diff --git a/core/cli/run.go b/core/cli/run.go
index d4eb3f597f..f3cdbc86c2 100644
--- a/core/cli/run.go
+++ b/core/cli/run.go
@@ -43,6 +43,9 @@ type RunCMD struct {
 	P2PEnableLimits           string `name:"p2p-enable-limits" env:"LOCALAI_P2P_ENABLE_LIMITS" help:"Set to true to enable P2P resource limits" group:"p2p"`
 	AddonHostPolicy           string `name:"addon-host-policy" env:"LOCALAI_ADDON_HOST_POLICY" help:"Absolute path to administrator host operation policy JSON, read once at startup. Empty disables environment policy" group:"addons"`
 	AddonHostOps              string `name:"addon-host-ops" env:"LOCALAI_ADDON_HOST_OPS" help:"Add-ons that may call host operations, as a comma list of addon-id=operation-prefix. An add-on that is not listed gets no host operation channel. Empty gives none" group:"addons"`
+	AddonHostDeny             string `name:"addon-host-deny" env:"LOCALAI_ADDON_HOST_DENY" help:"Host operations no grant may enable, as a comma list of addon-id=operation (a prefix such as egress., an exact name or *). Use *=prefix for every add-on. Deny always wins over grants and is unioned with the deny rules of the policy file" group:"addons"`
+	AddonHostBlanket          string `name:"addon-host-blanket" env:"LOCALAI_ADDON_HOST_BLANKET" help:"Blanket approval of declared host operations at install and upgrade: off, official or any. When set, the UI shows it read-only. Unset leaves the choice to the administrator in the UI" group:"addons"`
+	AddonHostUIGrants         bool   `name:"addon-host-ui-grants" env:"LOCALAI_ADDON_HOST_UI_GRANTS" default:"true" help:"Let an administrator grant host operations to add-ons in the UI. Turn it off with --addon-host-ui-grants=false to make the policy file and flags the only source of grants" group:"addons"`
 	AddonsEnabled             bool   `name:"addons-enabled" env:"LOCALAI_ADDONS_ENABLED" default:"true" help:"Run the add-on owner, which installs and supervises add-ons. Turn it off with --addons-enabled=false" group:"addons"`
 	AddonsOwnershipMode       string `name:"addons-ownership-mode" env:"LOCALAI_ADDONS_OWNERSHIP_MODE" help:"Who may use add-ons: named-user (each account has its own access; needs authentication) or local-owner (every caller shares one owner). Default: local-owner when authentication is off, named-user when it is on" group:"addons"`
 	AddonsRole                string `name:"addons-role" env:"LOCALAI_ADDONS_ROLE" default:"combined" help:"How this process takes part in the add-on owner: combined (this node is its own owner, the default), owner (only the owner, serves the carrier on the network) or frontend (no owner here; every add-on request goes to the owner). owner and frontend need --addons-owner-address and --addons-carrier-dir" group:"addons"`
@@ -329,6 +332,10 @@ func (r *RunCMD) Run(ctx *cliContext.Context) (result error) {
 		return err
 	}
 	logAddonHostOpsResolution(hostOps)
+	blanket, err := config.ParseAddonHostBlanket(r.AddonHostBlanket)
+	if err != nil {
+		return err
+	}
 
 	diagnosticOpts := r.diagnosticsOptions()
 	if err := diagnosticOpts.Validate(); err != nil {
@@ -384,6 +391,9 @@ func (r *RunCMD) Run(ctx *cliContext.Context) (result error) {
 	}
 	opts := []config.AppOption{
 		config.WithAddonHostOps(hostOps.Grants),
+		config.WithAddonHostDeny(hostOps.Deny),
+		config.WithAddonHostBlanket(blanket),
+		config.WithAddonHostUIGrantsLocked(!r.AddonHostUIGrants),
 		config.WithProxyAPIKeyEnvLookup(os.Getenv),
 		config.WithContext(runCtx),
 		config.WithArtifactDownloadConcurrency(r.ArtifactDownloadConcurrency),
diff --git a/core/cli/run_addon_host_ops_test.go b/core/cli/run_addon_host_ops_test.go
index 278ce73baa..27dd31543b 100644
--- a/core/cli/run_addon_host_ops_test.go
+++ b/core/cli/run_addon_host_ops_test.go
@@ -36,7 +36,7 @@ var _ = Describe("addon host policy CLI precedence", Serial, func() {
 		return &command.Run
 	}
 	BeforeEach(func() {
-		for _, key := range []string{"LOCALAI_ADDON_HOST_OPS", "LOCALAI_ADDON_HOST_POLICY"} {
+		for _, key := range []string{"LOCALAI_ADDON_HOST_OPS", "LOCALAI_ADDON_HOST_POLICY", "LOCALAI_ADDON_HOST_DENY"} {
 			old, ok := os.LookupEnv(key)
 			DeferCleanup(func() {
 				if ok {
@@ -57,31 +57,66 @@ var _ = Describe("addon host policy CLI precedence", Serial, func() {
 		Expect(got.Source).To(Equal("policy:" + p))
 		Expect(got.Grants).To(Equal(map[string][]string{"custom": {"workspace."}}))
 	})
-	It("uses flag presence even when empty and ignores an invalid policy", func() {
+	writePolicy := func(body string) string {
+		p := filepath.Join(GinkgoT().TempDir(), "policy.json")
+		Expect(os.WriteFile(p, []byte(body), 0600)).To(Succeed())
+		return p
+	}
+	It("uses flag presence even when empty, ignores the file grants and still applies its deny", func() {
 		GinkgoT().Setenv("LOCALAI_ADDON_HOST_OPS", "env=x.")
