv *HTTPServer) {
+		var ids []string
+		for i := 0; i < 10; i++ {
+			ids = append(ids, makeTestACL(t, srv))
+		}
+
+		req, err := http.NewRequest("GET", "/v1/acl/list", nil)
+		resp := httptest.NewRecorder()
+		obj, err := srv.ACLList(resp, req)
+		if err != nil {
+			t.Fatalf("err: %v", err)
+		}
+		respObj, ok := obj.(structs.ACLs)
+		if !ok {
+			t.Fatalf("should work")
+		}
+
+		// 10 + anonymous
+		if len(respObj) != 11 {
+			t.Fatalf("bad: %v", respObj)
+		}
+	})
+}
diff --git a/command/agent/agent.go b/command/agent/agent.go
index 0d8cecfdf..289637adc 100644
--- a/command/agent/agent.go
+++ b/command/agent/agent.go
@@ -181,6 +181,24 @@ func (a *Agent) consulConfig() *consul.Config {
 	if a.config.Protocol > 0 {
 		base.ProtocolVersion = uint8(a.config.Protocol)
 	}
+	if a.config.ACLToken != "" {
+		base.ACLToken = a.config.ACLToken
+	}
+	if a.config.ACLMasterToken != "" {
+		base.ACLMasterToken = a.config.ACLMasterToken
+	}
+	if a.config.ACLDatacenter != "" {
+		base.ACLDatacenter = a.config.ACLDatacenter
+	}
+	if a.config.ACLTTLRaw != "" {
+		base.ACLTTL = a.config.ACLTTL
+	}
+	if a.config.ACLDefaultPolicy != "" {
+		base.ACLDefaultPolicy = a.config.ACLDefaultPolicy
+	}
+	if a.config.ACLDownPolicy != "" {
+		base.ACLDownPolicy = a.config.ACLDownPolicy
+	}
 
 	// Format the build string
 	revision := a.config.Revision
diff --git a/command/agent/agent_test.go b/command/agent/agent_test.go
index a9ca15694..d03596b38 100644
--- a/command/agent/agent_test.go
+++ b/command/agent/agent_test.go
@@ -30,6 +30,7 @@ func nextConfig() *Config {
 	conf.Ports.SerfWan = 18300 + idx
 	conf.Ports.Server = 18100 + idx
 	conf.Server = true
+	conf.ACLDatacenter = "dc1"
 
 	cons := consul.DefaultConfig()
 	conf.ConsulConfig = cons
diff --git a/command/agent/config.go b/command/agent/config.go
index 9a6a043f8..87584e1a2 100644
--- a/command/agent/config.go
+++ b/command/agent/config.go
@@ -194,6 +194,41 @@ type Config struct {
 	CheckUpdateInterval    time.Duration `mapstructure:"-"`
 	CheckUpdateIntervalRaw string        `mapstructure:"check_update_interval" json:"-"`
 
+	// ACLToken is the default token used to make requests if a per-request
+	// token is not provided. If not configured the 'anonymous' token is used.
+	ACLToken string `mapstructure:"acl_token" json:"-"`
+
+	// ACLMasterToken is used to bootstrap the ACL system. It should be specified
+	// on the servers in the ACLDatacenter. When the leader comes online, it ensures
+	// that the Master token is available. This provides the initial token.
+	ACLMasterToken string `mapstructure:"acl_master_token" json:"-"`
+
+	// ACLDatacenter is the central datacenter that holds authoritative
+	// ACL records. This must be the same for the entire cluster.
+	// If this is not set, ACLs are not enabled. Off by default.
+	ACLDatacenter string `mapstructure:"acl_datacenter"`
+
+	// ACLTTL is used to control the time-to-live of cached ACLs . This has
+	// a major impact on performance. By default, it is set to 30 seconds.
+	ACLTTL    time.Duration `mapstructure:"-"`
+	ACLTTLRaw string        `mapstructure:"acl_ttl"`
+
+	// ACLDefaultPolicy is used to control the ACL interaction when
+	// there is no defined policy. This can be "allow" which means
+	// ACLs are used to black-list, or "deny" which means ACLs are
+	// white-lists.
+	ACLDefaultPolicy string `mapstructure:"acl_default_policy"`
+
+	// ACLDownPolicy is used to control the ACL interaction when we cannot
+	// reach the ACLDatacenter and the token is not in the cache.
+	// There are two modes:
+	//   * deny - Deny all requests
+	//   * extend-cache - Ignore the cache expiration, and allow cached
+	//                    ACL's to be used to service requests. This
+	//	                  is the default. If the ACL is not in the cache,
+	//                    this acts like deny.
+	ACLDownPolicy string `mapstructure:"acl_down_policy"`
+
 	// AEInterval controls the anti-entropy interval. This is how often
 	// the agent attempts to reconcile it's local state with the server'
 	// representation of our state. Defaults to every 60s.
@@ -246,6 +281,9 @@ func DefaultConfig() *Config {
 		Protocol:            consul.ProtocolVersionMax,
 		CheckUpdateInterval: 5 * time.Minute,
 		AEInterval:          time.Minute,
+		ACLTTL:              30 * time.Second,
+		ACLDownPolicy:       "extend-cache",
+		ACLDefaultPolicy:    "allow",
 	}
 }
 
@@ -341,6 +379,14 @@ func DecodeConfig(r io.Reader) (*Config, error) {
 		result.CheckUpdateInterval = dur
 	}
 
+	if raw := result.ACLTTLRaw; raw != "" {
+		dur, err := time.ParseDuration(raw)
+		if err != nil {
+			return nil, fmt.Errorf("ACL TTL invalid: %v", err)
+		}
+		result.ACLTTL = dur
+	}
+
 	return &result, nil
 }
 
@@ -583,6 +629,25 @@ func MergeConfig(a, b *Config) *Config {
 	if b.SyslogFacility != "" {
 		result.SyslogFacility = b.SyslogFacility
 	}
+	if b.ACLToken != "" {
+		result.ACLToken = b.ACLToken
+	}
+	if b.ACLMasterToken != "" {
+		result.ACLMasterToken = b.ACLMasterToken
+	}
+	if b.ACLDatacenter != "" {
+		result.ACLDatacenter = b.ACLDatacenter
+	}
+	if b.ACLTTLRaw != "" {
+		result.ACLTTL = b.ACLTTL
+		result.ACLTTLRaw = b.ACLTTLRaw
+	}
+	if b.ACLDownPolicy != "" {
+		result.ACLDownPolicy = b.ACLDownPolicy
+	}
+	if b.ACLDefaultPolicy != "" {
+		result.ACLDefaultPolicy = b.ACLDefaultPolicy
+	}
 
 	// Copy the start join addresses
 	result.StartJoin = make([]string, 0, len(a.StartJoin)+len(b.StartJoin))
diff --git a/command/agent/config_test.go b/command/agent/config_test.go
index 0c6db15e1..9bc67c69c 100644
--- a/command/agent/config_test.go
+++ b/command/agent/config_test.go
@@ -356,6 +356,34 @@ func TestDecodeConfig(t *testing.T) {
 	if config.CheckUpdateInterval != 10*time.Minute {
 		t.Fatalf("bad: %#v", config)
 	}
+
+	// ACLs
+	input = `{"acl_token": "1234", "acl_datacenter": "dc2",
+	"acl_ttl": "60s", "acl_down_policy": "deny",
+	"acl_default_policy": "deny", "acl_master_token": "2345"}`
+	config, err = DecodeConfig(bytes.NewReader([]byte(input)))
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	if config.ACLToken != "1234" {
+		t.Fatalf("bad: %#v", config)
+	}
+	if config.ACLMasterToken != "2345" {
+		t.Fatalf("bad: %#v", config)
+	}
+	if config.ACLDatacenter != "dc2" {
+		t.Fatalf("bad: %#v", config)
+	}
+	if config.ACLTTL != 60*time.Second {
+		t.Fatalf("bad: %#v", config)
+	}
+	if config.ACLDownPolicy != "deny" {
+		t.Fatalf("bad: %#v", config)
+	}
+	if config.ACLDefaultPolicy != "deny" {
+		t.Fatalf("bad: %#v", config)
+	}
 }
 
 func TestDecodeConfig_Service(t *testing.T) {
@@ -503,6 +531,13 @@ func TestMergeConfig(t *testing.T) {
 		RejoinAfterLeave:       true,
 		CheckUpdateInterval:    8 * time.Minute,
 		CheckUpdateIntervalRaw: "8m",
+		ACLToken:               "1234",
+		ACLMasterToken:         "2345",
+		ACLDatacenter:          "dc2",
+		ACLTTL:                 15 * time.Second,
+		ACLTTLRaw:              "15s",
+		ACLDownPolicy:          "deny",
+		ACLDefaultPolicy:       "deny",
 	}
 
 	c := MergeConfig(a, b)
diff --git a/command/agent/http.go b/command/agent/http.go
index a254ecf19..43b8019e9 100644
--- a/command/agent/http.go
+++ b/command/agent/http.go
@@ -99,6 +99,22 @@ func (s *HTTPServer) registerHandlers(enableDebug bool) {
 	s.mux.HandleFunc("/v1/session/node/", s.wrap(s.SessionsForNode))
 	s.mux.HandleFunc("/v1/session/list", s.wrap(s.SessionList))
 
+	if s.agent.config.ACLDatacenter != "" {
+		s.mux.HandleFunc("/v1/acl/create", s.wrap(s.ACLCreate))
+		s.mux.HandleFunc("/v1/acl/update", s.wrap(s.ACLUpdate))
+		s.mux.HandleFunc("/v1/acl/destroy/", s.wrap(s.ACLDestroy))
+		s.mux.HandleFunc("/v1/acl/info/", s.wrap(s.ACLGet))
+		s.mux.HandleFunc("/v1/acl/clone/", s.wrap(s.ACLClone))
+		s.mux.HandleFunc("/v1/acl/list", s.wrap(s.ACLList))
+	} else {
+		s.mux.HandleFunc("/v1/acl/create", s.wrap(aclDisabled))
+		s.mux.HandleFunc("/v1/acl/update", s.wrap(aclDisabled))
+		s.mux.HandleFunc("/v1/acl/destroy/", s.wrap(aclDisabled))
+		s.mux.HandleFunc("/v1/acl/info/", s.wrap(aclDisabled))
+		s.mux.HandleFunc("/v1/acl/clone/", s.wrap(aclDisabled))
+		s.mux.HandleFunc("/v1/acl/list", s.wrap(aclDisabled))
+	}
+
 	if enableDebug {
 		s.mux.HandleFunc("/debug/pprof/", pprof.Index)
 		s.mux.HandleFunc("/debug/pprof/cmdline", pprof.Cmdline)
@@ -273,10 +289,20 @@ func (s *HTTPServer) parseDC(req *http.Request, dc *string) {
 	}
 }
 
+// parseToken is used to parse the ?token query param
+func (s *HTTPServer) parseToken(req *http.Request, token *string) {
+	if other := req.URL.Query().Get("token"); other != "" {
+		*token = other
+	} else if *token == "" {
+		*token = s.agent.config.ACLToken
+	}
+}
+
 // parse is a convenience method for endpoints that need
 // to use both parseWait and parseDC.
 func (s *HTTPServer) parse(resp http.ResponseWriter, req *http.Request, dc *string, b *structs.QueryOptions) bool {
 	s.parseDC(req, dc)
+	s.parseToken(req, &b.Token)
 	if parseConsistency(resp, req, b) {
 		return true
 	}
diff --git a/command/agent/kvs_endpoint.go b/command/agent/kvs_endpoint.go
index dfcce3025..48d9ce19d 100644
--- a/command/agent/kvs_endpoint.go
+++ b/command/agent/kvs_endpoint.go
@@ -145,6 +145,7 @@ func (s *HTTPServer) KVSPut(resp http.ResponseWriter, req *http.Request, args *s
 			Value: nil,
 		},
 	}
+	applyReq.Token = args.Token
 
 	// Check for flags
 	params := req.URL.Query()
@@ -215,6 +216,7 @@ func (s *HTTPServer) KVSDelete(resp http.ResponseWriter, req *http.Request, args
 			Key: args.Key,
 		},
 	}
+	applyReq.Token = args.Token
 
