diff --git a/.gitignore b/.gitignore
index 0ab4ba75e..fc426eda4 100644
--- a/.gitignore
+++ b/.gitignore
@@ -23,3 +23,4 @@ web_custom_versions/
 .DS_Store
 filtered-openapi.yaml
 uv.lock
+.comfy_environment
diff --git a/comfy/deploy_environment.py b/comfy/deploy_environment.py
new file mode 100644
index 000000000..cd45d9576
--- /dev/null
+++ b/comfy/deploy_environment.py
@@ -0,0 +1,29 @@
+import functools
+import logging
+import os
+
+import folder_paths
+
+logger = logging.getLogger(__name__)
+
+_DEFAULT_DEPLOY_ENV = "local-git"
+_ENV_FILENAME = ".comfy_environment"
+
+
+@functools.cache
+def get_deploy_environment() -> str:
+    env_file = os.path.join(folder_paths.base_path, _ENV_FILENAME)
+    try:
+        with open(env_file, encoding="utf-8") as f:
+            # Cap the read so a malformed or maliciously crafted file (e.g.
+            # a single huge line with no newline) can't blow up memory.
+            first_line = f.readline(128).strip()
+            value = "".join(c for c in first_line if 32 <= ord(c) < 127)
+            if value:
+                return value
+    except FileNotFoundError:
+        pass
+    except Exception as e:
+        logger.error("Failed to read %s: %s", env_file, e)
+
+    return _DEFAULT_DEPLOY_ENV
diff --git a/comfy_api_nodes/util/client.py b/comfy_api_nodes/util/client.py
index a0b8d35e1..cb325c445 100644
--- a/comfy_api_nodes/util/client.py
+++ b/comfy_api_nodes/util/client.py
@@ -19,6 +19,8 @@ from comfy import utils
 from comfy_api.latest import IO
 from server import PromptServer
 
+from comfy.deploy_environment import get_deploy_environment
+
 from . import request_logger
 from ._helpers import (
     default_base_url,
@@ -624,6 +626,7 @@ async def _request_base(cfg: _RequestConfig, expect_binary: bool):
         payload_headers = {"Accept": "*/*"} if expect_binary else {"Accept": "application/json"}
         if not parsed_url.scheme and not parsed_url.netloc:  # is URL relative?
             payload_headers.update(get_auth_header(cfg.node_cls))
+            payload_headers["X-Comfy-Env"] = get_deploy_environment()
         if cfg.endpoint.headers:
             payload_headers.update(cfg.endpoint.headers)
 
diff --git a/tests-unit/deploy_environment_test.py b/tests-unit/deploy_environment_test.py
new file mode 100644
index 000000000..ef803f737
--- /dev/null
+++ b/tests-unit/deploy_environment_test.py
@@ -0,0 +1,83 @@
+"""Tests for comfy.deploy_environment."""
+
+import os
+
+import pytest
+
+from comfy.deploy_environment import get_deploy_environment
+
+
+@pytest.fixture(autouse=True)
+def _reset_cache_and_base_path(tmp_path, monkeypatch):
+    """Reset the functools cache and point folder_paths.base_path at a tmp dir for each test."""
+    get_deploy_environment.cache_clear()
+    import folder_paths
+    monkeypatch.setattr(folder_paths, "base_path", str(tmp_path))
+    yield
+    get_deploy_environment.cache_clear()
+
+
+def _write_env_file(tmp_path, content: str) -> str:
+    path = os.path.join(str(tmp_path), ".comfy_environment")
+    with open(path, "w", encoding="utf-8") as f:
+        f.write(content)
+    return path
+
+
+class TestGetDeployEnvironment:
+    def test_returns_local_git_when_file_missing(self):
+        assert get_deploy_environment() == "local-git"
+
+    def test_reads_value_from_file(self, tmp_path):
+        _write_env_file(tmp_path, "local-desktop2-standalone\n")
+        assert get_deploy_environment() == "local-desktop2-standalone"
+
+    def test_strips_trailing_whitespace_and_newline(self, tmp_path):
+        _write_env_file(tmp_path, "  local-desktop2-standalone  \n")
+        assert get_deploy_environment() == "local-desktop2-standalone"
+
+    def test_only_first_line_is_used(self, tmp_path):
+        _write_env_file(tmp_path, "first-line\nsecond-line\n")
+        assert get_deploy_environment() == "first-line"
+
+    def test_empty_file_falls_back_to_default(self, tmp_path):
+        _write_env_file(tmp_path, "")
+        assert get_deploy_environment() == "local-git"
+
+    def test_empty_after_whitespace_strip_falls_back_to_default(self, tmp_path):
+        _write_env_file(tmp_path, "   \n")
+        assert get_deploy_environment() == "local-git"
+
+    def test_strips_control_chars_within_first_line(self, tmp_path):
+        # Embedded NUL/control chars in the value should be stripped
+        # (header-injection / smuggling protection).
+        _write_env_file(tmp_path, "abc\x00\x07xyz\n")
+        assert get_deploy_environment() == "abcxyz"
+
+    def test_strips_non_ascii_characters(self, tmp_path):
+        _write_env_file(tmp_path, "café-é\n")
+        assert get_deploy_environment() == "caf-"
+
+    def test_caps_read_at_128_bytes(self, tmp_path):
+        # A single huge line with no newline must not be fully read into memory.
+        huge = "x" * 10_000
+        _write_env_file(tmp_path, huge)
+        result = get_deploy_environment()
+        assert result == "x" * 128
+
+    def test_result_is_cached_across_calls(self, tmp_path):
+        path = _write_env_file(tmp_path, "first_value\n")
+        assert get_deploy_environment() == "first_value"
+        # Overwrite the file — cached value should still be returned.
+        with open(path, "w", encoding="utf-8") as f:
+            f.write("second_value\n")
+        assert get_deploy_environment() == "first_value"
+
+    def test_unreadable_file_falls_back_to_default(self, tmp_path, monkeypatch):
+        _write_env_file(tmp_path, "should_not_be_used\n")
+
+        def _boom(*args, **kwargs):
+            raise OSError("simulated read failure")
+
+        monkeypatch.setattr("builtins.open", _boom)
+        assert get_deploy_environment() == "local-git"