fix(plugins): use size cap instead of wraparound check for CodeQL overflow warning

Check individual slice sizes against a 128 MiB cap before the addition,
so CodeQL can statically verify the sum cannot overflow.

cmd/root.go

@@ -14,10 +14,13 @@ import (
 	"github.com/navidrome/navidrome/db"
 	"github.com/navidrome/navidrome/log"
 	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/plugins"
 	"github.com/navidrome/navidrome/resources"
 	"github.com/navidrome/navidrome/scanner"
 	"github.com/navidrome/navidrome/scheduler"
+	"github.com/navidrome/navidrome/server"
 	"github.com/navidrome/navidrome/server/backgrounds"
+	"github.com/navidrome/navidrome/server/subsonic"
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
 	"golang.org/x/sync/errgroup"
@@ -138,6 +141,13 @@ func startServer(ctx context.Context) func() error {
 		if strings.HasPrefix(conf.Server.UILoginBackgroundURL, "/") {
 			a.MountRouter("Background images", conf.Server.UILoginBackgroundURL, backgrounds.NewHandler())
 		}
+		if conf.Server.Plugins.Enabled {
+			manager := GetPluginManager(ctx)
+			ds := CreateDataStore()
+			endpointRouter := plugins.NewEndpointRouter(manager, ds, subsonic.ValidateAuth, server.Authenticator)
+			a.MountRouter("Plugin Endpoints", consts.URLPathPluginEndpoints, endpointRouter)
+			a.MountRouter("Plugin Subsonic Endpoints", consts.URLPathPluginSubsonicEndpoints, endpointRouter)
+		}
 		return a.Run(ctx, conf.Server.Address, conf.Server.Port, conf.Server.TLSCert, conf.Server.TLSKey)
 	}
 }

conf/configuration.go

@@ -239,11 +239,13 @@ type inspectOptions struct {
 }
 
 type pluginsOptions struct {
-	Enabled    bool
-	Folder     string
-	CacheSize  string
-	AutoReload bool
-	LogLevel   string
+	Enabled               bool
+	Folder                string
+	CacheSize             string
+	AutoReload            bool
+	LogLevel              string
+	EndpointRequestLimit  int
+	EndpointRequestWindow time.Duration
 }
 
 type extAuthOptions struct {
@@ -671,6 +673,8 @@ func setViperDefaults() {
 	viper.SetDefault("plugins.enabled", true)
 	viper.SetDefault("plugins.cachesize", "200MB")
 	viper.SetDefault("plugins.autoreload", false)
+	viper.SetDefault("plugins.endpointrequestlimit", 60)
+	viper.SetDefault("plugins.endpointrequestwindow", time.Minute)
 
 	// DevFlags. These are used to enable/disable debugging and incomplete features
 	viper.SetDefault("devlogsourceline", false)

consts/consts.go

@@ -36,11 +36,13 @@ const (
 	DevInitialUserName = "admin"
 	DevInitialName     = "Dev Admin"
 
-	URLPathUI           = "/app"
-	URLPathNativeAPI    = "/api"
-	URLPathSubsonicAPI  = "/rest"
-	URLPathPublic       = "/share"
-	URLPathPublicImages = URLPathPublic + "/img"
+	URLPathUI                      = "/app"
+	URLPathNativeAPI               = "/api"
+	URLPathSubsonicAPI             = "/rest"
+	URLPathPluginEndpoints         = "/ext"
+	URLPathPluginSubsonicEndpoints = "/rest/ext"
+	URLPathPublic                  = "/share"
+	URLPathPublicImages            = URLPathPublic + "/img"
 
 	// DefaultUILoginBackgroundURL uses Navidrome curated background images collection,
 	// available at https://unsplash.com/collections/20072696/navidrome

plugins/capabilities/http_endpoint.go

@@ -0,0 +1,52 @@
+package capabilities
+
+// HTTPEndpoint allows plugins to handle incoming HTTP requests.
+// Plugins that declare the 'endpoints' permission must implement this capability.
+// The host dispatches incoming HTTP requests to the plugin's HandleRequest function.
+//
+//nd:capability name=httpendpoint required=true
+type HTTPEndpoint interface {
+	// HandleRequest processes an incoming HTTP request and returns a response.
+	//nd:export name=nd_http_handle_request raw=true
+	HandleRequest(HTTPHandleRequest) (HTTPHandleResponse, error)
+}
+
+// HTTPHandleRequest is the input provided when an HTTP request is dispatched to a plugin.
+type HTTPHandleRequest struct {
+	// Method is the HTTP method (GET, POST, PUT, DELETE, PATCH, etc.).
+	Method string `json:"method"`
+	// Path is the request path relative to the plugin's base URL.
+	// For example, if the full URL is /ext/my-plugin/webhook, Path is "/webhook".
+	// Both /ext/my-plugin and /ext/my-plugin/ are normalized to Path = "".
+	Path string `json:"path"`
+	// Query is the raw query string without the leading '?'.
+	Query string `json:"query,omitempty"`
+	// Headers contains the HTTP request headers.
+	Headers map[string][]string `json:"headers,omitempty"`
+	// Body is the request body content.
+	Body []byte `json:"body,omitempty"`
+	// User contains the authenticated user information. Nil for auth:"none" endpoints.
+	User *HTTPUser `json:"user,omitempty"`
+}
+
+// HTTPUser contains authenticated user information passed to the plugin.
+type HTTPUser struct {
+	// ID is the internal Navidrome user ID.
+	ID string `json:"id"`
+	// Username is the user's login name.
+	Username string `json:"username"`
+	// Name is the user's display name.
+	Name string `json:"name"`
+	// IsAdmin indicates whether the user has admin privileges.
+	IsAdmin bool `json:"isAdmin"`
+}
+
+// HTTPHandleResponse is the response returned by the plugin's HandleRequest function.
+type HTTPHandleResponse struct {
+	// Status is the HTTP status code. Defaults to 200 if zero or not set.
+	Status int32 `json:"status,omitempty"`
+	// Headers contains the HTTP response headers to set.
+	Headers map[string][]string `json:"headers,omitempty"`
+	// Body is the response body content.
+	Body []byte `json:"body,omitempty"`
+}

plugins/capabilities/http_endpoint.yaml

@@ -0,0 +1,81 @@
+version: v1-draft
+exports:
+    nd_http_handle_request:
+        description: HandleRequest processes an incoming HTTP request and returns a response.
+        input:
+            $ref: '#/components/schemas/HTTPHandleRequest'
+            contentType: application/json
+        output:
+            $ref: '#/components/schemas/HTTPHandleResponse'
+            contentType: application/json
+components:
+    schemas:
+        HTTPHandleRequest:
+            description: HTTPHandleRequest is the input provided when an HTTP request is dispatched to a plugin.
+            properties:
+                method:
+                    type: string
+                    description: Method is the HTTP method (GET, POST, PUT, DELETE, PATCH, etc.).
+                path:
+                    type: string
+                    description: |-
+                        Path is the request path relative to the plugin's base URL.
+                        For example, if the full URL is /ext/my-plugin/webhook, Path is "/webhook".
+                        Both /ext/my-plugin and /ext/my-plugin/ are normalized to Path = "".
+                query:
+                    type: string
+                    description: Query is the raw query string without the leading '?'.
+                headers:
+                    type: object
+                    description: Headers contains the HTTP request headers.
+                    additionalProperties:
+                        type: array
+                        items:
+                            type: string
+                body:
+                    type: buffer
+                    description: Body is the request body content.
+                user:
+                    $ref: '#/components/schemas/HTTPUser'
+                    description: User contains the authenticated user information. Nil for auth:"none" endpoints.
+                    nullable: true
+            required:
+                - method
+                - path
+        HTTPHandleResponse:
+            description: HTTPHandleResponse is the response returned by the plugin's HandleRequest function.
+            properties:
+                status:
+                    type: integer
+                    format: int32
+                    description: Status is the HTTP status code. Defaults to 200 if zero or not set.
+                headers:
+                    type: object
+                    description: Headers contains the HTTP response headers to set.
+                    additionalProperties:
+                        type: array
+                        items:
+                            type: string
+                body:
+                    type: buffer
+                    description: Body is the response body content.
+        HTTPUser:
+            description: HTTPUser contains authenticated user information passed to the plugin.
+            properties:
+                id:
+                    type: string
+                    description: ID is the internal Navidrome user ID.
+                username:
+                    type: string
+                    description: Username is the user's login name.
+                name:
+                    type: string
+                    description: Name is the user's display name.
+                isAdmin:
+                    type: boolean
+                    description: IsAdmin indicates whether the user has admin privileges.
+            required:
+                - id
+                - username
+                - name
+                - isAdmin

plugins/capability_http_endpoint.go

@@ -0,0 +1,14 @@
+package plugins
+
+// CapabilityHTTPEndpoint indicates the plugin can handle incoming HTTP requests.
+// Detected when the plugin exports the nd_http_handle_request function.
+const CapabilityHTTPEndpoint Capability = "HTTPEndpoint"
+
+const FuncHTTPHandleRequest = "nd_http_handle_request"
+
+func init() {
+	registerCapability(
+		CapabilityHTTPEndpoint,
+		FuncHTTPHandleRequest,
+	)
+}

plugins/cmd/ndpgen/internal/generator.go

@@ -364,6 +364,27 @@ func capabilityFuncMap(cap Capability) template.FuncMap {
 		"providerInterface": func(e Export) string { return e.ProviderInterfaceName() },
 		"implVar":           func(e Export) string { return e.ImplVarName() },
 		"exportFunc":        func(e Export) string { return e.ExportFuncName() },
+		"rawFieldName":      rawFieldName(cap),
+	}
+}
+
+// rawFieldName returns a template function that finds the first []byte field name
+// in a struct by type name. This is used by raw export templates to generate
+// field-specific binary frame code.
+func rawFieldName(cap Capability) func(string) string {
+	structMap := make(map[string]StructDef)
+	for _, s := range cap.Structs {
+		structMap[s.Name] = s
+	}
+	return func(typeName string) string {
+		if s, ok := structMap[typeName]; ok {
+			for _, f := range s.Fields {
+				if f.Type == "[]byte" {
+					return f.Name
+				}
+			}
+		}
+		return ""
 	}
 }
 
@@ -466,6 +487,7 @@ func rustCapabilityFuncMap(cap Capability) template.FuncMap {
 		"providerInterface":   func(e Export) string { return e.ProviderInterfaceName() },
 		"registerMacroName":   func(name string) string { return registerMacroName(cap.Name, name) },
 		"snakeCase":           ToSnakeCase,
+		"rawFieldName":        rawFieldName(cap),
 		"indent": func(spaces int, s string) string {
 			indent := strings.Repeat(" ", spaces)
 			lines := strings.Split(s, "\n")
@@ -560,9 +582,15 @@ func rustConstName(name string) string {
 
 // skipSerializingFunc returns the appropriate skip_serializing_if function name.
 func skipSerializingFunc(goType string) string {
-	if strings.HasPrefix(goType, "*") || strings.HasPrefix(goType, "[]") || strings.HasPrefix(goType, "map[") {
+	if goType == "[]byte" {
+		return "Vec::is_empty"
+	}
+	if strings.HasPrefix(goType, "*") || strings.HasPrefix(goType, "[]") {
 		return "Option::is_none"
 	}
+	if strings.HasPrefix(goType, "map[") {
+		return "HashMap::is_empty"
+	}
 	switch goType {
 	case "string":
 		return "String::is_empty"

plugins/cmd/ndpgen/internal/generator_test.go

@@ -1432,12 +1432,20 @@ type OnInitOutput struct {
 
 var _ = Describe("Rust Generation", func() {
 	Describe("skipSerializingFunc", func() {
-		It("should return Option::is_none for pointer, slice, and map types", func() {
+		It("should return Vec::is_empty for []byte type", func() {
+			Expect(skipSerializingFunc("[]byte")).To(Equal("Vec::is_empty"))
+		})
+
+		It("should return Option::is_none for pointer and slice types", func() {
 			Expect(skipSerializingFunc("*string")).To(Equal("Option::is_none"))
 			Expect(skipSerializingFunc("*MyStruct")).To(Equal("Option::is_none"))
 			Expect(skipSerializingFunc("[]string")).To(Equal("Option::is_none"))
 			Expect(skipSerializingFunc("[]int32")).To(Equal("Option::is_none"))
-			Expect(skipSerializingFunc("map[string]int")).To(Equal("Option::is_none"))
+		})
+
+		It("should return HashMap::is_empty for map types", func() {
+			Expect(skipSerializingFunc("map[string]int")).To(Equal("HashMap::is_empty"))
+			Expect(skipSerializingFunc("map[string]string")).To(Equal("HashMap::is_empty"))
 		})
 
 		It("should return String::is_empty for string type", func() {

plugins/cmd/ndpgen/internal/parser.go

@@ -269,6 +269,7 @@ func parseExport(name string, funcType *ast.FuncType, annotation map[string]stri
 		Name:       name,
 		ExportName: annotation["name"],
 		Doc:        doc,
+		Raw:        annotation["raw"] == "true",
 	}
 
 	// Capability exports have exactly one input parameter (the struct type)

plugins/cmd/ndpgen/internal/parser_test.go

@@ -635,6 +635,68 @@ type Output struct {
 		})
 	})
 
+	Describe("ParseCapabilities raw=true", func() {
+		It("should parse raw=true export annotation", func() {
+			src := `package capabilities
+
+//nd:capability name=httpendpoint required=true
+type HTTPEndpoint interface {
+	//nd:export name=nd_http_handle_request raw=true
+	HandleRequest(HTTPHandleRequest) (HTTPHandleResponse, error)
+}
+
+type HTTPHandleRequest struct {
+	Method string ` + "`json:\"method\"`" + `
+	Body   []byte ` + "`json:\"body,omitempty\"`" + `
+}
+
+type HTTPHandleResponse struct {
+	Status int32  ` + "`json:\"status,omitempty\"`" + `
+	Body   []byte ` + "`json:\"body,omitempty\"`" + `
+}
+`
+			err := os.WriteFile(filepath.Join(tmpDir, "http_endpoint.go"), []byte(src), 0600)
+			Expect(err).NotTo(HaveOccurred())
+
+			capabilities, err := ParseCapabilities(tmpDir)
+			Expect(err).NotTo(HaveOccurred())
+			Expect(capabilities).To(HaveLen(1))
+
+			cap := capabilities[0]
+			Expect(cap.Methods).To(HaveLen(1))
+			Expect(cap.Methods[0].Raw).To(BeTrue())
+			Expect(cap.HasRawMethods()).To(BeTrue())
+		})
+
+		It("should default Raw to false for export annotations without raw", func() {
+			src := `package capabilities
+
+//nd:capability name=test required=true
+type TestCapability interface {
+	//nd:export name=nd_test
+	Test(TestInput) (TestOutput, error)
+}
+
+type TestInput struct {
+	Value string ` + "`json:\"value\"`" + `
+}
+
+type TestOutput struct {
+	Result string ` + "`json:\"result\"`" + `
+}
+`
+			err := os.WriteFile(filepath.Join(tmpDir, "test.go"), []byte(src), 0600)
+			Expect(err).NotTo(HaveOccurred())
+
+			capabilities, err := ParseCapabilities(tmpDir)
+			Expect(err).NotTo(HaveOccurred())
+			Expect(capabilities).To(HaveLen(1))
+
+			Expect(capabilities[0].Methods[0].Raw).To(BeFalse())
+			Expect(capabilities[0].HasRawMethods()).To(BeFalse())
+		})
+	})
+
 	Describe("Export helpers", func() {
 		It("should generate correct provider interface name", func() {
 			e := Export{Name: "GetArtistBiography"}

plugins/cmd/ndpgen/internal/templates/capability.go.tmpl

@@ -9,6 +9,10 @@ package {{.Package}}
 
 import (
 	"github.com/navidrome/navidrome/plugins/pdk/go/pdk"
+{{- if .Capability.HasRawMethods}}
+	"encoding/binary"
+	"encoding/json"
+{{- end}}
 )
 
 {{- /* Generate type alias definitions */ -}}
@@ -56,6 +60,7 @@ func (e {{$typeName}}) Error() string { return string(e) }
 {{- end}}
 
 {{- /* Generate struct definitions */ -}}
+{{- $capability := .Capability}}
 {{- range .Capability.Structs}}
 
 {{- if .Doc}}
@@ -68,8 +73,12 @@ type {{.Name}} struct {
 {{- if .Doc}}
 {{formatDoc .Doc | indent 1}}
 {{- end}}
+{{- if and (eq .Type "[]byte") $capability.HasRawMethods}}
+	{{.Name}} {{.Type}} `json:"-"`
+{{- else}}
 	{{.Name}} {{.Type}} `json:"{{.JSONTag}}{{if .OmitEmpty}},omitempty{{end}}"`
 {{- end}}
+{{- end}}
 }
 {{- end}}
 
