feat: --chat-base-path

Author: hugodutka

Makefile

@@ -1,10 +1,12 @@
 CHAT_SOURCES_STAMP = chat/.sources.stamp
 CHAT_SOURCES = $(shell find chat \( -path chat/node_modules -o -path chat/out -o -path chat/.next \) -prune -o -not -path chat/.sources.stamp -type f -print)
 BINPATH ?= out/agentapi
+# This must be kept in sync with the magicBasePath in lib/httpapi/embed.go.
+BASE_PATH ?= /magic-base-path-placeholder
 
 $(CHAT_SOURCES_STAMP): $(CHAT_SOURCES)
 	@echo "Chat sources changed. Running build steps..."
-	cd chat && bun run build
+	cd chat && BASE_PATH=${BASE_PATH} bun run build
 	rm -rf lib/httpapi/chat && mkdir -p lib/httpapi/chat && touch lib/httpapi/chat/marker
 	cp -r chat/out/. lib/httpapi/chat/
 	touch $@

chat/next.config.mjs

@@ -1,7 +1,5 @@
 /** @type {import('next').NextConfig} */
-const isGitHubPages = process.env.GITHUB_PAGES === "true";
-const repo = "agentapi";
-const subPath = "chat"; // Subdirectory within the repo
+const basePath = process.env.BASE_PATH ?? "/chat";
 
 const nextConfig = {
   // Enable static exports
@@ -13,10 +11,10 @@ const nextConfig = {
   },
 
   // Configure base path for GitHub Pages (repo/chat)
-  basePath: isGitHubPages ? `/${repo}/${subPath}` : `/${subPath}`,
+  basePath,
 
   // Configure asset prefix for GitHub Pages - helps with static asset loading
-  assetPrefix: isGitHubPages ? `/${repo}/${subPath}/` : `/${subPath}/`,
+  assetPrefix: `${basePath}/`,
 
   // Configure trailing slashes (recommended for static exports)
   trailingSlash: true,

cmd/server/server.go

@@ -22,6 +22,7 @@ var (
 	agentTypeVar string
 	port         int
 	printOpenAPI bool
+	chatBasePath string
 )
 
 type AgentType = msgfmt.AgentType
@@ -86,7 +87,7 @@ func runServer(ctx context.Context, logger *slog.Logger, argsToPass []string) er
 			return xerrors.Errorf("failed to setup process: %w", err)
 		}
 	}
-	srv := httpapi.NewServer(ctx, agentType, process, port)
+	srv := httpapi.NewServer(ctx, agentType, process, port, chatBasePath)
 	if printOpenAPI {
 		fmt.Println(srv.GetOpenAPI())
 		return nil
@@ -137,4 +138,5 @@ func init() {
 	ServerCmd.Flags().StringVarP(&agentTypeVar, "type", "t", "", "Override the agent type (one of: claude, goose, aider, custom)")
 	ServerCmd.Flags().IntVarP(&port, "port", "p", 3284, "Port to run the server on")
 	ServerCmd.Flags().BoolVarP(&printOpenAPI, "print-openapi", "P", false, "Print the OpenAPI schema to stdout and exit")
+	ServerCmd.Flags().StringVarP(&chatBasePath, "chat-base-path", "c", "/chat", "Base path for assets and routes used in the static files of the chat interface")
 }