 	// Check for recurse
 	params := req.URL.Query()
diff --git a/consul/acl.go b/consul/acl.go
new file mode 100644
index 000000000..abc011054
--- /dev/null
+++ b/consul/acl.go
@@ -0,0 +1,194 @@
+package consul
+
+import (
+	"errors"
+	"strings"
+	"time"
+
+	"github.com/armon/go-metrics"
+	"github.com/hashicorp/consul/acl"
+	"github.com/hashicorp/consul/consul/structs"
+)
+
+const (
+	// aclNotFound indicates there is no matching ACL
+	aclNotFound = "ACL not found"
+
+	// rootDenied is returned when attempting to resolve a root ACL
+	rootDenied = "Cannot resolve root ACL"
+
+	// permissionDenied is returned when an ACL based rejection happens
+	permissionDenied = "Permission denied"
+
+	// aclDisabled is returned when ACL changes are not permitted
+	// since they are disabled.
+	aclDisabled = "ACL support disabled"
+
+	// anonymousToken is the token ID we re-write to if there
+	// is no token ID provided
+	anonymousToken = "anonymous"
+)
+
+var (
+	permissionDeniedErr = errors.New(permissionDenied)
+)
+
+// aclCacheEntry is used to cache non-authoritative ACL's
+// If non-authoritative, then we must respect a TTL
+type aclCacheEntry struct {
+	ACL     acl.ACL
+	Expires time.Time
+	ETag    string
+}
+
+// aclFault is used to fault in the rules for an ACL if we take a miss
+func (s *Server) aclFault(id string) (string, string, error) {
+	defer metrics.MeasureSince([]string{"consul", "acl", "fault"}, time.Now())
+	state := s.fsm.State()
+	_, acl, err := state.ACLGet(id)
+	if err != nil {
+		return "", "", err
+	}
+	if acl == nil {
+		return "", "", errors.New(aclNotFound)
+	}
+
+	// Management tokens have no policy and inherit from the
+	// 'manage' root policy
+	if acl.Type == structs.ACLTypeManagement {
+		return "manage", "", nil
+	}
+
+	// Otherwise use the base policy
+	return s.config.ACLDefaultPolicy, acl.Rules, nil
+}
+
+// resolveToken is used to resolve an ACL is any is appropriate
+func (s *Server) resolveToken(id string) (acl.ACL, error) {
+	// Check if there is no ACL datacenter (ACL's disabled)
+	authDC := s.config.ACLDatacenter
+	if len(authDC) == 0 {
+		return nil, nil
+	}
+	defer metrics.MeasureSince([]string{"consul", "acl", "resolveToken"}, time.Now())
+
+	// Handle the anonymous token
+	if len(id) == 0 {
+		id = anonymousToken
+	} else if acl.RootACL(id) != nil {
+		return nil, errors.New(rootDenied)
+	}
+
+	// Check if we are the ACL datacenter and the leader, use the
+	// authoritative cache
+	if s.config.Datacenter == authDC && s.IsLeader() {
+		return s.aclAuthCache.GetACL(id)
+	}
+
+	// Use our non-authoritative cache
+	return s.lookupACL(id, authDC)
+}
+
+// lookupACL is used when we are non-authoritative, and need
+// to resolve an ACL
+func (s *Server) lookupACL(id, authDC string) (acl.ACL, error) {
+	// Check the cache for the ACL
+	var cached *aclCacheEntry
+	raw, ok := s.aclCache.Get(id)
+	if ok {
+		cached = raw.(*aclCacheEntry)
+	}
+
+	// Check for live cache
+	if cached != nil && time.Now().Before(cached.Expires) {
+		metrics.IncrCounter([]string{"consul", "acl", "cache_hit"}, 1)
+		return cached.ACL, nil
+	} else {
+		metrics.IncrCounter([]string{"consul", "acl", "cache_miss"}, 1)
+	}
+
+	// Attempt to refresh the policy
+	args := structs.ACLPolicyRequest{
+		Datacenter: authDC,
+		ACL:        id,
+	}
+	if cached != nil {
+		args.ETag = cached.ETag
+	}
+	var out structs.ACLPolicy
+	err := s.RPC("ACL.GetPolicy", &args, &out)
+
+	// Handle the happy path
+	if err == nil {
+		return s.useACLPolicy(id, authDC, cached, &out)
+	}
+
+	// Check for not-found
+	if strings.Contains(err.Error(), aclNotFound) {
+		return nil, errors.New(aclNotFound)
+	} else {
+		s.logger.Printf("[ERR] consul.acl: Failed to get policy for '%s': %v", id, err)
+	}
+
+	// Unable to refresh, apply the down policy
+	switch s.config.ACLDownPolicy {
+	case "allow":
+		return acl.AllowAll(), nil
+	case "extend-cache":
+		if cached != nil {
+			return cached.ACL, nil
+		}
+		fallthrough
+	default:
+		return acl.DenyAll(), nil
+	}
+}
+
+// useACLPolicy handles an ACLPolicy response
+func (s *Server) useACLPolicy(id, authDC string, cached *aclCacheEntry, p *structs.ACLPolicy) (acl.ACL, error) {
+	// Check if we can used the cached policy
+	if cached != nil && cached.ETag == p.ETag {
+		if p.TTL > 0 {
+			cached.Expires = time.Now().Add(p.TTL)
+		}
+		return cached.ACL, nil
+	}
+
+	// Check for a cached compiled policy
+	var compiled acl.ACL
+	raw, ok := s.aclPolicyCache.Get(p.ETag)
+	if ok {
+		compiled = raw.(acl.ACL)
+	} else {
+		// Resolve the parent policy
+		parent := acl.RootACL(p.Parent)
+		if parent == nil {
+			var err error
+			parent, err = s.lookupACL(p.Parent, authDC)
+			if err != nil {
+				return nil, err
+			}
+		}
+
+		// Compile the ACL
+		acl, err := acl.New(parent, p.Policy)
+		if err != nil {
+			return nil, err
+		}
+
+		// Cache the policy
+		s.aclPolicyCache.Add(p.ETag, acl)
+		compiled = acl
+	}
+
+	// Cache the ACL
+	cached = &aclCacheEntry{
+		ACL:  compiled,
+		ETag: p.ETag,
+	}
+	if p.TTL > 0 {
+		cached.Expires = time.Now().Add(p.TTL)
+	}
+	s.aclCache.Add(id, cached)
+	return compiled, nil
+}
diff --git a/consul/acl_endpoint.go b/consul/acl_endpoint.go
new file mode 100644
index 000000000..211a78574
--- /dev/null
+++ b/consul/acl_endpoint.go
@@ -0,0 +1,175 @@
+package consul
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/armon/go-metrics"
+	"github.com/hashicorp/consul/acl"
+	"github.com/hashicorp/consul/consul/structs"
+)
+
+// ACL endpoint is used to manipulate ACLs
+type ACL struct {
+	srv *Server
+}
+
+// Apply is used to apply a modifying request to the data store. This should
+// only be used for operations that modify the data
+func (a *ACL) Apply(args *structs.ACLRequest, reply *string) error {
+	if done, err := a.srv.forward("ACL.Apply", args, args, reply); done {
+		return err
+	}
+	defer metrics.MeasureSince([]string{"consul", "acl", "apply"}, time.Now())
+
+	// Verify we are allowed to serve this request
+	if a.srv.config.ACLDatacenter != a.srv.config.Datacenter {
+		return fmt.Errorf(aclDisabled)
+	}
+
+	// Verify token is permitted to list ACLs
+	if acl, err := a.srv.resolveToken(args.Token); err != nil {
+		return err
+	} else if acl == nil || !acl.ACLModify() {
+		return permissionDeniedErr
+	}
+
+	switch args.Op {
+	case structs.ACLSet:
+		// Verify the ACL type
+		switch args.ACL.Type {
+		case structs.ACLTypeClient:
+		case structs.ACLTypeManagement:
+		default:
+			return fmt.Errorf("Invalid ACL Type")
+		}
+
+		// Validate the rules compile
+		_, err := acl.Parse(args.ACL.Rules)
+		if err != nil {
+			return fmt.Errorf("ACL rule compilation failed: %v", err)
+		}
+
+	case structs.ACLDelete:
+		if args.ACL.ID == "" {
+			return fmt.Errorf("Missing ACL ID")
+		}
+
+	default:
+		return fmt.Errorf("Invalid ACL Operation")
+	}
+
+	// Apply the update
+	resp, err := a.srv.raftApply(structs.ACLRequestType, args)
+	if err != nil {
+		a.srv.logger.Printf("[ERR] consul.acl: Apply failed: %v", err)
+		return err
+	}
+	if respErr, ok := resp.(error); ok {
+		return respErr
+	}
+
+	// Clear the cache if applicable
+	if args.ACL.ID != "" {
+		a.srv.aclAuthCache.ClearACL(args.ACL.ID)
+	}
+
+	// Check if the return type is a string
+	if respString, ok := resp.(string); ok {
+		*reply = respString
+	}
+	return nil
+}
+
+// Get is used to retrieve a single ACL
+func (a *ACL) Get(args *structs.ACLSpecificRequest,
+	reply *structs.IndexedACLs) error {
+	if done, err := a.srv.forward("ACL.Get", args, args, reply); done {
+		return err
+	}
+
+	// Verify we are allowed to serve this request
+	if a.srv.config.ACLDatacenter != a.srv.config.Datacenter {
+		return fmt.Errorf(aclDisabled)
+	}
+
+	// Get the local state
+	state := a.srv.fsm.State()
+	return a.srv.blockingRPC(&args.QueryOptions,
+		&reply.QueryMeta,
+		state.QueryTables("ACLGet"),
+		func() error {
+			index, acl, err := state.ACLGet(args.ACL)
+			reply.Index = index
+			if acl != nil {
+				reply.ACLs = structs.ACLs{acl}
+			}
+			return err
+		})
+}
+
+// GetPolicy is used to retrieve a compiled policy object with a TTL. Does not
+// support a blocking query.
+func (a *ACL) GetPolicy(args *structs.ACLPolicyRequest, reply *structs.ACLPolicy) error {
+	if done, err := a.srv.forward("ACL.GetPolicy", args, args, reply); done {
+		return err
+	}
+
+	// Verify we are allowed to serve this request
+	if a.srv.config.ACLDatacenter != a.srv.config.Datacenter {
+		return fmt.Errorf(aclDisabled)
+	}
+
+	// Get the policy via the cache
+	parent, policy, err := a.srv.aclAuthCache.GetACLPolicy(args.ACL)
+	if err != nil {
+		return err
+	}
+
+	// Generate an ETag
+	conf := a.srv.config
+	etag := fmt.Sprintf("%s:%s", parent, policy.ID)
+
+	// Setup the response
+	reply.ETag = etag
+	reply.TTL = conf.ACLTTL
+	a.srv.setQueryMeta(&reply.QueryMeta)
+
+	// Only send the policy on an Etag mis-match
+	if args.ETag != etag {
+		reply.Parent = parent
+		reply.Policy = policy
+	}
+	return nil
+}
+
+// List is used to list all the ACLs
+func (a *ACL) List(args *structs.DCSpecificRequest,
+	reply *structs.IndexedACLs) error {
+	if done, err := a.srv.forward("ACL.List", args, args, reply); done {
+		return err
+	}
+
+	// Verify we are allowed to serve this request
+	if a.srv.config.ACLDatacenter != a.srv.config.Datacenter {
+		return fmt.Errorf(aclDisabled)
+	}
+
+	// Verify token is permitted to list ACLs
+	if acl, err := a.srv.resolveToken(args.Token); err != nil {
+		return err
+	} else if acl == nil || !acl.ACLList() {
+		return permissionDeniedErr
+	}
+
+	// Get the local state
+	state := a.srv.fsm.State()
+	return a.srv.blockingRPC(&args.QueryOptions,
+		&reply.QueryMeta,
+		state.QueryTables("ACLList"),
+		func() error {
+			var err error
+			reply.Index, reply.ACLs, err = state.ACLList()
+			return err
+		})
+}
diff --git a/consul/acl_endpoint_test.go b/consul/acl_endpoint_test.go
new file mode 100644
index 000000000..18e1ddf38
--- /dev/null
+++ b/consul/acl_endpoint_test.go
@@ -0,0 +1,361 @@
+package consul
+
+import (
+	"os"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/hashicorp/consul/consul/structs"
+	"github.com/hashicorp/consul/testutil"
+)
+
+func TestACLEndpoint_Apply(t *testing.T) {
+	dir1, s1 := testServerWithConfig(t, func(c *Config) {
+		c.ACLDatacenter = "dc1"
+		c.ACLMasterToken = "root"
+	})
+	defer os.RemoveAll(dir1)
+	defer s1.Shutdown()
+	client := rpcClient(t, s1)
+	defer client.Close()
+
+	testutil.WaitForLeader(t, client.Call, "dc1")
+
+	arg := structs.ACLRequest{
+		Datacenter: "dc1",
+		Op:         structs.ACLSet,
+		ACL: structs.ACL{
+			Name: "User token",
+			Type: structs.ACLTypeClient,
+		},
+		WriteRequest: structs.WriteRequest{Token: "root"},
+	}
+	var out string
+	if err := client.Call("ACL.Apply", &arg, &out); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	id := out
+
+	// Verify
+	state := s1.fsm.State()
+	_, s, err := state.ACLGet(out)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if s == nil {
+		t.Fatalf("should not be nil")
+	}
+	if s.ID != out {
+		t.Fatalf("bad: %v", s)
+	}
+	if s.Name != "User token" {
+		t.Fatalf("bad: %v", s)
+	}
+
+	// Do a delete
+	arg.Op = structs.ACLDelete
+	arg.ACL.ID = out
+	if err := client.Call("ACL.Apply", &arg, &out); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	// Verify
+	_, s, err = state.ACLGet(id)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if s != nil {
+		t.Fatalf("bad: %v", s)
+	}
+}
+
+func TestACLEndpoint_Update_PurgeCache(t *testing.T) {
+	dir1, s1 := testServerWithConfig(t, func(c *Config) {
+		c.ACLDatacenter = "dc1"
+		c.ACLMasterToken = "root"
+	})
+	defer os.RemoveAll(dir1)
+	defer s1.Shutdown()
+	client := rpcClient(t, s1)
+	defer client.Close()
+
+	testutil.WaitForLeader(t, client.Call, "dc1")
+
+	arg := structs.ACLRequest{
+		Datacenter: "dc1",
+		Op:         structs.ACLSet,
+		ACL: structs.ACL{
+			Name: "User token",
+			Type: structs.ACLTypeClient,
+		},
+		WriteRequest: structs.WriteRequest{Token: "root"},
+	}
+	var out string
+	if err := client.Call("ACL.Apply", &arg, &out); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	id := out
+
+	// Resolve
+	acl1, err := s1.resolveToken(id)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if acl1 == nil {
+		t.Fatalf("should not be nil")
+	}
+	if !acl1.KeyRead("foo") {
+		t.Fatalf("should be allowed")
+	}
+
+	// Do an update
+	arg.ACL.ID = out
+	arg.ACL.Rules = `{"key": {"": {"policy": "deny"}}}`
+	if err := client.Call("ACL.Apply", &arg, &out); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	// Resolve again
+	acl2, err := s1.resolveToken(id)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if acl2 == nil {
+		t.Fatalf("should not be nil")
+	}
+	if acl2 == acl1 {
+		t.Fatalf("should not be cached")
+	}
+	if acl2.KeyRead("foo") {
+		t.Fatalf("should not be allowed")
+	}
+
+	// Do a delete
+	arg.Op = structs.ACLDelete
+	arg.ACL.Rules = ""
+	if err := client.Call("ACL.Apply", &arg, &out); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	// Resolve again
+	acl3, err := s1.resolveToken(id)
+	if err == nil || err.Error() != aclNotFound {
+		t.Fatalf("err: %v", err)
+	}
+	if acl3 != nil {
+		t.Fatalf("should be nil")
+	}
+}
+
+func TestACLEndpoint_Apply_Denied(t *testing.T) {
+	dir1, s1 := testServerWithConfig(t, func(c *Config) {
+		c.ACLDatacenter = "dc1"
+	})
+	defer os.RemoveAll(dir1)
+	defer s1.Shutdown()
+	client := rpcClient(t, s1)
+	defer client.Close()
+
+	testutil.WaitForLeader(t, client.Call, "dc1")
+
+	arg := structs.ACLRequest{
+		Datacenter: "dc1",
+		Op:         structs.ACLSet,
+		ACL: structs.ACL{
+			Name: "User token",
+			Type: structs.ACLTypeClient,
+		},
+	}
+	var out string
+	err := client.Call("ACL.Apply", &arg, &out)
+	if err == nil || !strings.Contains(err.Error(), permissionDenied) {
+		t.Fatalf("err: %v", err)
+	}
+}
+
+func TestACLEndpoint_Get(t *testing.T) {
+	dir1, s1 := testServerWithConfig(t, func(c *Config) {
+		c.ACLDatacenter = "dc1"
+		c.ACLMasterToken = "root"
+	})
+	defer os.RemoveAll(dir1)
+	defer s1.Shutdown()
+	client := rpcClient(t, s1)
+	defer client.Close()
+
+	testutil.WaitForLeader(t, client.Call, "dc1")
+
+	arg := structs.ACLRequest{
+		Datacenter: "dc1",
+		Op:         structs.ACLSet,
+		ACL: structs.ACL{
+			Name: "User token",
+			Type: structs.ACLTypeClient,
+		},
+		WriteRequest: structs.WriteRequest{Token: "root"},
+	}
+	var out string
+	if err := client.Call("ACL.Apply", &arg, &out); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	getR := structs.ACLSpecificRequest{
+		Datacenter: "dc1",
+		ACL:        out,
+	}
+	var acls structs.IndexedACLs
+	if err := client.Call("ACL.Get", &getR, &acls); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	if acls.Index == 0 {
+		t.Fatalf("Bad: %v", acls)
+	}
+	if len(acls.ACLs) != 1 {
+		t.Fatalf("Bad: %v", acls)
+	}
+	s := acls.ACLs[0]
+	if s.ID != out {
+		t.Fatalf("bad: %v", s)
+	}
+}
+
+func TestACLEndpoint_GetPolicy(t *testing.T) {
+	dir1, s1 := testServerWithConfig(t, func(c *Config) {
+		c.ACLDatacenter = "dc1"
+		c.ACLMasterToken = "root"
+	})
+	defer os.RemoveAll(dir1)
+	defer s1.Shutdown()
+	client := rpcClient(t, s1)
+	defer client.Close()
+
+	testutil.WaitForLeader(t, client.Call, "dc1")
+
+	arg := structs.ACLRequest{
+		Datacenter: "dc1",
+		Op:         structs.ACLSet,
+		ACL: structs.ACL{
+			Name: "User token",
+			Type: structs.ACLTypeClient,
+		},
+		WriteRequest: structs.WriteRequest{Token: "root"},
+	}
+	var out string
+	if err := client.Call("ACL.Apply", &arg, &out); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	getR := structs.ACLPolicyRequest{
+		Datacenter: "dc1",
+		ACL:        out,
+	}
+	var acls structs.ACLPolicy
+	if err := client.Call("ACL.GetPolicy", &getR, &acls); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	if acls.Policy == nil {
+		t.Fatalf("Bad: %v", acls)
+	}
+	if acls.TTL != 30*time.Second {
+		t.Fatalf("bad: %v", acls)
+	}
+
+	// Do a conditional lookup with etag
+	getR.ETag = acls.ETag
+	var out2 structs.ACLPolicy
+	if err := client.Call("ACL.GetPolicy", &getR, &out2); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	if out2.Policy != nil {
+		t.Fatalf("Bad: %v", out2)
+	}
+	if out2.TTL != 30*time.Second {
+		t.Fatalf("bad: %v", out2)
+	}
+}
+
+func TestACLEndpoint_List(t *testing.T) {
+	dir1, s1 := testServerWithConfig(t, func(c *Config) {
+		c.ACLDatacenter = "dc1"
+		c.ACLMasterToken = "root"
+	})
+	defer os.RemoveAll(dir1)
+	defer s1.Shutdown()
+	client := rpcClient(t, s1)
+	defer client.Close()
+
+	testutil.WaitForLeader(t, client.Call, "dc1")
+
+	ids := []string{}
+	for i := 0; i < 5; i++ {
+		arg := structs.ACLRequest{
+			Datacenter: "dc1",
+			Op:         structs.ACLSet,
+			ACL: structs.ACL{
+				Name: "User token",
+				Type: structs.ACLTypeClient,
+			},
+			WriteRequest: structs.WriteRequest{Token: "root"},
+		}
+		var out string
+		if err := client.Call("ACL.Apply", &arg, &out); err != nil {
+			t.Fatalf("err: %v", err)
+		}
+		ids = append(ids, out)
+	}
+
+	getR := structs.DCSpecificRequest{
+		Datacenter:   "dc1",
+		QueryOptions: structs.QueryOptions{Token: "root"},
+	}
+	var acls structs.IndexedACLs
+	if err := client.Call("ACL.List", &getR, &acls); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	if acls.Index == 0 {
+		t.Fatalf("Bad: %v", acls)
+	}
+
+	// 5 + anonymous + master
+	if len(acls.ACLs) != 7 {
+		t.Fatalf("Bad: %v", acls.ACLs)
+	}
+	for i := 0; i < len(acls.ACLs); i++ {
+		s := acls.ACLs[i]