@@ -172,6 +181,53 @@ func {{exportFunc .}}() int32 {
 		// Return standard code - host will skip this plugin gracefully
 		return NotImplementedCode
 	}
+{{- if .Raw}}
+{{- /* Raw binary frame input/output */ -}}
+{{- if .HasInput}}
+
+	// Parse input frame: [json_len:4B][JSON without []byte field][raw bytes]
+	raw := pdk.Input()
+	if len(raw) < 4 {
+		pdk.SetErrorString("malformed input frame")
+		return -1
+	}
+	jsonLen := binary.BigEndian.Uint32(raw[:4])
+	if uint32(len(raw)-4) < jsonLen {
+		pdk.SetErrorString("invalid json length in input frame")
+		return -1
+	}
+	var input {{.Input.Type}}
+	if err := json.Unmarshal(raw[4:4+jsonLen], &input); err != nil {
+		pdk.SetError(err)
+		return -1
+	}
+	input.{{rawFieldName .Input.Type}} = raw[4+jsonLen:]
+{{- end}}
+{{- if and .HasInput .HasOutput}}
+
+	output, err := {{implVar .}}(input)
+	if err != nil {
+		// Error frame: [0x01][UTF-8 error message]
+		errMsg := []byte(err.Error())
+		errFrame := make([]byte, 1+len(errMsg))
+		errFrame[0] = 0x01
+		copy(errFrame[1:], errMsg)
+		pdk.Output(errFrame)
+		return 0
+	}
+
+	// Success frame: [0x00][json_len:4B][JSON without []byte field][raw bytes]
+	jsonBytes, _ := json.Marshal(output)
+	rawBytes := output.{{rawFieldName .Output.Type}}
+	frame := make([]byte, 1+4+len(jsonBytes)+len(rawBytes))
+	frame[0] = 0x00
+	binary.BigEndian.PutUint32(frame[1:5], uint32(len(jsonBytes)))
+	copy(frame[5:5+len(jsonBytes)], jsonBytes)
+	copy(frame[5+len(jsonBytes):], rawBytes)
+	pdk.Output(frame)
+{{- end}}
+{{- else}}
+{{- /* Standard JSON input/output */ -}}
 {{- if .HasInput}}
 
 	var input {{.Input.Type}}
@@ -216,6 +272,7 @@ func {{exportFunc .}}() int32 {
 		pdk.SetError(err)
 		return -1
 	}
+{{- end}}
 {{- end}}
 
 	return 0

plugins/cmd/ndpgen/internal/templates/capability.rs.tmpl

@@ -52,6 +52,7 @@ pub const {{rustConstName $v.Name}}: &'static str = {{$v.Value}};
 {{- end}}
 
 {{- /* Generate struct definitions */ -}}
+{{- $capability := .Capability}}
 {{- range .Capability.Structs}}
 
 {{- if .Doc}}
@@ -66,13 +67,17 @@ pub struct {{.Name}} {
 {{- if .Doc}}
 {{rustDocComment .Doc | indent 4}}
 {{- end}}
-{{- if .OmitEmpty}}
+{{- if and (eq .Type "[]byte") $capability.HasRawMethods}}
+    #[serde(skip)]
+    pub {{rustFieldName .Name}}: {{fieldRustType .}},
+{{- else if .OmitEmpty}}
     #[serde(default, skip_serializing_if = "{{skipSerializingFunc .Type}}")]
+    pub {{rustFieldName .Name}}: {{fieldRustType .}},
 {{- else}}
     #[serde(default)]
-{{- end}}
     pub {{rustFieldName .Name}}: {{fieldRustType .}},
 {{- end}}
+{{- end}}
 }
 {{- end}}
 
@@ -124,6 +129,56 @@ pub trait {{agentName .Capability}} {
 macro_rules! register_{{snakeCase .Package}} {
     ($plugin_type:ty) => {
         {{- range .Capability.Methods}}
+        {{- if .Raw}}
+        #[extism_pdk::plugin_fn]
+        pub fn {{.ExportName}}(
+            {{- if .HasInput}}
+            _raw_input: extism_pdk::Raw<Vec<u8>>
+            {{- end}}
+        ) -> extism_pdk::FnResult<extism_pdk::Raw<Vec<u8>>> {
+            let plugin = <$plugin_type>::default();
+            {{- if .HasInput}}
+            // Parse input frame: [json_len:4B][JSON without []byte field][raw bytes]
+            let raw_bytes = _raw_input.0;
+            if raw_bytes.len() < 4 {
+                let mut err_frame = vec![0x01u8];
+                err_frame.extend_from_slice(b"malformed input frame");
+                return Ok(extism_pdk::Raw(err_frame));
+            }
+            let json_len = u32::from_be_bytes([raw_bytes[0], raw_bytes[1], raw_bytes[2], raw_bytes[3]]) as usize;
+            if json_len > raw_bytes.len() - 4 {
+                let mut err_frame = vec![0x01u8];
+                err_frame.extend_from_slice(b"invalid json length in input frame");
+                return Ok(extism_pdk::Raw(err_frame));
+            }
+            let mut req: $crate::{{snakeCase $.Package}}::{{rustOutputType .Input.Type}} = serde_json::from_slice(&raw_bytes[4..4+json_len])
+                .map_err(|e| extism_pdk::Error::msg(e.to_string()))?;
+            req.{{rustFieldName (rawFieldName .Input.Type)}} = raw_bytes[4+json_len..].to_vec();
+            {{- end}}
+            {{- if and .HasInput .HasOutput}}
+            match $crate::{{snakeCase $.Package}}::{{agentName $.Capability}}::{{rustMethodName .Name}}(&plugin, req) {
+                Ok(output) => {
+                    // Success frame: [0x00][json_len:4B][JSON without []byte field][raw bytes]
+                    let json_bytes = serde_json::to_vec(&output)
+                        .map_err(|e| extism_pdk::Error::msg(e.to_string()))?;
+                    let raw_field = &output.{{rustFieldName (rawFieldName .Output.Type)}};
+                    let mut frame = Vec::with_capacity(1 + 4 + json_bytes.len() + raw_field.len());
+                    frame.push(0x00);
+                    frame.extend_from_slice(&(json_bytes.len() as u32).to_be_bytes());
+                    frame.extend_from_slice(&json_bytes);
+                    frame.extend_from_slice(raw_field);
+                    Ok(extism_pdk::Raw(frame))
+                }
+                Err(e) => {
+                    // Error frame: [0x01][UTF-8 error message]
+                    let mut err_frame = vec![0x01u8];
+                    err_frame.extend_from_slice(e.message.as_bytes());
+                    Ok(extism_pdk::Raw(err_frame))
+                }
+            }
+            {{- end}}
+        }
+        {{- else}}
         #[extism_pdk::plugin_fn]
         pub fn {{.ExportName}}(
             {{- if .HasInput}}
@@ -146,6 +201,7 @@ macro_rules! register_{{snakeCase .Package}} {
             {{- end}}
         }
         {{- end}}
+        {{- end}}
     };
 }
 {{- else}}
@@ -171,6 +227,56 @@ pub trait {{providerInterface .}} {
 #[macro_export]
 macro_rules! {{registerMacroName .Name}} {
     ($plugin_type:ty) => {
+        {{- if .Raw}}
+        #[extism_pdk::plugin_fn]
+        pub fn {{.ExportName}}(
+            {{- if .HasInput}}
+            _raw_input: extism_pdk::Raw<Vec<u8>>
+            {{- end}}
+        ) -> extism_pdk::FnResult<extism_pdk::Raw<Vec<u8>>> {
+            let plugin = <$plugin_type>::default();
+            {{- if .HasInput}}
+            // Parse input frame: [json_len:4B][JSON without []byte field][raw bytes]
+            let raw_bytes = _raw_input.0;
+            if raw_bytes.len() < 4 {
+                let mut err_frame = vec![0x01u8];
+                err_frame.extend_from_slice(b"malformed input frame");
+                return Ok(extism_pdk::Raw(err_frame));
+            }
+            let json_len = u32::from_be_bytes([raw_bytes[0], raw_bytes[1], raw_bytes[2], raw_bytes[3]]) as usize;
+            if json_len > raw_bytes.len() - 4 {
+                let mut err_frame = vec![0x01u8];
+                err_frame.extend_from_slice(b"invalid json length in input frame");
+                return Ok(extism_pdk::Raw(err_frame));
+            }
+            let mut req: $crate::{{snakeCase $.Package}}::{{rustOutputType .Input.Type}} = serde_json::from_slice(&raw_bytes[4..4+json_len])
+                .map_err(|e| extism_pdk::Error::msg(e.to_string()))?;
+            req.{{rustFieldName (rawFieldName .Input.Type)}} = raw_bytes[4+json_len..].to_vec();
+            {{- end}}
+            {{- if and .HasInput .HasOutput}}
+            match $crate::{{snakeCase $.Package}}::{{providerInterface .}}::{{rustMethodName .Name}}(&plugin, req) {
+                Ok(output) => {
+                    // Success frame: [0x00][json_len:4B][JSON without []byte field][raw bytes]
+                    let json_bytes = serde_json::to_vec(&output)
+                        .map_err(|e| extism_pdk::Error::msg(e.to_string()))?;
+                    let raw_field = &output.{{rustFieldName (rawFieldName .Output.Type)}};
+                    let mut frame = Vec::with_capacity(1 + 4 + json_bytes.len() + raw_field.len());
+                    frame.push(0x00);
+                    frame.extend_from_slice(&(json_bytes.len() as u32).to_be_bytes());
+                    frame.extend_from_slice(&json_bytes);
+                    frame.extend_from_slice(raw_field);
+                    Ok(extism_pdk::Raw(frame))
+                }
+                Err(e) => {
+                    // Error frame: [0x01][UTF-8 error message]
+                    let mut err_frame = vec![0x01u8];
+                    err_frame.extend_from_slice(e.message.as_bytes());
+                    Ok(extism_pdk::Raw(err_frame))
+                }
+            }
+            {{- end}}
+        }
+        {{- else}}
         #[extism_pdk::plugin_fn]
         pub fn {{.ExportName}}(
             {{- if .HasInput}}
@@ -192,6 +298,7 @@ macro_rules! {{registerMacroName .Name}} {
             Ok(())
             {{- end}}
         }
+        {{- end}}
     };
 }
 {{- end}}

plugins/cmd/ndpgen/internal/templates/capability_stub.go.tmpl

@@ -53,6 +53,7 @@ func (e {{$typeName}}) Error() string { return string(e) }
 {{- end}}
 
 {{- /* Generate struct definitions */ -}}
+{{- $capability := .Capability}}
 {{- range .Capability.Structs}}
 
 {{- if .Doc}}
@@ -65,8 +66,12 @@ type {{.Name}} struct {
 {{- if .Doc}}
 {{formatDoc .Doc | indent 1}}
 {{- end}}
+{{- if and (eq .Type "[]byte") $capability.HasRawMethods}}
+	{{.Name}} {{.Type}} `json:"-"`
+{{- else}}
 	{{.Name}} {{.Type}} `json:"{{.JSONTag}}{{if .OmitEmpty}},omitempty{{end}}"`
 {{- end}}
+{{- end}}
 }
 {{- end}}
 

plugins/cmd/ndpgen/internal/types.go

@@ -48,6 +48,16 @@ type ConstDef struct {
 	Doc   string // Documentation comment
 }
 
+// HasRawMethods returns true if any export in the capability uses raw binary framing.
+func (c Capability) HasRawMethods() bool {
+	for _, m := range c.Methods {
+		if m.Raw {
+			return true
+		}
+	}
+	return false
+}
+
 // KnownStructs returns a map of struct names defined in this capability.
 func (c Capability) KnownStructs() map[string]bool {
 	result := make(map[string]bool)
@@ -64,6 +74,7 @@ type Export struct {
 	Input      Param  // Single input parameter (the struct type)
 	Output     Param  // Single output return value (the struct type)
 	Doc        string // Documentation comment for the method
+	Raw        bool   // If true, uses binary framing instead of JSON for []byte fields
 }
 
 // ProviderInterfaceName returns the optional provider interface name.

plugins/cmd/ndpgen/internal/xtp_schema.go

@@ -54,6 +54,14 @@ type (
 		Nullable    bool         `yaml:"nullable,omitempty"`
 		Items       *xtpProperty `yaml:"items,omitempty"`
 	}
+
+	// xtpMapProperty represents a map property in XTP (type: object with additionalProperties).
+	xtpMapProperty struct {
+		Type                 string       `yaml:"type"`
+		Description          string       `yaml:"description,omitempty"`
+		Nullable             bool         `yaml:"nullable,omitempty"`
+		AdditionalProperties *xtpProperty `yaml:"additionalProperties"`
+	}
 )
 
 // GenerateSchema generates an XTP YAML schema from a capability.
@@ -206,7 +214,12 @@ func buildObjectSchema(st StructDef, knownTypes map[string]bool) xtpObjectSchema
 
 	for _, field := range st.Fields {
 		propName := getJSONFieldName(field)
-		addToMap(&schema.Properties, propName, buildProperty(field, knownTypes))
+		goType := strings.TrimPrefix(field.Type, "*")
+		if strings.HasPrefix(goType, "map[") {
+			addToMap(&schema.Properties, propName, buildMapProperty(goType, field.Doc, strings.HasPrefix(field.Type, "*"), knownTypes))
+		} else {
+			addToMap(&schema.Properties, propName, buildProperty(field, knownTypes))
+		}
 
 		if !strings.HasPrefix(field.Type, "*") && !field.OmitEmpty {
 			schema.Required = append(schema.Required, propName)
@@ -246,6 +259,12 @@ func buildProperty(field FieldDef, knownTypes map[string]bool) xtpProperty {
 		return prop
 	}
 
+	// Handle []byte as buffer type (must be checked before generic slice handling)
+	if goType == "[]byte" {
+		prop.Type = "buffer"
+		return prop
+	}
+
 	// Handle slice types
 	if strings.HasPrefix(goType, "[]") {
 		elemType := goType[2:]
@@ -264,6 +283,55 @@ func buildProperty(field FieldDef, knownTypes map[string]bool) xtpProperty {
 	return prop
 }
 
+// buildMapProperty builds an XTP MapProperty for a Go map type.
+// It parses map[K]V and generates additionalProperties describing V.
+func buildMapProperty(goType, doc string, isPointer bool, knownTypes map[string]bool) xtpMapProperty {
+	prop := xtpMapProperty{
+		Type:        "object",
+		Description: cleanDocForYAML(doc),
+		Nullable:    isPointer,
+	}
+
+	// Parse value type from map[K]V
+	valueType := parseMapValueType(goType)
+
+	valProp := &xtpProperty{}
+	if strings.HasPrefix(valueType, "[]") {
+		elemType := valueType[2:]
+		valProp.Type = "array"
+		valProp.Items = &xtpProperty{}
+		if isKnownType(elemType, knownTypes) {
+			valProp.Items.Ref = "#/components/schemas/" + elemType
+		} else {
+			valProp.Items.Type = goTypeToXTPType(elemType)
+		}
+	} else if isKnownType(valueType, knownTypes) {
+		valProp.Ref = "#/components/schemas/" + valueType
+	} else {
+		valProp.Type, valProp.Format = goTypeToXTPTypeAndFormat(valueType)
+	}
+	prop.AdditionalProperties = valProp
+
+	return prop
+}
+
+// parseMapValueType extracts the value type from a Go map type string like "map[string][]string".
+func parseMapValueType(goType string) string {
+	// Find the closing bracket of the key type
+	depth := 0
+	for i, ch := range goType {
+		if ch == '[' {
+			depth++
+		} else if ch == ']' {
+			depth--
+			if depth == 0 {
+				return goType[i+1:]
+			}
+		}
+	}
+	return "object" // fallback
+}
+
 // addToMap adds a key-value pair to a yaml.Node map, preserving insertion order.
 func addToMap[T any](node *yaml.Node, key string, value T) {
 	var valNode yaml.Node

plugins/cmd/ndpgen/internal/xtp_schema_test.go

@@ -719,4 +719,139 @@ var _ = Describe("XTP Schema Generation", func() {
 			Expect(schemas).NotTo(HaveKey("UnusedStatus"))
 		})
 	})
+
+	Describe("GenerateSchema with []byte fields", func() {
+		It("should render []byte as buffer type and validate against XTP JSONSchema", func() {
+			capability := Capability{
+				Name:       "buffer_test",
+				SourceFile: "buffer_test",
+				Methods: []Export{
+					{ExportName: "test", Input: NewParam("input", "Input"), Output: NewParam("output", "Output")},
+				},
+				Structs: []StructDef{
+					{
+						Name: "Input",
+						Fields: []FieldDef{
+							{Name: "Name", Type: "string", JSONTag: "name"},
+							{Name: "Data", Type: "[]byte", JSONTag: "data,omitempty", OmitEmpty: true},
+						},
+					},
+					{
+						Name: "Output",
+						Fields: []FieldDef{
+							{Name: "Body", Type: "[]byte", JSONTag: "body,omitempty", OmitEmpty: true},
+						},
+					},
+				},
+			}
+			schema, err := GenerateSchema(capability)
+			Expect(err).NotTo(HaveOccurred())
+			Expect(ValidateXTPSchema(schema)).To(Succeed())
+
+			doc := parseSchema(schema)
+			components := doc["components"].(map[string]any)
+			schemas := components["schemas"].(map[string]any)
+			input := schemas["Input"].(map[string]any)
+			props := input["properties"].(map[string]any)
+			data := props["data"].(map[string]any)
+			Expect(data["type"]).To(Equal("buffer"))
+			Expect(data).NotTo(HaveKey("items"))
+			Expect(data).NotTo(HaveKey("format"))
+
+			output := schemas["Output"].(map[string]any)
+			outProps := output["properties"].(map[string]any)
+			body := outProps["body"].(map[string]any)
+			Expect(body["type"]).To(Equal("buffer"))
+		})
+	})
+
+	Describe("GenerateSchema with map fields", func() {
+		It("should render map[string][]string as object with additionalProperties and validate", func() {
+			capability := Capability{
+				Name:       "map_test",
+				SourceFile: "map_test",
+				Methods: []Export{
+					{ExportName: "test", Input: NewParam("input", "Input"), Output: NewParam("output", "Output")},
+				},
+				Structs: []StructDef{
+					{
+						Name: "Input",
+						Fields: []FieldDef{
+							{Name: "Headers", Type: "map[string][]string", JSONTag: "headers,omitempty", OmitEmpty: true},
+						},
+					},
+					{
+						Name: "Output",
+						Fields: []FieldDef{
+							{Name: "Value", Type: "string", JSONTag: "value"},
+						},
+					},
+				},
+			}
+			schema, err := GenerateSchema(capability)
+			Expect(err).NotTo(HaveOccurred())
+			Expect(ValidateXTPSchema(schema)).To(Succeed())
+
+			doc := parseSchema(schema)
+			components := doc["components"].(map[string]any)
+			schemas := components["schemas"].(map[string]any)
+			input := schemas["Input"].(map[string]any)
+			props := input["properties"].(map[string]any)
+			headers := props["headers"].(map[string]any)
+			Expect(headers).To(HaveKey("additionalProperties"))
+			addlProps := headers["additionalProperties"].(map[string]any)
+			Expect(addlProps["type"]).To(Equal("array"))
+			items := addlProps["items"].(map[string]any)
+			Expect(items["type"]).To(Equal("string"))
+		})
+
+		It("should render map[string]string as object with string additionalProperties", func() {
+			capability := Capability{
+				Name:       "map_string_test",
+				SourceFile: "map_string_test",
+				Methods: []Export{
+					{ExportName: "test", Input: NewParam("input", "Input"), Output: NewParam("output", "Output")},
+				},
+				Structs: []StructDef{
+					{
+						Name: "Input",
+						Fields: []FieldDef{
+							{Name: "Metadata", Type: "map[string]string", JSONTag: "metadata,omitempty", OmitEmpty: true},
+						},
+					},
+					{
+						Name: "Output",
+						Fields: []FieldDef{
+							{Name: "Value", Type: "string", JSONTag: "value"},
+						},
+					},
+				},
+			}
+			schema, err := GenerateSchema(capability)
+			Expect(err).NotTo(HaveOccurred())
+			Expect(ValidateXTPSchema(schema)).To(Succeed())
+
+			doc := parseSchema(schema)
+			components := doc["components"].(map[string]any)
+			schemas := components["schemas"].(map[string]any)
+			input := schemas["Input"].(map[string]any)
+			props := input["properties"].(map[string]any)
+			metadata := props["metadata"].(map[string]any)
+			Expect(metadata).To(HaveKey("additionalProperties"))
+			addlProps := metadata["additionalProperties"].(map[string]any)
+			Expect(addlProps["type"]).To(Equal("string"))
+		})
+	})
+
+	Describe("parseMapValueType", func() {
+		DescribeTable("should extract value type from Go map types",
+			func(goType, wantValue string) {
+				Expect(parseMapValueType(goType)).To(Equal(wantValue))
+			},
+			Entry("map[string]string", "map[string]string", "string"),
+			Entry("map[string]int", "map[string]int", "int"),
+			Entry("map[string][]string", "map[string][]string", "[]string"),
+			Entry("map[string][]byte", "map[string][]byte", "[]byte"),
+		)
+	})
 })