-		GinkgoT().Setenv("LOCALAI_ADDON_HOST_POLICY", "/missing/policy")
+		GinkgoT().Setenv("LOCALAI_ADDON_HOST_POLICY", writePolicy(`{"schemaVersion":2,"grants":{"file":["z."]},"deny":{"*":["egress."]}}`))
 		got, err := parse("--addon-host-ops=").resolveAddonHostOps()
 		Expect(err).NotTo(HaveOccurred())
 		Expect(got.Grants).To(BeEmpty())
 		Expect(got.Source).To(Equal("flag"))
-		Expect(got.PolicyIgnored).To(BeTrue())
+		Expect(got.GrantsIgnored).To(BeTrue())
+		Expect(got.Deny).To(Equal(map[string][]string{"*": {"egress."}}))
 	})
-	It("uses explicit empty environment instead of policy", func() {
+	It("uses explicit empty environment instead of file grants and still applies its deny", func() {
 		GinkgoT().Setenv("LOCALAI_ADDON_HOST_OPS", "")
-		GinkgoT().Setenv("LOCALAI_ADDON_HOST_POLICY", "/missing/policy")
+		GinkgoT().Setenv("LOCALAI_ADDON_HOST_POLICY", writePolicy(`{"schemaVersion":2,"deny":{"a":["*"]}}`))
 		got, err := parse().resolveAddonHostOps()
 		Expect(err).NotTo(HaveOccurred())
 		Expect(got.Grants).To(BeEmpty())
 		Expect(got.Source).To(Equal("environment"))
-		Expect(got.PolicyIgnored).To(BeTrue())
+		Expect(got.GrantsIgnored).To(BeTrue())
+		Expect(got.Deny).To(Equal(map[string][]string{"a": {"*"}}))
 	})
-	It("does not union a nonempty flag with environment or policy", func() {
-		GinkgoT().Setenv("LOCALAI_ADDON_HOST_OPS", "env=x.")
+	It("stops startup on an invalid selected file even when a flat list replaces its grants", func() {
 		GinkgoT().Setenv("LOCALAI_ADDON_HOST_POLICY", "/missing/policy")
+		_, err := parse("--addon-host-ops=flag=y.").resolveAddonHostOps()
+		Expect(err).To(HaveOccurred())
+	})
+	It("does not union a nonempty flag with the file grants", func() {
+		GinkgoT().Setenv("LOCALAI_ADDON_HOST_OPS", "env=x.")
+		GinkgoT().Setenv("LOCALAI_ADDON_HOST_POLICY", writePolicy(`{"schemaVersion":1,"grants":{"file":["z."]}}`))
 		got, err := parse("--addon-host-ops=flag=y.").resolveAddonHostOps()
 		Expect(err).NotTo(HaveOccurred())
 		Expect(got.Grants).To(Equal(map[string][]string{"flag": {"y."}}))
 	})
+	It("unions the deny flag with the file deny", func() {
+		got, err := parse("--addon-host-policy="+writePolicy(`{"schemaVersion":2,"deny":{"web":["workspace.admin"]}}`), "--addon-host-deny=web=egress.").resolveAddonHostOps()
+		Expect(err).NotTo(HaveOccurred())
+		Expect(got.Deny).To(Equal(map[string][]string{"web": {"workspace.admin", "egress."}}))
+	})
+	It("reads the deny environment variable", func() {
+		GinkgoT().Setenv("LOCALAI_ADDON_HOST_DENY", "*=connector.")
+		got, err := parse("--addon-host-policy=" + writePolicy(`{"schemaVersion":2,"deny":{"web":["workspace.admin"]}}`)).resolveAddonHostOps()
+		Expect(err).NotTo(HaveOccurred())
+		Expect(got.Deny).To(Equal(map[string][]string{"web": {"workspace.admin"}, "*": {"connector."}}))
+	})
+	It("rejects an invalid deny flag and blanket mode", func() {
+		_, err := parse("--addon-host-deny=nonsense").resolveAddonHostOps()
+		Expect(err).To(HaveOccurred())
+		_, err = config.ParseAddonHostBlanket("sometimes")
+		Expect(err).To(HaveOccurred())
+	})
+	It("leaves UI grants on and the blanket unset by default", func() {
+		r := parse()
+		Expect(r.AddonHostUIGrants).To(BeTrue())
+		Expect(r.AddonHostBlanket).To(BeEmpty())
+		Expect(parse("--addon-host-ui-grants=false").AddonHostUIGrants).To(BeFalse())
+	})
 	It("lets an empty policy flag disable environment policy without restoring defaults", func() {
 		GinkgoT().Setenv("LOCALAI_ADDON_HOST_POLICY", "/missing/policy")
 		got, err := parse("--addon-host-policy=").resolveAddonHostOps()
diff --git a/core/cli/run_addon_host_policy.go b/core/cli/run_addon_host_policy.go
index 8ea389d6bb..7c435cedc5 100644
--- a/core/cli/run_addon_host_policy.go
+++ b/core/cli/run_addon_host_policy.go
@@ -41,7 +41,13 @@ func (r *RunCMD) resolveAddonHostOps() (config.AddonHostOpsResolution, error) {
 	} else if value, present := os.LookupEnv("LOCALAI_ADDON_HOST_POLICY"); present {
 		policy = &value
 	}
-	resolved, err := config.ResolveAddonHostOps(flag, environment, policy)
+	var deny *string
+	if r.AddonHostDeny != "" {
+		deny = &r.AddonHostDeny
+	}
+	// Kong has already merged the deny environment variable into the field,
+	// so there is no separate environment value to union.