go.mod

@@ -40,10 +40,11 @@ require (
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/rivo/uniseg v0.4.7 // indirect
 	github.com/rogpeppe/go-internal v1.14.1 // indirect
+	github.com/spf13/afero v1.14.0
 	github.com/spf13/pflag v1.0.6 // indirect
-	golang.org/x/sync v0.11.0 // indirect
+	golang.org/x/sync v0.12.0 // indirect
 	golang.org/x/sys v0.31.0 // indirect
-	golang.org/x/text v0.21.0 // indirect
+	golang.org/x/text v0.23.0 // indirect
 	gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -79,6 +79,8 @@ github.com/rogpeppe/go-internal v1.14.1/go.mod h1:MaRKkUm5W0goXpeCfT7UZI6fk/L7L7
 github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
 github.com/smartystreets/assertions v0.0.0-20180927180507-b2de0cb4f26d/go.mod h1:OnSkiWE9lh6wB0YB77sQom3nweQdgAjqCqsofrRNTgc=
 github.com/smartystreets/goconvey v1.6.4/go.mod h1:syvi0/a8iFYH4r/RixwvyeAJjdLS9QV7WQ/tjFTllLA=
+github.com/spf13/afero v1.14.0 h1:9tH6MapGnn/j0eb0yIXiLjERO8RB6xIVZRDCX7PtqWA=
+github.com/spf13/afero v1.14.0/go.mod h1:acJQ8t0ohCGuMN3O+Pv0V0hgMxNYDlvdk+VTfyZmbYo=
 github.com/spf13/cobra v1.9.1 h1:CXSaggrXdbHK9CF+8ywj8Amf7PBRmPCOJugH954Nnlo=
 github.com/spf13/cobra v1.9.1/go.mod h1:nDyEzZ8ogv936Cinf6g1RU9MRY64Ir93oCnqb9wxYW0=
 github.com/spf13/pflag v1.0.6 h1:jFzHGLGAlb3ruxLB8MhbI6A8+AQX/2eW4qeyNZXNp2o=
@@ -96,8 +98,8 @@ golang.org/x/crypto v0.31.0 h1:ihbySMvVjLAeSH1IbfcRTkD/iNscyz8rGzjF/E5hV6U=
 golang.org/x/crypto v0.31.0/go.mod h1:kDsLvtWBEx7MV9tJOj9bnXsPbxwJQ6csT/x4KIN4Ssk=
 golang.org/x/net v0.0.0-20190311183353-d8887717615a/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
-golang.org/x/sync v0.11.0 h1:GGz8+XQP4FvTTrjZPzNKTMFtSXH80RAzG+5ghFPgK9w=
-golang.org/x/sync v0.11.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
+golang.org/x/sync v0.12.0 h1:MHc5BpPuC30uJk597Ri8TV3CNZcTLu6B6z4lJy+g6Jw=
+golang.org/x/sync v0.12.0/go.mod h1:1dzgHSNfp02xaA81J2MS99Qcpr2w7fw1gpm99rleRqA=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200428200454-593003d681fa/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
@@ -109,8 +111,8 @@ golang.org/x/sys v0.31.0/go.mod h1:BJP2sWEmIv4KK5OTEluFJCKSidICx8ciO85XgH3Ak8k=
 golang.org/x/term v0.30.0 h1:PQ39fJZ+mfadBm0y5WlL4vlM7Sx1Hgf13sMIY2+QS9Y=
 golang.org/x/term v0.30.0/go.mod h1:NYYFdzHoI5wRh/h5tDMdMqCqPJZEuNqVR5xJLd/n67g=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
-golang.org/x/text v0.21.0 h1:zyQAAkrwaneQ066sspRyJaG9VNi/YJ1NfzcGB3hZ/qo=
-golang.org/x/text v0.21.0/go.mod h1:4IBbMaMmOPCJ8SecivzSH54+73PCFmPWxNTLm+vZkEQ=
+golang.org/x/text v0.23.0 h1:D71I7dUrlY+VX0gQShAThNGHFxZ13dGLBHQLVl1mJlY=
+golang.org/x/text v0.23.0/go.mod h1:/BLNzu4aZCJ1+kcD0DNRotWKage4q2rGVAg4o22unh4=
 golang.org/x/tools v0.0.0-20190328211700-ab21143f2384/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
 golang.org/x/xerrors v0.0.0-20240903120638-7835f813f4da h1:noIWHXmPHxILtqtCOPIhSt0ABwskkZKjD3bXGnZGpNY=
 golang.org/x/xerrors v0.0.0-20240903120638-7835f813f4da/go.mod h1:NDW/Ps6MPRej6fsCIbMTohpP40sJ/P/vI1MoTEGwX90=

lib/httpapi/embed.go

@@ -7,23 +7,65 @@ import (
 	"net/http"
 	"os"
 	"strings"
+
+	"github.com/spf13/afero"
+	"golang.org/x/xerrors"
 )
 