plugins/host_subsonicapi.go

@@ -26,27 +26,19 @@ const subsonicAPIVersion = "1.16.1"
 // URL Format: Only the path and query parameters are used - host/protocol are ignored.
 // Automatic Parameters: The service adds 'c' (client), 'v' (version), and optionally 'f' (format).
 type subsonicAPIServiceImpl struct {
-	pluginID       string
-	router         SubsonicRouter
-	ds             model.DataStore
-	allowedUserIDs []string // User IDs this plugin can access (from DB configuration)
-	allUsers       bool     // If true, plugin can access all users
-	userIDMap      map[string]struct{}
+	pluginName string
+	router     SubsonicRouter
+	ds         model.DataStore
+	userAccess UserAccess
 }
 
 // newSubsonicAPIService creates a new SubsonicAPIService for a plugin.
-func newSubsonicAPIService(pluginID string, router SubsonicRouter, ds model.DataStore, allowedUserIDs []string, allUsers bool) host.SubsonicAPIService {
-	userIDMap := make(map[string]struct{})
-	for _, id := range allowedUserIDs {
-		userIDMap[id] = struct{}{}
-	}
+func newSubsonicAPIService(pluginName string, router SubsonicRouter, ds model.DataStore, userAccess UserAccess) host.SubsonicAPIService {
 	return &subsonicAPIServiceImpl{
-		pluginID:       pluginID,
-		router:         router,
-		ds:             ds,
-		allowedUserIDs: allowedUserIDs,
-		allUsers:       allUsers,
-		userIDMap:      userIDMap,
+		pluginName: pluginName,
+		router:     router,
+		ds:         ds,
+		userAccess: userAccess,
 	}
 }
 
@@ -74,12 +66,12 @@ func (s *subsonicAPIServiceImpl) executeRequest(ctx context.Context, uri string,
 	}
 
 	if err := s.checkPermissions(ctx, username); err != nil {
-		log.Warn(ctx, "SubsonicAPI call blocked by permissions", "plugin", s.pluginID, "user", username, err)
+		log.Warn(ctx, "SubsonicAPI call blocked by permissions", "plugin", s.pluginName, "user", username, err)
 		return nil, err
 	}
 
 	// Add required Subsonic API parameters
-	query.Set("c", s.pluginID)         // Client name (plugin ID)
+	query.Set("c", s.pluginName)       // Client name (plugin ID)
 	query.Set("v", subsonicAPIVersion) // API version
 	if setJSON {
 		query.Set("f", "json") // Response format
@@ -94,11 +86,8 @@ func (s *subsonicAPIServiceImpl) executeRequest(ctx context.Context, uri string,
 		RawQuery: query.Encode(),
 	}
 
-	// Create HTTP request with a fresh context to avoid Chi RouteContext pollution.
-	// Using http.NewRequest (instead of http.NewRequestWithContext) ensures the internal
-	// SubsonicAPI call doesn't inherit routing information from the parent handler,
-	// which would cause Chi to invoke the wrong handler. Authentication context is
-	// explicitly added in the next step via request.WithInternalAuth.
+	// Use http.NewRequest (not WithContext) to avoid inheriting Chi RouteContext;
+	// auth context is set explicitly below via request.WithInternalAuth.
 	httpReq, err := http.NewRequest("GET", finalURL.String(), nil)
 	if err != nil {
 		return nil, fmt.Errorf("failed to create HTTP request: %w", err)
@@ -135,14 +124,13 @@ func (s *subsonicAPIServiceImpl) CallRaw(ctx context.Context, uri string) (strin
 }
 
 func (s *subsonicAPIServiceImpl) checkPermissions(ctx context.Context, username string) error {
-	// If allUsers is true, allow any user
-	if s.allUsers {
+	if s.userAccess.allUsers {
 		return nil
 	}
 
-	// Must have at least one allowed user ID configured
-	if len(s.allowedUserIDs) == 0 {
-		return fmt.Errorf("no users configured for plugin %s", s.pluginID)
+	// Must have at least one allowed user configured
+	if !s.userAccess.HasConfiguredUsers() {
+		return fmt.Errorf("no users configured for plugin %s", s.pluginName)
 	}
 
 	// Look up the user by username to get their ID
@@ -155,7 +143,7 @@ func (s *subsonicAPIServiceImpl) checkPermissions(ctx context.Context, username
 	}
 
 	// Check if the user's ID is in the allowed list
-	if _, ok := s.userIDMap[usr.ID]; !ok {
+	if !s.userAccess.IsAllowed(usr.ID) {
 		return fmt.Errorf("user %s is not authorized for this plugin", username)
 	}
 

plugins/host_subsonicapi_test.go

@@ -268,7 +268,7 @@ var _ = Describe("SubsonicAPIService", func() {
 		Context("with specific user IDs allowed", func() {
 			It("blocks users not in the allowed list", func() {
 				// allowedUserIDs contains "user2", but testuser is "user1"
-				service := newSubsonicAPIService("test-plugin", router, dataStore, []string{"user2"}, false)
+				service := newSubsonicAPIService("test-plugin", router, dataStore, NewUserAccess(false, []string{"user2"}))
 
 				ctx := GinkgoT().Context()
 				_, err := service.Call(ctx, "/ping?u=testuser")
@@ -278,7 +278,7 @@ var _ = Describe("SubsonicAPIService", func() {
 
 			It("allows users in the allowed list", func() {
 				// allowedUserIDs contains "user2" which is "alloweduser"
-				service := newSubsonicAPIService("test-plugin", router, dataStore, []string{"user2"}, false)
+				service := newSubsonicAPIService("test-plugin", router, dataStore, NewUserAccess(false, []string{"user2"}))
 
 				ctx := GinkgoT().Context()
 				response, err := service.Call(ctx, "/ping?u=alloweduser")
@@ -288,7 +288,7 @@ var _ = Describe("SubsonicAPIService", func() {
 
 			It("blocks admin users when not in allowed list", func() {
 				// allowedUserIDs only contains "user1" (testuser), not "admin1"
-				service := newSubsonicAPIService("test-plugin", router, dataStore, []string{"user1"}, false)
+				service := newSubsonicAPIService("test-plugin", router, dataStore, NewUserAccess(false, []string{"user1"}))
 
 				ctx := GinkgoT().Context()
 				_, err := service.Call(ctx, "/ping?u=adminuser")
@@ -298,7 +298,7 @@ var _ = Describe("SubsonicAPIService", func() {
 
 			It("allows admin users when in allowed list", func() {
 				// allowedUserIDs contains "admin1"
-				service := newSubsonicAPIService("test-plugin", router, dataStore, []string{"admin1"}, false)
+				service := newSubsonicAPIService("test-plugin", router, dataStore, NewUserAccess(false, []string{"admin1"}))
 
 				ctx := GinkgoT().Context()
 				response, err := service.Call(ctx, "/ping?u=adminuser")
@@ -309,7 +309,7 @@ var _ = Describe("SubsonicAPIService", func() {
 
 		Context("with allUsers=true", func() {
 			It("allows all users regardless of allowed list", func() {
-				service := newSubsonicAPIService("test-plugin", router, dataStore, nil, true)
+				service := newSubsonicAPIService("test-plugin", router, dataStore, NewUserAccess(true, nil))
 
 				ctx := GinkgoT().Context()
 				response, err := service.Call(ctx, "/ping?u=testuser")
@@ -318,7 +318,7 @@ var _ = Describe("SubsonicAPIService", func() {
 			})
 
 			It("allows admin users when allUsers is true", func() {
-				service := newSubsonicAPIService("test-plugin", router, dataStore, nil, true)
+				service := newSubsonicAPIService("test-plugin", router, dataStore, NewUserAccess(true, nil))
 
 				ctx := GinkgoT().Context()
 				response, err := service.Call(ctx, "/ping?u=adminuser")
@@ -329,7 +329,7 @@ var _ = Describe("SubsonicAPIService", func() {
 
 		Context("with no users configured", func() {
 			It("returns error when no users are configured", func() {
-				service := newSubsonicAPIService("test-plugin", router, dataStore, nil, false)
+				service := newSubsonicAPIService("test-plugin", router, dataStore, NewUserAccess(false, nil))
 
 				ctx := GinkgoT().Context()
 				_, err := service.Call(ctx, "/ping?u=testuser")
@@ -338,7 +338,7 @@ var _ = Describe("SubsonicAPIService", func() {
 			})
 
 			It("returns error for empty user list", func() {
-				service := newSubsonicAPIService("test-plugin", router, dataStore, []string{}, false)
+				service := newSubsonicAPIService("test-plugin", router, dataStore, NewUserAccess(false, []string{}))
 
 				ctx := GinkgoT().Context()
 				_, err := service.Call(ctx, "/ping?u=testuser")
@@ -350,7 +350,7 @@ var _ = Describe("SubsonicAPIService", func() {
 
 	Describe("URL Handling", func() {
 		It("returns error for missing username parameter", func() {
-			service := newSubsonicAPIService("test-plugin", router, dataStore, nil, true)
+			service := newSubsonicAPIService("test-plugin", router, dataStore, NewUserAccess(true, nil))
 
 			ctx := GinkgoT().Context()
 			_, err := service.Call(ctx, "/ping")
@@ -359,7 +359,7 @@ var _ = Describe("SubsonicAPIService", func() {
 		})
 
 		It("returns error for invalid URL", func() {
-			service := newSubsonicAPIService("test-plugin", router, dataStore, nil, true)
+			service := newSubsonicAPIService("test-plugin", router, dataStore, NewUserAccess(true, nil))
 
 			ctx := GinkgoT().Context()
 			_, err := service.Call(ctx, "://invalid")
@@ -368,7 +368,7 @@ var _ = Describe("SubsonicAPIService", func() {
 		})
 
 		It("extracts endpoint from path correctly", func() {
-			service := newSubsonicAPIService("test-plugin", router, dataStore, []string{"user1"}, false)
+			service := newSubsonicAPIService("test-plugin", router, dataStore, NewUserAccess(false, []string{"user1"}))
 
 			ctx := GinkgoT().Context()
 			_, err := service.Call(ctx, "/rest/ping.view?u=testuser")
@@ -381,7 +381,7 @@ var _ = Describe("SubsonicAPIService", func() {
 
 	Describe("CallRaw", func() {
 		It("returns binary data and content-type", func() {
-			service := newSubsonicAPIService("test-plugin", router, dataStore, nil, true)
+			service := newSubsonicAPIService("test-plugin", router, dataStore, NewUserAccess(true, nil))
 
 			ctx := GinkgoT().Context()
 			contentType, data, err := service.CallRaw(ctx, "/getCoverArt?u=testuser&id=al-1")
@@ -391,7 +391,7 @@ var _ = Describe("SubsonicAPIService", func() {
 		})
 
 		It("does not set f=json parameter", func() {
-			service := newSubsonicAPIService("test-plugin", router, dataStore, nil, true)
+			service := newSubsonicAPIService("test-plugin", router, dataStore, NewUserAccess(true, nil))
 
 			ctx := GinkgoT().Context()
 			_, _, err := service.CallRaw(ctx, "/getCoverArt?u=testuser&id=al-1")
@@ -403,7 +403,7 @@ var _ = Describe("SubsonicAPIService", func() {
 		})
 
 		It("enforces permission checks", func() {
-			service := newSubsonicAPIService("test-plugin", router, dataStore, []string{"user2"}, false)
+			service := newSubsonicAPIService("test-plugin", router, dataStore, NewUserAccess(false, []string{"user2"}))
 
 			ctx := GinkgoT().Context()
 			_, _, err := service.CallRaw(ctx, "/getCoverArt?u=testuser&id=al-1")
@@ -412,7 +412,7 @@ var _ = Describe("SubsonicAPIService", func() {
 		})
 
 		It("returns error when username is missing", func() {
-			service := newSubsonicAPIService("test-plugin", router, dataStore, nil, true)
+			service := newSubsonicAPIService("test-plugin", router, dataStore, NewUserAccess(true, nil))
 
 			ctx := GinkgoT().Context()
 			_, _, err := service.CallRaw(ctx, "/getCoverArt")
@@ -421,7 +421,7 @@ var _ = Describe("SubsonicAPIService", func() {
 		})
 
 		It("returns error when router is nil", func() {
-			service := newSubsonicAPIService("test-plugin", nil, dataStore, nil, true)
+			service := newSubsonicAPIService("test-plugin", nil, dataStore, NewUserAccess(true, nil))
 
 			ctx := GinkgoT().Context()
 			_, _, err := service.CallRaw(ctx, "/getCoverArt?u=testuser")
@@ -430,7 +430,7 @@ var _ = Describe("SubsonicAPIService", func() {
 		})
 
 		It("returns error for invalid URL", func() {
-			service := newSubsonicAPIService("test-plugin", router, dataStore, nil, true)
+			service := newSubsonicAPIService("test-plugin", router, dataStore, NewUserAccess(true, nil))
 
 			ctx := GinkgoT().Context()
 			_, _, err := service.CallRaw(ctx, "://invalid")
@@ -441,7 +441,7 @@ var _ = Describe("SubsonicAPIService", func() {
 
 	Describe("Router Availability", func() {
 		It("returns error when router is nil", func() {
-			service := newSubsonicAPIService("test-plugin", nil, dataStore, nil, true)
+			service := newSubsonicAPIService("test-plugin", nil, dataStore, NewUserAccess(true, nil))
 
 			ctx := GinkgoT().Context()
 			_, err := service.Call(ctx, "/ping?u=testuser")

plugins/host_users.go

@@ -9,16 +9,14 @@ import (
 )
 
 type usersServiceImpl struct {
-	ds           model.DataStore
-	allowedUsers []string // User IDs this plugin can access
-	allUsers     bool     // If true, plugin can access all users
+	ds         model.DataStore
+	userAccess UserAccess
 }
 
-func newUsersService(ds model.DataStore, allowedUsers []string, allUsers bool) host.UsersService {
+func newUsersService(ds model.DataStore, userAccess UserAccess) host.UsersService {
 	return &usersServiceImpl{
-		ds:           ds,
-		allowedUsers: allowedUsers,
-		allUsers:     allUsers,
+		ds:         ds,
+		userAccess: userAccess,
 	}
 }
 
@@ -28,17 +26,9 @@ func (s *usersServiceImpl) GetUsers(ctx context.Context) ([]host.User, error) {
 		return nil, err
 	}
 
-	// Build allowed users map for efficient lookup
-	allowedMap := make(map[string]bool, len(s.allowedUsers))
-	for _, id := range s.allowedUsers {
-		allowedMap[id] = true
-	}
-
 	var result []host.User
 	for _, u := range users {
-		// If allUsers is true, include all users
-		// Otherwise, only include users in the allowed list
-		if s.allUsers || allowedMap[u.ID] {
+		if s.userAccess.IsAllowed(u.ID) {
 			result = append(result, host.User{
 				UserName: u.UserName,
 				Name:     u.Name,

plugins/host_users_test.go

@@ -61,7 +61,7 @@ var _ = Describe("UsersService", Ordered, func() {
 
 		Context("with allUsers=true", func() {
 			BeforeEach(func() {
-				service = newUsersService(ds, nil, true)
+				service = newUsersService(ds, NewUserAccess(true, nil))
 			})
 
 			It("should return all users", func() {
@@ -100,7 +100,7 @@ var _ = Describe("UsersService", Ordered, func() {
 		Context("with specific allowed users", func() {
 			BeforeEach(func() {
 				// Only allow access to user1 and user3
-				service = newUsersService(ds, []string{"user1", "user3"}, false)
+				service = newUsersService(ds, NewUserAccess(false, []string{"user1", "user3"}))
 			})
 