+	resolved, err := config.ResolveAddonHostOps(flag, environment, policy, deny, nil)
 	if err == nil && resolved.Source == "policy" {
 		resolved.Source = "policy:" + *policy
 	}
@@ -50,15 +56,19 @@ func (r *RunCMD) resolveAddonHostOps() (config.AddonHostOpsResolution, error) {
 
 func logAddonHostOpsResolution(resolved config.AddonHostOpsResolution) {
 	if resolved.Source == "empty" {
-		xlog.Warn("Addons receive no host operations: select --addon-host-policy or explicitly configure --addon-host-ops")
+		xlog.Warn("Addons receive no host operations from the policy file or flags: an administrator can grant them in the UI at install, or select --addon-host-policy or --addon-host-ops")
 	}
 	prefixes := 0
 	for _, grants := range resolved.Grants {
 		prefixes += len(grants)
 	}
-	xlog.Info("Addon host operation policy resolved", "source", resolved.Source, "addons", len(resolved.Grants), "prefixes", prefixes)
-	if resolved.PolicyIgnored {
-		xlog.Warn("Addon host policy ignored: explicit host operations override takes precedence")
+	denied := 0
+	for _, entries := range resolved.Deny {
+		denied += len(entries)
 	}
-	xlog.Info("Addon manifests and libraries cannot grant host operations; policy changes require restart")
+	xlog.Info("Addon host operation policy resolved", "source", resolved.Source, "addons", len(resolved.Grants), "prefixes", prefixes, "denyRules", denied)
+	if resolved.GrantsIgnored {
+		xlog.Warn("Addon host policy grants ignored, deny applied: an explicit host operations list replaces the file grants")
+	}
+	xlog.Info("Addon manifests and libraries cannot grant host operations; file and flag policy changes require restart")
 }
diff --git a/core/config/addon_host_ops.go b/core/config/addon_host_ops.go
index 239587131d..4a8a2345a6 100644
--- a/core/config/addon_host_ops.go
+++ b/core/config/addon_host_ops.go
@@ -4,12 +4,14 @@ package config
 import (
 	"fmt"
 	"regexp"
+	"slices"
 	"strings"
 )
 
 var (
 	addonIDForHostOps = regexp.MustCompile(`^[a-z0-9][a-z0-9-]*$`)
 	hostOpPrefix      = regexp.MustCompile(`^[a-z]+\.([a-z]+\.)*$`)
+	hostOpExact       = regexp.MustCompile(`^[a-z]+(\.[a-z]+)+$`)
 )
 
 // ParseAddonHostOps reads a comma list of addon-id=op-prefix pairs. An add-on
@@ -38,3 +40,94 @@ func WithAddonHostOps(ops map[string][]string) AppOption {
 	snapshot := CloneAddonHostOps(ops)
 	return func(o *ApplicationConfig) { o.AddonHostOps = CloneAddonHostOps(snapshot) }
 }
+
+// validDenyEntry accepts what a deny rule may name: a prefix (workspace.),
+// one exact operation (workspace.admin) or the single token "*".
+func validDenyEntry(s string) bool {
+	return s == "*" || hostOpPrefix.MatchString(s) || hostOpExact.MatchString(s)
+}
+
+// ParseAddonHostDeny reads a comma list of addon-id=entry pairs, where addon-id
+// may be "*" for every add-on and entry is a prefix, an exact operation name
+// or "*". Duplicates are errors; "*" must be the only entry of its add-on.
+func ParseAddonHostDeny(s string) (map[string][]string, error) {
+	out := map[string][]string{}
+	for _, item := range strings.Split(s, ",") {
+		item = strings.TrimSpace(item)
+		if item == "" {
+			continue
+		}
+		id, entry, ok := strings.Cut(item, "=")
+		id, entry = strings.TrimSpace(id), strings.TrimSpace(entry)
+		if !ok || !(id == "*" || addonIDForHostOps.MatchString(id)) || !validDenyEntry(entry) {
+			return nil, fmt.Errorf("invalid host deny entry %q: want addon-id=op-prefix or *=op-prefix, such as *=egress. or custom-addon=*", item)
+		}
+		for _, existing := range out[id] {
+			if existing == entry {
+				return nil, fmt.Errorf("duplicate host deny entry %q", item)
+			}
+		}
+		out[id] = append(out[id], entry)
+	}
+	if len(out) > 128 {
+		return nil, fmt.Errorf("host deny exceeds 128 addons")
+	}
+	for id, entries := range out {
+		if len(entries) > 32 {
+			return nil, fmt.Errorf("host deny exceeds 32 entries for %q", id)
+		}
+		for _, e := range entries {
+			if e == "*" && len(entries) != 1 {
+				return nil, fmt.Errorf(`host deny "*" must be the only entry of %q`, id)
+			}
+		}
+	}
+	return out, nil
+}
+
+// MergeAddonHostDeny unions deny maps. Entries stay in first-seen order and a
+// "*" absorbs every other entry of its key. The result is never nil.
+func MergeAddonHostDeny(maps ...map[string][]string) map[string][]string {
+	out := map[string][]string{}
+	for _, m := range maps {
+		for id, entries := range m {
+			for _, e := range entries {
+				if !slices.Contains(out[id], e) {
+					out[id] = append(out[id], e)
+				}
+			}
+		}
+	}
+	for id, entries := range out {
+		if slices.Contains(entries, "*") {
+			out[id] = []string{"*"}
+		}
+	}
+	return out
+}
+
+// ParseAddonHostBlanket validates the deployment blanket mode. The empty
+// string means the deployment does not set it and the UI decides.