+		if s.ID == anonymousToken || s.ID == "root" {
+			continue
+		}
+		if !strContains(ids, s.ID) {
+			t.Fatalf("bad: %v", s)
+		}
+		if s.Name != "User token" {
+			t.Fatalf("bad: %v", s)
+		}
+	}
+}
+
+func TestACLEndpoint_List_Denied(t *testing.T) {
+	dir1, s1 := testServerWithConfig(t, func(c *Config) {
+		c.ACLDatacenter = "dc1"
+	})
+	defer os.RemoveAll(dir1)
+	defer s1.Shutdown()
+	client := rpcClient(t, s1)
+	defer client.Close()
+
+	testutil.WaitForLeader(t, client.Call, "dc1")
+
+	getR := structs.DCSpecificRequest{
+		Datacenter: "dc1",
+	}
+	var acls structs.IndexedACLs
+	err := client.Call("ACL.List", &getR, &acls)
+	if err == nil || !strings.Contains(err.Error(), permissionDenied) {
+		t.Fatalf("err: %v", err)
+	}
+}
diff --git a/consul/acl_test.go b/consul/acl_test.go
new file mode 100644
index 000000000..2fabcbee9
--- /dev/null
+++ b/consul/acl_test.go
@@ -0,0 +1,684 @@
+package consul
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"testing"
+
+	"github.com/hashicorp/consul/acl"
+	"github.com/hashicorp/consul/consul/structs"
+	"github.com/hashicorp/consul/testutil"
+)
+
+func TestACL_Disabled(t *testing.T) {
+	dir1, s1 := testServer(t)
+	defer os.RemoveAll(dir1)
+	defer s1.Shutdown()
+	client := rpcClient(t, s1)
+	defer client.Close()
+
+	testutil.WaitForLeader(t, client.Call, "dc1")
+
+	acl, err := s1.resolveToken("does not exist")
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if acl != nil {
+		t.Fatalf("got acl")
+	}
+}
+
+func TestACL_ResolveRootACL(t *testing.T) {
+	dir1, s1 := testServerWithConfig(t, func(c *Config) {
+		c.ACLDatacenter = "dc1" // Enable ACLs!
+	})
+	defer os.RemoveAll(dir1)
+	defer s1.Shutdown()
+
+	acl, err := s1.resolveToken("allow")
+	if err == nil || err.Error() != rootDenied {
+		t.Fatalf("err: %v", err)
+	}
+	if acl != nil {
+		t.Fatalf("bad: %v", acl)
+	}
+
+	acl, err = s1.resolveToken("deny")
+	if err == nil || err.Error() != rootDenied {
+		t.Fatalf("err: %v", err)
+	}
+	if acl != nil {
+		t.Fatalf("bad: %v", acl)
+	}
+}
+
+func TestACL_Authority_NotFound(t *testing.T) {
+	dir1, s1 := testServerWithConfig(t, func(c *Config) {
+		c.ACLDatacenter = "dc1" // Enable ACLs!
+	})
+	defer os.RemoveAll(dir1)
+	defer s1.Shutdown()
+	client := rpcClient(t, s1)
+	defer client.Close()
+
+	testutil.WaitForLeader(t, client.Call, "dc1")
+
+	acl, err := s1.resolveToken("does not exist")
+	if err == nil || err.Error() != aclNotFound {
+		t.Fatalf("err: %v", err)
+	}
+	if acl != nil {
+		t.Fatalf("got acl")
+	}
+}
+
+func TestACL_Authority_Found(t *testing.T) {
+	dir1, s1 := testServerWithConfig(t, func(c *Config) {
+		c.ACLDatacenter = "dc1" // Enable ACLs!
+		c.ACLMasterToken = "root"
+	})
+	defer os.RemoveAll(dir1)
+	defer s1.Shutdown()
+	client := rpcClient(t, s1)
+	defer client.Close()
+
+	testutil.WaitForLeader(t, client.Call, "dc1")
+
+	// Create a new token
+	arg := structs.ACLRequest{
+		Datacenter: "dc1",
+		Op:         structs.ACLSet,
+		ACL: structs.ACL{
+			Name:  "User token",
+			Type:  structs.ACLTypeClient,
+			Rules: testACLPolicy,
+		},
+		WriteRequest: structs.WriteRequest{Token: "root"},
+	}
+	var id string
+	if err := client.Call("ACL.Apply", &arg, &id); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	// Resolve the token
+	acl, err := s1.resolveToken(id)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if acl == nil {
+		t.Fatalf("missing acl")
+	}
+
+	// Check the policy
+	if acl.KeyRead("bar") {
+		t.Fatalf("unexpected read")
+	}
+	if !acl.KeyRead("foo/test") {
+		t.Fatalf("unexpected failed read")
+	}
+}
+
+func TestACL_Authority_Anonymous_Found(t *testing.T) {
+	dir1, s1 := testServerWithConfig(t, func(c *Config) {
+		c.ACLDatacenter = "dc1" // Enable ACLs!
+	})
+	defer os.RemoveAll(dir1)
+	defer s1.Shutdown()
+	client := rpcClient(t, s1)
+	defer client.Close()
+
+	testutil.WaitForLeader(t, client.Call, "dc1")
+
+	// Resolve the token
+	acl, err := s1.resolveToken("")
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if acl == nil {
+		t.Fatalf("missing acl")
+	}
+
+	// Check the policy, should allow all
+	if !acl.KeyRead("foo/test") {
+		t.Fatalf("unexpected failed read")
+	}
+}
+
+func TestACL_Authority_Master_Found(t *testing.T) {
+	dir1, s1 := testServerWithConfig(t, func(c *Config) {
+		c.ACLDatacenter = "dc1" // Enable ACLs!
+		c.ACLMasterToken = "foobar"
+	})
+	defer os.RemoveAll(dir1)
+	defer s1.Shutdown()
+	client := rpcClient(t, s1)
+	defer client.Close()
+
+	testutil.WaitForLeader(t, client.Call, "dc1")
+
+	// Resolve the token
+	acl, err := s1.resolveToken("foobar")
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if acl == nil {
+		t.Fatalf("missing acl")
+	}
+
+	// Check the policy, should allow all
+	if !acl.KeyRead("foo/test") {
+		t.Fatalf("unexpected failed read")
+	}
+}
+
+func TestACL_Authority_Management(t *testing.T) {
+	dir1, s1 := testServerWithConfig(t, func(c *Config) {
+		c.ACLDatacenter = "dc1" // Enable ACLs!
+		c.ACLMasterToken = "foobar"
+		c.ACLDefaultPolicy = "deny"
+	})
+	defer os.RemoveAll(dir1)
+	defer s1.Shutdown()
+	client := rpcClient(t, s1)
+	defer client.Close()
+
+	testutil.WaitForLeader(t, client.Call, "dc1")
+
+	// Resolve the token
+	acl, err := s1.resolveToken("foobar")
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if acl == nil {
+		t.Fatalf("missing acl")
+	}
+
+	// Check the policy, should allow all
+	if !acl.KeyRead("foo/test") {
+		t.Fatalf("unexpected failed read")
+	}
+}
+
+func TestACL_NonAuthority_NotFound(t *testing.T) {
+	dir1, s1 := testServerWithConfig(t, func(c *Config) {
+		c.ACLDatacenter = "dc1"
+	})
+	defer os.RemoveAll(dir1)
+	defer s1.Shutdown()
+
+	dir2, s2 := testServerWithConfig(t, func(c *Config) {
+		c.ACLDatacenter = "dc1" // Enable ACLs!
+		c.Bootstrap = false     // Disable bootstrap
+	})
+	defer os.RemoveAll(dir2)
+	defer s2.Shutdown()
+
+	// Try to join
+	addr := fmt.Sprintf("127.0.0.1:%d",
+		s1.config.SerfLANConfig.MemberlistConfig.BindPort)
+	if _, err := s2.JoinLAN([]string{addr}); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	testutil.WaitForResult(func() (bool, error) {
+		p1, _ := s1.raftPeers.Peers()
+		return len(p1) == 2, errors.New(fmt.Sprintf("%v", p1))
+	}, func(err error) {
+		t.Fatalf("should have 2 peers: %v", err)
+	})
+
+	client := rpcClient(t, s1)
+	defer client.Close()
+	testutil.WaitForLeader(t, client.Call, "dc1")
+
+	// find the non-authoritative server
+	var nonAuth *Server
+	if !s1.IsLeader() {
+		nonAuth = s1
+	} else {
+		nonAuth = s2
+	}
+
+	acl, err := nonAuth.resolveToken("does not exist")
+	if err == nil || err.Error() != aclNotFound {
+		t.Fatalf("err: %v", err)
+	}
+	if acl != nil {
+		t.Fatalf("got acl")
+	}
+}
+
+func TestACL_NonAuthority_Found(t *testing.T) {
+	dir1, s1 := testServerWithConfig(t, func(c *Config) {
+		c.ACLDatacenter = "dc1"
+		c.ACLMasterToken = "root"
+	})
+	defer os.RemoveAll(dir1)
+	defer s1.Shutdown()
+	client := rpcClient(t, s1)
+	defer client.Close()
+
+	dir2, s2 := testServerWithConfig(t, func(c *Config) {
+		c.ACLDatacenter = "dc1" // Enable ACLs!
+		c.Bootstrap = false     // Disable bootstrap
+	})
+	defer os.RemoveAll(dir2)
+	defer s2.Shutdown()
+
+	// Try to join
+	addr := fmt.Sprintf("127.0.0.1:%d",
+		s1.config.SerfLANConfig.MemberlistConfig.BindPort)
+	if _, err := s2.JoinLAN([]string{addr}); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	testutil.WaitForResult(func() (bool, error) {
+		p1, _ := s1.raftPeers.Peers()
+		return len(p1) == 2, errors.New(fmt.Sprintf("%v", p1))
+	}, func(err error) {
+		t.Fatalf("should have 2 peers: %v", err)
+	})
+	testutil.WaitForLeader(t, client.Call, "dc1")
+
+	// Create a new token
+	arg := structs.ACLRequest{
+		Datacenter: "dc1",
+		Op:         structs.ACLSet,
+		ACL: structs.ACL{
+			Name:  "User token",
+			Type:  structs.ACLTypeClient,
+			Rules: testACLPolicy,
+		},
+		WriteRequest: structs.WriteRequest{Token: "root"},
+	}
+	var id string
+	if err := client.Call("ACL.Apply", &arg, &id); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	// find the non-authoritative server
+	var nonAuth *Server
+	if !s1.IsLeader() {
+		nonAuth = s1
+	} else {
+		nonAuth = s2
+	}
+
+	// Token should resolve
+	acl, err := nonAuth.resolveToken(id)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if acl == nil {
+		t.Fatalf("missing acl")
+	}
+
+	// Check the policy
+	if acl.KeyRead("bar") {
+		t.Fatalf("unexpected read")
+	}
+	if !acl.KeyRead("foo/test") {
+		t.Fatalf("unexpected failed read")
+	}
+}
+
+func TestACL_NonAuthority_Management(t *testing.T) {
+	dir1, s1 := testServerWithConfig(t, func(c *Config) {
+		c.ACLDatacenter = "dc1" // Enable ACLs!
+		c.ACLMasterToken = "foobar"
+		c.ACLDefaultPolicy = "deny"
+	})
+	defer os.RemoveAll(dir1)
+	defer s1.Shutdown()
+	client := rpcClient(t, s1)
+	defer client.Close()
+
+	dir2, s2 := testServerWithConfig(t, func(c *Config) {
+		c.ACLDatacenter = "dc1" // Enable ACLs!
+		c.ACLDefaultPolicy = "deny"
+		c.Bootstrap = false // Disable bootstrap
+	})
+	defer os.RemoveAll(dir2)
+	defer s2.Shutdown()
+
+	// Try to join
+	addr := fmt.Sprintf("127.0.0.1:%d",
+		s1.config.SerfLANConfig.MemberlistConfig.BindPort)
+	if _, err := s2.JoinLAN([]string{addr}); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	testutil.WaitForResult(func() (bool, error) {
+		p1, _ := s1.raftPeers.Peers()
+		return len(p1) == 2, errors.New(fmt.Sprintf("%v", p1))
+	}, func(err error) {
+		t.Fatalf("should have 2 peers: %v", err)
+	})
+	testutil.WaitForLeader(t, client.Call, "dc1")
+
+	// find the non-authoritative server
+	var nonAuth *Server
+	if !s1.IsLeader() {
+		nonAuth = s1
+	} else {
+		nonAuth = s2
+	}
+
+	// Resolve the token
+	acl, err := nonAuth.resolveToken("foobar")
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if acl == nil {
+		t.Fatalf("missing acl")
+	}
+
+	// Check the policy, should allow all
+	if !acl.KeyRead("foo/test") {
+		t.Fatalf("unexpected failed read")
+	}
+}
+
+func TestACL_DownPolicy_Deny(t *testing.T) {
+	dir1, s1 := testServerWithConfig(t, func(c *Config) {
+		c.ACLDatacenter = "dc1"
+		c.ACLDownPolicy = "deny"
+		c.ACLMasterToken = "root"
+	})
+	defer os.RemoveAll(dir1)
+	defer s1.Shutdown()
+	client := rpcClient(t, s1)
+	defer client.Close()
+
+	dir2, s2 := testServerWithConfig(t, func(c *Config) {
+		c.ACLDatacenter = "dc1" // Enable ACLs!
+		c.ACLDownPolicy = "deny"
+		c.Bootstrap = false // Disable bootstrap
+	})
+	defer os.RemoveAll(dir2)
+	defer s2.Shutdown()
+
+	// Try to join
+	addr := fmt.Sprintf("127.0.0.1:%d",
+		s1.config.SerfLANConfig.MemberlistConfig.BindPort)
+	if _, err := s2.JoinLAN([]string{addr}); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	testutil.WaitForResult(func() (bool, error) {
+		p1, _ := s1.raftPeers.Peers()
+		return len(p1) == 2, errors.New(fmt.Sprintf("%v", p1))
+	}, func(err error) {
+		t.Fatalf("should have 2 peers: %v", err)
+	})
+	testutil.WaitForLeader(t, client.Call, "dc1")
+
+	// Create a new token
+	arg := structs.ACLRequest{
+		Datacenter: "dc1",
+		Op:         structs.ACLSet,
+		ACL: structs.ACL{
+			Name:  "User token",
+			Type:  structs.ACLTypeClient,
+			Rules: testACLPolicy,
+		},
+		WriteRequest: structs.WriteRequest{Token: "root"},
+	}
+	var id string
+	if err := client.Call("ACL.Apply", &arg, &id); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	// find the non-authoritative server
+	var nonAuth *Server
+	var auth *Server
+	if !s1.IsLeader() {
+		nonAuth = s1
+		auth = s2
+	} else {
+		nonAuth = s2
+		auth = s1
+	}
+
+	// Kill the authoritative server
+	auth.Shutdown()
+
+	// Token should resolve into a DenyAll
+	aclR, err := nonAuth.resolveToken(id)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if aclR != acl.DenyAll() {
+		t.Fatalf("bad acl: %#v", aclR)
+	}
+}
+
+func TestACL_DownPolicy_Allow(t *testing.T) {
+	dir1, s1 := testServerWithConfig(t, func(c *Config) {
+		c.ACLDatacenter = "dc1"
+		c.ACLDownPolicy = "allow"
+		c.ACLMasterToken = "root"
+	})
+	defer os.RemoveAll(dir1)
+	defer s1.Shutdown()
+	client := rpcClient(t, s1)
+	defer client.Close()
+
+	dir2, s2 := testServerWithConfig(t, func(c *Config) {
+		c.ACLDatacenter = "dc1" // Enable ACLs!
+		c.ACLDownPolicy = "allow"
+		c.Bootstrap = false // Disable bootstrap
+	})
+	defer os.RemoveAll(dir2)
+	defer s2.Shutdown()
+
+	// Try to join
+	addr := fmt.Sprintf("127.0.0.1:%d",
+		s1.config.SerfLANConfig.MemberlistConfig.BindPort)
+	if _, err := s2.JoinLAN([]string{addr}); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	testutil.WaitForResult(func() (bool, error) {
+		p1, _ := s1.raftPeers.Peers()
+		return len(p1) == 2, errors.New(fmt.Sprintf("%v", p1))
+	}, func(err error) {
+		t.Fatalf("should have 2 peers: %v", err)
+	})
+	testutil.WaitForLeader(t, client.Call, "dc1")
+
+	// Create a new token
+	arg := structs.ACLRequest{
+		Datacenter: "dc1",
+		Op:         structs.ACLSet,
+		ACL: structs.ACL{
+			Name:  "User token",
+			Type:  structs.ACLTypeClient,
+			Rules: testACLPolicy,
+		},
+		WriteRequest: structs.WriteRequest{Token: "root"},
+	}
+	var id string
+	if err := client.Call("ACL.Apply", &arg, &id); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	// find the non-authoritative server
+	var nonAuth *Server
+	var auth *Server
+	if !s1.IsLeader() {
+		nonAuth = s1
+		auth = s2
+	} else {
+		nonAuth = s2
+		auth = s1
+	}
+
+	// Kill the authoritative server
+	auth.Shutdown()
+
+	// Token should resolve into a AllowAll
+	aclR, err := nonAuth.resolveToken(id)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if aclR != acl.AllowAll() {
+		t.Fatalf("bad acl: %#v", aclR)
+	}
+}
+
+func TestACL_DownPolicy_ExtendCache(t *testing.T) {
+	dir1, s1 := testServerWithConfig(t, func(c *Config) {
+		c.ACLDatacenter = "dc1"
+		c.ACLTTL = 0
+		c.ACLDownPolicy = "extend-cache"
+		c.ACLMasterToken = "root"
+	})
+	defer os.RemoveAll(dir1)
+	defer s1.Shutdown()
+	client := rpcClient(t, s1)
+	defer client.Close()
+
+	dir2, s2 := testServerWithConfig(t, func(c *Config) {
+		c.ACLDatacenter = "dc1" // Enable ACLs!
+		c.ACLTTL = 0
+		c.ACLDownPolicy = "extend-cache"
+		c.Bootstrap = false // Disable bootstrap
+	})
+	defer os.RemoveAll(dir2)
+	defer s2.Shutdown()
+
+	// Try to join
+	addr := fmt.Sprintf("127.0.0.1:%d",
+		s1.config.SerfLANConfig.MemberlistConfig.BindPort)
+	if _, err := s2.JoinLAN([]string{addr}); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	testutil.WaitForResult(func() (bool, error) {
+		p1, _ := s1.raftPeers.Peers()
+		return len(p1) == 2, errors.New(fmt.Sprintf("%v", p1))
+	}, func(err error) {
+		t.Fatalf("should have 2 peers: %v", err)
+	})
+	testutil.WaitForLeader(t, client.Call, "dc1")
+
+	// Create a new token
+	arg := structs.ACLRequest{
+		Datacenter: "dc1",
+		Op:         structs.ACLSet,
+		ACL: structs.ACL{
+			Name:  "User token",
+			Type:  structs.ACLTypeClient,
+			Rules: testACLPolicy,
+		},
+		WriteRequest: structs.WriteRequest{Token: "root"},
+	}
+	var id string
+	if err := client.Call("ACL.Apply", &arg, &id); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	// find the non-authoritative server
+	var nonAuth *Server
+	var auth *Server
+	if !s1.IsLeader() {
+		nonAuth = s1
+		auth = s2
+	} else {
+		nonAuth = s2
+		auth = s1
+	}
+
+	// Warm the caches
+	aclR, err := nonAuth.resolveToken(id)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if aclR == nil {
+		t.Fatalf("bad acl: %#v", aclR)
+	}
+
+	// Kill the authoritative server
+	auth.Shutdown()
+
+	// Token should resolve into cached copy
+	aclR2, err := nonAuth.resolveToken(id)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if aclR2 != aclR {
+		t.Fatalf("bad acl: %#v", aclR)
+	}
+}
+
+func TestACL_MultiDC_Found(t *testing.T) {
+	dir1, s1 := testServerWithConfig(t, func(c *Config) {
+		c.ACLDatacenter = "dc1"
+		c.ACLMasterToken = "root"
+	})
+	defer os.RemoveAll(dir1)
+	defer s1.Shutdown()
+	client := rpcClient(t, s1)
+	defer client.Close()
+
+	dir2, s2 := testServerWithConfig(t, func(c *Config) {
+		c.Datacenter = "dc2"
+		c.ACLDatacenter = "dc1" // Enable ACLs!
+	})
+	defer os.RemoveAll(dir2)
+	defer s2.Shutdown()
+
+	// Try to join
+	addr := fmt.Sprintf("127.0.0.1:%d",
+		s1.config.SerfWANConfig.MemberlistConfig.BindPort)
+	if _, err := s2.JoinWAN([]string{addr}); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	testutil.WaitForLeader(t, client.Call, "dc1")
+	testutil.WaitForLeader(t, client.Call, "dc2")
+
+	// Create a new token
+	arg := structs.ACLRequest{
+		Datacenter: "dc1",
+		Op:         structs.ACLSet,
+		ACL: structs.ACL{
+			Name:  "User token",
+			Type:  structs.ACLTypeClient,
+			Rules: testACLPolicy,
+		},
+		WriteRequest: structs.WriteRequest{Token: "root"},
+	}
+	var id string
+	if err := client.Call("ACL.Apply", &arg, &id); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	// Token should resolve
+	acl, err := s2.resolveToken(id)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if acl == nil {
+		t.Fatalf("missing acl")
+	}
+
+	// Check the policy
+	if acl.KeyRead("bar") {
+		t.Fatalf("unexpected read")
+	}
+	if !acl.KeyRead("foo/test") {
+		t.Fatalf("unexpected failed read")
+	}
+}
+
+var testACLPolicy = `
+key "" {
+	policy = "deny"
+}
+key "foo/" {
+	policy = "write"
+}
+`
diff --git a/consul/client.go b/consul/client.go
index 92d923195..70626d2de 100644
--- a/consul/client.go
+++ b/consul/client.go
@@ -80,6 +80,11 @@ func NewClient(config *Config) (*Client, error) {
 		return nil, fmt.Errorf("Config must provide a DataDir")
 	}
 