 			It("should return only allowed users", func() {
@@ -119,7 +119,7 @@ var _ = Describe("UsersService", Ordered, func() {
 
 		Context("with empty allowed users and allUsers=false", func() {
 			BeforeEach(func() {
-				service = newUsersService(ds, []string{}, false)
+				service = newUsersService(ds, NewUserAccess(false, []string{}))
 			})
 
 			It("should return no users", func() {
@@ -132,7 +132,7 @@ var _ = Describe("UsersService", Ordered, func() {
 		Context("when datastore returns error", func() {
 			BeforeEach(func() {
 				mockUserRepo.Error = model.ErrNotFound
-				service = newUsersService(ds, nil, true)
+				service = newUsersService(ds, NewUserAccess(true, nil))
 			})
 
 			It("should propagate the error", func() {
@@ -170,7 +170,7 @@ var _ = Describe("UsersService", Ordered, func() {
 
 		Context("with allUsers=true", func() {
 			BeforeEach(func() {
-				service = newUsersService(ds, nil, true)
+				service = newUsersService(ds, NewUserAccess(true, nil))
 			})
 
 			It("should return only admin users", func() {
@@ -185,7 +185,7 @@ var _ = Describe("UsersService", Ordered, func() {
 		Context("with specific allowed users including admin", func() {
 			BeforeEach(func() {
 				// Allow access to user1 (admin) and user2 (non-admin)
-				service = newUsersService(ds, []string{"user1", "user2"}, false)
+				service = newUsersService(ds, NewUserAccess(false, []string{"user1", "user2"}))
 			})
 
 			It("should return only admin users from allowed list", func() {
@@ -199,7 +199,7 @@ var _ = Describe("UsersService", Ordered, func() {
 		Context("with specific allowed users excluding admin", func() {
 			BeforeEach(func() {
 				// Only allow access to non-admin users
-				service = newUsersService(ds, []string{"user2", "user3"}, false)
+				service = newUsersService(ds, NewUserAccess(false, []string{"user2", "user3"}))
 			})
 
 			It("should return empty when no admins in allowed list", func() {
@@ -212,7 +212,7 @@ var _ = Describe("UsersService", Ordered, func() {
 		Context("when datastore returns error", func() {
 			BeforeEach(func() {
 				mockUserRepo.Error = model.ErrNotFound
-				service = newUsersService(ds, nil, true)
+				service = newUsersService(ds, NewUserAccess(true, nil))
 			})
 
 			It("should propagate the error", func() {

plugins/http_endpoint.go

@@ -0,0 +1,189 @@
+package plugins
+
+import (
+	"io"
+	"net/http"
+
+	"github.com/go-chi/chi/v5"
+	"github.com/go-chi/httprate"
+	"github.com/navidrome/navidrome/conf"
+	"github.com/navidrome/navidrome/log"
+	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/model/request"
+	"github.com/navidrome/navidrome/plugins/capabilities"
+)
+
+const maxEndpointBodySize = 1 << 20 // 1MB
+
+// SubsonicAuthValidator validates Subsonic authentication and returns the user.
+// This is set by the cmd/ package to avoid import cycles (plugins -> server/subsonic).
+type SubsonicAuthValidator func(ds model.DataStore, r *http.Request) (*model.User, error)
+
+// NativeAuthMiddleware is an HTTP middleware that authenticates using JWT tokens.
+// This is set by the cmd/ package to avoid import cycles (plugins -> server).
+type NativeAuthMiddleware func(ds model.DataStore) func(next http.Handler) http.Handler
+
+// NewEndpointRouter creates an HTTP handler that dispatches requests to plugin endpoints.
+// It should be mounted at both /ext and /rest/ext. The handler uses a catch-all pattern
+// because Chi does not support adding routes after startup, and plugins can be loaded/unloaded
+// at runtime. Plugin lookup happens per-request under RLock.
+func NewEndpointRouter(manager *Manager, ds model.DataStore, subsonicAuth SubsonicAuthValidator, nativeAuth NativeAuthMiddleware) http.Handler {
+	r := chi.NewRouter()
+
+	// Apply rate limiting if configured
+	if conf.Server.Plugins.EndpointRequestLimit > 0 {
+		r.Use(httprate.LimitByIP(conf.Server.Plugins.EndpointRequestLimit, conf.Server.Plugins.EndpointRequestWindow))
+	}
+
+	h := &endpointHandler{
+		manager:      manager,
+		ds:           ds,
+		subsonicAuth: subsonicAuth,
+		nativeAuth:   nativeAuth,
+	}
+	r.HandleFunc("/{pluginID}/*", h.ServeHTTP)
+	r.HandleFunc("/{pluginID}", h.ServeHTTP)
+	return r
+}
+
+type endpointHandler struct {
+	manager      *Manager
+	ds           model.DataStore
+	subsonicAuth SubsonicAuthValidator
+	nativeAuth   NativeAuthMiddleware
+}
+
+func (h *endpointHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	pluginID := chi.URLParam(r, "pluginID")
+
+	h.manager.mu.RLock()
+	p, ok := h.manager.plugins[pluginID]
+	h.manager.mu.RUnlock()
+
+	if !ok || !hasCapability(p.capabilities, CapabilityHTTPEndpoint) {
+		http.NotFound(w, r)
+		return
+	}
+
+	if p.manifest.Permissions == nil || p.manifest.Permissions.Endpoints == nil {
+		http.NotFound(w, r)
+		return
+	}
+
+	authType := p.manifest.Permissions.Endpoints.Auth
+
+	switch authType {
+	case EndpointsPermissionAuthSubsonic:
+		h.serveWithSubsonicAuth(w, r, p)
+	case EndpointsPermissionAuthNative:
+		h.serveWithNativeAuth(w, r, p)
+	case EndpointsPermissionAuthNone:
+		h.dispatch(w, r, p)
+	default:
+		http.Error(w, "Unknown auth type", http.StatusInternalServerError)
+	}
+}
+
+func (h *endpointHandler) serveWithSubsonicAuth(w http.ResponseWriter, r *http.Request, p *plugin) {
+	usr, err := h.subsonicAuth(h.ds, r)
+	if err != nil {
+		log.Warn(r.Context(), "Plugin endpoint auth failed", "plugin", p.name, "auth", "subsonic", err)
+		http.Error(w, "Unauthorized", http.StatusUnauthorized)
+		return
+	}
+	ctx := request.WithUser(r.Context(), *usr)
+	h.dispatch(w, r.WithContext(ctx), p)
+}
+
+func (h *endpointHandler) serveWithNativeAuth(w http.ResponseWriter, r *http.Request, p *plugin) {
+	h.nativeAuth(h.ds)(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		h.dispatch(w, r, p)
+	})).ServeHTTP(w, r)
+}
+
+func (h *endpointHandler) dispatch(w http.ResponseWriter, r *http.Request, p *plugin) {
+	ctx := r.Context()
+
+	// Check user authorization and extract user info (skip for auth:"none")
+	var httpUser *capabilities.HTTPUser
+	if p.manifest.Permissions.Endpoints.Auth != EndpointsPermissionAuthNone {
+		user, ok := request.UserFrom(ctx)
+		if !ok {
+			http.Error(w, "Unauthorized", http.StatusUnauthorized)
+			return
+		}
+		if !p.userAccess.IsAllowed(user.ID) {
+			log.Warn(ctx, "Plugin endpoint access denied", "plugin", p.name, "user", user.UserName)
+			http.Error(w, "Forbidden", http.StatusForbidden)
+			return
+		}
+		httpUser = &capabilities.HTTPUser{
+			ID:       user.ID,
+			Username: user.UserName,
+			Name:     user.Name,
+			IsAdmin:  user.IsAdmin,
+		}
+	}
+
+	// Read request body with size limit
+	body, err := io.ReadAll(io.LimitReader(r.Body, maxEndpointBodySize))
+	if err != nil {
+		log.Error(ctx, "Failed to read request body", "plugin", p.name, err)
+		http.Error(w, "Failed to read request body", http.StatusBadRequest)
+		return
+	}
+
+	// Build the plugin request
+	// Normalize path: both /ext/plugin and /ext/plugin/ map to ""
+	rawPath := chi.URLParam(r, "*")
+	relPath := ""
+	if rawPath != "" {
+		relPath = "/" + rawPath
+	}
+
+	pluginReq := capabilities.HTTPHandleRequest{
+		Method:  r.Method,
+		Path:    relPath,
+		Query:   r.URL.RawQuery,
+		Headers: r.Header,
+		Body:    body,
+		User:    httpUser,
+	}
+
+	// Call the plugin using binary framing for []byte Body fields
+	resp, err := callPluginFunctionRaw(
+		ctx, p, FuncHTTPHandleRequest,
+		pluginReq, pluginReq.Body,
+		func(r *capabilities.HTTPHandleResponse, raw []byte) { r.Body = raw },
+	)
+	if err != nil {
+		log.Error(ctx, "Plugin endpoint call failed", "plugin", p.name, "path", relPath, err)
+		http.Error(w, "Internal Server Error", http.StatusInternalServerError)
+		return
+	}
+
+	// Write response headers from plugin
+	for key, values := range resp.Headers {
+		for _, v := range values {
+			w.Header().Add(key, v)
+		}
+	}
+
+	// Security hardening: override any plugin-set security headers
+	w.Header().Set("X-Content-Type-Options", "nosniff")
+	w.Header().Set("Content-Security-Policy", "default-src 'none'; style-src 'unsafe-inline'; img-src data:; sandbox")
+
+	// Write status code (default to 200)
+	status := int(resp.Status)
+	if status == 0 {
+		status = http.StatusOK
+	}
+	w.WriteHeader(status)
+
+	// Write response body
+	if len(resp.Body) > 0 {
+		if _, err := w.Write(resp.Body); err != nil {
+			log.Error(ctx, "Failed to write plugin endpoint response", "plugin", p.name, err)
+		}
+	}
+}

