diff --git a/databuild/rules.bzl b/databuild/rules.bzl
index 05cf69d..8471a22 100644
--- a/databuild/rules.bzl
+++ b/databuild/rules.bzl
@@ -295,6 +295,8 @@ def databuild_graph(name, jobs, lookup, visibility = None):
     _databuild_graph_service(
         name = "%s.service" % name,
         lookup = "%s.lookup" % name,
+        analyze = "%s.analyze" % name,
+        exec = "%s.exec" % name,
         jobs = jobs,
         graph_label = "//%s:%s" % (native.package_name(), name),
         visibility = visibility,
@@ -699,30 +701,53 @@ def _databuild_graph_service_impl(ctx):
     env_setup = """
 export DATABUILD_CANDIDATE_JOBS="{candidate_jobs}"
 export DATABUILD_JOB_LOOKUP_PATH=$(rlocation _main/{lookup_path})
-
-# Default service arguments (can be overridden by user)
-DEFAULT_ARGS="--port {port} --event-log {db} --graph-label {graph_label} --job-lookup-path $(rlocation _main/{lookup_path})"
-
-# Use user args if provided, otherwise use defaults
-if [ "$#" -eq 0 ]; then
-    set -- $DEFAULT_ARGS
-fi
+export DATABUILD_ANALYZE_BINARY=$(rlocation _main/{analyze_path})
+export DATABUILD_EXECUTE_BINARY=$(rlocation _main/{exec_path})
     """.format(
         candidate_jobs = config_paths_str,
         lookup_path = ctx.attr.lookup.files_to_run.executable.short_path,
-        port = default_port,
-        db = default_db,
-        graph_label = ctx.attr.graph_label,
+        analyze_path = ctx.attr.analyze.files_to_run.executable.short_path,
+        exec_path = ctx.attr.exec.files_to_run.executable.short_path,
     )
     
-    ctx.actions.expand_template(
-        template = ctx.file._template,
+    # Generate a custom script instead of using the template to handle the external binary correctly  
+    script_content = RUNFILES_PREFIX + env_setup + """
+EXECUTABLE_BINARY="$(rlocation "databuild+/databuild/build_graph_service")"
+
+# Always pass graph-specific configuration, allow user args to override defaults like port/host
+# Graph-specific args that should always be set:
+GRAPH_ARGS=(
+    "--graph-label" "{graph_label}"
+    "--job-lookup-path" "$(rlocation _main/{lookup_path})"
+    "--event-log" "{db}"
+)
+
+# Add default port if no port specified in user args
+if [[ ! "$*" =~ --port ]]; then
+    GRAPH_ARGS+=("--port" "{port}")
+fi
+
+# Add default host if no host specified in user args  
+if [[ ! "$*" =~ --host ]]; then
+    GRAPH_ARGS+=("--host" "0.0.0.0")
+fi
+
+# Run the service with graph-specific args + user args
+if [[ -n "${{EXECUTABLE_SUBCOMMAND:-}}" ]]; then
+    exec "${{EXECUTABLE_BINARY}}" "${{EXECUTABLE_SUBCOMMAND}}" "${{GRAPH_ARGS[@]}}" "$@"
+else
+    exec "${{EXECUTABLE_BINARY}}" "${{GRAPH_ARGS[@]}}" "$@"
+fi
+""".format(
+        graph_label = ctx.attr.graph_label,
+        lookup_path = ctx.attr.lookup.files_to_run.executable.short_path,
+        db = default_db,
+        port = default_port,
+    )
+    
+    ctx.actions.write(
         output = script,
-        substitutions = {
-            "%{EXECUTABLE_PATH}": ctx.attr._service.files_to_run.executable.path,
-            "%{RUNFILES_PREFIX}": RUNFILES_PREFIX,
-            "%{PREFIX}": env_setup,
-        },
+        content = script_content,
         is_executable = True,
     )
     
@@ -733,8 +758,9 @@ fi
     ]
     
     runfiles = ctx.runfiles(
-        files = [ctx.executable.lookup, ctx.executable._service] + configure_executables,
+        files = [ctx.executable.lookup, ctx.executable._service, ctx.executable.analyze, ctx.executable.exec] + configure_executables,
     ).merge(ctx.attr.lookup.default_runfiles).merge(ctx.attr._service.default_runfiles).merge(
+        ctx.attr.analyze.default_runfiles).merge(ctx.attr.exec.default_runfiles).merge(
         ctx.attr._bash_runfiles.default_runfiles
     ).merge_all([job.default_runfiles for job in ctx.attr.jobs])
     
@@ -763,6 +789,18 @@ _databuild_graph_service = rule(
             doc = "The list of jobs that are candidates for building partitions in this databuild graph",
             allow_empty = False,
         ),
+        "analyze": attr.label(
+            doc = "Target that implements the graph analysis logic",
+            mandatory = True,
+            executable = True,
+            cfg = "target",
+        ),
+        "exec": attr.label(
+            doc = "Target that implements the graph execution logic", 
+            mandatory = True,
+            executable = True,
+            cfg = "target",
+        ),
         "graph_label": attr.string(
             doc = "The label of this graph for service identification",
             mandatory = True,