+func ParseAddonHostBlanket(s string) (string, error) {
+	switch s = strings.TrimSpace(s); s {
+	case "", "off", "official", "any":
+		return s, nil
+	}
+	return "", fmt.Errorf("invalid --addon-host-blanket %q: want off, official or any", s)
+}
+
+// WithAddonHostDeny sets the startup deny rules. The map is copied.
+func WithAddonHostDeny(deny map[string][]string) AppOption {
+	snapshot := CloneAddonHostOps(deny)
+	return func(o *ApplicationConfig) { o.AddonHostDeny = CloneAddonHostOps(snapshot) }
+}
+
+// WithAddonHostBlanket sets the deployment blanket mode ("" leaves it to the UI).
+func WithAddonHostBlanket(mode string) AppOption {
+	return func(o *ApplicationConfig) { o.AddonHostBlanket = mode }
+}
+
+// WithAddonHostUIGrantsLocked makes the UI grant store read-only.
+func WithAddonHostUIGrantsLocked(locked bool) AppOption {
+	return func(o *ApplicationConfig) { o.AddonHostUIGrantsLocked = locked }
+}
diff --git a/core/config/addon_host_policy.go b/core/config/addon_host_policy.go
index 8812950092..7e8ade0703 100644
--- a/core/config/addon_host_policy.go
+++ b/core/config/addon_host_policy.go
@@ -12,19 +12,33 @@ import (
 
 const maxAddonHostPolicyBytes = 64 * 1024
 
-// AddonHostOpsResolution is a startup snapshot. Consumers must not mutate Grants.
-// Source and PolicyIgnored are bounded diagnostics, never policy file contents.
+// AddonHostOpsResolution is a startup snapshot. Consumers must not mutate
+// Grants or Deny. Source and GrantsIgnored are bounded diagnostics, never
+// policy file contents.
 type AddonHostOpsResolution struct {
-	Grants        map[string][]string
-	Source        string
-	PolicyIgnored bool
+	Grants map[string][]string
+	// Deny is the union of the deny rules of the selected policy file, the
+	// --addon-host-deny flag and its environment variable. Keys are add-on
+	// IDs or "*". Values are prefixes, exact operation names or the single
+	// token "*".
+	Deny   map[string][]string
+	Source string
+	// GrantsIgnored is true when a selected policy file had its grants
+	// replaced by a flat --addon-host-ops list. Its deny rules still apply.
+	GrantsIgnored bool
 }
 
-// ResolveAddonHostOps applies presence-based precedence. Nil means absent;
-// a pointer to an empty string is an explicit decision to grant nothing.
-// policyPath is already selected by the caller (flag, including empty, over env).
-func ResolveAddonHostOps(flag, environment, policyPath *string) (AddonHostOpsResolution, error) {
-	out := AddonHostOpsResolution{Grants: map[string][]string{}, Source: "empty"}
+// ResolveAddonHostOps applies presence-based precedence to grants. Nil means
+// absent; a pointer to an empty string is an explicit decision to grant
+// nothing. policyPath is already selected by the caller (flag, including
+// empty, over env).
+//
+// A selected policy file is always opened, because its deny rules must
+// survive a flat grants list: a deny that disappears when someone adds a flag
+// is a security failure. Deny rules from the file, denyFlag and denyEnv are
+// unioned.
+func ResolveAddonHostOps(flag, environment, policyPath, denyFlag, denyEnv *string) (AddonHostOpsResolution, error) {
+	out := AddonHostOpsResolution{Grants: map[string][]string{}, Deny: map[string][]string{}, Source: "empty"}
 	selected := flag
 	if selected != nil {
 		out.Source = "flag"
@@ -33,62 +47,104 @@ func ResolveAddonHostOps(flag, environment, policyPath *string) (AddonHostOpsRes
 		out.Source = "environment"
 	}
 	var err error
+	var file AddonHostPolicy
+	filePresent := policyPath != nil && *policyPath != ""
+	if filePresent {
+		file, err = LoadAddonHostPolicyFile(*policyPath)
+		if err != nil {
+			if out.Source == "empty" {
+				out.Source = "policy"
+			}
+			return out, fmt.Errorf("addon host operations (%s): %w", out.Source, err)
+		}
+	}
 	if selected != nil {
-		out.PolicyIgnored = policyPath != nil && *policyPath != ""
+		out.GrantsIgnored = filePresent
 		out.Grants, err = ParseAddonHostOps(*selected)
-	} else if policyPath != nil && *policyPath != "" {
+	} else if filePresent {
 		out.Source = "policy"
-		out.Grants, err = LoadAddonHostPolicy(*policyPath)
+		out.Grants = file.Grants
 	}
 	if err != nil {
 		return out, fmt.Errorf("addon host operations (%s): %w", out.Source, err)
 	}
+	out.Deny = MergeAddonHostDeny(file.Deny)
+	for _, raw := range []*string{denyFlag, denyEnv} {
+		if raw == nil {
+			continue
+		}
+		parsed, perr := ParseAddonHostDeny(*raw)
+		if perr != nil {
+			return out, fmt.Errorf("addon host deny: %w", perr)
+		}
+		out.Deny = MergeAddonHostDeny(out.Deny, parsed)
+	}
 	return out, nil
 }
 
-// LoadAddonHostPolicy reads only an explicitly selected administrator file.