plugins/http_endpoint_test.go

@@ -0,0 +1,480 @@
+//go:build !windows
+
+package plugins
+
+import (
+	"crypto/sha256"
+	"encoding/hex"
+	"encoding/json"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/navidrome/navidrome/conf"
+	"github.com/navidrome/navidrome/conf/configtest"
+	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/model/request"
+	"github.com/navidrome/navidrome/tests"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+// fakeNativeAuth is a mock native auth middleware that authenticates by looking up
+// the "X-Test-User" header and setting the user in the context.
+func fakeNativeAuth(ds model.DataStore) func(next http.Handler) http.Handler {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			username := r.Header.Get("X-Test-User")
+			if username == "" {
+				http.Error(w, "Not authenticated", http.StatusUnauthorized)
+				return
+			}
+			user, err := ds.User(r.Context()).FindByUsername(username)
+			if err != nil {
+				http.Error(w, "Not authenticated", http.StatusUnauthorized)
+				return
+			}
+			ctx := request.WithUser(r.Context(), *user)
+			ctx = request.WithUsername(ctx, user.UserName)
+			next.ServeHTTP(w, r.WithContext(ctx))
+		})
+	}
+}
+
+// fakeSubsonicAuth is a mock subsonic auth that validates by looking up
+// the "u" query parameter.
+func fakeSubsonicAuth(ds model.DataStore, r *http.Request) (*model.User, error) {
+	username := r.URL.Query().Get("u")
+	if username == "" {
+		return nil, model.ErrInvalidAuth
+	}
+	user, err := ds.User(r.Context()).FindByUsername(username)
+	if err != nil {
+		return nil, model.ErrInvalidAuth
+	}
+	return user, nil
+}
+
+var _ = Describe("HTTP Endpoint Handler", Ordered, func() {
+	var (
+		manager   *Manager
+		tmpDir    string
+		userRepo  *tests.MockedUserRepo
+		dataStore *tests.MockDataStore
+		router    http.Handler
+	)
+
+	BeforeAll(func() {
+		var err error
+		tmpDir, err = os.MkdirTemp("", "http-endpoint-test-*")
+		Expect(err).ToNot(HaveOccurred())
+
+		// Copy all test plugins
+		for _, pluginName := range []string{"test-http-endpoint", "test-http-endpoint-public", "test-http-endpoint-native"} {
+			srcPath := filepath.Join(testdataDir, pluginName+PackageExtension)
+			destPath := filepath.Join(tmpDir, pluginName+PackageExtension)
+			data, err := os.ReadFile(srcPath)
+			Expect(err).ToNot(HaveOccurred())
+			err = os.WriteFile(destPath, data, 0600)
+			Expect(err).ToNot(HaveOccurred())
+		}
+
+		// Setup config
+		DeferCleanup(configtest.SetupConfig())
+		conf.Server.Plugins.Enabled = true
+		conf.Server.Plugins.Folder = tmpDir
+		conf.Server.Plugins.AutoReload = false
+		conf.Server.CacheFolder = filepath.Join(tmpDir, "cache")
+
+		// Setup mock data store
+		userRepo = tests.CreateMockUserRepo()
+		dataStore = &tests.MockDataStore{MockedUser: userRepo}
+
+		// Add test users
+		_ = userRepo.Put(&model.User{
+			ID:       "user1",
+			UserName: "testuser",
+			Name:     "Test User",
+			IsAdmin:  false,
+		})
+		_ = userRepo.Put(&model.User{
+			ID:       "admin1",
+			UserName: "adminuser",
+			Name:     "Admin User",
+			IsAdmin:  true,
+		})
+
+		// Build enabled plugins list
+		var enabledPlugins model.Plugins
+		for _, pluginName := range []string{"test-http-endpoint", "test-http-endpoint-public", "test-http-endpoint-native"} {
+			pluginPath := filepath.Join(tmpDir, pluginName+PackageExtension)
+			data, err := os.ReadFile(pluginPath)
+			Expect(err).ToNot(HaveOccurred())
+			hash := sha256.Sum256(data)
+			hashHex := hex.EncodeToString(hash[:])
+
+			enabledPlugins = append(enabledPlugins, model.Plugin{
+				ID:       pluginName,
+				Path:     pluginPath,
+				SHA256:   hashHex,
+				Enabled:  true,
+				AllUsers: true,
+			})
+		}
+
+		// Setup mock plugin repo
+		mockPluginRepo := dataStore.Plugin(GinkgoT().Context()).(*tests.MockPluginRepo)
+		mockPluginRepo.Permitted = true
+		mockPluginRepo.SetData(enabledPlugins)
+
+		// Create and start manager
+		manager = &Manager{
+			plugins:        make(map[string]*plugin),
+			ds:             dataStore,
+			metrics:        noopMetricsRecorder{},
+			subsonicRouter: http.NotFoundHandler(),
+		}
+		err = manager.Start(GinkgoT().Context())
+		Expect(err).ToNot(HaveOccurred())
+
+		// Create the endpoint router with fake auth functions
+		router = NewEndpointRouter(manager, dataStore, fakeSubsonicAuth, fakeNativeAuth)
+
+		DeferCleanup(func() {
+			_ = manager.Stop()
+			_ = os.RemoveAll(tmpDir)
+		})
+	})
+
+	Describe("Plugin Loading", func() {
+		It("loads the authenticated endpoint plugin", func() {
+			manager.mu.RLock()
+			p := manager.plugins["test-http-endpoint"]
+			manager.mu.RUnlock()
+
+			Expect(p).ToNot(BeNil())
+			Expect(p.manifest.Name).To(Equal("Test HTTP Endpoint Plugin"))
+			Expect(p.manifest.Permissions.Endpoints).ToNot(BeNil())
+			Expect(string(p.manifest.Permissions.Endpoints.Auth)).To(Equal("subsonic"))
+			Expect(hasCapability(p.capabilities, CapabilityHTTPEndpoint)).To(BeTrue())
+		})
+
+		It("loads the native auth endpoint plugin", func() {
+			manager.mu.RLock()
+			p := manager.plugins["test-http-endpoint-native"]
+			manager.mu.RUnlock()
+
+			Expect(p).ToNot(BeNil())
+			Expect(p.manifest.Name).To(Equal("Test HTTP Endpoint Native Plugin"))
+			Expect(p.manifest.Permissions.Endpoints).ToNot(BeNil())
+			Expect(string(p.manifest.Permissions.Endpoints.Auth)).To(Equal("native"))
+			Expect(hasCapability(p.capabilities, CapabilityHTTPEndpoint)).To(BeTrue())
+		})
+
+		It("loads the public endpoint plugin", func() {
+			manager.mu.RLock()
+			p := manager.plugins["test-http-endpoint-public"]
+			manager.mu.RUnlock()
+
+			Expect(p).ToNot(BeNil())
+			Expect(p.manifest.Name).To(Equal("Test HTTP Endpoint Public Plugin"))
+			Expect(p.manifest.Permissions.Endpoints).ToNot(BeNil())
+			Expect(string(p.manifest.Permissions.Endpoints.Auth)).To(Equal("none"))
+			Expect(hasCapability(p.capabilities, CapabilityHTTPEndpoint)).To(BeTrue())
+		})
+	})
+
+	Describe("Subsonic Auth Endpoints", func() {
+		It("returns hello response with valid auth", func() {
+			req := httptest.NewRequest("GET", "/test-http-endpoint/hello?u=testuser", nil)
+			w := httptest.NewRecorder()
+			router.ServeHTTP(w, req)
+
+			Expect(w.Code).To(Equal(http.StatusOK))
+			Expect(w.Body.String()).To(Equal("Hello from plugin!"))
+			Expect(w.Header().Get("Content-Type")).To(Equal("text/plain"))
+		})
+
+		It("returns echo response with request details", func() {
+			req := httptest.NewRequest("POST", "/test-http-endpoint/echo?u=testuser&foo=bar", strings.NewReader("test body"))
+			w := httptest.NewRecorder()
+			router.ServeHTTP(w, req)
+
+			Expect(w.Code).To(Equal(http.StatusOK))
+			Expect(w.Header().Get("Content-Type")).To(Equal("application/json"))
+
+			var resp map[string]any
+			err := json.Unmarshal(w.Body.Bytes(), &resp)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(resp["method"]).To(Equal("POST"))
+			Expect(resp["path"]).To(Equal("/echo"))
+			Expect(resp["body"]).To(Equal("test body"))
+			Expect(resp["hasUser"]).To(BeTrue())
+			Expect(resp["username"]).To(Equal("testuser"))
+		})
+
+		It("returns plugin-defined error status", func() {
+			req := httptest.NewRequest("GET", "/test-http-endpoint/error?u=testuser", nil)
+			w := httptest.NewRecorder()
+			router.ServeHTTP(w, req)
+
+			Expect(w.Code).To(Equal(http.StatusInternalServerError))
+			Expect(w.Body.String()).To(Equal("Something went wrong"))
+		})
+
+		It("returns plugin 404 for unknown paths", func() {
+			req := httptest.NewRequest("GET", "/test-http-endpoint/unknown?u=testuser", nil)
+			w := httptest.NewRecorder()
+			router.ServeHTTP(w, req)
+
+			Expect(w.Code).To(Equal(http.StatusNotFound))
+			Expect(w.Body.String()).To(Equal("Not found: /unknown"))
+		})
+
+		It("returns 401 without auth credentials", func() {
+			req := httptest.NewRequest("GET", "/test-http-endpoint/hello", nil)
+			w := httptest.NewRecorder()
+			router.ServeHTTP(w, req)
+
+			Expect(w.Code).To(Equal(http.StatusUnauthorized))
+		})
+
+		It("returns 401 with invalid auth credentials", func() {
+			req := httptest.NewRequest("GET", "/test-http-endpoint/hello?u=nonexistent", nil)
+			w := httptest.NewRecorder()
+			router.ServeHTTP(w, req)
+
+			Expect(w.Code).To(Equal(http.StatusUnauthorized))
+		})
+	})
+
+	Describe("Native Auth Endpoints", func() {
+		It("returns hello response with valid native auth", func() {
+			req := httptest.NewRequest("GET", "/test-http-endpoint-native/hello", nil)
+			req.Header.Set("X-Test-User", "testuser")
+			w := httptest.NewRecorder()
+			router.ServeHTTP(w, req)
+
+			Expect(w.Code).To(Equal(http.StatusOK))
+			Expect(w.Body.String()).To(Equal("Hello from native auth plugin!"))
+			Expect(w.Header().Get("Content-Type")).To(Equal("text/plain"))
+		})
+
+		It("returns echo response with user details", func() {
+			req := httptest.NewRequest("POST", "/test-http-endpoint-native/echo?foo=bar", strings.NewReader("native body"))
+			req.Header.Set("X-Test-User", "adminuser")
+			w := httptest.NewRecorder()
+			router.ServeHTTP(w, req)
+
+			Expect(w.Code).To(Equal(http.StatusOK))
+			Expect(w.Header().Get("Content-Type")).To(Equal("application/json"))
+
+			var resp map[string]any
+			err := json.Unmarshal(w.Body.Bytes(), &resp)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(resp["method"]).To(Equal("POST"))
+			Expect(resp["path"]).To(Equal("/echo"))
+			Expect(resp["body"]).To(Equal("native body"))
+			Expect(resp["hasUser"]).To(BeTrue())
+			Expect(resp["username"]).To(Equal("adminuser"))
+		})
+
+		It("returns 401 without auth header", func() {
+			req := httptest.NewRequest("GET", "/test-http-endpoint-native/hello", nil)
+			w := httptest.NewRecorder()
+			router.ServeHTTP(w, req)
+
+			Expect(w.Code).To(Equal(http.StatusUnauthorized))
+		})
+
+		It("returns 401 with invalid auth header", func() {
+			req := httptest.NewRequest("GET", "/test-http-endpoint-native/hello", nil)
+			req.Header.Set("X-Test-User", "nonexistent")
+			w := httptest.NewRecorder()
+			router.ServeHTTP(w, req)
+
+			Expect(w.Code).To(Equal(http.StatusUnauthorized))
+		})
+	})
+
+	Describe("Public Endpoints (auth: none)", func() {
+		It("returns webhook response without auth", func() {
+			req := httptest.NewRequest("POST", "/test-http-endpoint-public/webhook", nil)
+			w := httptest.NewRecorder()
+			router.ServeHTTP(w, req)
+
+			Expect(w.Code).To(Equal(http.StatusOK))
+			Expect(w.Body.String()).To(Equal("webhook received"))
+		})
+
+		It("does not pass user info to public endpoints", func() {
+			req := httptest.NewRequest("GET", "/test-http-endpoint-public/check-no-user", nil)
+			w := httptest.NewRecorder()
+			router.ServeHTTP(w, req)
+
+			Expect(w.Code).To(Equal(http.StatusOK))
+			Expect(w.Body.String()).To(Equal("hasUser=false"))
+		})
+	})
+
+	Describe("Security Headers", func() {
+		It("includes security headers in authenticated endpoint responses", func() {
+			req := httptest.NewRequest("GET", "/test-http-endpoint/hello?u=testuser", nil)
+			w := httptest.NewRecorder()
+			router.ServeHTTP(w, req)
+
+			Expect(w.Code).To(Equal(http.StatusOK))
+			Expect(w.Header().Get("X-Content-Type-Options")).To(Equal("nosniff"))
+			Expect(w.Header().Get("Content-Security-Policy")).To(Equal("default-src 'none'; style-src 'unsafe-inline'; img-src data:; sandbox"))
+		})
+
+		It("includes security headers in public endpoint responses", func() {
+			req := httptest.NewRequest("POST", "/test-http-endpoint-public/webhook", nil)
+			w := httptest.NewRecorder()
+			router.ServeHTTP(w, req)
+
+			Expect(w.Code).To(Equal(http.StatusOK))
+			Expect(w.Header().Get("X-Content-Type-Options")).To(Equal("nosniff"))
+			Expect(w.Header().Get("Content-Security-Policy")).To(Equal("default-src 'none'; style-src 'unsafe-inline'; img-src data:; sandbox"))
+		})
+
+		It("overrides plugin-set security headers", func() {
+			req := httptest.NewRequest("POST", "/test-http-endpoint/echo?u=testuser", strings.NewReader("body"))
+			w := httptest.NewRecorder()
+			router.ServeHTTP(w, req)
+
+			Expect(w.Code).To(Equal(http.StatusOK))
+			Expect(w.Header().Get("X-Content-Type-Options")).To(Equal("nosniff"))
+			Expect(w.Header().Get("Content-Security-Policy")).To(Equal("default-src 'none'; style-src 'unsafe-inline'; img-src data:; sandbox"))
+		})
+	})
+
+	Describe("Unknown Plugin", func() {
+		It("returns 404 for nonexistent plugin", func() {
+			req := httptest.NewRequest("GET", "/nonexistent-plugin/hello", nil)
+			w := httptest.NewRecorder()
+			router.ServeHTTP(w, req)
+
+			Expect(w.Code).To(Equal(http.StatusNotFound))
+		})
+	})
+
+	Describe("User Authorization", func() {
+		var restrictedRouter http.Handler
+
+		BeforeAll(func() {
+			// Create a manager with a plugin restricted to specific users
+			restrictedTmpDir, err := os.MkdirTemp("", "http-endpoint-restricted-test-*")
+			Expect(err).ToNot(HaveOccurred())
+
+			srcPath := filepath.Join(testdataDir, "test-http-endpoint"+PackageExtension)
+			destPath := filepath.Join(restrictedTmpDir, "test-http-endpoint"+PackageExtension)
+			data, err := os.ReadFile(srcPath)
+			Expect(err).ToNot(HaveOccurred())
+			err = os.WriteFile(destPath, data, 0600)
+			Expect(err).ToNot(HaveOccurred())
+
+			hash := sha256.Sum256(data)
+			hashHex := hex.EncodeToString(hash[:])
+
+			DeferCleanup(configtest.SetupConfig())
+			conf.Server.Plugins.Enabled = true
+			conf.Server.Plugins.Folder = restrictedTmpDir
+			conf.Server.Plugins.AutoReload = false
+			conf.Server.CacheFolder = filepath.Join(restrictedTmpDir, "cache")
+
+			restrictedPluginRepo := tests.CreateMockPluginRepo()
+			restrictedPluginRepo.Permitted = true
+			restrictedPluginRepo.SetData(model.Plugins{{
+				ID:       "test-http-endpoint",
+				Path:     destPath,
+				SHA256:   hashHex,
+				Enabled:  true,
+				AllUsers: false,
+				Users:    `["admin1"]`, // Only admin1 is allowed
+			}})
+			restrictedDS := &tests.MockDataStore{
+				MockedPlugin: restrictedPluginRepo,
+				MockedUser:   userRepo,
+			}
+
+			restrictedManager := &Manager{
+				plugins:        make(map[string]*plugin),
+				ds:             restrictedDS,
+				metrics:        noopMetricsRecorder{},
+				subsonicRouter: http.NotFoundHandler(),
+			}
+			err = restrictedManager.Start(GinkgoT().Context())
+			Expect(err).ToNot(HaveOccurred())
+
+			restrictedRouter = NewEndpointRouter(restrictedManager, restrictedDS, fakeSubsonicAuth, fakeNativeAuth)
+
+			DeferCleanup(func() {
+				_ = restrictedManager.Stop()
+				_ = os.RemoveAll(restrictedTmpDir)
+			})
+		})
+
+		It("allows authorized users", func() {
+			req := httptest.NewRequest("GET", "/test-http-endpoint/hello?u=adminuser", nil)
+			w := httptest.NewRecorder()
+			restrictedRouter.ServeHTTP(w, req)
+
+			Expect(w.Code).To(Equal(http.StatusOK))
+			Expect(w.Body.String()).To(Equal("Hello from plugin!"))
+		})
+
+		It("denies unauthorized users", func() {
+			req := httptest.NewRequest("GET", "/test-http-endpoint/hello?u=testuser", nil)
+			w := httptest.NewRecorder()
+			restrictedRouter.ServeHTTP(w, req)
+
+			Expect(w.Code).To(Equal(http.StatusForbidden))
+		})
+	})
+
+	Describe("Request without trailing path", func() {
+		It("handles requests to plugin root", func() {
+			req := httptest.NewRequest("GET", "/test-http-endpoint-public/webhook", nil)
+			w := httptest.NewRecorder()
+			router.ServeHTTP(w, req)
+
+			Expect(w.Code).To(Equal(http.StatusOK))
+		})
+	})
+
+	Describe("Binary Response", func() {
+		It("returns raw binary data intact", func() {
+			req := httptest.NewRequest("GET", "/test-http-endpoint/binary?u=testuser", nil)
+			w := httptest.NewRecorder()
+			router.ServeHTTP(w, req)
+
+			Expect(w.Code).To(Equal(http.StatusOK))
+			Expect(w.Header().Get("Content-Type")).To(Equal("image/png"))
+			// PNG header bytes
+			Expect(w.Body.Bytes()).To(Equal([]byte{0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A}))
+		})
+	})
+
+	Describe("Request body handling", func() {
+		It("passes request body to the plugin", func() {
+			body := `{"event":"push","ref":"refs/heads/main"}`
+			req := httptest.NewRequest("POST", "/test-http-endpoint/echo?u=testuser", strings.NewReader(body))
+			w := httptest.NewRecorder()
+			router.ServeHTTP(w, req)
+
+			Expect(w.Code).To(Equal(http.StatusOK))
+
+			respBody, err := io.ReadAll(w.Body)
+			Expect(err).ToNot(HaveOccurred())
+
+			var resp map[string]any
+			err = json.Unmarshal(respBody, &resp)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(resp["body"]).To(Equal(body))
+		})
+	})
+})

plugins/manager.go

@@ -260,19 +260,10 @@ func (m *Manager) LoadScrobbler(name string) (scrobbler.Scrobbler, bool) {
 		return nil, false
 	}
 
-	// Build user ID map for fast lookups
-	userIDMap := make(map[string]struct{})
-	for _, id := range plugin.allowedUserIDs {
-		userIDMap[id] = struct{}{}
-	}
-
-	// Create a new scrobbler adapter for this plugin with user authorization config
+	// Create a new scrobbler adapter for this plugin
 	return &ScrobblerPlugin{
-		name:           plugin.name,
-		plugin:         plugin,
-		allowedUserIDs: plugin.allowedUserIDs,
-		allUsers:       plugin.allUsers,
-		userIDMap:      userIDMap,
+		name:   plugin.name,
+		plugin: plugin,
 	}, true
 }
 

plugins/manager_call.go

@@ -2,6 +2,7 @@ package plugins
 
 import (
 	"context"
+	"encoding/binary"
 	"encoding/json"
 	"errors"
 	"fmt"
@@ -60,39 +61,147 @@ func callPluginFunction[I any, O any](ctx context.Context, plugin *plugin, funcN
 	startCall := time.Now()
 	exit, output, err := p.CallWithContext(ctx, funcName, inputBytes)
 	elapsed := time.Since(startCall)
+
+	success := false
+	skipMetrics := false
+	defer func() {
+		if !skipMetrics {
+			plugin.metrics.RecordPluginRequest(ctx, plugin.name, funcName, success, elapsed.Milliseconds())
+		}
+	}()
+
 	if err != nil {
 		// If context was cancelled, return that error instead of the plugin error
 		if ctx.Err() != nil {
+			skipMetrics = true
 			log.Debug(ctx, "Plugin call cancelled", "plugin", plugin.name, "function", funcName, "pluginDuration", elapsed)
 			return result, ctx.Err()
 		}
-		plugin.metrics.RecordPluginRequest(ctx, plugin.name, funcName, false, elapsed.Milliseconds())
 		log.Trace(ctx, "Plugin call failed", "plugin", plugin.name, "function", funcName, "pluginDuration", elapsed, "navidromeDuration", startCall.Sub(start), err)
 		return result, fmt.Errorf("plugin call failed: %w", err)
 	}
 	if exit != 0 {
 		if exit == notImplementedCode {
+			skipMetrics = true
 			log.Trace(ctx, "Plugin function not implemented", "plugin", plugin.name, "function", funcName, "pluginDuration", elapsed, "navidromeDuration", startCall.Sub(start))
-			// TODO Should we record metrics for not implemented calls?
-			//plugin.metrics.RecordPluginRequest(ctx, plugin.name, funcName, true, elapsed.Milliseconds())
 			return result, fmt.Errorf("%w: %s", errNotImplemented, funcName)
 		}
-		plugin.metrics.RecordPluginRequest(ctx, plugin.name, funcName, false, elapsed.Milliseconds())
 		return result, fmt.Errorf("plugin call exited with code %d", exit)
 	}
 
 	if len(output) > 0 {
-		err = json.Unmarshal(output, &result)
-		if err != nil {
+		if err = json.Unmarshal(output, &result); err != nil {
 			log.Trace(ctx, "Plugin call failed", "plugin", plugin.name, "function", funcName, "pluginDuration", elapsed, "navidromeDuration", startCall.Sub(start), err)
+			return result, err
 		}
 	}
 
-	// Record metrics for successful calls (or JSON unmarshal failures)
-	plugin.metrics.RecordPluginRequest(ctx, plugin.name, funcName, err == nil, elapsed.Milliseconds())
-
+	success = true
 	log.Trace(ctx, "Plugin call succeeded", "plugin", plugin.name, "function", funcName, "pluginDuration", time.Since(startCall), "navidromeDuration", startCall.Sub(start))
-	return result, err
+	return result, nil
+}
+
+// callPluginFunctionRaw calls a plugin function using binary framing for []byte fields.
+// The input is JSON-encoded (with []byte field excluded via json:"-"), followed by raw bytes.
+// The output frame is: [status:1B][json_len:4B][JSON][raw bytes] for success (0x00),
+// or [0x01][UTF-8 error message] for errors.
+func callPluginFunctionRaw[I any, O any](
+	ctx context.Context, plugin *plugin, funcName string,
+	input I, rawInputBytes []byte,
+	setRawOutput func(*O, []byte),
+) (O, error) {
+	start := time.Now()
+
+	var result O
+
+	p, err := plugin.instance(ctx)
+	if err != nil {
+		return result, fmt.Errorf("failed to create plugin: %w", err)
+	}
+	defer p.Close(ctx)
+
+	if !p.FunctionExists(funcName) {
+		log.Trace(ctx, "Plugin function not found", "plugin", plugin.name, "function", funcName)
+		return result, fmt.Errorf("%w: %s", errFunctionNotFound, funcName)
+	}
+
+	// Build input frame: [json_len:4B][JSON][raw bytes]
+	jsonBytes, err := json.Marshal(input)
+	if err != nil {
+		return result, fmt.Errorf("failed to marshal input: %w", err)
+	}
+	const maxFrameSize = 2 << 20 // 2 MiB
+	if len(jsonBytes) > maxFrameSize || len(rawInputBytes) > maxFrameSize {
+		return result, fmt.Errorf("input frame too large")
+	}
+	frame := make([]byte, 4+len(jsonBytes)+len(rawInputBytes))
+	binary.BigEndian.PutUint32(frame[:4], uint32(len(jsonBytes)))
+	copy(frame[4:4+len(jsonBytes)], jsonBytes)
+	copy(frame[4+len(jsonBytes):], rawInputBytes)
+
+	startCall := time.Now()
+	exit, output, err := p.CallWithContext(ctx, funcName, frame)
+	elapsed := time.Since(startCall)
+
+	success := false
+	skipMetrics := false
+	defer func() {
+		if !skipMetrics {
+			plugin.metrics.RecordPluginRequest(ctx, plugin.name, funcName, success, elapsed.Milliseconds())
+		}
+	}()
+
+	if err != nil {
+		if ctx.Err() != nil {
+			skipMetrics = true
+			log.Debug(ctx, "Plugin call cancelled", "plugin", plugin.name, "function", funcName, "pluginDuration", elapsed)
+			return result, ctx.Err()
+		}
+		log.Trace(ctx, "Plugin call failed", "plugin", plugin.name, "function", funcName, "pluginDuration", elapsed, "navidromeDuration", startCall.Sub(start), err)
+		return result, fmt.Errorf("plugin call failed: %w", err)
+	}
+	if exit != 0 {
+		if exit == notImplementedCode {
+			skipMetrics = true
+			log.Trace(ctx, "Plugin function not implemented", "plugin", plugin.name, "function", funcName, "pluginDuration", elapsed, "navidromeDuration", startCall.Sub(start))
+			return result, fmt.Errorf("%w: %s", errNotImplemented, funcName)
+		}
+		return result, fmt.Errorf("plugin call exited with code %d", exit)
+	}
+
+	// Parse output frame
+	if len(output) < 1 {
+		return result, fmt.Errorf("empty response from plugin")
+	}
+
+	statusByte := output[0]
+	if statusByte == 0x01 {
+		return result, fmt.Errorf("plugin error: %s", string(output[1:]))
+	}
+	if statusByte != 0x00 {
+		return result, fmt.Errorf("unknown response status byte: 0x%02x", statusByte)
+	}
+
+	// Success frame: [0x00][json_len:4B][JSON][raw bytes]
+	if len(output) < 5 {
+		return result, fmt.Errorf("malformed success response from plugin")
+	}
+
+	jsonLen := binary.BigEndian.Uint32(output[1:5])
+	if uint32(len(output)-5) < jsonLen {
+		return result, fmt.Errorf("invalid json length in response frame: %d exceeds available %d bytes", jsonLen, len(output)-5)
+	}
+	jsonData := output[5 : 5+jsonLen]
+	rawData := output[5+jsonLen:]
+
+	if err := json.Unmarshal(jsonData, &result); err != nil {
+		return result, fmt.Errorf("failed to unmarshal response: %w", err)
+	}
+	setRawOutput(&result, rawData)
+
+	success = true
+	log.Trace(ctx, "Plugin call succeeded", "plugin", plugin.name, "function", funcName, "pluginDuration", time.Since(startCall), "navidromeDuration", startCall.Sub(start))
+	return result, nil
 }
 