 //go:embed chat/*
 var chatStaticFiles embed.FS
 
+// This must be kept in sync with the BASE_PATH in the Makefile.
+const magicBasePath = "/magic-base-path-placeholder"
+
+func createModifiedFS(baseFS fs.FS, oldBasePath string, newBasePath string) (*afero.HttpFs, error) {
+	ro := afero.FromIOFS{FS: baseFS}
+	overlay := afero.NewMemMapFs()
+	newFS := afero.NewCopyOnWriteFs(ro, overlay)
+
+	if err := afero.Walk(ro, ".", func(path string, info fs.FileInfo, err error) error {
+		if err != nil {
+			return xerrors.Errorf("failed to walk: %w", err)
+		}
+		if info.IsDir() {
+			return nil
+		}
+		byteContents, err := afero.ReadFile(ro, path)
+		if err != nil {
+			return xerrors.Errorf("failed to read file: %w", err)
+		}
+		contents := string(byteContents)
+		if newBasePath == "/" {
+			contents = strings.ReplaceAll(contents, oldBasePath+"/", newBasePath)
+		}
+		contents = strings.ReplaceAll(contents, oldBasePath, newBasePath)
+		if err := afero.WriteFile(overlay, path, []byte(contents), 0644); err != nil {
+			return xerrors.Errorf("failed to write file: %w", err)
+		}
+		return nil
+	}); err != nil {
+		return nil, xerrors.Errorf("afero.Walk: %w", err)
+	}
+
+	return afero.NewHttpFs(newFS), nil
+}
+
 // FileServerWithIndexFallback creates a file server that serves the given filesystem
 // and falls back to index.html for any path that doesn't match a file
-func FileServerWithIndexFallback() http.Handler {
-	// First, try to get the embedded files
+func FileServerWithIndexFallback(chatBasePath string) http.Handler {
 	subFS, err := fs.Sub(chatStaticFiles, "chat")
 	if err != nil {
 		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 			http.Error(w, fmt.Sprintf("failed to get subfs: %s", err), http.StatusInternalServerError)
 		})
 	}
-	chatFS := http.FS(subFS)
-	fileServer := http.FileServer(chatFS)
+	chatFS, err := createModifiedFS(subFS, magicBasePath, chatBasePath)
+	if err != nil {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			http.Error(w, fmt.Sprintf("failed to create modified fs: %s", err), http.StatusInternalServerError)
+		})
+	}
+	fileServer := http.FileServer(chatFS.Dir("."))
 	isChatDirEmpty := false
 	if _, err := chatFS.Open("index.html"); err != nil {
 		isChatDirEmpty = true
@@ -43,8 +85,9 @@ func FileServerWithIndexFallback() http.Handler {
 		}
 
 		// Try to serve the file directly
-		_, err := chatFS.Open(trimmedPath)
+		f, err := chatFS.Open(trimmedPath)
 		if err == nil {
+			defer f.Close()
 			fileServer.ServeHTTP(w, r)
 			return
 		}

lib/httpapi/server.go

@@ -57,7 +57,7 @@ func (s *Server) GetOpenAPI() string {
 const snapshotInterval = 25 * time.Millisecond
 
 // NewServer creates a new server instance
-func NewServer(ctx context.Context, agentType mf.AgentType, process *termexec.Process, port int) *Server {
+func NewServer(ctx context.Context, agentType mf.AgentType, process *termexec.Process, port int, chatBasePath string) *Server {
 	router := chi.NewMux()
 
 	corsMiddleware := cors.New(cors.Options{
@@ -98,7 +98,7 @@ func NewServer(ctx context.Context, agentType mf.AgentType, process *termexec.Pr
 	}
 
 	// Register API routes
-	s.registerRoutes()
+	s.registerRoutes(chatBasePath)
 
 	return s
 }
@@ -116,7 +116,7 @@ func (s *Server) StartSnapshotLoop(ctx context.Context) {
 }
 
 // registerRoutes sets up all API endpoints
-func (s *Server) registerRoutes() {
+func (s *Server) registerRoutes(chatBasePath string) {
 	// GET /status endpoint
 	huma.Get(s.api, "/status", s.getStatus, func(o *huma.Operation) {
 		o.Description = "Returns the current status of the agent."
@@ -156,7 +156,7 @@ func (s *Server) registerRoutes() {
 	}, s.subscribeScreen)
 
 	// Serve static files for the chat interface under /chat
-	s.registerStaticFileRoutes()
+	s.registerStaticFileRoutes(chatBasePath)
 }
 
 // getStatus handles GET /status
@@ -303,8 +303,8 @@ func (s *Server) Stop(ctx context.Context) error {
 }
 
 // registerStaticFileRoutes sets up routes for serving static files
-func (s *Server) registerStaticFileRoutes() {
-	chatHandler := FileServerWithIndexFallback()
+func (s *Server) registerStaticFileRoutes(chatBasePath string) {
+	chatHandler := FileServerWithIndexFallback(chatBasePath)
 
 	// Mount the file server at /chat
 	s.router.Handle("/chat", http.StripPrefix("/chat", chatHandler))

lib/httpapi/server_test.go

@@ -44,7 +44,7 @@ func TestOpenAPISchema(t *testing.T) {
 	t.Parallel()
 
 	ctx := logctx.WithLogger(context.Background(), slog.New(slog.NewTextHandler(os.Stdout, nil)))
-	srv := httpapi.NewServer(ctx, msgfmt.AgentTypeClaude, nil, 0)
+	srv := httpapi.NewServer(ctx, msgfmt.AgentTypeClaude, nil, 0, "/chat")
 	currentSchemaStr := srv.GetOpenAPI()
 	var currentSchema any
 	if err := json.Unmarshal([]byte(currentSchemaStr), &currentSchema); err != nil {