+// AddonHostPolicy is the decoded content of a policy file.
+type AddonHostPolicy struct {
+	SchemaVersion int
+	Grants        map[string][]string
+	Deny          map[string][]string
+}
+
+// LoadAddonHostPolicy reads a policy file and returns only its grants. It
+// remains for callers that predate the deny list.
+func LoadAddonHostPolicy(path string) (map[string][]string, error) {
+	p, err := LoadAddonHostPolicyFile(path)
+	return p.Grants, err
+}
+
+// LoadAddonHostPolicyFile reads only an explicitly selected administrator file.
 // Ownership and mount permissions are the deployment administrator's responsibility.
 // Symlinks to regular files are permitted; this is not a filesystem sandbox.
-func LoadAddonHostPolicy(path string) (map[string][]string, error) {
+func LoadAddonHostPolicyFile(path string) (AddonHostPolicy, error) {
 	if !filepath.IsAbs(path) {
-		return nil, fmt.Errorf("policy path must be absolute")
+		return AddonHostPolicy{}, fmt.Errorf("policy path must be absolute")
 	}
 	// Stat before opening rejects directories and special files (including FIFOs)
 	// without a potentially blocking read. Recheck the opened descriptor as well.
 	info, err := os.Stat(path)
 	if err != nil {
-		return nil, fmt.Errorf("stat policy: %w", err)
+		return AddonHostPolicy{}, fmt.Errorf("stat policy: %w", err)
 	}
 	if !info.Mode().IsRegular() {
-		return nil, fmt.Errorf("policy must be a regular file")
+		return AddonHostPolicy{}, fmt.Errorf("policy must be a regular file")
 	}
 	// #nosec G304 -- Only the administrator selects this startup policy path via CLI/config; regular-file and 64 KiB checks bound its read.
 	f, err := os.Open(path)
 	if err != nil {
-		return nil, fmt.Errorf("open policy: %w", err)
+		return AddonHostPolicy{}, fmt.Errorf("open policy: %w", err)
 	}
 	// Read-only cleanup: close errors cannot change the decoded result.
 	defer func() { _ = f.Close() }()
 	info, err = f.Stat()
 	if err != nil {
-		return nil, fmt.Errorf("stat opened policy: %w", err)
+		return AddonHostPolicy{}, fmt.Errorf("stat opened policy: %w", err)
 	}
 	if !info.Mode().IsRegular() || info.Size() > maxAddonHostPolicyBytes {
-		return nil, fmt.Errorf("policy must be a regular file of at most 64 KiB")
+		return AddonHostPolicy{}, fmt.Errorf("policy must be a regular file of at most 64 KiB")
 	}
 	data, err := io.ReadAll(io.LimitReader(f, maxAddonHostPolicyBytes+1))
 	if err != nil {
-		return nil, fmt.Errorf("read policy: %w", err)
+		return AddonHostPolicy{}, fmt.Errorf("read policy: %w", err)
 	}
 	if len(data) > maxAddonHostPolicyBytes {
-		return nil, fmt.Errorf("policy exceeds 64 KiB")
+		return AddonHostPolicy{}, fmt.Errorf("policy exceeds 64 KiB")
 	}
 	return parseAddonHostPolicy(data)
 }
 
+// Policy file schema versions this binary reads.
+const (
+	addonHostPolicyV1 = 1
+	addonHostPolicyV2 = 2
+)
+
 // Token decoding deliberately avoids encoding/json struct-field case folding
 // and map decoding's last-key-wins behavior.
-func parseAddonHostPolicy(data []byte) (map[string][]string, error) {
+func parseAddonHostPolicy(data []byte) (AddonHostPolicy, error) {
 	d := json.NewDecoder(bytes.NewReader(data))
 	d.UseNumber()
 	expect := func(want json.Delim) error {
@@ -101,91 +157,127 @@ func parseAddonHostPolicy(data []byte) (map[string][]string, error) {
 		}
 		return nil
 	}
+	fail := func(err error) (AddonHostPolicy, error) { return AddonHostPolicy{}, err }
 	if err := expect('{'); err != nil {
-		return nil, err
+		return fail(err)
 	}
 	seen := map[string]bool{}
-	grants := map[string][]string{}
+	out := AddonHostPolicy{Grants: map[string][]string{}, Deny: map[string][]string{}}
 	for d.More() {
 		key, err := d.Token()
 		if err != nil {
-			return nil, err
+			return fail(err)
 		}
 		name, ok := key.(string)
 		if !ok || seen[name] {
-			return nil, fmt.Errorf("duplicate or invalid policy key")
+			return fail(fmt.Errorf("duplicate or invalid policy key"))
 		}
 		seen[name] = true
 		switch name {
 		case "schemaVersion":
 			version, err := d.Token()
 			if err != nil {
-				return nil, err
+				return fail(err)
 			}
-			if version != json.Number("1") {
-				return nil, fmt.Errorf("schemaVersion must be integer 1")
+			n, isNumber := version.(json.Number)
+			v, convErr := n.Int64()
+			switch {
+			case !isNumber || convErr != nil || v < addonHostPolicyV1:
+				return fail(fmt.Errorf("schemaVersion must be an integer (supported versions: 1, 2)"))