 // extismLogger is a helper to log messages from Extism plugins

plugins/manager_loader.go

@@ -24,10 +24,9 @@ type serviceContext struct {
 	manager          *Manager
 	permissions      *Permissions
 	config           map[string]string
-	allowedUsers     []string // User IDs this plugin can access
-	allUsers         bool     // If true, plugin can access all users
-	allowedLibraries []int    // Library IDs this plugin can access
-	allLibraries     bool     // If true, plugin can access all libraries
+	userAccess       UserAccess // User authorization for this plugin
+	allowedLibraries []int      // Library IDs this plugin can access
+	allLibraries     bool       // If true, plugin can access all libraries
 }
 
 // hostServiceEntry defines a host service for table-driven registration.
@@ -52,7 +51,7 @@ var hostServices = []hostServiceEntry{
 		name:          "SubsonicAPI",
 		hasPermission: func(p *Permissions) bool { return p != nil && p.Subsonicapi != nil },
 		create: func(ctx *serviceContext) ([]extism.HostFunction, io.Closer) {
-			service := newSubsonicAPIService(ctx.pluginName, ctx.manager.subsonicRouter, ctx.manager.ds, ctx.allowedUsers, ctx.allUsers)
+			service := newSubsonicAPIService(ctx.pluginName, ctx.manager.subsonicRouter, ctx.manager.ds, ctx.userAccess)
 			return host.RegisterSubsonicAPIHostFunctions(service), nil
 		},
 	},
@@ -115,7 +114,7 @@ var hostServices = []hostServiceEntry{
 		name:          "Users",
 		hasPermission: func(p *Permissions) bool { return p != nil && p.Users != nil },
 		create: func(ctx *serviceContext) ([]extism.HostFunction, io.Closer) {
-			service := newUsersService(ctx.manager.ds, ctx.allowedUsers, ctx.allUsers)
+			service := newUsersService(ctx.manager.ds, ctx.userAccess)
 			return host.RegisterUsersHostFunctions(service), nil
 		},
 	},
@@ -302,13 +301,14 @@ func (m *Manager) loadPluginWithConfig(p *model.Plugin) error {
 	var hostFunctions []extism.HostFunction
 	var closers []io.Closer
 
+	userAccess := NewUserAccess(p.AllUsers, allowedUsers)
+
 	svcCtx := &serviceContext{
 		pluginName:       p.ID,
 		manager:          m,
 		permissions:      pkg.Manifest.Permissions,
 		config:           pluginConfig,
-		allowedUsers:     allowedUsers,
-		allUsers:         p.AllUsers,
+		userAccess:       userAccess,
 		allowedLibraries: allowedLibraries,
 		allLibraries:     p.AllLibraries,
 	}
@@ -361,15 +361,14 @@ func (m *Manager) loadPluginWithConfig(p *model.Plugin) error {
 
 	m.mu.Lock()
 	m.plugins[p.ID] = &plugin{
-		name:           p.ID,
-		path:           p.Path,
-		manifest:       pkg.Manifest,
-		compiled:       compiled,
-		capabilities:   capabilities,
-		closers:        closers,
-		metrics:        m.metrics,
-		allowedUserIDs: allowedUsers,
-		allUsers:       p.AllUsers,
+		name:         p.ID,
+		path:         p.Path,
+		manifest:     pkg.Manifest,
+		compiled:     compiled,
+		capabilities: capabilities,
+		closers:      closers,
+		metrics:      m.metrics,
+		userAccess:   userAccess,
 	}
 	m.mu.Unlock()
 

plugins/manager_plugin.go

@@ -12,15 +12,14 @@ import (
 
 // plugin represents a loaded plugin
 type plugin struct {
-	name           string // Plugin name (from filename)
-	path           string // Path to the wasm file
-	manifest       *Manifest
-	compiled       *extism.CompiledPlugin
-	capabilities   []Capability // Auto-detected capabilities based on exported functions
-	closers        []io.Closer  // Cleanup functions to call on unload
-	metrics        PluginMetricsRecorder
-	allowedUserIDs []string // User IDs this plugin can access (from DB configuration)
-	allUsers       bool     // If true, plugin can access all users
+	name         string // Plugin name (from filename)
+	path         string // Path to the wasm file
+	manifest     *Manifest
+	compiled     *extism.CompiledPlugin
+	capabilities []Capability // Auto-detected capabilities based on exported functions
+	closers      []io.Closer  // Cleanup functions to call on unload
+	metrics      PluginMetricsRecorder
+	userAccess   UserAccess // User authorization for this plugin
 }
 
 // instance creates a new plugin instance for the given context.

plugins/manifest-schema.json

@@ -110,6 +110,33 @@
         },
         "users": {
           "$ref": "#/$defs/UsersPermission"
+        },
+        "endpoints": {
+          "$ref": "#/$defs/EndpointsPermission"
+        }
+      }
+    },
+    "EndpointsPermission": {
+      "type": "object",
+      "description": "HTTP endpoint permissions for registering custom HTTP endpoints on the Navidrome server. Requires 'users' permission when auth is 'native' or 'subsonic'.",
+      "additionalProperties": false,
+      "required": ["auth"],
+      "properties": {
+        "reason": {
+          "type": "string",
+          "description": "Explanation for why HTTP endpoint registration is needed"
+        },
+        "auth": {
+          "type": "string",
+          "enum": ["native", "subsonic", "none"],
+          "description": "Authentication type for plugin endpoints: 'native' (JWT), 'subsonic' (params), or 'none' (public/unauthenticated)"
+        },
+        "paths": {
+          "type": "array",
+          "description": "Declared endpoint paths (informational, for admin UI display). Relative to plugin base URL.",
+          "items": {
+            "type": "string"
+          }
         }
       }
     },

plugins/manifest.go

@@ -32,6 +32,15 @@ func (m *Manifest) Validate() error {
 		}
 	}
 
+	// Endpoints permission with auth 'native' or 'subsonic' requires users permission
+	if m.Permissions != nil && m.Permissions.Endpoints != nil {
+		if m.Permissions.Endpoints.Auth != EndpointsPermissionAuthNone {
+			if m.Permissions.Users == nil {
+				return fmt.Errorf("'endpoints' permission with auth '%s' requires 'users' permission to be declared", m.Permissions.Endpoints.Auth)
+			}
+		}
+	}
+
 	// Validate config schema if present
 	if m.Config != nil && m.Config.Schema != nil {
 		if err := validateConfigSchema(m.Config.Schema); err != nil {
@@ -64,6 +73,14 @@ func ValidateWithCapabilities(m *Manifest, capabilities []Capability) error {
 			return fmt.Errorf("scrobbler capability requires 'users' permission to be declared in manifest")
 		}
 	}
+
+	// HTTPEndpoint capability requires endpoints permission
+	if hasCapability(capabilities, CapabilityHTTPEndpoint) {
+		if m.Permissions == nil || m.Permissions.Endpoints == nil {
+			return fmt.Errorf("HTTP endpoint capability requires 'endpoints' permission to be declared in manifest")
+		}
+	}
+
 	return nil
 }
 

plugins/manifest_gen.go

@@ -4,6 +4,7 @@ package plugins
 
 import "encoding/json"
 import "fmt"
+import "reflect"
 
 // Artwork service permissions for generating artwork URLs
 type ArtworkPermission struct {
@@ -45,6 +46,71 @@ func (j *ConfigDefinition) UnmarshalJSON(value []byte) error {
 	return nil
 }
 
+// HTTP endpoint permissions for registering custom HTTP endpoints on the Navidrome
+// server. Requires 'users' permission when auth is 'native' or 'subsonic'.
+type EndpointsPermission struct {
+	// Authentication type for plugin endpoints: 'native' (JWT), 'subsonic' (params),
+	// or 'none' (public/unauthenticated)
+	Auth EndpointsPermissionAuth `json:"auth" yaml:"auth" mapstructure:"auth"`
+
+	// Declared endpoint paths (informational, for admin UI display). Relative to
+	// plugin base URL.
+	Paths []string `json:"paths,omitempty" yaml:"paths,omitempty" mapstructure:"paths,omitempty"`
+
+	// Explanation for why HTTP endpoint registration is needed
+	Reason *string `json:"reason,omitempty" yaml:"reason,omitempty" mapstructure:"reason,omitempty"`
+}
+
+type EndpointsPermissionAuth string
+
+const EndpointsPermissionAuthNative EndpointsPermissionAuth = "native"
+const EndpointsPermissionAuthNone EndpointsPermissionAuth = "none"
+const EndpointsPermissionAuthSubsonic EndpointsPermissionAuth = "subsonic"
+
+var enumValues_EndpointsPermissionAuth = []interface{}{
+	"native",
+	"subsonic",
+	"none",
+}
+
+// UnmarshalJSON implements json.Unmarshaler.
+func (j *EndpointsPermissionAuth) UnmarshalJSON(value []byte) error {
+	var v string
+	if err := json.Unmarshal(value, &v); err != nil {
+		return err
+	}
+	var ok bool
+	for _, expected := range enumValues_EndpointsPermissionAuth {
+		if reflect.DeepEqual(v, expected) {
+			ok = true
+			break
+		}
+	}
+	if !ok {
+		return fmt.Errorf("invalid value (expected one of %#v): %#v", enumValues_EndpointsPermissionAuth, v)
+	}
+	*j = EndpointsPermissionAuth(v)
+	return nil
+}
+
+// UnmarshalJSON implements json.Unmarshaler.
+func (j *EndpointsPermission) UnmarshalJSON(value []byte) error {
+	var raw map[string]interface{}
+	if err := json.Unmarshal(value, &raw); err != nil {
+		return err
+	}
+	if _, ok := raw["auth"]; raw != nil && !ok {
+		return fmt.Errorf("field auth in EndpointsPermission: required")
+	}
+	type Plain EndpointsPermission
+	var plain Plain
+	if err := json.Unmarshal(value, &plain); err != nil {
+		return err
+	}
+	*j = EndpointsPermission(plain)
+	return nil
+}
+
 // Experimental features that may change or be removed in future versions
 type Experimental struct {
 	// Threads corresponds to the JSON schema field "threads".
@@ -166,6 +232,9 @@ type Permissions struct {
 	// Cache corresponds to the JSON schema field "cache".
 	Cache *CachePermission `json:"cache,omitempty" yaml:"cache,omitempty" mapstructure:"cache,omitempty"`
 
+	// Endpoints corresponds to the JSON schema field "endpoints".
+	Endpoints *EndpointsPermission `json:"endpoints,omitempty" yaml:"endpoints,omitempty" mapstructure:"endpoints,omitempty"`
+
 	// Http corresponds to the JSON schema field "http".
 	Http *HTTPPermission `json:"http,omitempty" yaml:"http,omitempty" mapstructure:"http,omitempty"`
 

plugins/pdk/go/go.mod

@@ -6,3 +6,10 @@ require (
 	github.com/extism/go-pdk v1.1.3
 	github.com/stretchr/testify v1.11.1
 )
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/stretchr/objx v0.5.2 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)

plugins/pdk/go/httpendpoint/httpendpoint.go

@@ -0,0 +1,126 @@
+// Code generated by ndpgen. DO NOT EDIT.
+//
+// This file contains export wrappers for the HTTPEndpoint capability.
+// It is intended for use in Navidrome plugins built with TinyGo.
+//
+//go:build wasip1
+
+package httpendpoint
+
+import (
+	"encoding/binary"
+	"encoding/json"
+
+	"github.com/navidrome/navidrome/plugins/pdk/go/pdk"
+)
+
+// HTTPHandleRequest is the input provided when an HTTP request is dispatched to a plugin.
+type HTTPHandleRequest struct {
+	// Method is the HTTP method (GET, POST, PUT, DELETE, PATCH, etc.).
+	Method string `json:"method"`
+	// Path is the request path relative to the plugin's base URL.
+	// For example, if the full URL is /ext/my-plugin/webhook, Path is "/webhook".
+	// Both /ext/my-plugin and /ext/my-plugin/ are normalized to Path = "".
+	Path string `json:"path"`
+	// Query is the raw query string without the leading '?'.
+	Query string `json:"query,omitempty"`
+	// Headers contains the HTTP request headers.
+	Headers map[string][]string `json:"headers,omitempty"`
+	// Body is the request body content.
+	Body []byte `json:"-"`
+	// User contains the authenticated user information. Nil for auth:"none" endpoints.
+	User *HTTPUser `json:"user,omitempty"`
+}
+
+// HTTPHandleResponse is the response returned by the plugin's HandleRequest function.
+type HTTPHandleResponse struct {
+	// Status is the HTTP status code. Defaults to 200 if zero or not set.
+	Status int32 `json:"status,omitempty"`
+	// Headers contains the HTTP response headers to set.
+	Headers map[string][]string `json:"headers,omitempty"`
+	// Body is the response body content.
+	Body []byte `json:"-"`
+}
+
+// HTTPUser contains authenticated user information passed to the plugin.
+type HTTPUser struct {
+	// ID is the internal Navidrome user ID.
+	ID string `json:"id"`
+	// Username is the user's login name.
+	Username string `json:"username"`
+	// Name is the user's display name.
+	Name string `json:"name"`
+	// IsAdmin indicates whether the user has admin privileges.
+	IsAdmin bool `json:"isAdmin"`
+}
+
+// HTTPEndpoint requires all methods to be implemented.
+// HTTPEndpoint allows plugins to handle incoming HTTP requests.
+// Plugins that declare the 'endpoints' permission must implement this capability.
+// The host dispatches incoming HTTP requests to the plugin's HandleRequest function.
+type HTTPEndpoint interface {
+	// HandleRequest - HandleRequest processes an incoming HTTP request and returns a response.
+	HandleRequest(HTTPHandleRequest) (HTTPHandleResponse, error)
+} // Internal implementation holders
+var (
+	handleRequestImpl func(HTTPHandleRequest) (HTTPHandleResponse, error)
+)
+
+// Register registers a httpendpoint implementation.
+// All methods are required.
+func Register(impl HTTPEndpoint) {
+	handleRequestImpl = impl.HandleRequest
+}
+
+// NotImplementedCode is the standard return code for unimplemented functions.
+// The host recognizes this and skips the plugin gracefully.
+const NotImplementedCode int32 = -2
+
+//go:wasmexport nd_http_handle_request
+func _NdHttpHandleRequest() int32 {
+	if handleRequestImpl == nil {
+		// Return standard code - host will skip this plugin gracefully
+		return NotImplementedCode
+	}
+
+	// Parse input frame: [json_len:4B][JSON without []byte field][raw bytes]
+	raw := pdk.Input()
+	if len(raw) < 4 {
+		pdk.SetErrorString("malformed input frame")
+		return -1
+	}
+	jsonLen := binary.BigEndian.Uint32(raw[:4])
+	if uint32(len(raw)-4) < jsonLen {
+		pdk.SetErrorString("invalid json length in input frame")
+		return -1
+	}
+	var input HTTPHandleRequest
+	if err := json.Unmarshal(raw[4:4+jsonLen], &input); err != nil {
+		pdk.SetError(err)
+		return -1
+	}
+	input.Body = raw[4+jsonLen:]
+
+	output, err := handleRequestImpl(input)
+	if err != nil {
+		// Error frame: [0x01][UTF-8 error message]
+		errMsg := []byte(err.Error())
+		errFrame := make([]byte, 1+len(errMsg))
+		errFrame[0] = 0x01
+		copy(errFrame[1:], errMsg)
+		pdk.Output(errFrame)
+		return 0
+	}
+
+	// Success frame: [0x00][json_len:4B][JSON without []byte field][raw bytes]
+	jsonBytes, _ := json.Marshal(output)
+	rawBytes := output.Body
+	frame := make([]byte, 1+4+len(jsonBytes)+len(rawBytes))
+	frame[0] = 0x00
+	binary.BigEndian.PutUint32(frame[1:5], uint32(len(jsonBytes)))
+	copy(frame[5:5+len(jsonBytes)], jsonBytes)
+	copy(frame[5+len(jsonBytes):], rawBytes)
+	pdk.Output(frame)
+
+	return 0
+}