+	// Sanity check the ACLs
+	if err := config.CheckACL(); err != nil {
+		return nil, err
+	}
+
 	// Ensure we have a log output
 	if config.LogOutput == nil {
 		config.LogOutput = os.Stderr
diff --git a/consul/config.go b/consul/config.go
index 8105e2e24..f49c8933a 100644
--- a/consul/config.go
+++ b/consul/config.go
@@ -128,6 +128,38 @@ type Config struct {
 	// operators track which versions are actively deployed
 	Build string
 
+	// ACLToken is the default token to use when making a request.
+	// If not provided, the anonymous token is used. This enables
+	// backwards compatibility as well.
+	ACLToken string
+
+	// ACLMasterToken is used to bootstrap the ACL system. It should be specified
+	// on the servers in the ACLDatacenter. When the leader comes online, it ensures
+	// that the Master token is available. This provides the initial token.
+	ACLMasterToken string
+
+	// ACLDatacenter provides the authoritative datacenter for ACL
+	// tokens. If not provided, ACL verification is disabled.
+	ACLDatacenter string
+
+	// ACLTTL controls the time-to-live of cached ACL policies.
+	// It can be set to zero to disable caching, but this adds
+	// a substantial cost.
+	ACLTTL time.Duration
+
+	// ACLDefaultPolicy is used to control the ACL interaction when
+	// there is no defined policy. This can be "allow" which means
+	// ACLs are used to black-list, or "deny" which means ACLs are
+	// white-lists.
+	ACLDefaultPolicy string
+
+	// ACLDownPolicy controls the behavior of ACLs if the ACLDatacenter
+	// cannot be contacted. It can be either "deny" to deny all requests,
+	// or "extend-cache" which ignores the ACLCacheInterval and uses
+	// cached policies. If a policy is not in the cache, it acts like deny.
+	// "allow" can be used to allow all requests. This is not recommended.
+	ACLDownPolicy string
+
 	// ServerUp callback can be used to trigger a notification that
 	// a Consul server is now up and known about.
 	ServerUp func()
@@ -145,6 +177,24 @@ func (c *Config) CheckVersion() error {
 	return nil
 }
 
+// CheckACL is used to sanity check the ACL configuration
+func (c *Config) CheckACL() error {
+	switch c.ACLDefaultPolicy {
+	case "allow":
+	case "deny":
+	default:
+		return fmt.Errorf("Unsupported default ACL policy: %s", c.ACLDefaultPolicy)
+	}
+	switch c.ACLDownPolicy {
+	case "allow":
+	case "deny":
+	case "extend-cache":
+	default:
+		return fmt.Errorf("Unsupported down ACL policy: %s", c.ACLDownPolicy)
+	}
+	return nil
+}
+
 // AppendCA opens and parses the CA file and adds the certificates to
 // the provided CertPool.
 func (c *Config) AppendCA(pool *x509.CertPool) error {
@@ -324,6 +374,9 @@ func DefaultConfig() *Config {
 		SerfWANConfig:     serf.DefaultConfig(),
 		ReconcileInterval: 60 * time.Second,
 		ProtocolVersion:   ProtocolVersionMax,
+		ACLTTL:            30 * time.Second,
+		ACLDefaultPolicy:  "allow",
+		ACLDownPolicy:     "extend-cache",
 	}
 
 	// Increase our reap interval to 3 days instead of 24h.
diff --git a/consul/filter.go b/consul/filter.go
new file mode 100644
index 000000000..5577aa47a
--- /dev/null
+++ b/consul/filter.go
@@ -0,0 +1,89 @@
+package consul
+
+import (
+	"github.com/hashicorp/consul/acl"
+	"github.com/hashicorp/consul/consul/structs"
+)
+
+type dirEntFilter struct {
+	acl acl.ACL
+	ent structs.DirEntries
+}
+
+func (d *dirEntFilter) Len() int {
+	return len(d.ent)
+}
+func (d *dirEntFilter) Filter(i int) bool {
+	return !d.acl.KeyRead(d.ent[i].Key)
+}
+func (d *dirEntFilter) Move(dst, src, span int) {
+	copy(d.ent[dst:dst+span], d.ent[src:src+span])
+}
+
+// FilterDirEnt is used to filter a list of directory entries
+// by applying an ACL policy
+func FilterDirEnt(acl acl.ACL, ent structs.DirEntries) structs.DirEntries {
+	df := dirEntFilter{acl: acl, ent: ent}
+	return ent[:FilterEntries(&df)]
+}
+
+type keyFilter struct {
+	acl  acl.ACL
+	keys []string
+}
+
+func (k *keyFilter) Len() int {
+	return len(k.keys)
+}
+func (k *keyFilter) Filter(i int) bool {
+	return !k.acl.KeyRead(k.keys[i])
+}
+
+func (k *keyFilter) Move(dst, src, span int) {
+	copy(k.keys[dst:dst+span], k.keys[src:src+span])
+}
+
+// FilterKeys is used to filter a list of keys by
+// applying an ACL policy
+func FilterKeys(acl acl.ACL, keys []string) []string {
+	kf := keyFilter{acl: acl, keys: keys}
+	return keys[:FilterEntries(&kf)]
+}
+
+// Filter interfae is used with FilterEntries to do an
+// in-place filter of a slice.
+type Filter interface {
+	Len() int
+	Filter(int) bool
+	Move(dst, src, span int)
+}
+
+// FilterEntries is used to do an inplace filter of
+// a slice. This has cost proportional to the list length.
+func FilterEntries(f Filter) int {
+	// Compact the list
+	dst := 0
+	src := 0
+	n := f.Len()
+	for dst < n {
+		for src < n && f.Filter(src) {
+			src++
+		}
+		if src == n {
+			break
+		}
+		end := src + 1
+		for end < n && !f.Filter(end) {
+			end++
+		}
+		span := end - src
+		if span > 0 {
+			f.Move(dst, src, span)
+			dst += span
+			src += span
+		}
+	}
+
+	// Return the size of the slice
+	return dst
+}
diff --git a/consul/filter_test.go b/consul/filter_test.go
new file mode 100644
index 000000000..15feb1e68
--- /dev/null
+++ b/consul/filter_test.go
@@ -0,0 +1,96 @@
+package consul
+
+import (
+	"reflect"
+	"testing"
+
+	"github.com/hashicorp/consul/acl"
+	"github.com/hashicorp/consul/consul/structs"
+)
+
+func TestFilterDirEnt(t *testing.T) {
+	policy, _ := acl.Parse(testFilterRules)
+	aclR, _ := acl.New(acl.DenyAll(), policy)
+
+	type tcase struct {
+		in  []string
+		out []string
+	}
+	cases := []tcase{
+		tcase{
+			in:  []string{"foo/test", "foo/priv/nope", "foo/other", "zoo"},
+			out: []string{"foo/test", "foo/other"},
+		},
+		tcase{
+			in:  []string{"abe", "lincoln"},
+			out: nil,
+		},
+		tcase{
+			in:  []string{"abe", "foo/1", "foo/2", "foo/3", "nope"},
+			out: []string{"foo/1", "foo/2", "foo/3"},
+		},
+	}
+
+	for _, tc := range cases {
+		ents := structs.DirEntries{}
+		for _, in := range tc.in {
+			ents = append(ents, &structs.DirEntry{Key: in})
+		}
+
+		ents = FilterDirEnt(aclR, ents)
+		var outL []string
+		for _, e := range ents {
+			outL = append(outL, e.Key)
+		}
+
+		if !reflect.DeepEqual(outL, tc.out) {
+			t.Fatalf("bad: %#v %#v", outL, tc.out)
+		}
+	}
+}
+
+func TestKeys(t *testing.T) {
+	policy, _ := acl.Parse(testFilterRules)
+	aclR, _ := acl.New(acl.DenyAll(), policy)
+
+	type tcase struct {
+		in  []string
+		out []string
+	}
+	cases := []tcase{
+		tcase{
+			in:  []string{"foo/test", "foo/priv/nope", "foo/other", "zoo"},
+			out: []string{"foo/test", "foo/other"},
+		},
+		tcase{
+			in:  []string{"abe", "lincoln"},
+			out: nil,
+		},
+		tcase{
+			in:  []string{"abe", "foo/1", "foo/2", "foo/3", "nope"},
+			out: []string{"foo/1", "foo/2", "foo/3"},
+		},
+	}
+
+	for _, tc := range cases {
+		out := FilterKeys(aclR, tc.in)
+		if !reflect.DeepEqual(out, tc.out) {
+			t.Fatalf("bad: %#v %#v", out, tc.out)
+		}
+	}
+}
+
+var testFilterRules = `
+key "" {
+	policy = "deny"
+}
+key "foo/" {
+	policy = "read"
+}
+key "foo/priv/" {
+	policy = "deny"
+}
+key "zip/" {
+	policy = "read"
+}
+`
diff --git a/consul/fsm.go b/consul/fsm.go
index 8b4fd3d65..9810a289b 100644
--- a/consul/fsm.go
+++ b/consul/fsm.go
@@ -69,6 +69,8 @@ func (c *consulFSM) Apply(log *raft.Log) interface{} {
 		return c.applyKVSOperation(buf[1:], log.Index)
 	case structs.SessionRequestType:
 		return c.applySessionOperation(buf[1:], log.Index)
+	case structs.ACLRequestType:
+		return c.applyACLOperation(buf[1:], log.Index)
 	default:
 		panic(fmt.Errorf("failed to apply request: %#v", buf))
 	}
@@ -196,6 +198,33 @@ func (c *consulFSM) applySessionOperation(buf []byte, index uint64) interface{}
 	return nil
 }
 