+			case v > addonHostPolicyV2:
+				return fail(fmt.Errorf("policy requires a newer LocalAI (supported versions: 1, 2)"))
 			}
+			out.SchemaVersion = int(v)
 		case "grants":
-			if err := expect('{'); err != nil {
-				return nil, err
+			m, err := readHostOpMap(d, expect, hostOpPrefix.MatchString, false)
+			if err != nil {
+				return fail(err)
 			}
-			for d.More() {
-				token, err := d.Token()
-				if err != nil {
-					return nil, err
-				}
-				id, ok := token.(string)
-				if !ok || !addonIDForHostOps.MatchString(id) {
-					return nil, fmt.Errorf("invalid policy addon ID")
-				}
-				if _, exists := grants[id]; exists {
-					return nil, fmt.Errorf("duplicate policy addon ID")
-				}
-				if len(grants) >= 128 {
-					return nil, fmt.Errorf("policy exceeds 128 addons")
-				}
-				if err := expect('['); err != nil {
-					return nil, err
-				}
-				prefixes := []string{}
-				seenPrefixes := map[string]bool{}
-				for d.More() {
-					token, err := d.Token()
-					if err != nil {
-						return nil, err
-					}
-					prefix, ok := token.(string)
-					if !ok || !hostOpPrefix.MatchString(prefix) || seenPrefixes[prefix] {
-						return nil, fmt.Errorf("invalid or duplicate policy prefix")
-					}
-					if len(prefixes) >= 32 {
-						return nil, fmt.Errorf("policy exceeds 32 prefixes per addon")
-					}
-					prefixes = append(prefixes, prefix)
-					seenPrefixes[prefix] = true
-				}
-				if err := expect(']'); err != nil {
-					return nil, err
-				}
-				grants[id] = prefixes
-			}
-			if err := expect('}'); err != nil {
-				return nil, err
+			out.Grants = m
+		case "deny":
+			m, err := readHostOpMap(d, expect, validDenyEntry, true)
+			if err != nil {
+				return fail(err)
 			}
+			out.Deny = m
 		default:
-			return nil, fmt.Errorf("unknown policy key")
+			return fail(fmt.Errorf("unknown policy key"))
 		}
 	}
+	if err := expect('}'); err != nil {
+		return fail(err)
+	}
+	if !seen["schemaVersion"] {
+		return fail(fmt.Errorf("policy requires schemaVersion"))
+	}
+	if out.SchemaVersion == addonHostPolicyV1 {
+		if seen["deny"] {
+			return fail(fmt.Errorf("deny requires schemaVersion 2"))
+		}
+		if !seen["grants"] {
+			return fail(fmt.Errorf("policy requires schemaVersion and grants"))
+		}
+	}
+	if _, err := d.Token(); err != io.EOF {
+		return fail(fmt.Errorf("unexpected trailing policy data"))
+	}
+	return out, nil
+}
+
+// readHostOpMap reads {"id": ["entry", ...]}. For a deny map the key "*" is
+// valid and the entry "*" must stand alone.
+func readHostOpMap(d *json.Decoder, expect func(json.Delim) error, validEntry func(string) bool, deny bool) (map[string][]string, error) {
+	if err := expect('{'); err != nil {
+		return nil, err
+	}
+	out := map[string][]string{}
+	for d.More() {
+		token, err := d.Token()
+		if err != nil {
+			return nil, err
+		}
+		id, ok := token.(string)
+		if !ok || !(addonIDForHostOps.MatchString(id) || (deny && id == "*")) {
+			return nil, fmt.Errorf("invalid policy addon ID")
+		}
+		if _, exists := out[id]; exists {
+			return nil, fmt.Errorf("duplicate policy addon ID")
+		}
+		if len(out) >= 128 {
+			return nil, fmt.Errorf("policy exceeds 128 addons")
+		}
+		if err := expect('['); err != nil {
+			return nil, err
+		}
+		entries := []string{}
+		seenEntries := map[string]bool{}
+		for d.More() {
+			token, err := d.Token()
+			if err != nil {
+				return nil, err
+			}
+			entry, ok := token.(string)
+			if !ok || !validEntry(entry) || seenEntries[entry] {
+				return nil, fmt.Errorf("invalid or duplicate policy prefix")
+			}
+			if len(entries) >= 32 {
+				return nil, fmt.Errorf("policy exceeds 32 prefixes per addon")
+			}
+			entries = append(entries, entry)
+			seenEntries[entry] = true
+		}
+		if err := expect(']'); err != nil {
+			return nil, err
+		}
+		if seenEntries["*"] && len(entries) != 1 {
+			return nil, fmt.Errorf(`policy deny "*" must be the only entry of its list`)
+		}
+		out[id] = entries
+	}
 	if err := expect('}'); err != nil {
 		return nil, err
 	}
-	if !seen["schemaVersion"] || !seen["grants"] {
-		return nil, fmt.Errorf("policy requires schemaVersion and grants")
-	}
-	if _, err := d.Token(); err != io.EOF {
-		return nil, fmt.Errorf("unexpected trailing policy data")
-	}
-	return grants, nil
+	return out, nil
 }
 
 // CloneAddonHostOps isolates startup grants from caller-owned maps and slices.