plugins/pdk/go/httpendpoint/httpendpoint_stub.go

@@ -0,0 +1,65 @@
+// Code generated by ndpgen. DO NOT EDIT.
+//
+// This file provides stub implementations for non-WASM platforms.
+// It allows Go plugins to compile and run tests outside of WASM,
+// but the actual functionality is only available in WASM builds.
+//
+//go:build !wasip1
+
+package httpendpoint
+
+// HTTPHandleRequest is the input provided when an HTTP request is dispatched to a plugin.
+type HTTPHandleRequest struct {
+	// Method is the HTTP method (GET, POST, PUT, DELETE, PATCH, etc.).
+	Method string `json:"method"`
+	// Path is the request path relative to the plugin's base URL.
+	// For example, if the full URL is /ext/my-plugin/webhook, Path is "/webhook".
+	// Both /ext/my-plugin and /ext/my-plugin/ are normalized to Path = "".
+	Path string `json:"path"`
+	// Query is the raw query string without the leading '?'.
+	Query string `json:"query,omitempty"`
+	// Headers contains the HTTP request headers.
+	Headers map[string][]string `json:"headers,omitempty"`
+	// Body is the request body content.
+	Body []byte `json:"-"`
+	// User contains the authenticated user information. Nil for auth:"none" endpoints.
+	User *HTTPUser `json:"user,omitempty"`
+}
+
+// HTTPHandleResponse is the response returned by the plugin's HandleRequest function.
+type HTTPHandleResponse struct {
+	// Status is the HTTP status code. Defaults to 200 if zero or not set.
+	Status int32 `json:"status,omitempty"`
+	// Headers contains the HTTP response headers to set.
+	Headers map[string][]string `json:"headers,omitempty"`
+	// Body is the response body content.
+	Body []byte `json:"-"`
+}
+
+// HTTPUser contains authenticated user information passed to the plugin.
+type HTTPUser struct {
+	// ID is the internal Navidrome user ID.
+	ID string `json:"id"`
+	// Username is the user's login name.
+	Username string `json:"username"`
+	// Name is the user's display name.
+	Name string `json:"name"`
+	// IsAdmin indicates whether the user has admin privileges.
+	IsAdmin bool `json:"isAdmin"`
+}
+
+// HTTPEndpoint requires all methods to be implemented.
+// HTTPEndpoint allows plugins to handle incoming HTTP requests.
+// Plugins that declare the 'endpoints' permission must implement this capability.
+// The host dispatches incoming HTTP requests to the plugin's HandleRequest function.
+type HTTPEndpoint interface {
+	// HandleRequest - HandleRequest processes an incoming HTTP request and returns a response.
+	HandleRequest(HTTPHandleRequest) (HTTPHandleResponse, error)
+}
+
+// NotImplementedCode is the standard return code for unimplemented functions.
+const NotImplementedCode int32 = -2
+
+// Register is a no-op on non-WASM platforms.
+// This stub allows code to compile outside of WASM.
+func Register(_ HTTPEndpoint) {}

plugins/pdk/rust/nd-pdk-capabilities/src/httpendpoint.rs

@@ -0,0 +1,156 @@
+// Code generated by ndpgen. DO NOT EDIT.
+//
+// This file contains export wrappers for the HTTPEndpoint capability.
+// It is intended for use in Navidrome plugins built with extism-pdk.
+
+use serde::{Deserialize, Serialize};
+use std::collections::HashMap;
+
+// Helper functions for skip_serializing_if with numeric types
+#[allow(dead_code)]
+fn is_zero_i32(value: &i32) -> bool { *value == 0 }
+#[allow(dead_code)]
+fn is_zero_u32(value: &u32) -> bool { *value == 0 }
+#[allow(dead_code)]
+fn is_zero_i64(value: &i64) -> bool { *value == 0 }
+#[allow(dead_code)]
+fn is_zero_u64(value: &u64) -> bool { *value == 0 }
+#[allow(dead_code)]
+fn is_zero_f32(value: &f32) -> bool { *value == 0.0 }
+#[allow(dead_code)]
+fn is_zero_f64(value: &f64) -> bool { *value == 0.0 }
+/// HTTPHandleRequest is the input provided when an HTTP request is dispatched to a plugin.
+#[derive(Debug, Clone, Default, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct HTTPHandleRequest {
+    /// Method is the HTTP method (GET, POST, PUT, DELETE, PATCH, etc.).
+    #[serde(default)]
+    pub method: String,
+    /// Path is the request path relative to the plugin's base URL.
+    /// For example, if the full URL is /ext/my-plugin/webhook, Path is "/webhook".
+    /// Both /ext/my-plugin and /ext/my-plugin/ are normalized to Path = "".
+    #[serde(default)]
+    pub path: String,
+    /// Query is the raw query string without the leading '?'.
+    #[serde(default, skip_serializing_if = "String::is_empty")]
+    pub query: String,
+    /// Headers contains the HTTP request headers.
+    #[serde(default, skip_serializing_if = "HashMap::is_empty")]
+    pub headers: std::collections::HashMap<String, Vec<String>>,
+    /// Body is the request body content.
+    #[serde(skip)]
+    pub body: Vec<u8>,
+    /// User contains the authenticated user information. Nil for auth:"none" endpoints.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub user: Option<HTTPUser>,
+}
+/// HTTPHandleResponse is the response returned by the plugin's HandleRequest function.
+#[derive(Debug, Clone, Default, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct HTTPHandleResponse {
+    /// Status is the HTTP status code. Defaults to 200 if zero or not set.
+    #[serde(default, skip_serializing_if = "is_zero_i32")]
+    pub status: i32,
+    /// Headers contains the HTTP response headers to set.
+    #[serde(default, skip_serializing_if = "HashMap::is_empty")]
+    pub headers: std::collections::HashMap<String, Vec<String>>,
+    /// Body is the response body content.
+    #[serde(skip)]
+    pub body: Vec<u8>,
+}
+/// HTTPUser contains authenticated user information passed to the plugin.
+#[derive(Debug, Clone, Default, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct HTTPUser {
+    /// ID is the internal Navidrome user ID.
+    #[serde(default)]
+    pub id: String,
+    /// Username is the user's login name.
+    #[serde(default)]
+    pub username: String,
+    /// Name is the user's display name.
+    #[serde(default)]
+    pub name: String,
+    /// IsAdmin indicates whether the user has admin privileges.
+    #[serde(default)]
+    pub is_admin: bool,
+}
+
+/// Error represents an error from a capability method.
+#[derive(Debug)]
+pub struct Error {
+    pub message: String,
+}
+
+impl std::fmt::Display for Error {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", self.message)
+    }
+}
+
+impl std::error::Error for Error {}
+
+impl Error {
+    pub fn new(message: impl Into<String>) -> Self {
+        Self { message: message.into() }
+    }
+}
+
+/// HTTPEndpoint requires all methods to be implemented.
+/// HTTPEndpoint allows plugins to handle incoming HTTP requests.
+/// Plugins that declare the 'endpoints' permission must implement this capability.
+/// The host dispatches incoming HTTP requests to the plugin's HandleRequest function.
+pub trait HTTPEndpoint {
+    /// HandleRequest - HandleRequest processes an incoming HTTP request and returns a response.
+    fn handle_request(&self, req: HTTPHandleRequest) -> Result<HTTPHandleResponse, Error>;
+}
+
+/// Register all exports for the HTTPEndpoint capability.
+/// This macro generates the WASM export functions for all trait methods.
+#[macro_export]
+macro_rules! register_httpendpoint {
+    ($plugin_type:ty) => {
+        #[extism_pdk::plugin_fn]
+        pub fn nd_http_handle_request(
+            _raw_input: extism_pdk::Raw<Vec<u8>>
+        ) -> extism_pdk::FnResult<extism_pdk::Raw<Vec<u8>>> {
+            let plugin = <$plugin_type>::default();
+            // Parse input frame: [json_len:4B][JSON without []byte field][raw bytes]
+            let raw_bytes = _raw_input.0;
+            if raw_bytes.len() < 4 {
+                let mut err_frame = vec![0x01u8];
+                err_frame.extend_from_slice(b"malformed input frame");
+                return Ok(extism_pdk::Raw(err_frame));
+            }
+            let json_len = u32::from_be_bytes([raw_bytes[0], raw_bytes[1], raw_bytes[2], raw_bytes[3]]) as usize;
+            if json_len > raw_bytes.len() - 4 {
+                let mut err_frame = vec![0x01u8];
+                err_frame.extend_from_slice(b"invalid json length in input frame");
+                return Ok(extism_pdk::Raw(err_frame));
+            }
+            let mut req: $crate::httpendpoint::HTTPHandleRequest = serde_json::from_slice(&raw_bytes[4..4+json_len])
+                .map_err(|e| extism_pdk::Error::msg(e.to_string()))?;
+            req.body = raw_bytes[4+json_len..].to_vec();
+            match $crate::httpendpoint::HTTPEndpoint::handle_request(&plugin, req) {
+                Ok(output) => {
+                    // Success frame: [0x00][json_len:4B][JSON without []byte field][raw bytes]
+                    let json_bytes = serde_json::to_vec(&output)
+                        .map_err(|e| extism_pdk::Error::msg(e.to_string()))?;
+                    let raw_field = &output.body;
+                    let mut frame = Vec::with_capacity(1 + 4 + json_bytes.len() + raw_field.len());
+                    frame.push(0x00);
+                    frame.extend_from_slice(&(json_bytes.len() as u32).to_be_bytes());
+                    frame.extend_from_slice(&json_bytes);
+                    frame.extend_from_slice(raw_field);
+                    Ok(extism_pdk::Raw(frame))
+                }
+                Err(e) => {
+                    // Error frame: [0x01][UTF-8 error message]
+                    let mut err_frame = vec![0x01u8];
+                    err_frame.extend_from_slice(e.message.as_bytes());
+                    Ok(extism_pdk::Raw(err_frame))
+                }
+            }
+        }
+    };
+}

plugins/pdk/rust/nd-pdk-capabilities/src/lib.rs

@@ -5,6 +5,7 @@
 //! This crate provides type definitions, traits, and registration macros
 //! for implementing Navidrome plugin capabilities in Rust.
 
+pub mod httpendpoint;
 pub mod lifecycle;
 pub mod metadata;
 pub mod scheduler;

plugins/scrobbler_adapter.go

@@ -33,11 +33,8 @@ func init() {
 // ScrobblerPlugin is an adapter that wraps an Extism plugin and implements
 // the scrobbler.Scrobbler interface for scrobbling to external services.
 type ScrobblerPlugin struct {
-	name           string
-	plugin         *plugin
-	allowedUserIDs []string            // User IDs this plugin can access (from DB configuration)
-	allUsers       bool                // If true, plugin can access all users
-	userIDMap      map[string]struct{} // Cached map for fast lookups
+	name   string
+	plugin *plugin
 }
 
 // IsAuthorized checks if the user is authorized with this scrobbler.
@@ -45,7 +42,7 @@ type ScrobblerPlugin struct {
 // then delegates to the plugin for service-specific authorization.
 func (s *ScrobblerPlugin) IsAuthorized(ctx context.Context, userId string) bool {
 	// First check server-side authorization based on plugin configuration
-	if !s.isUserAllowed(userId) {
+	if !s.plugin.userAccess.IsAllowed(userId) {
 		return false
 	}
 
@@ -63,18 +60,6 @@ func (s *ScrobblerPlugin) IsAuthorized(ctx context.Context, userId string) bool
 	return result
 }
 
-// isUserAllowed checks if the given user ID is allowed to use this plugin.
-func (s *ScrobblerPlugin) isUserAllowed(userId string) bool {
-	if s.allUsers {
-		return true
-	}
-	if len(s.allowedUserIDs) == 0 {
-		return false
-	}
-	_, ok := s.userIDMap[userId]
-	return ok
-}
-
 // NowPlaying sends a now playing notification to the scrobbler
 func (s *ScrobblerPlugin) NowPlaying(ctx context.Context, userId string, track *model.MediaFile, position int) error {
 	username := getUsernameFromContext(ctx)

plugins/scrobbler_adapter_test.go

@@ -71,41 +71,6 @@ var _ = Describe("ScrobblerPlugin", Ordered, func() {
 		})
 	})
 
-	Describe("isUserAllowed", func() {
-		It("returns true when allUsers is true", func() {
-			sp := &ScrobblerPlugin{allUsers: true}
-			Expect(sp.isUserAllowed("any-user")).To(BeTrue())
-		})
-
-		It("returns false when allowedUserIDs is empty and allUsers is false", func() {
-			sp := &ScrobblerPlugin{allUsers: false, allowedUserIDs: []string{}}
-			Expect(sp.isUserAllowed("user-1")).To(BeFalse())
-		})
-
-		It("returns false when allowedUserIDs is nil and allUsers is false", func() {
-			sp := &ScrobblerPlugin{allUsers: false}
-			Expect(sp.isUserAllowed("user-1")).To(BeFalse())
-		})
-
-		It("returns true when user is in allowedUserIDs", func() {
-			sp := &ScrobblerPlugin{
-				allUsers:       false,
-				allowedUserIDs: []string{"user-1", "user-2"},
-				userIDMap:      map[string]struct{}{"user-1": {}, "user-2": {}},
-			}
-			Expect(sp.isUserAllowed("user-1")).To(BeTrue())
-		})
-
-		It("returns false when user is not in allowedUserIDs", func() {
-			sp := &ScrobblerPlugin{
-				allUsers:       false,
-				allowedUserIDs: []string{"user-1", "user-2"},
-				userIDMap:      map[string]struct{}{"user-1": {}, "user-2": {}},
-			}
-			Expect(sp.isUserAllowed("user-3")).To(BeFalse())
-		})
-	})
-
 	Describe("NowPlaying", func() {
 		It("successfully calls the plugin", func() {
 			track := &model.MediaFile{

plugins/testdata/test-http-endpoint-native/go.mod

@@ -0,0 +1,16 @@
+module test-http-endpoint-native
+
+go 1.25
+
+require github.com/navidrome/navidrome/plugins/pdk/go v0.0.0
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/extism/go-pdk v1.1.3 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/stretchr/objx v0.5.2 // indirect
+	github.com/stretchr/testify v1.11.1 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)
+
+replace github.com/navidrome/navidrome/plugins/pdk/go => ../../pdk/go

plugins/testdata/test-http-endpoint-native/go.sum

@@ -0,0 +1,14 @@
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/extism/go-pdk v1.1.3 h1:hfViMPWrqjN6u67cIYRALZTZLk/enSPpNKa+rZ9X2SQ=
+github.com/extism/go-pdk v1.1.3/go.mod h1:Gz+LIU/YCKnKXhgge8yo5Yu1F/lbv7KtKFkiCSzW/P4=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.5.2 h1:xuMeJ0Sdp5ZMRXx/aWO6RZxdr3beISkG5/G/aIRr3pY=
+github.com/stretchr/objx v0.5.2/go.mod h1:FRsXN1f5AsAjCGJKqEizvkpNtU+EGNCLh3NxZ/8L+MA=
+github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
+github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

plugins/testdata/test-http-endpoint-native/main.go

@@ -0,0 +1,61 @@
+// Test plugin for native auth (JWT) HTTP endpoint integration tests.
+// Build with: tinygo build -o ../test-http-endpoint-native.wasm -target wasip1 -buildmode=c-shared .
+package main
+
+import (
+	"encoding/json"
+
+	"github.com/navidrome/navidrome/plugins/pdk/go/httpendpoint"
+)
+
+func init() {
+	httpendpoint.Register(&testNativeEndpoint{})
+}
+
+type testNativeEndpoint struct{}
+
+func (t *testNativeEndpoint) HandleRequest(req httpendpoint.HTTPHandleRequest) (httpendpoint.HTTPHandleResponse, error) {
+	switch req.Path {
+	case "/hello":
+		return httpendpoint.HTTPHandleResponse{
+			Status: 200,
+			Headers: map[string][]string{
+				"Content-Type": {"text/plain"},
+			},
+			Body: []byte("Hello from native auth plugin!"),
+		}, nil
+
+	case "/echo":
+		// Echo back the request as JSON
+		data, _ := json.Marshal(map[string]any{
+			"method":   req.Method,
+			"path":     req.Path,
+			"query":    req.Query,
+			"body":     string(req.Body),
+			"hasUser":  req.User != nil,
+			"username": userName(req.User),
+		})
+		return httpendpoint.HTTPHandleResponse{
+			Status: 200,
+			Headers: map[string][]string{
+				"Content-Type": {"application/json"},
+			},
+			Body: data,
+		}, nil
+
+	default:
+		return httpendpoint.HTTPHandleResponse{
+			Status: 404,
+			Body:   []byte("Not found: " + req.Path),
+		}, nil
+	}
+}
+
+func userName(u *httpendpoint.HTTPUser) string {
+	if u == nil {
+		return ""
+	}
+	return u.Username
+}
+
+func main() {}

plugins/testdata/test-http-endpoint-native/manifest.json

@@ -0,0 +1,16 @@
+{
+  "name": "Test HTTP Endpoint Native Plugin",
+  "author": "Navidrome Test",
+  "version": "1.0.0",
+  "description": "Test plugin for native (JWT) HTTP endpoint integration testing",
+  "permissions": {
+    "endpoints": {
+      "auth": "native",
+      "paths": ["/hello", "/echo"],
+      "reason": "Testing native auth HTTP endpoint handling"
+    },
+    "users": {
+      "reason": "Authenticated endpoints require user access"
+    }
+  }
+}