+func (c *consulFSM) applyACLOperation(buf []byte, index uint64) interface{} {
+	var req structs.ACLRequest
+	if err := structs.Decode(buf, &req); err != nil {
+		panic(fmt.Errorf("failed to decode request: %v", err))
+	}
+	switch req.Op {
+	case structs.ACLSet:
+		if err := c.state.ACLSet(index, &req.ACL, false); err != nil {
+			return err
+		} else {
+			return req.ACL.ID
+		}
+	case structs.ACLForceSet:
+		if err := c.state.ACLSet(index, &req.ACL, true); err != nil {
+			return err
+		} else {
+			return req.ACL.ID
+		}
+	case structs.ACLDelete:
+		return c.state.ACLDelete(index, req.ACL.ID)
+	default:
+		c.logger.Printf("[WARN] consul.fsm: Invalid ACL operation '%s'", req.Op)
+		return fmt.Errorf("Invalid ACL operation '%s'", req.Op)
+	}
+	return nil
+}
+
 func (c *consulFSM) Snapshot() (raft.FSMSnapshot, error) {
 	defer func(start time.Time) {
 		c.logger.Printf("[INFO] consul.fsm: snapshot created in %v", time.Now().Sub(start))
@@ -267,6 +296,15 @@ func (c *consulFSM) Restore(old io.ReadCloser) error {
 				return err
 			}
 
+		case structs.ACLRequestType:
+			var req structs.ACL
+			if err := dec.Decode(&req); err != nil {
+				return err
+			}
+			if err := c.state.ACLRestore(&req); err != nil {
+				return err
+			}
+
 		default:
 			return fmt.Errorf("Unrecognized msg type: %v", msgType)
 		}
@@ -298,6 +336,11 @@ func (s *consulSnapshot) Persist(sink raft.SnapshotSink) error {
 		return err
 	}
 
+	if err := s.persistACLs(sink, encoder); err != nil {
+		sink.Cancel()
+		return err
+	}
+
 	if err := s.persistKV(sink, encoder); err != nil {
 		sink.Cancel()
 		return err
@@ -364,6 +407,22 @@ func (s *consulSnapshot) persistSessions(sink raft.SnapshotSink,
 	return nil
 }
 
+func (s *consulSnapshot) persistACLs(sink raft.SnapshotSink,
+	encoder *codec.Encoder) error {
+	acls, err := s.state.ACLList()
+	if err != nil {
+		return err
+	}
+
+	for _, s := range acls {
+		sink.Write([]byte{byte(structs.ACLRequestType)})
+		if err := encoder.Encode(s); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
 func (s *consulSnapshot) persistKV(sink raft.SnapshotSink,
 	encoder *codec.Encoder) error {
 	streamCh := make(chan interface{}, 256)
diff --git a/consul/fsm_test.go b/consul/fsm_test.go
index 5e5d086d8..d188de9ff 100644
--- a/consul/fsm_test.go
+++ b/consul/fsm_test.go
@@ -328,6 +328,8 @@ func TestFSM_SnapshotRestore(t *testing.T) {
 	})
 	session := &structs.Session{Node: "foo"}
 	fsm.state.SessionCreate(9, session)
+	acl := &structs.ACL{Name: "User Token"}
+	fsm.state.ACLSet(10, acl, false)
 
 	// Snapshot
 	snap, err := fsm.Snapshot()
@@ -392,7 +394,16 @@ func TestFSM_SnapshotRestore(t *testing.T) {
 		t.Fatalf("err: %v", err)
 	}
 	if s.Node != "foo" {
-		t.Fatalf("bad: %v", d)
+		t.Fatalf("bad: %v", s)
+	}
+
+	// Verify ACL is restored
+	_, a, err := fsm.state.ACLGet(acl.ID)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if a.Name != "User Token" {
+		t.Fatalf("bad: %v", a)
 	}
 }
 
@@ -767,3 +778,75 @@ func TestFSM_KVSUnlock(t *testing.T) {
 		t.Fatalf("bad: %v", *d)
 	}
 }
+
+func TestFSM_ACL_Set_Delete(t *testing.T) {
+	fsm, err := NewFSM(os.Stderr)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	defer fsm.Close()
+
+	// Create a new ACL
+	req := structs.ACLRequest{
+		Datacenter: "dc1",
+		Op:         structs.ACLSet,
+		ACL: structs.ACL{
+			Name: "User token",
+			Type: structs.ACLTypeClient,
+		},
+	}
+	buf, err := structs.Encode(structs.ACLRequestType, req)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	resp := fsm.Apply(makeLog(buf))
+	if err, ok := resp.(error); ok {
+		t.Fatalf("resp: %v", err)
+	}
+
+	// Get the ACL
+	id := resp.(string)
+	_, acl, err := fsm.state.ACLGet(id)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if acl == nil {
+		t.Fatalf("missing")
+	}
+
+	// Verify the ACL
+	if acl.ID != id {
+		t.Fatalf("bad: %v", *acl)
+	}
+	if acl.Name != "User token" {
+		t.Fatalf("bad: %v", *acl)
+	}
+	if acl.Type != structs.ACLTypeClient {
+		t.Fatalf("bad: %v", *acl)
+	}
+
+	// Try to destroy
+	destroy := structs.ACLRequest{
+		Datacenter: "dc1",
+		Op:         structs.ACLDelete,
+		ACL: structs.ACL{
+			ID: id,
+		},
+	}
+	buf, err = structs.Encode(structs.ACLRequestType, destroy)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	resp = fsm.Apply(makeLog(buf))
+	if resp != nil {
+		t.Fatalf("resp: %v", resp)
+	}
+
+	_, acl, err = fsm.state.ACLGet(id)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if acl != nil {
+		t.Fatalf("should be destroyed")
+	}
+}
diff --git a/consul/kvs_endpoint.go b/consul/kvs_endpoint.go
index 91d8f3bde..53ed238be 100644
--- a/consul/kvs_endpoint.go
+++ b/consul/kvs_endpoint.go
@@ -2,9 +2,10 @@ package consul
 
 import (
 	"fmt"
+	"time"
+
 	"github.com/armon/go-metrics"
 	"github.com/hashicorp/consul/consul/structs"
-	"time"
 )
 
 // KVS endpoint is used to manipulate the Key-Value store
@@ -25,6 +26,23 @@ func (k *KVS) Apply(args *structs.KVSRequest, reply *bool) error {
 		return fmt.Errorf("Must provide key")
 	}
 
+	// Apply the ACL policy if any
+	acl, err := k.srv.resolveToken(args.Token)
+	if err != nil {
+		return err
+	} else if acl != nil {
+		switch args.Op {
+		case structs.KVSDeleteTree:
+			if !acl.KeyWritePrefix(args.DirEnt.Key) {
+				return permissionDeniedErr
+			}
+		default:
+			if !acl.KeyWrite(args.DirEnt.Key) {
+				return permissionDeniedErr
+			}
+		}
+	}
+
 	// If this is a lock, we must check for a lock-delay. Since lock-delay
 	// is based on wall-time, each peer expire the lock-delay at a slightly
 	// different time. This means the enforcement of lock-delay cannot be done
@@ -65,6 +83,11 @@ func (k *KVS) Get(args *structs.KeyRequest, reply *structs.IndexedDirEntries) er
 		return err
 	}
 
+	acl, err := k.srv.resolveToken(args.Token)
+	if err != nil {
+		return err
+	}
+
 	// Get the local state
 	state := k.srv.fsm.State()
 	return k.srv.blockingRPC(&args.QueryOptions,
@@ -75,6 +98,9 @@ func (k *KVS) Get(args *structs.KeyRequest, reply *structs.IndexedDirEntries) er
 			if err != nil {
 				return err
 			}
+			if acl != nil && !acl.KeyRead(args.Key) {
+				ent = nil
+			}
 			if ent == nil {
 				// Must provide non-zero index to prevent blocking
 				// Index 1 is impossible anyways (due to Raft internals)
@@ -98,6 +124,11 @@ func (k *KVS) List(args *structs.KeyRequest, reply *structs.IndexedDirEntries) e
 		return err
 	}
 
+	acl, err := k.srv.resolveToken(args.Token)
+	if err != nil {
+		return err
+	}
+
 	// Get the local state
 	state := k.srv.fsm.State()
 	return k.srv.blockingRPC(&args.QueryOptions,
@@ -108,6 +139,9 @@ func (k *KVS) List(args *structs.KeyRequest, reply *structs.IndexedDirEntries) e
 			if err != nil {
 				return err
 			}
+			if acl != nil {
+				ent = FilterDirEnt(acl, ent)
+			}
 			if len(ent) == 0 {
 				// Must provide non-zero index to prevent blocking
 				// Index 1 is impossible anyways (due to Raft internals)
@@ -139,14 +173,23 @@ func (k *KVS) ListKeys(args *structs.KeyListRequest, reply *structs.IndexedKeyLi
 		return err
 	}
 
+	acl, err := k.srv.resolveToken(args.Token)
+	if err != nil {
+		return err
+	}
+
 	// Get the local state
 	state := k.srv.fsm.State()
 	return k.srv.blockingRPC(&args.QueryOptions,
 		&reply.QueryMeta,
 		state.QueryTables("KVSListKeys"),
 		func() error {
-			var err error
-			reply.Index, reply.Keys, err = state.KVSListKeys(args.Prefix, args.Seperator)
+			index, keys, err := state.KVSListKeys(args.Prefix, args.Seperator)
+			reply.Index = index
+			if acl != nil {
+				keys = FilterKeys(acl, keys)
+			}
+			reply.Keys = keys
 			return err
 		})
 }
diff --git a/consul/kvs_endpoint_test.go b/consul/kvs_endpoint_test.go
index c4131fdcb..3a3769825 100644
--- a/consul/kvs_endpoint_test.go
+++ b/consul/kvs_endpoint_test.go
@@ -1,11 +1,13 @@
 package consul
 
 import (
-	"github.com/hashicorp/consul/consul/structs"
-	"github.com/hashicorp/consul/testutil"
 	"os"
+	"strings"
 	"testing"
 	"time"
+
+	"github.com/hashicorp/consul/consul/structs"
+	"github.com/hashicorp/consul/testutil"
 )
 
 func TestKVS_Apply(t *testing.T) {
@@ -64,6 +66,68 @@ func TestKVS_Apply(t *testing.T) {
 	}
 }
 
+func TestKVS_Apply_ACLDeny(t *testing.T) {
+	dir1, s1 := testServerWithConfig(t, func(c *Config) {
+		c.ACLDatacenter = "dc1"
+		c.ACLMasterToken = "root"
+		c.ACLDefaultPolicy = "deny"
+	})
+	defer os.RemoveAll(dir1)
+	defer s1.Shutdown()
+	client := rpcClient(t, s1)
+	defer client.Close()
+
+	testutil.WaitForLeader(t, client.Call, "dc1")
+
+	// Create the ACL
+	arg := structs.ACLRequest{
+		Datacenter: "dc1",
+		Op:         structs.ACLSet,
+		ACL: structs.ACL{
+			Name:  "User token",
+			Type:  structs.ACLTypeClient,
+			Rules: testListRules,
+		},
+		WriteRequest: structs.WriteRequest{Token: "root"},
+	}
+	var out string
+	if err := client.Call("ACL.Apply", &arg, &out); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	id := out
+
+	// Try a write
+	argR := structs.KVSRequest{
+		Datacenter: "dc1",
+		Op:         structs.KVSSet,
+		DirEnt: structs.DirEntry{
+			Key:   "foo/bar",
+			Flags: 42,
+			Value: []byte("test"),
+		},
+		WriteRequest: structs.WriteRequest{Token: id},
+	}
+	var outR bool
+	err := client.Call("KVS.Apply", &argR, &outR)
+	if err == nil || !strings.Contains(err.Error(), permissionDenied) {
+		t.Fatalf("err: %v", err)
+	}
+
+	// Try a recursive delete
+	argR = structs.KVSRequest{
+		Datacenter: "dc1",
+		Op:         structs.KVSDeleteTree,
+		DirEnt: structs.DirEntry{
+			Key: "test",
+		},
+		WriteRequest: structs.WriteRequest{Token: id},
+	}
+	err = client.Call("KVS.Apply", &argR, &outR)
+	if err == nil || !strings.Contains(err.Error(), permissionDenied) {
+		t.Fatalf("err: %v", err)
+	}
+}
+
 func TestKVS_Get(t *testing.T) {
 	dir1, s1 := testServer(t)
 	defer os.RemoveAll(dir1)
@@ -111,6 +175,51 @@ func TestKVS_Get(t *testing.T) {
 	}
 }
 