diff --git a/core/config/addon_host_policy_test.go b/core/config/addon_host_policy_test.go
index e548bbc86e..a8aa9a304c 100644
--- a/core/config/addon_host_policy_test.go
+++ b/core/config/addon_host_policy_test.go
@@ -33,7 +33,8 @@ var _ = Describe("Addon host policy", func() {
 		Entry("missing grants", `{"schemaVersion":1}`),
 		Entry("null grants", `{"schemaVersion":1,"grants":null}`),
 		Entry("null prefixes", `{"schemaVersion":1,"grants":{"a":null}}`),
-		Entry("wrong version", `{"schemaVersion":2,"grants":{}}`),
+		Entry("version 3", `{"schemaVersion":3,"grants":{}}`),
+		Entry("version 0", `{"schemaVersion":0,"grants":{}}`),
 		Entry("string version", `{"schemaVersion":"1","grants":{}}`),
 		Entry("fraction version", `{"schemaVersion":1.0,"grants":{}}`),
 		Entry("unknown key", `{"schemaVersion":1,"grants":{},"extra":true}`),
@@ -97,9 +98,9 @@ var _ = Describe("Addon host policy", func() {
 		_, err = LoadAddonHostPolicy(write(`{"schemaVersion":1,"grants":{"a":[` + strings.Join(prefixes, ",") + `]}}`))
 		Expect(err).To(HaveOccurred())
 	})
-	It("resolves presence without union or opening an ignored policy", func() {
+	It("resolves presence without union, always opening the selected policy", func() {
 		empty, env, flag := "", "env=x.", "flag=y."
-		bad := "/not-present-policy.json"
+		bad := write(`{"schemaVersion":2,"grants":{"unused":["q."]},"deny":{"*":["egress."]}}`)
 		policy := write(`{"schemaVersion":1,"grants":{"file":["z."]}}`)
 		for _, tc := range []struct {
 			flag, env, policy *string
@@ -115,14 +116,17 @@ var _ = Describe("Addon host policy", func() {
 			{nil, &empty, &bad, map[string][]string{}, "environment", true},
 			{nil, nil, &empty, map[string][]string{}, "empty", false},
 		} {
-			got, err := ResolveAddonHostOps(tc.flag, tc.env, tc.policy)
+			got, err := ResolveAddonHostOps(tc.flag, tc.env, tc.policy, nil, nil)
 			Expect(err).NotTo(HaveOccurred())
 			Expect(got.Grants).To(Equal(tc.want))
 			Expect(got.Source).To(Equal(tc.source))
-			Expect(got.PolicyIgnored).To(Equal(tc.ignored))
+			Expect(got.GrantsIgnored).To(Equal(tc.ignored))
 		}
-		_, err := ResolveAddonHostOps(nil, nil, &bad)
+		missing := "/not-present-policy.json"
+		_, err := ResolveAddonHostOps(nil, nil, &missing, nil, nil)
 		Expect(err).To(HaveOccurred())
+		_, err = ResolveAddonHostOps(&flag, nil, &missing, nil, nil)
+		Expect(err).To(HaveOccurred(), "an invalid selected file stops startup even when a flat list replaces its grants")
 	})
 	It("snapshots programmatic grants including an exact empty decision", func() {
 		original := map[string][]string{"a": {"x."}}
@@ -138,4 +142,88 @@ var _ = Describe("Addon host policy", func() {
 		WithAddonHostOps(map[string][]string{})(c)
 		Expect(c.AddonHostOps).To(BeEmpty())
 	})
+
+	Describe("schemaVersion 2 and the deny list", func() {
+		It("reads grants and deny, and accepts a deny-only file", func() {
+			p, err := LoadAddonHostPolicyFile(write(`{"schemaVersion":2,"grants":{"sandbox":["workspace.","egress."]},"deny":{"*":["connector."],"web":["workspace.admin"],"telegram":["*"]}}`))
+			Expect(err).NotTo(HaveOccurred())
+			Expect(p.Grants).To(Equal(map[string][]string{"sandbox": {"workspace.", "egress."}}))
+			Expect(p.Deny).To(Equal(map[string][]string{"*": {"connector."}, "web": {"workspace.admin"}, "telegram": {"*"}}))
+			p, err = LoadAddonHostPolicyFile(write(`{"schemaVersion":2,"deny":{"*":["egress."]}}`))
+			Expect(err).NotTo(HaveOccurred())
+			Expect(p.Grants).To(BeEmpty())
+			Expect(p.Deny).To(HaveLen(1))
+		})
+		DescribeTable("rejects", func(body, message string) {
+			_, err := LoadAddonHostPolicyFile(write(body))
+			Expect(err).To(MatchError(ContainSubstring(message)))
+		},
+			Entry("deny in a v1 file", `{"schemaVersion":1,"grants":{},"deny":{}}`, "deny requires schemaVersion 2"),
+			Entry("deny before the version in a v1 file", `{"deny":{},"schemaVersion":1,"grants":{}}`, "deny requires schemaVersion 2"),
+			Entry("v1 without grants", `{"schemaVersion":1}`, "requires schemaVersion and grants"),
+			Entry("version 3", `{"schemaVersion":3,"grants":{}}`, "requires a newer LocalAI"),
+			Entry("a version that is not an integer", `{"schemaVersion":"2","grants":{}}`, "supported versions: 1, 2"),
+			Entry("a missing version", `{"grants":{}}`, "requires schemaVersion"),
+			Entry("duplicate deny key", `{"schemaVersion":2,"deny":{},"deny":{}}`, "duplicate"),
+			Entry("duplicate deny add-on", `{"schemaVersion":2,"deny":{"a":["x."],"a":["y."]}}`, "duplicate"),
+			Entry("duplicate deny entry", `{"schemaVersion":2,"deny":{"a":["x.","x."]}}`, "duplicate"),