plugins/testdata/test-http-endpoint-public/go.mod

@@ -0,0 +1,16 @@
+module test-http-endpoint-public
+
+go 1.25
+
+require github.com/navidrome/navidrome/plugins/pdk/go v0.0.0
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/extism/go-pdk v1.1.3 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/stretchr/objx v0.5.2 // indirect
+	github.com/stretchr/testify v1.11.1 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)
+
+replace github.com/navidrome/navidrome/plugins/pdk/go => ../../pdk/go

plugins/testdata/test-http-endpoint-public/go.sum

@@ -0,0 +1,14 @@
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/extism/go-pdk v1.1.3 h1:hfViMPWrqjN6u67cIYRALZTZLk/enSPpNKa+rZ9X2SQ=
+github.com/extism/go-pdk v1.1.3/go.mod h1:Gz+LIU/YCKnKXhgge8yo5Yu1F/lbv7KtKFkiCSzW/P4=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.5.2 h1:xuMeJ0Sdp5ZMRXx/aWO6RZxdr3beISkG5/G/aIRr3pY=
+github.com/stretchr/objx v0.5.2/go.mod h1:FRsXN1f5AsAjCGJKqEizvkpNtU+EGNCLh3NxZ/8L+MA=
+github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
+github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

plugins/testdata/test-http-endpoint-public/main.go

@@ -0,0 +1,45 @@
+// Test plugin for public (unauthenticated) HTTP endpoint integration tests.
+// Build with: tinygo build -o ../test-http-endpoint-public.wasm -target wasip1 -buildmode=c-shared .
+package main
+
+import (
+	"github.com/navidrome/navidrome/plugins/pdk/go/httpendpoint"
+)
+
+func init() {
+	httpendpoint.Register(&testPublicEndpoint{})
+}
+
+type testPublicEndpoint struct{}
+
+func (t *testPublicEndpoint) HandleRequest(req httpendpoint.HTTPHandleRequest) (httpendpoint.HTTPHandleResponse, error) {
+	switch req.Path {
+	case "/webhook":
+		return httpendpoint.HTTPHandleResponse{
+			Status: 200,
+			Headers: map[string][]string{
+				"Content-Type": {"text/plain"},
+			},
+			Body: []byte("webhook received"),
+		}, nil
+
+	case "/check-no-user":
+		// Verify that no user info is provided for public endpoints
+		hasUser := "false"
+		if req.User != nil {
+			hasUser = "true"
+		}
+		return httpendpoint.HTTPHandleResponse{
+			Status: 200,
+			Body:   []byte("hasUser=" + hasUser),
+		}, nil
+
+	default:
+		return httpendpoint.HTTPHandleResponse{
+			Status: 404,
+			Body:   []byte("Not found: " + req.Path),
+		}, nil
+	}
+}
+
+func main() {}

plugins/testdata/test-http-endpoint-public/manifest.json

@@ -0,0 +1,13 @@
+{
+  "name": "Test HTTP Endpoint Public Plugin",
+  "author": "Navidrome Test",
+  "version": "1.0.0",
+  "description": "Test plugin for public (unauthenticated) HTTP endpoint integration testing",
+  "permissions": {
+    "endpoints": {
+      "auth": "none",
+      "paths": ["/webhook"],
+      "reason": "Testing public HTTP endpoints"
+    }
+  }
+}

plugins/testdata/test-http-endpoint/go.mod

@@ -0,0 +1,16 @@
+module test-http-endpoint
+
+go 1.25
+
+require github.com/navidrome/navidrome/plugins/pdk/go v0.0.0
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/extism/go-pdk v1.1.3 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/stretchr/objx v0.5.2 // indirect
+	github.com/stretchr/testify v1.11.1 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)
+
+replace github.com/navidrome/navidrome/plugins/pdk/go => ../../pdk/go

plugins/testdata/test-http-endpoint/go.sum

@@ -0,0 +1,14 @@
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/extism/go-pdk v1.1.3 h1:hfViMPWrqjN6u67cIYRALZTZLk/enSPpNKa+rZ9X2SQ=
+github.com/extism/go-pdk v1.1.3/go.mod h1:Gz+LIU/YCKnKXhgge8yo5Yu1F/lbv7KtKFkiCSzW/P4=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.5.2 h1:xuMeJ0Sdp5ZMRXx/aWO6RZxdr3beISkG5/G/aIRr3pY=
+github.com/stretchr/objx v0.5.2/go.mod h1:FRsXN1f5AsAjCGJKqEizvkpNtU+EGNCLh3NxZ/8L+MA=
+github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
+github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

plugins/testdata/test-http-endpoint/main.go

@@ -0,0 +1,77 @@
+// Test plugin for HTTP endpoint integration tests.
+// Build with: tinygo build -o ../test-http-endpoint.wasm -target wasip1 -buildmode=c-shared .
+package main
+
+import (
+	"encoding/json"
+
+	"github.com/navidrome/navidrome/plugins/pdk/go/httpendpoint"
+)
+
+func init() {
+	httpendpoint.Register(&testEndpoint{})
+}
+
+type testEndpoint struct{}
+
+func (t *testEndpoint) HandleRequest(req httpendpoint.HTTPHandleRequest) (httpendpoint.HTTPHandleResponse, error) {
+	switch req.Path {
+	case "/hello":
+		return httpendpoint.HTTPHandleResponse{
+			Status: 200,
+			Headers: map[string][]string{
+				"Content-Type": {"text/plain"},
+			},
+			Body: []byte("Hello from plugin!"),
+		}, nil
+
+	case "/echo":
+		// Echo back the request as JSON
+		data, _ := json.Marshal(map[string]any{
+			"method":   req.Method,
+			"path":     req.Path,
+			"query":    req.Query,
+			"body":     string(req.Body),
+			"hasUser":  req.User != nil,
+			"username": userName(req.User),
+		})
+		return httpendpoint.HTTPHandleResponse{
+			Status: 200,
+			Headers: map[string][]string{
+				"Content-Type": {"application/json"},
+			},
+			Body: data,
+		}, nil
+
+	case "/binary":
+		// Return raw binary data (PNG header)
+		return httpendpoint.HTTPHandleResponse{
+			Status: 200,
+			Headers: map[string][]string{
+				"Content-Type": {"image/png"},
+			},
+			Body: []byte{0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A},
+		}, nil
+
+	case "/error":
+		return httpendpoint.HTTPHandleResponse{
+			Status: 500,
+			Body:   []byte("Something went wrong"),
+		}, nil
+
+	default:
+		return httpendpoint.HTTPHandleResponse{
+			Status: 404,
+			Body:   []byte("Not found: " + req.Path),
+		}, nil
+	}
+}
+
+func userName(u *httpendpoint.HTTPUser) string {
+	if u == nil {
+		return ""
+	}
+	return u.Username
+}
+
+func main() {}

plugins/testdata/test-http-endpoint/manifest.json

@@ -0,0 +1,16 @@
+{
+  "name": "Test HTTP Endpoint Plugin",
+  "author": "Navidrome Test",
+  "version": "1.0.0",
+  "description": "Test plugin for HTTP endpoint integration testing",
+  "permissions": {
+    "endpoints": {
+      "auth": "subsonic",
+      "paths": ["/hello", "/echo"],
+      "reason": "Testing HTTP endpoint handling"
+    },
+    "users": {
+      "reason": "Authenticated endpoints require user access"
+    }
+  }
+}

plugins/user_access.go

@@ -0,0 +1,35 @@
+package plugins
+
+// UserAccess encapsulates user authorization for a plugin,
+// determining which users are allowed to interact with it.
+type UserAccess struct {
+	allUsers  bool
+	userIDMap map[string]struct{}
+}
+
+// NewUserAccess creates a UserAccess from the plugin's configuration.
+// If allUsers is true, all users are allowed regardless of the list.
+func NewUserAccess(allUsers bool, userIDs []string) UserAccess {
+	userIDMap := make(map[string]struct{}, len(userIDs))
+	for _, id := range userIDs {
+		userIDMap[id] = struct{}{}
+	}
+	return UserAccess{
+		allUsers:  allUsers,
+		userIDMap: userIDMap,
+	}
+}
+
+// IsAllowed checks if the given user ID is permitted.
+func (ua UserAccess) IsAllowed(userID string) bool {
+	if ua.allUsers {
+		return true
+	}
+	_, ok := ua.userIDMap[userID]
+	return ok
+}
+
+// HasConfiguredUsers reports whether any specific user IDs have been configured.
+func (ua UserAccess) HasConfiguredUsers() bool {
+	return ua.allUsers || len(ua.userIDMap) > 0
+}

plugins/user_access_test.go

@@ -0,0 +1,64 @@
+//go:build !windows
+
+package plugins
+
+import (
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("UserAccess", func() {
+	Describe("IsAllowed", func() {
+		It("returns true when allUsers is true", func() {
+			ua := NewUserAccess(true, nil)
+			Expect(ua.IsAllowed("any-user")).To(BeTrue())
+		})
+
+		It("returns true when allUsers is true even with an explicit list", func() {
+			ua := NewUserAccess(true, []string{"user-1"})
+			Expect(ua.IsAllowed("other-user")).To(BeTrue())
+		})
+
+		It("returns false when userIDs is empty", func() {
+			ua := NewUserAccess(false, []string{})
+			Expect(ua.IsAllowed("user-1")).To(BeFalse())
+		})
+
+		It("returns false when userIDs is nil", func() {
+			ua := NewUserAccess(false, nil)
+			Expect(ua.IsAllowed("user-1")).To(BeFalse())
+		})
+
+		It("returns true when user is in the list", func() {
+			ua := NewUserAccess(false, []string{"user-1", "user-2"})
+			Expect(ua.IsAllowed("user-1")).To(BeTrue())
+		})
+
+		It("returns false when user is not in the list", func() {
+			ua := NewUserAccess(false, []string{"user-1", "user-2"})
+			Expect(ua.IsAllowed("user-3")).To(BeFalse())
+		})
+	})
+
+	Describe("HasConfiguredUsers", func() {
+		It("returns true when allUsers is true", func() {
+			ua := NewUserAccess(true, nil)
+			Expect(ua.HasConfiguredUsers()).To(BeTrue())
+		})
+
+		It("returns true when specific users are configured", func() {
+			ua := NewUserAccess(false, []string{"user-1"})
+			Expect(ua.HasConfiguredUsers()).To(BeTrue())
+		})
+
+		It("returns false when no users are configured", func() {
+			ua := NewUserAccess(false, nil)
+			Expect(ua.HasConfiguredUsers()).To(BeFalse())
+		})
+
+		It("returns false when user list is empty", func() {
+			ua := NewUserAccess(false, []string{})
+			Expect(ua.HasConfiguredUsers()).To(BeFalse())
+		})
+	})
+})

server/subsonic/middlewares.go

@@ -25,24 +25,32 @@ import (
 	"github.com/navidrome/navidrome/model/request"
 	"github.com/navidrome/navidrome/server"
 	"github.com/navidrome/navidrome/server/subsonic/responses"
-	. "github.com/navidrome/navidrome/utils/gg"
 	"github.com/navidrome/navidrome/utils/req"
 )
 
+// mergeFormIntoQuery parses form data (both URL query params and POST body)
+// and writes all values back into r.URL.RawQuery. This is needed because
+// some Subsonic clients send parameters as form fields instead of query params.
+// This support the OpenSubsonic `formPost` extension
+func mergeFormIntoQuery(r *http.Request) error {
+	if err := r.ParseForm(); err != nil {
+		return err
+	}
+	var parts []string
+	for key, values := range r.Form {
+		for _, v := range values {
+			parts = append(parts, url.QueryEscape(key)+"="+url.QueryEscape(v))
+		}
+	}
+	r.URL.RawQuery = strings.Join(parts, "&")
+	return nil
+}
+
 func postFormToQueryParams(next http.Handler) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		err := r.ParseForm()
-		if err != nil {
+		if err := mergeFormIntoQuery(r); err != nil {
 			sendError(w, r, newError(responses.ErrorGeneric, err.Error()))
 		}
-		var parts []string
-		for key, values := range r.Form {
-			for _, v := range values {
-				parts = append(parts, url.QueryEscape(key)+"="+url.QueryEscape(v))
-			}
-		}
-		r.URL.RawQuery = strings.Join(parts, "&")
-
 		next.ServeHTTP(w, r)
 	})
 }
@@ -95,54 +103,64 @@ func checkRequiredParameters(next http.Handler) http.Handler {
 	})
 }
 
+// authenticateRequest validates the authentication credentials in an HTTP request and returns
+// the authenticated user. It supports internal auth, reverse proxy auth, and Subsonic classic
+// auth (username + password/token/salt/jwt query params).
+//
+// Callers should handle specific error types as needed:
+//   - context.Canceled: request was canceled during authentication
+//   - model.ErrNotFound: username not found in database
+//   - model.ErrInvalidAuth: invalid credentials (wrong password, token, etc.)
+func authenticateRequest(ds model.DataStore, r *http.Request) (*model.User, error) {
+	ctx := r.Context()
+
+	// Check internal auth or reverse proxy auth first
+	username, _ := fromInternalOrProxyAuth(r)
+	if username != "" {
+		return ds.User(ctx).FindByUsername(username)
+	}
+
+	// Fall back to Subsonic classic auth (query params)
+	p := req.Params(r)
+	username, _ = p.String("u")
+	if username == "" {
+		return nil, model.ErrInvalidAuth
+	}
+
+	pass, _ := p.String("p")
+	token, _ := p.String("t")
+	salt, _ := p.String("s")
+	jwt, _ := p.String("jwt")
+
+	usr, err := ds.User(ctx).FindByUsernameWithPassword(username)
+	if err != nil {
+		return nil, err
+	}
+
+	if err := validateCredentials(usr, pass, token, salt, jwt); err != nil {
+		return nil, err
+	}
+
+	return usr, nil
+}
+
 func authenticate(ds model.DataStore) func(next http.Handler) http.Handler {
 	return func(next http.Handler) http.Handler {
 		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 			ctx := r.Context()
 
-			var usr *model.User
-			var err error
-
-			username, isInternalAuth := fromInternalOrProxyAuth(r)
-			if username != "" {
-				authType := If(isInternalAuth, "internal", "reverse-proxy")
-				usr, err = ds.User(ctx).FindByUsername(username)
-				if errors.Is(err, context.Canceled) {
-					log.Debug(ctx, "API: Request canceled when authenticating", "auth", authType, "username", username, "remoteAddr", r.RemoteAddr, err)
-					return
-				}
-				if errors.Is(err, model.ErrNotFound) {
-					log.Warn(ctx, "API: Invalid login", "auth", authType, "username", username, "remoteAddr", r.RemoteAddr, err)
-				} else if err != nil {
-					log.Error(ctx, "API: Error authenticating username", "auth", authType, "username", username, "remoteAddr", r.RemoteAddr, err)
-				}
-			} else {
-				p := req.Params(r)
-				username, _ := p.String("u")
-				pass, _ := p.String("p")
-				token, _ := p.String("t")
-				salt, _ := p.String("s")
-				jwt, _ := p.String("jwt")
-
-				usr, err = ds.User(ctx).FindByUsernameWithPassword(username)
-				if errors.Is(err, context.Canceled) {
-					log.Debug(ctx, "API: Request canceled when authenticating", "auth", "subsonic", "username", username, "remoteAddr", r.RemoteAddr, err)
-					return
-				}
-				switch {
-				case errors.Is(err, model.ErrNotFound):
-					log.Warn(ctx, "API: Invalid login", "auth", "subsonic", "username", username, "remoteAddr", r.RemoteAddr, err)
-				case err != nil:
-					log.Error(ctx, "API: Error authenticating username", "auth", "subsonic", "username", username, "remoteAddr", r.RemoteAddr, err)
-				default:
-					err = validateCredentials(usr, pass, token, salt, jwt)
-					if err != nil {
-						log.Warn(ctx, "API: Invalid login", "auth", "subsonic", "username", username, "remoteAddr", r.RemoteAddr, err)
-					}
-				}
-			}
-
+			usr, err := authenticateRequest(ds, r)
 			if err != nil {
+				username, _ := request.UsernameFrom(ctx)
+				switch {
+				case errors.Is(err, context.Canceled):
+					log.Debug(ctx, "API: Request canceled when authenticating", "username", username, "remoteAddr", r.RemoteAddr, err)
+					return
+				case errors.Is(err, model.ErrNotFound), errors.Is(err, model.ErrInvalidAuth):
+					log.Warn(ctx, "API: Invalid login", "username", username, "remoteAddr", r.RemoteAddr, err)
+				default:
+					log.Error(ctx, "API: Error authenticating", "username", username, "remoteAddr", r.RemoteAddr, err)
+				}
 				sendError(w, r, newError(responses.ErrorAuthenticationFail))
 				return
 			}
@@ -153,6 +171,19 @@ func authenticate(ds model.DataStore) func(next http.Handler) http.Handler {
 	}
 }
 
+// ValidateAuth validates Subsonic authentication from an HTTP request and returns the authenticated user.
+// Unlike the authenticate middleware, this function does not write any HTTP response, making it suitable
+// for use by external consumers (e.g., plugin endpoints) that need Subsonic auth but want to handle
+// errors themselves.
+func ValidateAuth(ds model.DataStore, r *http.Request) (*model.User, error) {
+	// Parse form data into query params (same as postFormToQueryParams middleware,
+	// which is not in the call chain when ValidateAuth is used directly)
+	if err := mergeFormIntoQuery(r); err != nil {
+		return nil, fmt.Errorf("parsing form: %w", err)
+	}
+	return authenticateRequest(ds, r)
+}
+
 func validateCredentials(user *model.User, pass, token, salt, jwt string) error {
 	valid := false