+func TestKVS_Get_ACLDeny(t *testing.T) {
+	dir1, s1 := testServerWithConfig(t, func(c *Config) {
+		c.ACLDatacenter = "dc1"
+		c.ACLMasterToken = "root"
+		c.ACLDefaultPolicy = "deny"
+	})
+	defer os.RemoveAll(dir1)
+	defer s1.Shutdown()
+	client := rpcClient(t, s1)
+	defer client.Close()
+
+	testutil.WaitForLeader(t, client.Call, "dc1")
+
+	arg := structs.KVSRequest{
+		Datacenter: "dc1",
+		Op:         structs.KVSSet,
+		DirEnt: structs.DirEntry{
+			Key:   "zip",
+			Flags: 42,
+			Value: []byte("test"),
+		},
+		WriteRequest: structs.WriteRequest{Token: "root"},
+	}
+	var out bool
+	if err := client.Call("KVS.Apply", &arg, &out); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	getR := structs.KeyRequest{
+		Datacenter: "dc1",
+		Key:        "zip",
+	}
+	var dirent structs.IndexedDirEntries
+	if err := client.Call("KVS.Get", &getR, &dirent); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	if dirent.Index == 0 {
+		t.Fatalf("Bad: %v", dirent)
+	}
+	if len(dirent.Entries) != 0 {
+		t.Fatalf("Bad: %v", dirent)
+	}
+}
+
 func TestKVSEndpoint_List(t *testing.T) {
 	dir1, s1 := testServer(t)
 	defer os.RemoveAll(dir1)
@@ -170,6 +279,90 @@ func TestKVSEndpoint_List(t *testing.T) {
 	}
 }
 
+func TestKVSEndpoint_List_ACLDeny(t *testing.T) {
+	dir1, s1 := testServerWithConfig(t, func(c *Config) {
+		c.ACLDatacenter = "dc1"
+		c.ACLMasterToken = "root"
+		c.ACLDefaultPolicy = "deny"
+	})
+	defer os.RemoveAll(dir1)
+	defer s1.Shutdown()
+	client := rpcClient(t, s1)
+	defer client.Close()
+
+	testutil.WaitForLeader(t, client.Call, "dc1")
+
+	keys := []string{
+		"abe",
+		"bar",
+		"foo",
+		"test",
+		"zip",
+	}
+
+	for _, key := range keys {
+		arg := structs.KVSRequest{
+			Datacenter: "dc1",
+			Op:         structs.KVSSet,
+			DirEnt: structs.DirEntry{
+				Key:   key,
+				Flags: 1,
+			},
+			WriteRequest: structs.WriteRequest{Token: "root"},
+		}
+		var out bool
+		if err := client.Call("KVS.Apply", &arg, &out); err != nil {
+			t.Fatalf("err: %v", err)
+		}
+	}
+
+	arg := structs.ACLRequest{
+		Datacenter: "dc1",
+		Op:         structs.ACLSet,
+		ACL: structs.ACL{
+			Name:  "User token",
+			Type:  structs.ACLTypeClient,
+			Rules: testListRules,
+		},
+		WriteRequest: structs.WriteRequest{Token: "root"},
+	}
+	var out string
+	if err := client.Call("ACL.Apply", &arg, &out); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	id := out
+
+	getR := structs.KeyRequest{
+		Datacenter:   "dc1",
+		Key:          "",
+		QueryOptions: structs.QueryOptions{Token: id},
+	}
+	var dirent structs.IndexedDirEntries
+	if err := client.Call("KVS.List", &getR, &dirent); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	if dirent.Index == 0 {
+		t.Fatalf("Bad: %v", dirent)
+	}
+	if len(dirent.Entries) != 2 {
+		t.Fatalf("Bad: %v", dirent.Entries)
+	}
+	for i := 0; i < len(dirent.Entries); i++ {
+		d := dirent.Entries[i]
+		switch i {
+		case 0:
+			if d.Key != "foo" {
+				t.Fatalf("bad key")
+			}
+		case 1:
+			if d.Key != "test" {
+				t.Fatalf("bad key")
+			}
+		}
+	}
+}
+
 func TestKVSEndpoint_ListKeys(t *testing.T) {
 	dir1, s1 := testServer(t)
 	defer os.RemoveAll(dir1)
@@ -227,6 +420,84 @@ func TestKVSEndpoint_ListKeys(t *testing.T) {
 	}
 }
 
+func TestKVSEndpoint_ListKeys_ACLDeny(t *testing.T) {
+	dir1, s1 := testServerWithConfig(t, func(c *Config) {
+		c.ACLDatacenter = "dc1"
+		c.ACLMasterToken = "root"
+		c.ACLDefaultPolicy = "deny"
+	})
+	defer os.RemoveAll(dir1)
+	defer s1.Shutdown()
+	client := rpcClient(t, s1)
+	defer client.Close()
+
+	testutil.WaitForLeader(t, client.Call, "dc1")
+
+	keys := []string{
+		"abe",
+		"bar",
+		"foo",
+		"test",
+		"zip",
+	}
+
+	for _, key := range keys {
+		arg := structs.KVSRequest{
+			Datacenter: "dc1",
+			Op:         structs.KVSSet,
+			DirEnt: structs.DirEntry{
+				Key:   key,
+				Flags: 1,
+			},
+			WriteRequest: structs.WriteRequest{Token: "root"},
+		}
+		var out bool
+		if err := client.Call("KVS.Apply", &arg, &out); err != nil {
+			t.Fatalf("err: %v", err)
+		}
+	}
+
+	arg := structs.ACLRequest{
+		Datacenter: "dc1",
+		Op:         structs.ACLSet,
+		ACL: structs.ACL{
+			Name:  "User token",
+			Type:  structs.ACLTypeClient,
+			Rules: testListRules,
+		},
+		WriteRequest: structs.WriteRequest{Token: "root"},
+	}
+	var out string
+	if err := client.Call("ACL.Apply", &arg, &out); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	id := out
+
+	getR := structs.KeyListRequest{
+		Datacenter:   "dc1",
+		Prefix:       "",
+		Seperator:    "/",
+		QueryOptions: structs.QueryOptions{Token: id},
+	}
+	var dirent structs.IndexedKeyList
+	if err := client.Call("KVS.ListKeys", &getR, &dirent); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	if dirent.Index == 0 {
+		t.Fatalf("Bad: %v", dirent)
+	}
+	if len(dirent.Keys) != 2 {
+		t.Fatalf("Bad: %v", dirent.Keys)
+	}
+	if dirent.Keys[0] != "foo" {
+		t.Fatalf("Bad: %v", dirent.Keys)
+	}
+	if dirent.Keys[1] != "test" {
+		t.Fatalf("Bad: %v", dirent.Keys)
+	}
+}
+
 func TestKVS_Apply_LockDelay(t *testing.T) {
 	dir1, s1 := testServer(t)
 	defer os.RemoveAll(dir1)
@@ -294,3 +565,18 @@ func TestKVS_Apply_LockDelay(t *testing.T) {
 		t.Fatalf("should acquire")
 	}
 }
+
+var testListRules = `
+key "" {
+	policy = "deny"
+}
+key "foo" {
+	policy = "read"
+}
+key "test" {
+	policy = "write"
+}
+key "test/priv" {
+	policy = "read"
+}
+`
diff --git a/consul/leader.go b/consul/leader.go
index b63f7bbe8..60a6737f9 100644
--- a/consul/leader.go
+++ b/consul/leader.go
@@ -1,6 +1,7 @@
 package consul
 
 import (
+	"fmt"
 	"net"
 	"strconv"
 	"time"
@@ -54,6 +55,11 @@ func (s *Server) leaderLoop(stopCh chan struct{}) {
 		s.logger.Printf("[WARN] consul: failed to broadcast new leader event: %v", err)
 	}
 
+	// Setup ACLs if we are the leader and need to
+	if err := s.initializeACL(); err != nil {
+		s.logger.Printf("[ERR] consul: ACL initialization failed: %v", err)
+	}
+
 	// Reconcile channel is only used once initial reconcile
 	// has succeeded
 	var reconcileCh chan serf.Member
@@ -99,6 +105,73 @@ WAIT:
 	}
 }
 
+// initializeACL is used to setup the ACLs if we are the leader
+// and need to do this.
+func (s *Server) initializeACL() error {
+	// Bail if not configured or we are not authoritative
+	authDC := s.config.ACLDatacenter
+	if len(authDC) == 0 || authDC != s.config.Datacenter {
+		return nil
+	}
+
+	// Purge the cache, since it could've changed while we
+	// were not the leader
+	s.aclAuthCache.Purge()
+
+	// Look for the anonymous token
+	state := s.fsm.State()
+	_, acl, err := state.ACLGet(anonymousToken)
+	if err != nil {
+		return fmt.Errorf("failed to get anonymous token: %v", err)
+	}
+
+	// Create anonymous token if missing
+	if acl == nil {
+		req := structs.ACLRequest{
+			Datacenter: authDC,
+			Op:         structs.ACLForceSet,
+			ACL: structs.ACL{
+				ID:   anonymousToken,
+				Name: "Anonymous Token",
+				Type: structs.ACLTypeClient,
+			},
+		}
+		_, err := s.raftApply(structs.ACLRequestType, &req)
+		if err != nil {
+			return fmt.Errorf("failed to create anonymous token: %v", err)
+		}
+	}
+
+	// Check for configured master token
+	master := s.config.ACLMasterToken
+	if len(master) == 0 {
+		return nil
+	}
+
+	// Look for the master token
+	_, acl, err = state.ACLGet(master)
+	if err != nil {
+		return fmt.Errorf("failed to get master token: %v", err)
+	}
+	if acl == nil {
+		req := structs.ACLRequest{
+			Datacenter: authDC,
+			Op:         structs.ACLForceSet,
+			ACL: structs.ACL{
+				ID:   master,
+				Name: "Master Token",
+				Type: structs.ACLTypeManagement,
+			},
+		}
+		_, err := s.raftApply(structs.ACLRequestType, &req)
+		if err != nil {
+			return fmt.Errorf("failed to create master token: %v", err)
+		}
+
+	}
+	return nil
+}
+
 // reconcile is used to reconcile the differences between Serf
 // membership and what is reflected in our strongly consistent store.
 // Mainly we need to ensure all live nodes are registered, all failed
diff --git a/consul/server.go b/consul/server.go
index af61dc94c..d3fe6da92 100644
--- a/consul/server.go
+++ b/consul/server.go
@@ -15,6 +15,8 @@ import (
 	"sync"
 	"time"
 
+	"github.com/hashicorp/consul/acl"
+	"github.com/hashicorp/golang-lru"
 	"github.com/hashicorp/raft"
 	"github.com/hashicorp/raft-mdb"
 	"github.com/hashicorp/serf/serf"
@@ -43,11 +45,24 @@ const (
 	// serverMaxStreams controsl how many idle streams we keep
 	// open to a server
 	serverMaxStreams = 64
+
+	// Maximum number of cached ACL entries
+	aclCacheSize = 256
 )
 
 // Server is Consul server which manages the service discovery,
 // health checking, DC forwarding, Raft, and multiple Serf pools.
 type Server struct {
+	// aclAuthCache is the authoritative ACL cache
+	aclAuthCache *acl.Cache
+
+	// aclCache is a non-authoritative ACL cache
+	aclCache *lru.Cache
+
+	// aclPolicyCache is a policy cache
+	aclPolicyCache *lru.Cache
+
+	// Consul configuration
 	config *Config
 
 	// Connection pool to other consul servers
@@ -125,6 +140,7 @@ type endpoints struct {
 	KVS      *KVS
 	Session  *Session
 	Internal *Internal
+	ACL      *ACL
 }
 
 // NewServer is used to construct a new Consul server from the
@@ -140,6 +156,11 @@ func NewServer(config *Config) (*Server, error) {
 		return nil, fmt.Errorf("Config must provide a DataDir")
 	}
 
+	// Sanity check the ACLs
+	if err := config.CheckACL(); err != nil {
+		return nil, err
+	}
+
 	// Ensure we have a log output
 	if config.LogOutput == nil {
 		config.LogOutput = os.Stderr
@@ -175,6 +196,27 @@ func NewServer(config *Config) (*Server, error) {
 		shutdownCh:    make(chan struct{}),
 	}
 
+	// Initialize the authoritative ACL cache
+	s.aclAuthCache, err = acl.NewCache(aclCacheSize, s.aclFault)
+	if err != nil {
+		s.Shutdown()
+		return nil, fmt.Errorf("Failed to create ACL cache: %v", err)
+	}
+
+	// Initialize the non-authoritative ACL cache
+	s.aclCache, err = lru.New(aclCacheSize)
+	if err != nil {
+		s.Shutdown()
+		return nil, fmt.Errorf("Failed to create ACL cache: %v", err)
+	}
+
+	// Initialize the ACL policy cache
+	s.aclPolicyCache, err = lru.New(aclCacheSize)
+	if err != nil {
+		s.Shutdown()
+		return nil, fmt.Errorf("Failed to create ACL policy cache: %v", err)
+	}
+
 	// Initialize the RPC layer
 	if err := s.setupRPC(tlsConfig); err != nil {
 		s.Shutdown()
@@ -336,6 +378,7 @@ func (s *Server) setupRPC(tlsConfig *tls.Config) error {
 	s.endpoints.KVS = &KVS{s}
 	s.endpoints.Session = &Session{s}
 	s.endpoints.Internal = &Internal{s}
+	s.endpoints.ACL = &ACL{s}
 
 	// Register the handlers
 	s.rpcServer.Register(s.endpoints.Status)
@@ -344,6 +387,7 @@ func (s *Server) setupRPC(tlsConfig *tls.Config) error {
 	s.rpcServer.Register(s.endpoints.KVS)
 	s.rpcServer.Register(s.endpoints.Session)
 	s.rpcServer.Register(s.endpoints.Internal)
+	s.rpcServer.Register(s.endpoints.ACL)
 
 	list, err := net.ListenTCP("tcp", s.config.RPCAddr)
 	if err != nil {
diff --git a/consul/server_test.go b/consul/server_test.go
index 70aa5811f..76b7d4ed4 100644
--- a/consul/server_test.go
+++ b/consul/server_test.go
@@ -101,6 +101,17 @@ func testServerDCExpect(t *testing.T, dc string, expect int) (string, *Server) {
 	return dir, server
 }
 
+func testServerWithConfig(t *testing.T, cb func(c *Config)) (string, *Server) {
+	name := fmt.Sprintf("Node %d", getPort())
+	dir, config := testServerConfig(t, name)
+	cb(config)
+	server, err := NewServer(config)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	return dir, server
+}
+
 func TestServer_StartStop(t *testing.T) {
 	dir := tmpDir(t)
 	defer os.RemoveAll(dir)
diff --git a/consul/state_store.go b/consul/state_store.go
index f95b0554e..6a43aa027 100644
--- a/consul/state_store.go
+++ b/consul/state_store.go
@@ -21,6 +21,7 @@ const (
 	dbKVS                    = "kvs"
 	dbSessions               = "sessions"
 	dbSessionChecks          = "sessionChecks"
+	dbACLs                   = "acls"
 	dbMaxMapSize32bit uint64 = 512 * 1024 * 1024       // 512MB maximum size
 	dbMaxMapSize64bit uint64 = 32 * 1024 * 1024 * 1024 // 32GB maximum size
 )
@@ -53,6 +54,7 @@ type StateStore struct {
 	kvsTable          *MDBTable
 	sessionTable      *MDBTable
 	sessionCheckTable *MDBTable
+	aclTable          *MDBTable
 	tables            MDBTables
 	watch             map[*MDBTable]*NotifyGroup
 	queryTables       map[string]MDBTables
@@ -306,9 +308,26 @@ func (s *StateStore) initialize() error {
 		},
 	}
 
