feat: add --base-path flag so UI routes API calls to correct prefix

Allows running multiple instances (e.g. /claudomator and /claudomator-oss)
behind a reverse proxy. The server rewrites the base-path meta tag in
index.html at request time rather than baking it into the embed.

Also adds --branch support to deploy script for isolated branch builds
via git worktrees.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

1 files changed, 35 insertions, 1 deletions

diff --git a/internal/api/server.go b/internal/api/server.go
index 2dcbf77..afb80ad 100644
--- a/internal/api/server.go
+++ b/internal/api/server.go
@@ -1,9 +1,11 @@
 package api
 
 import (
+	"bytes"
 	"context"
 	"encoding/json"
 	"fmt"
+	"io/fs"
 	"log/slog"
 	"net/http"
 	"os"
@@ -60,6 +62,7 @@ type Server struct {
 	pushStore        pushSubscriptionStore
 	dropsDir         string
 	llm              *llm.Client
+	basePath         string // URL prefix the UI is mounted at, e.g. "/claudomator"
 }
 
 // SetAPIToken configures a bearer token that must be supplied to access the API.
@@ -89,6 +92,12 @@ func (s *Server) SetWorkspaceRoot(path string) {
 	s.workspaceRoot = path
 }
 
+// SetBasePath sets the URL prefix the UI is served under (e.g. "/claudomator-oss").
+// The server rewrites the base-path meta tag in index.html at request time.
+func (s *Server) SetBasePath(p string) {
+	s.basePath = p
+}
+
 // Pool returns the executor pool, for graceful shutdown by the caller.
 func (s *Server) Pool() *executor.Pool { return s.pool }
 
@@ -180,7 +189,7 @@ func (s *Server) routes() {
 	s.mux.HandleFunc("GET /api/drops", s.handleListDrops)
 	s.mux.HandleFunc("GET /api/drops/{filename}", s.handleGetDrop)
 	s.mux.HandleFunc("POST /api/drops", s.handlePostDrop)
-	s.mux.Handle("GET /", http.FileServerFS(webui.Files))
+	s.mux.HandleFunc("GET /", s.handleStaticFiles)
 }
 
 // forwardResults listens on the executor pool's result and started channels and broadcasts via WebSocket.
@@ -777,6 +786,31 @@ func (s *Server) handleGetExecution(w http.ResponseWriter, r *http.Request) {
 	writeJSON(w, http.StatusOK, exec)
 }
 
+// handleStaticFiles serves embedded web UI files. For index.html it rewrites the
+// base-path meta tag so the UI knows which API prefix to use.
+func (s *Server) handleStaticFiles(w http.ResponseWriter, r *http.Request) {
+	if r.URL.Path == "/" || r.URL.Path == "/index.html" {
+		raw, err := fs.ReadFile(webui.Files, "index.html")
+		if err != nil {
+			http.Error(w, "not found", http.StatusNotFound)
+			return
+		}
+		basePath := s.basePath
+		if basePath == "" {
+			basePath = "/claudomator"
+		}
+		rewritten := bytes.ReplaceAll(raw,
+			[]byte(`content="/claudomator"`),
+			[]byte(`content="`+basePath+`"`),
+		)
+		w.Header().Set("Content-Type", "text/html; charset=utf-8")
+		w.WriteHeader(http.StatusOK)
+		_, _ = w.Write(rewritten)
+		return
+	}
+	http.FileServerFS(webui.Files).ServeHTTP(w, r)
+}
+
 func writeJSON(w http.ResponseWriter, status int, v interface{}) {
 	w.Header().Set("Content-Type", "application/json")
 	w.WriteHeader(status)