+			Entry("star next to another entry", `{"schemaVersion":2,"deny":{"a":["*","x."]}}`, "only entry"),
+			Entry("star as a grants key", `{"schemaVersion":2,"grants":{"*":["x."]}}`, "invalid policy addon ID"),
+			Entry("star as a grant", `{"schemaVersion":2,"grants":{"a":["*"]}}`, "invalid"),
+			Entry("a bad deny entry", `{"schemaVersion":2,"deny":{"a":["X."]}}`, "invalid"),
+			Entry("a bad deny key", `{"schemaVersion":2,"deny":{"A":["x."]}}`, "invalid policy addon ID"),
+			Entry("null deny", `{"schemaVersion":2,"deny":null}`, "expected"),
+			Entry("unknown key in v2", `{"schemaVersion":2,"grant":{}}`, "unknown policy key"),
+			Entry("trailing data", `{"schemaVersion":2,"deny":{}} {}`, "trailing"),
+		)
+		It("bounds the deny list", func() {
+			ids := []string{}
+			for i := 0; i < 129; i++ {
+				ids = append(ids, fmt.Sprintf(`"a-%d":["x."]`, i))
+			}
+			_, err := LoadAddonHostPolicyFile(write(`{"schemaVersion":2,"deny":{` + strings.Join(ids[:128], ",") + `}}`))
+			Expect(err).NotTo(HaveOccurred())
+			_, err = LoadAddonHostPolicyFile(write(`{"schemaVersion":2,"deny":{` + strings.Join(ids, ",") + `}}`))
+			Expect(err).To(HaveOccurred())
+			entries := []string{}
+			for i := 0; i < 33; i++ {
+				entries = append(entries, fmt.Sprintf(`"x.%s."`, string(rune('a'+i/26))+string(rune('a'+i%26))))
+			}
+			_, err = LoadAddonHostPolicyFile(write(`{"schemaVersion":2,"deny":{"a":[` + strings.Join(entries[:32], ",") + `]}}`))
+			Expect(err).NotTo(HaveOccurred())
+			_, err = LoadAddonHostPolicyFile(write(`{"schemaVersion":2,"deny":{"a":[` + strings.Join(entries, ",") + `]}}`))
+			Expect(err).To(HaveOccurred())
+		})
+		It("keeps the 64 KiB file limit", func() {
+			body := `{"schemaVersion":2,"deny":{}}`
+			_, err := LoadAddonHostPolicyFile(write(body + strings.Repeat(" ", 65537-len(body))))
+			Expect(err).To(HaveOccurred())
+		})
+		It("parses the flag grammar and unions it with the file", func() {
+			got, err := ParseAddonHostDeny("*=egress., web=workspace.admin ,telegram=*")
+			Expect(err).NotTo(HaveOccurred())
+			Expect(got).To(Equal(map[string][]string{"*": {"egress."}, "web": {"workspace.admin"}, "telegram": {"*"}}))
+			Expect(ParseAddonHostDeny("")).To(BeEmpty())
+			for _, bad := range []string{"x", "a=", "A=x.", "a=X.", "a=x.,a=x.", "a=*,a=x.", "=x.", "a=workspace", "*=*,*=x."} {
+				_, err := ParseAddonHostDeny(bad)
+				Expect(err).To(HaveOccurred(), bad)
+			}
+			Expect(MergeAddonHostDeny(map[string][]string{"a": {"x."}}, map[string][]string{"a": {"x.", "y."}, "b": {"*"}})).
+				To(Equal(map[string][]string{"a": {"x.", "y."}, "b": {"*"}}))
+			Expect(MergeAddonHostDeny(map[string][]string{"a": {"x."}}, map[string][]string{"a": {"*"}})).
+				To(Equal(map[string][]string{"a": {"*"}}))
+		})
+		It("unions the file deny with the flag deny and applies it under a flat list", func() {
+			policy := write(`{"schemaVersion":2,"grants":{"f":["w."]},"deny":{"a":["x."]}}`)
+			ops, deny := "o=y.", "a=z.,*=*"
+			got, err := ResolveAddonHostOps(&ops, nil, &policy, &deny, nil)
+			Expect(err).NotTo(HaveOccurred())
+			Expect(got.Grants).To(Equal(map[string][]string{"o": {"y."}}))
+			Expect(got.GrantsIgnored).To(BeTrue())
+			Expect(got.Deny).To(Equal(map[string][]string{"a": {"x.", "z."}, "*": {"*"}}))
+			bad := "nonsense"
+			_, err = ResolveAddonHostOps(nil, nil, &policy, &bad, nil)
+			Expect(err).To(HaveOccurred())
+		})
+	})
 })
diff --git a/core/config/application_config.go b/core/config/application_config.go
index e9c4d13781..306fbe78f1 100644
--- a/core/config/application_config.go
+++ b/core/config/application_config.go
@@ -100,6 +100,16 @@ type ApplicationConfig struct {
 	// call. It is startup-only. Nil or empty means no add-on gets a host
 	// operation endpoint.
 	AddonHostOps map[string][]string `json:"-" yaml:"-"`
+	// AddonHostDeny maps an add-on ID, or "*" for all, to host operation
+	// prefixes, exact names or "*" that no grant may enable. Startup-only;
+	// deny set in the UI is stored separately and applies live.
+	AddonHostDeny map[string][]string `json:"-" yaml:"-"`
+	// AddonHostBlanket is the blanket approval mode set by the deployment
+	// ("off", "official", "any"). Empty leaves the choice to the UI.
+	AddonHostBlanket string `json:"-" yaml:"-"`
+	// AddonHostUIGrantsLocked makes the UI grant store read-only, so the
+	// policy file and flags are the only source of grants.
+	AddonHostUIGrantsLocked bool `json:"-" yaml:"-"`
 
 	// DiagnosticsRecorder is startup-only and local to this frontend process.
 	DiagnosticsRecorder *diagnostics.Recorder `json:"-" yaml:"-"`