+	s.aclTable = &MDBTable{
+		Name: dbACLs,
+		Indexes: map[string]*MDBIndex{
+			"id": &MDBIndex{
+				Unique: true,
+				Fields: []string{"ID"},
+			},
+		},
+		Decoder: func(buf []byte) interface{} {
+			out := new(structs.ACL)
+			if err := structs.Decode(buf, out); err != nil {
+				panic(err)
+			}
+			return out
+		},
+	}
+
 	// Store the set of tables
 	s.tables = []*MDBTable{s.nodeTable, s.serviceTable, s.checkTable,
-		s.kvsTable, s.sessionTable, s.sessionCheckTable}
+		s.kvsTable, s.sessionTable, s.sessionCheckTable, s.aclTable}
 	for _, table := range s.tables {
 		table.Env = s.env
 		table.Encoder = encoder
@@ -338,6 +357,8 @@ func (s *StateStore) initialize() error {
 		"SessionGet":        MDBTables{s.sessionTable},
 		"SessionList":       MDBTables{s.sessionTable},
 		"NodeSessions":      MDBTables{s.sessionTable},
+		"ACLGet":            MDBTables{s.aclTable},
+		"ACLList":           MDBTables{s.aclTable},
 	}
 	return nil
 }
@@ -1249,8 +1270,8 @@ func (s *StateStore) SessionCreate(index uint64, session *structs.Session) error
 	}
 
 	// Generate a new session ID, verify uniqueness
-	session.ID = generateUUID()
 	for {
+		session.ID = generateUUID()
 		res, err = s.sessionTable.GetTxn(tx, "id", session.ID)
 		if err != nil {
 			return err
@@ -1346,7 +1367,7 @@ func (s *StateStore) NodeSessions(node string) (uint64, []*structs.Session, erro
 	return idx, out, err
 }
 
-// SessionDelete is used to destroy a session.
+// SessionDestroy is used to destroy a session.
 func (s *StateStore) SessionDestroy(index uint64, id string) error {
 	tx, err := s.tables.StartTxn(false)
 	if err != nil {
@@ -1482,6 +1503,124 @@ func (s *StateStore) invalidateLocks(index uint64, tx *MDBTxn,
 	return nil
 }
 
+// ACLSet is used to create or update an ACL entry
+// allowCreate is used for initialization of the anonymous and master tokens,
+// since it permits them to be created with a specified ID that does not exist.
+func (s *StateStore) ACLSet(index uint64, acl *structs.ACL, allowCreate bool) error {
+	// Start a new txn
+	tx, err := s.tables.StartTxn(false)
+	if err != nil {
+		return err
+	}
+	defer tx.Abort()
+
+	// Generate a new session ID
+	if acl.ID == "" {
+		for {
+			acl.ID = generateUUID()
+			res, err := s.aclTable.GetTxn(tx, "id", acl.ID)
+			if err != nil {
+				return err
+			}
+			// Quit if this ID is unique
+			if len(res) == 0 {
+				break
+			}
+		}
+		acl.CreateIndex = index
+		acl.ModifyIndex = index
+
+	} else {
+		// Look for the existing node
+		res, err := s.aclTable.GetTxn(tx, "id", acl.ID)
+		if err != nil {
+			return err
+		}
+
+		switch len(res) {
+		case 0:
+			if !allowCreate {
+				return fmt.Errorf("Invalid ACL")
+			}
+			acl.CreateIndex = index
+			acl.ModifyIndex = index
+		case 1:
+			exist := res[0].(*structs.ACL)
+			acl.CreateIndex = exist.CreateIndex
+			acl.ModifyIndex = index
+		default:
+			panic(fmt.Errorf("Duplicate ACL definition. Internal error"))
+		}
+	}
+
+	// Insert the ACL
+	if err := s.aclTable.InsertTxn(tx, acl); err != nil {
+		return err
+	}
+
+	// Trigger the update notifications
+	if err := s.aclTable.SetLastIndexTxn(tx, index); err != nil {
+		return err
+	}
+	tx.Defer(func() { s.watch[s.aclTable].Notify() })
+	return tx.Commit()
+}
+
+// ACLRestore is used to restore an ACL. It should only be used when
+// doing a restore, otherwise ACLSet should be used.
+func (s *StateStore) ACLRestore(acl *structs.ACL) error {
+	// Start a new txn
+	tx, err := s.aclTable.StartTxn(false, nil)
+	if err != nil {
+		return err
+	}
+	defer tx.Abort()
+
+	if err := s.aclTable.InsertTxn(tx, acl); err != nil {
+		return err
+	}
+	return tx.Commit()
+}
+
+// ACLGet is used to get an ACL by ID
+func (s *StateStore) ACLGet(id string) (uint64, *structs.ACL, error) {
+	idx, res, err := s.aclTable.Get("id", id)
+	var d *structs.ACL
+	if len(res) > 0 {
+		d = res[0].(*structs.ACL)
+	}
+	return idx, d, err
+}
+
+// ACLList is used to list all the acls
+func (s *StateStore) ACLList() (uint64, []*structs.ACL, error) {
+	idx, res, err := s.aclTable.Get("id")
+	out := make([]*structs.ACL, len(res))
+	for i, raw := range res {
+		out[i] = raw.(*structs.ACL)
+	}
+	return idx, out, err
+}
+
+// ACLDelete is used to remove an ACL
+func (s *StateStore) ACLDelete(index uint64, id string) error {
+	tx, err := s.tables.StartTxn(false)
+	if err != nil {
+		panic(fmt.Errorf("Failed to start txn: %v", err))
+	}
+	defer tx.Abort()
+
+	if n, err := s.aclTable.DeleteTxn(tx, "id", id); err != nil {
+		return err
+	} else if n > 0 {
+		if err := s.aclTable.SetLastIndexTxn(tx, index); err != nil {
+			return err
+		}
+		tx.Defer(func() { s.watch[s.aclTable].Notify() })
+	}
+	return tx.Commit()
+}
+
 // Snapshot is used to create a point in time snapshot
 func (s *StateStore) Snapshot() (*StateSnapshot, error) {
 	// Begin a new txn on all tables
@@ -1555,3 +1694,13 @@ func (s *StateSnapshot) SessionList() ([]*structs.Session, error) {
 	}
 	return out, err
 }
+
+// ACLList is used to list all of the ACLs
+func (s *StateSnapshot) ACLList() ([]*structs.ACL, error) {
+	res, err := s.store.aclTable.GetTxn(s.tx, "id")
+	out := make([]*structs.ACL, len(res))
+	for i, raw := range res {
+		out[i] = raw.(*structs.ACL)
+	}
+	return out, err
+}
diff --git a/consul/state_store_test.go b/consul/state_store_test.go
index a5130131a..f0cdae90f 100644
--- a/consul/state_store_test.go
+++ b/consul/state_store_test.go
@@ -652,6 +652,22 @@ func TestStoreSnapshot(t *testing.T) {
 		t.Fatalf("err: %v", err)
 	}
 
+	a1 := &structs.ACL{
+		Name: "User token",
+		Type: structs.ACLTypeClient,
+	}
+	if err := store.ACLSet(19, a1, false); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	a2 := &structs.ACL{
+		Name: "User token",
+		Type: structs.ACLTypeClient,
+	}
+	if err := store.ACLSet(20, a2, false); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
 	// Take a snapshot
 	snap, err := store.Snapshot()
 	if err != nil {
@@ -660,7 +676,7 @@ func TestStoreSnapshot(t *testing.T) {
 	defer snap.Close()
 
 	// Check the last nodes
-	if idx := snap.LastIndex(); idx != 18 {
+	if idx := snap.LastIndex(); idx != 20 {
 		t.Fatalf("bad: %v", idx)
 	}
 
@@ -724,14 +740,23 @@ func TestStoreSnapshot(t *testing.T) {
 		t.Fatalf("missing sessions")
 	}
 
+	// Check for an acl
+	acls, err := snap.ACLList()
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if len(acls) != 2 {
+		t.Fatalf("missing acls")
+	}
+
 	// Make some changes!
-	if err := store.EnsureService(19, "foo", &structs.NodeService{"db", "db", []string{"slave"}, 8000}); err != nil {
+	if err := store.EnsureService(21, "foo", &structs.NodeService{"db", "db", []string{"slave"}, 8000}); err != nil {
 		t.Fatalf("err: %v", err)
 	}
-	if err := store.EnsureService(20, "bar", &structs.NodeService{"db", "db", []string{"master"}, 8000}); err != nil {
+	if err := store.EnsureService(22, "bar", &structs.NodeService{"db", "db", []string{"master"}, 8000}); err != nil {
 		t.Fatalf("err: %v", err)
 	}
-	if err := store.EnsureNode(21, structs.Node{"baz", "127.0.0.3"}); err != nil {
+	if err := store.EnsureNode(23, structs.Node{"baz", "127.0.0.3"}); err != nil {
 		t.Fatalf("err: %v", err)
 	}
 	checkAfter := &structs.HealthCheck{
@@ -741,11 +766,16 @@ func TestStoreSnapshot(t *testing.T) {
 		Status:    structs.HealthCritical,
 		ServiceID: "db",
 	}
-	if err := store.EnsureCheck(22, checkAfter); err != nil {
+	if err := store.EnsureCheck(24, checkAfter); err != nil {
 		t.Fatalf("err: %v", err)
 	}
 
-	if err := store.KVSDelete(23, "/web/b"); err != nil {
+	if err := store.KVSDelete(25, "/web/b"); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	// Nuke an ACL
+	if err := store.ACLDelete(26, a1.ID); err != nil {
 		t.Fatalf("err: %v", err)
 	}
 
@@ -807,6 +837,15 @@ func TestStoreSnapshot(t *testing.T) {
 	if len(sessions) != 2 {
 		t.Fatalf("missing sessions")
 	}
+
+	// Check for an acl
+	acls, err = snap.ACLList()
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if len(acls) != 2 {
+		t.Fatalf("missing acls")
+	}
 }
 
 func TestEnsureCheck(t *testing.T) {
@@ -2117,3 +2156,144 @@ func TestSessionInvalidate_KeyUnlock(t *testing.T) {
 		t.Fatalf("Bad: %v", expires)
 	}
 }
+
+func TestACLSet_Get(t *testing.T) {
+	store, err := testStateStore()
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	defer store.Close()
+
+	idx, out, err := store.ACLGet("1234")
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if idx != 0 {
+		t.Fatalf("bad: %v", idx)
+	}
+	if out != nil {
+		t.Fatalf("bad: %v", out)
+	}
+
+	a := &structs.ACL{
+		Name:  "User token",
+		Type:  structs.ACLTypeClient,
+		Rules: "",
+	}
+	if err := store.ACLSet(50, a, false); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if a.CreateIndex != 50 {
+		t.Fatalf("Bad: %v", a)
+	}
+	if a.ModifyIndex != 50 {
+		t.Fatalf("Bad: %v", a)
+	}
+	if a.ID == "" {
+		t.Fatalf("Bad: %v", a)
+	}
+
+	idx, out, err = store.ACLGet(a.ID)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if idx != 50 {
+		t.Fatalf("bad: %v", idx)
+	}
+	if !reflect.DeepEqual(out, a) {
+		t.Fatalf("bad: %v", out)
+	}
+
+	// Update
+	a.Rules = "foo bar baz"
+	if err := store.ACLSet(52, a, false); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if a.CreateIndex != 50 {
+		t.Fatalf("Bad: %v", a)
+	}
+	if a.ModifyIndex != 52 {
+		t.Fatalf("Bad: %v", a)
+	}
+
+	idx, out, err = store.ACLGet(a.ID)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if idx != 52 {
+		t.Fatalf("bad: %v", idx)
+	}
+	if !reflect.DeepEqual(out, a) {
+		t.Fatalf("bad: %v", out)
+	}
+}
+
+func TestACLDelete(t *testing.T) {
+	store, err := testStateStore()
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	defer store.Close()
+
+	a := &structs.ACL{
+		Name:  "User token",
+		Type:  structs.ACLTypeClient,
+		Rules: "",
+	}
+	if err := store.ACLSet(50, a, false); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	if err := store.ACLDelete(52, a.ID); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if err := store.ACLDelete(53, a.ID); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	idx, out, err := store.ACLGet(a.ID)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if idx != 52 {
+		t.Fatalf("bad: %v", idx)
+	}
+	if out != nil {
+		t.Fatalf("bad: %v", out)
+	}
+}
+
+func TestACLList(t *testing.T) {
+	store, err := testStateStore()
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	defer store.Close()
+
+	a1 := &structs.ACL{
+		Name: "User token",
+		Type: structs.ACLTypeClient,
+	}
+	if err := store.ACLSet(50, a1, false); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	a2 := &structs.ACL{
+		Name: "User token",
+		Type: structs.ACLTypeClient,
+	}
+	if err := store.ACLSet(51, a2, false); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	idx, out, err := store.ACLList()
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if idx != 51 {
+		t.Fatalf("bad: %v", idx)
+	}
+	if len(out) != 2 {
+		t.Fatalf("bad: %v", out)
+	}
+}
diff --git a/consul/structs/structs.go b/consul/structs/structs.go
index 56ec95c35..95f273f4f 100644
--- a/consul/structs/structs.go
+++ b/consul/structs/structs.go
@@ -3,8 +3,10 @@ package structs
 import (
 	"bytes"
 	"fmt"
-	"github.com/ugorji/go/codec"
 	"time"
+
+	"github.com/hashicorp/consul/acl"
+	"github.com/ugorji/go/codec"
 )
 
 var (
@@ -20,6 +22,7 @@ const (
 	DeregisterRequestType
 	KVSRequestType
 	SessionRequestType
+	ACLRequestType
 )
 
 const (
@@ -32,6 +35,15 @@ const (
 	HealthCritical = "critical"
 )
 
+const (
+	// Client tokens have rules applied
+	ACLTypeClient = "client"
+
+	// Management tokens have an always allow policy.
+	// They are used for token management.
+	ACLTypeManagement = "management"
+)
+
 const (
 	// MaxLockDelay provides a maximum LockDelay value for
 	// a session. Any value above this will not be respected.
@@ -43,10 +55,15 @@ type RPCInfo interface {
 	RequestDatacenter() string
 	IsRead() bool
 	AllowStaleRead() bool
+	ACLToken() string
 }
 
 // QueryOptions is used to specify various flags for read queries
 type QueryOptions struct {
+	// Token is the ACL token ID. If not provided, the 'anonymous'
+	// token is assumed for backwards compatibility.
+	Token string
+
 	// If set, wait until query exceeds given index. Must be provided
 	// with MaxQueryTime.
 	MinQueryIndex uint64
@@ -72,7 +89,15 @@ func (q QueryOptions) AllowStaleRead() bool {
 	return q.AllowStale
 }
 
-type WriteRequest struct{}
+func (q QueryOptions) ACLToken() string {
+	return q.Token
+}
+
+type WriteRequest struct {
+	// Token is the ACL token ID. If not provided, the 'anonymous'
+	// token is assumed for backwards compatibility.
+	Token string
+}
 
 // WriteRequest only applies to writes, always false
 func (w WriteRequest) IsRead() bool {
@@ -83,6 +108,10 @@ func (w WriteRequest) AllowStaleRead() bool {
 	return false
 }
 
+func (w WriteRequest) ACLToken() string {
+	return w.Token
+}
+
 // QueryMeta allows a query response to include potentially
 // useful metadata about a query
 type QueryMeta struct {
@@ -396,6 +425,74 @@ type IndexedSessions struct {
 	QueryMeta
 }
 
+// ACL is used to represent a token and it's rules
+type ACL struct {
+	CreateIndex uint64
+	ModifyIndex uint64
+	ID          string
+	Name        string
+	Type        string
+	Rules       string
+}
+type ACLs []*ACL
+
+type ACLOp string
+
+const (
+	ACLSet      ACLOp = "set"
+	ACLForceSet       = "force-set"
+	ACLDelete         = "delete"
+)
+
+// ACLRequest is used to create, update or delete an ACL
+type ACLRequest struct {
+	Datacenter string
+	Op         ACLOp
+	ACL        ACL
+	WriteRequest
+}
+
+func (r *ACLRequest) RequestDatacenter() string {
+	return r.Datacenter
+}
+
+// ACLSpecificRequest is used to request an ACL by ID
+type ACLSpecificRequest struct {
+	Datacenter string
+	ACL        string
+	QueryOptions
+}
+
+func (r *ACLSpecificRequest) RequestDatacenter() string {
+	return r.Datacenter
+}
+
+// ACLPolicyRequest is used to request an ACL by ID, conditionally
+// filtering on an ID
+type ACLPolicyRequest struct {
+	Datacenter string
+	ACL        string
+	ETag       string
+	QueryOptions
+}
+
+func (r *ACLPolicyRequest) RequestDatacenter() string {
+	return r.Datacenter
+}
+
+type IndexedACLs struct {
+	ACLs ACLs
+	QueryMeta
+}
+
+type ACLPolicy struct {
+	ETag   string
+	Parent string
+	Policy *acl.Policy
+	TTL    time.Duration
+	QueryMeta
+}
+
 // msgpackHandle is a shared handle for encoding/decoding of structs
 var msgpackHandle = &codec.MsgpackHandle{}
 
diff --git a/website/source/docs/agent/http.html.markdown b/website/source/docs/agent/http.html.markdown
index 980dd807f..2b59a2da9 100644
--- a/website/source/docs/agent/http.html.markdown
+++ b/website/source/docs/agent/http.html.markdown
@@ -17,6 +17,7 @@ All endpoints fall into one of several categories:
 * catalog - Manages nodes and services
 * health - Manages health checks
 * session - Session manipulation
+* acl - ACL creations and management
 * status - Consul system status
 * internal - Internal APIs. Purposely undocumented, subject to change.
 
@@ -85,6 +86,14 @@ By default, the output of all HTTP API requests return minimized JSON with all
 whitespace removed.  By adding "?pretty" to the HTTP request URL,
 formatted JSON will be returned.
 
+## ACLs
+
+Several endpoints in Consul use or require ACL tokens to operate. An agent
+can be configured to use a default token in requests using the `acl_token`
+configuration option. However, the token can also be specified per-request
+by using the "?token=" query parameter. This will take precedence over the
+default token.
+
 ## KV
 
 The KV endpoint is used to expose a simple key/value store. This can be used
@@ -99,7 +108,8 @@ are all supported. It is important to note that each datacenter has its
 own K/V store, and that there is no replication between datacenters.
 By default the datacenter of the agent is queried, however the dc can
 be provided using the "?dc=" query parameter. If a client wants to write
-to all Datacenters, one request per datacenter must be made.
+to all Datacenters, one request per datacenter must be made. The KV endpoint
+supports the use of ACL tokens.
 
 ### GET Method
 
@@ -1039,6 +1049,145 @@ It returns a JSON body like this:
 
 This endpoint supports blocking queries and all consistency modes.
 
+## ACL
+
+The ACL endpoints are used to create, update, destroy and query ACL tokens.
+The following endpoints are supported:
+
+* /v1/acl/create: Creates a new token with policy
+* /v1/acl/update: Update the policy of a token
+* /v1/acl/destroy/\<id\>: Destroys a given token
+* /v1/acl/info/\<id\>: Queries the policy of a given token
+* /v1/acl/clone/\<id\>: Creates a new token by cloning an existing token
+* /v1/acl/list: Lists all the active tokens
+
+### /v1/acl/create
+
+The create endpoint is used to make a new token. A token has a name,
+type, and a set of ACL rules. The name is opaque to Consul, and type
+is either "client" or "management". A management token is effectively
+like a root user, and has the ability to perform any action including
+creating, modifying, and deleting ACLs. A client token can only perform
+actions as permitted by the rules associated, and may never manage ACLs.
+This means the request to this endpoint must be made with a management
+token.
+
+In any Consul cluster, only a single datacenter is authoritative for ACLs, so
+all requests are automatically routed to that datacenter regardless
+of the agent that the request is made to.
+
+The create endpoint expects a JSON request body to be PUT. The request
+body must look like:
+
+    {
+        "Name": "my-app-token",
+        "Type": "client",
+        "Rules": "",
+    }
+
+None of the fields are mandatory, and in fact no body needs to be PUT
+if the defaults are to be used. The `Name` and `Rules` default to being
+blank, and the `Type` defaults to "client". The format of `Rules` is
+[documented here](/docs/internals/acl.html).
+
+The return code is 200 on success, along with a body like:
+
+    {"ID":"adf4238a-882b-9ddc-4a9d-5b6758e4159e"}
+
+This is used to provide the ID of the newly created ACL token.
+
+### /v1/acl/update
+
+The update endpoint is used to modify the policy for a given
+ACL token. It is very similar to the create endpoint, however
+instead of generating a new token ID, the `ID` field must be
+provided. Requests to this endpoint must be made with a management
+token.
+
+In any Consul cluster, only a single datacenter is authoritative for ACLs, so
+all requests are automatically routed to that datacenter regardless
+of the agent that the request is made to.
+
+The update endpoint expects a JSON request body to be PUT. The request
+body must look like:
+
+    {
+        "ID": "adf4238a-882b-9ddc-4a9d-5b6758e4159e"
+        "Name": "my-app-token-updated",
+        "Type": "client",
+        "Rules": "# New Rules",
+    }
+
+Only the `ID` field is mandatory, the other fields provide defaults.
+The `Name` and `Rules` default to being blank, and the `Type` defaults to "client".
+The format of `Rules` is [documented here](/docs/internals/acl.html).
+
+The return code is 200 on success.
+
+### /v1/acl/destroy/\<id\>
+
+The destroy endpoint is hit with a PUT and destroys the given ACL token.
+The request is automatically routed to the authoritative ACL datacenter.
+The token being destroyed must be provided after the slash, and requests
+to the endpoint must be made with a management token.
+
+The return code is 200 on success.
+
+### /v1/acl/info/\<id\>
+
+This endpoint is hit with a GET and returns the token information
+by ID. All requests are routed to the authoritative ACL datacenter
+The token being queried must be provided after the slash.
+
+It returns a JSON body like this:
+
+    [
+        {
+            "CreateIndex":3,
+            "ModifyIndex":3,
+            "ID":"8f246b77-f3e1-ff88-5b48-8ec93abf3e05",
+            "Name":"Client Token",
+            "Type":"client",
+            "Rules":"..."
+        }
+    ]
+
+If the session is not found, null is returned instead of a JSON list.
+
+### /v1/acl/clone/\<id\>
+
+The clone endpoint is hit with a PUT and returns a token ID that
+is cloned from an existing token. This allows a token to serve
+as a template for others, making it simple to generate new tokens
+without complex rule management. The source token must be provided
+after the slash. Requests to this endpoint require a management token.
+
+The return code is 200 on success, along with a body like:
+
+    {"ID":"adf4238a-882b-9ddc-4a9d-5b6758e4159e"}
+
+This is used to provide the ID of the newly created ACL token.
+
+### /v1/acl/list
+
+The list endpoint is hit with a GET and lists all the active
+ACL tokens. This is a privileged endpoint, and requires a
+management token.
+
+It returns a JSON body like this:
+
+    [
+        {
+            "CreateIndex":3,
+            "ModifyIndex":3,
+            "ID":"8f246b77-f3e1-ff88-5b48-8ec93abf3e05",
+            "Name":"Client Token",
+            "Type":"client",
+            "Rules":"..."
+        },
+        ...
+    ]
+
 ## Status
 
 The Status endpoints are used to get information about the status
diff --git a/website/source/docs/agent/options.html.markdown b/website/source/docs/agent/options.html.markdown
index b436c90f0..4e6d66590 100644
--- a/website/source/docs/agent/options.html.markdown
+++ b/website/source/docs/agent/options.html.markdown
@@ -284,6 +284,38 @@ definitions support being updated during a reload.
   will not make use of TLS for outgoing connections. This applies to clients and servers,
   as both will make outgoing connections.
 
+* `acl_datacenter` - Only used by servers. This designates the datacenter which
+   is authoritative for ACL information. It must be provided to enable ACLs.
+   All servers and datacenters must agree on the ACL datacenter.
+
+* `acl_token` - When provided, the agent will use this token when making requests
+   to the Consul servers. Clients can override this token on a per-request basis
+   by providing the ?token parameter. When not provided, the empty token is used
+   which maps to the 'anonymous' ACL policy.
+
+* `acl_master_token` - Only used for servers in the `acl_datacenter`. This token
+   will be created if it does not exist with management level permissions. It allows
+   operators to bootstrap the ACL system with a token ID that is well-known.
+
+* `acl_default_policy` - Either "allow" or "deny", defaults to "allow". The
+  default policy controls the behavior of a token when there is no matching
+  rule. In "allow" mode, ACLs are a blacklist: any operation not specifically
+  prohibited is allowed. In "deny" mode, ACLs are a whilelist: any operation not
+  specifically allowed is blocked.
+
+* `acl_down_policy` - Either "allow", "deny" or "extend-cache" which is the
+  default. In the case that the policy for a token cannot be read from the
+  `acl_datacenter` or leader node, the down policy is applied. In "allow" mode,
+  all actions are permitted, "deny" restricts all operations, and "extend-cache"
+  allows any cached ACLs to be used, ignoring their TTL values. If a non-cached
+  ACL is used, "extend-cache" acts like "deny".
+
+* `acl_ttl` - Used to control Time-To-Live caching of ACLs. By default this
+   is 30 seconds. This setting has a major performance impact: reducing it will
+   cause more frequent refreshes, while increasing it reduces the number of caches.
+   However, because the caches are not actively invalidated, ACL policy may be stale
+   up to the TTL value.
+
 ## Ports Used
 
 Consul requires up to 5 different ports to work properly, some requiring
diff --git a/website/source/docs/internals/acl.html.markdown b/website/source/docs/internals/acl.html.markdown
new file mode 100644
index 000000000..166094fa0
--- /dev/null
+++ b/website/source/docs/internals/acl.html.markdown
@@ -0,0 +1,112 @@
+---
+layout: "docs"
+page_title: "ACL System"
+sidebar_current: "docs-internals-acl"
+---
+
+# ACL System
+
+Consul provides an optional Access Control List (ACL) system which can be used to control
+access to data and APIs. The ACL system is a
+[Capability-based system](http://en.wikipedia.org/wiki/Capability-based_security) that relies
+on tokens which can have fine grained rules applied to them. It is very similar to
+[AWS IAM](http://aws.amazon.com/iam/) in many ways.
+
+## ACL Design
+
+The ACL system is designed to be easy to use, fast to enforce, flexible to new
+policies, all while providing administrative insight. It has been modeled on
+the AWS IAM system, as well as the more general object-capability model. The system
+is modeled around "tokens".
+
+Every token has an ID, name, type and rule set. The ID is a randomly generated
+UUID, making it unfeasible to guess. The name is opaque and human readable.
+Lastly the type is either "client" meaning it cannot modify ACL rules, and
+is restricted by the provided rules, or is "management" and is allowed to
+perform all actions.
+
+The token ID is passed along with each RPC request to the servers. Agents
+[can be configured](/docs/agent/options.html) with `acl_token` to provide a default token,
+but the token can also be specified by a client on a [per-request basis](/docs/agent/http.html).
+ACLs are new as of Consul 0.4, meaning versions prior do not provide a token.
+This is handled by the special "anonymous" token. Anytime there is no token provided,
+the rules defined by that token are automatically applied. This lets policy be enforced
+on legacy clients.
+
+Enforcement is always done by the server nodes. All servers must be [configured
+to provide](/docs/agent/options.html) an `acl_datacenter`, which enables
+ACL enforcement but also specified the authoritative datacenter. Consul does not
+replicate data cross-WAN, and instead relies on [RPC forwarding](/docs/internal/architecture.html)
+to support Multi-Datacenter configurations. However, because requests can be
+made across datacenter boundaries, ACL tokens must be valid globally. To avoid
+replication issues, a single datacenter is considered authoritative and stores
+all the tokens.
+
+When a request is made to any non-authoritative server with a token, it must
+be resolved into the appropriate policy. This is done by reading the token
+from the authoritative server and caching a configurable `acl_ttl`. The implication
+of caching is that the cache TTL is an upper-bound on the staleness of policy
+that is enforced. It is possible to set a zero TTL, but this has adverse
+performance impacts, as every request requires refreshing the policy.
+
+Another possible issue is an outage of the `acl_datacenter` or networking
+issues preventing access. In this case, it may be impossible for non-authoritative
+servers to resolve tokens. Consul provides a number of configurable `acl_down_policy`
+choices to tune behavior. It is possible to deny or permit all actions, or to ignore
+cache TTLs and enter a fail-safe mode.
+
+ACLs can also act in either a whilelist or blacklist mode depending
+on the configuration of `acl_default_policy`. If the default policy is
+to deny all actions, then token rules can be set to allow or whitelist
+actions. In the inverse, the allow all default behavior is a blacklist,
+where rules are used to prohibit actions.
+
+Bootstrapping the ACL system is done by providing an initial `acl_master_token`
+[configuration](/docs/agent/options.html), which will be created as a
+"management" type token if it does not exist.
+
+## Rule Specification
+
+A core part of the ACL system is a rule language which is used
+to describe the policy that must be enforced. We make use of
+the [HashiCorp Configuration Language (HCL)](https://github.com/hashicorp/hcl/)
+to specify policy. This language is human readable and interoperable
+with JSON making it easy to machine generate.
+
+As of Consul 0.4, it is only possible to specify policies for the
+KV store. Specification in the HCL format looks like:
+
+    # Default all keys to read-only
+    key "" {
+        policy = "read"
+    }
+    key "foo/" {
+        policy = "write"
+    }
+    key "foo/private/" {
+        # Deny access to the private dir
+        policy = "deny"
+    }
+
+This is equivalent to the following JSON input:
+
+    {
+        "key": {
+            "": {
+                "policy": "read",
+            },
+            "foo/": {
+                "policy": "write",
+            },
+            "foo/private": {
+                "policy": "deny",
+            }
+        }
+    }
+
+Key policies provide both a prefix and a policy. The rules are enforced
+using a longest-prefix match policy. This means we pick the most specific
+policy possible. The policy is either "read", "write" or "deny". A "write"
+policy implies "read", and there is no way to specify write-only. If there
+is no applicable rule, the `acl_default_policy` is applied.
+
diff --git a/website/source/layouts/docs.erb b/website/source/layouts/docs.erb
index 8ade7749c..fcad0930e 100644
--- a/website/source/layouts/docs.erb
+++ b/website/source/layouts/docs.erb
@@ -38,6 +38,10 @@
 					<a href="/docs/internals/sessions.html">Sessions</a>
                     </li>
 
+					<li<%= sidebar_current("docs-internals-acl") %>>
+					<a href="/docs/internals/acl.html">ACLs</a>
+                    </li>
+
 					<li<%= sidebar_current("docs-internals-security") %>>
 					<a href="/docs/internals/security.html">Security Model</a>
                     </li>