diff --git a/README.md b/README.md
index c4dfc8be1..6541cefd4 100644
--- a/README.md
+++ b/README.md
@@ -382,6 +382,12 @@ Use `--tls-keyfile key.pem --tls-certfile cert.pem` to enable TLS/SSL, the app w
> Note: Windows users can use [alexisrolland/docker-openssl](https://github.com/alexisrolland/docker-openssl) or one of the [3rd party binary distributions](https://wiki.openssl.org/index.php/Binaries) to run the command example above.
If you use a container, note that the volume mount `-v` can be a relative path so `... -v ".\:/openssl-certs" ...` would create the key & cert files in the current directory of your command prompt or powershell terminal.
+## How to browse the HTTP API?
+
+Launch with `--enable-api-docs` to serve the OpenAPI specification at `/openapi.yaml` and a browsable API reference at `/api-docs`.
+
+Both are off by default. The reference page loads its viewer from a CDN, so it needs outbound network access to render; the specification itself is served locally and can be read with any offline viewer, such as `npx @redocly/cli preview-docs openapi.yaml`.
+
## Support and dev channel
[Discord](https://comfy.org/discord): Try the #help or #feedback channels.
diff --git a/app/api_docs.py b/app/api_docs.py
new file mode 100644
index 000000000..ee9247624
--- /dev/null
+++ b/app/api_docs.py
@@ -0,0 +1,111 @@
+"""Browsable API documentation for the ComfyUI HTTP API.
+
+Renders the repository's ``openapi.yaml`` with Redoc. Redoc is used rather than
+Swagger UI because it has no request-execution feature at all: the local server
+is unauthenticated by default, so a docs page that could fire requests would
+give one-click access to destructive endpoints such as ``/api/interrupt``,
+``/api/free`` and ``DELETE /api/userdata/{file}``.
+
+The viewer bundle is loaded from a CDN, so the page needs outbound network
+access to render. Installs without it still get the raw spec from
+``/openapi.yaml``; the fallback notice below points there.
+"""
+
+import os
+
+from aiohttp import web
+
+# openapi.yaml lives next to server.py at the repository root. Resolve it from
+# __file__ rather than the cwd: ComfyUI is routinely launched from other
+# directories and through wrappers, and a relative path would 404 unpredictably.
+SPEC_PATH = os.path.join(
+ os.path.dirname(os.path.dirname(os.path.realpath(__file__))), "openapi.yaml"
+)
+
+# Pinned to an exact version rather than a floating tag so a CDN-side release
+# cannot change what this page executes.
+#
+# TODO: add an integrity="sha384-..." attribute. The pinned path is immutable,
+# so SRI is worth having; the hash simply could not be computed where this was
+# written (no outbound network), and a wrong hash fails the page closed.
+REDOC_BUNDLE_URL = "https://cdn.jsdelivr.net/npm/redoc@2.5.0/bundles/redoc.standalone.js"
+
+# The spec URL is deliberately relative. add_routes() re-registers every route
+# under an /api prefix, so this page is reachable at both /api-docs and
+# /api/api-docs; a relative URL resolves to the sibling spec in either case.
+SPEC_URL = "openapi.yaml"
+
+# Substituted with str.replace rather than str.format/f-string so the CSS braces
+# below stay literal and a future style edit does not have to double them.
+API_DOCS_HTML = """
+
+
+
+
+ ComfyUI API Reference
+
+
+
+
+
+
API docs viewer unavailable
+
+ The documentation viewer is loaded from a CDN and could not be reached.
+ This is expected on an offline or air-gapped install.
+
+
+ The specification itself is served locally and needs no network access:
+ openapi.yaml. Render it with any local viewer,
+ for example npx @redocly/cli preview-docs openapi.yaml.
+
+
+
+
+
+""".replace("__SPEC_URL__", SPEC_URL).replace("__BUNDLE_URL__", REDOC_BUNDLE_URL)
+
+
+def add_api_docs_routes(routes: web.RouteTableDef) -> None:
+ """Register the spec and docs-page routes on the given route table.
+
+ Registering on PromptServer's route table (rather than on the app directly)
+ matters twice over: the table is added before the ``web.static('/')``
+ catch-all that would otherwise shadow these paths, and every route in it is
+ also re-registered under an ``/api`` prefix.
+ """
+
+ @routes.get("/openapi.yaml")
+ async def get_openapi_spec(request):
+ if not os.path.isfile(SPEC_PATH):
+ return web.Response(status=404, text="openapi.yaml not found")
+ response = web.FileResponse(SPEC_PATH)
+ response.headers["Content-Type"] = "application/yaml"
+ # The cache_control middleware only special-cases js/css/images, so a
+ # .yaml response falls through untouched. Without this, a user editing
+ # the spec would keep getting a stale copy from the browser cache.
+ response.headers["Cache-Control"] = "no-store, must-revalidate"
+ return response
+
+ @routes.get("/api-docs")
+ async def get_api_docs(request):
+ response = web.Response(text=API_DOCS_HTML, content_type="text/html")
+ response.headers["Cache-Control"] = "no-store, must-revalidate"
+ return response
diff --git a/comfy/cli_args.py b/comfy/cli_args.py
index c6660846d..97d977639 100644
--- a/comfy/cli_args.py
+++ b/comfy/cli_args.py
@@ -66,6 +66,7 @@ parser.add_argument("--tls-keyfile", type=str, help="Path to TLS (SSL) key file.
parser.add_argument("--tls-certfile", type=str, help="Path to TLS (SSL) certificate file. Enables TLS, makes app accessible at https://... requires --tls-keyfile to function")
parser.add_argument("--enable-cors-header", type=str, default=None, metavar="ORIGIN", nargs="?", const="*", help="Enable CORS (Cross-Origin Resource Sharing) with optional origin or allow all with default '*'.")
parser.add_argument("--max-upload-size", type=float, default=100, help="Set the maximum upload size in MB.")
+parser.add_argument("--enable-api-docs", action="store_true", help="Serve the OpenAPI spec at /openapi.yaml and browsable API docs at /api-docs. The docs page loads its viewer from a CDN, so it needs outbound network access to render.")
parser.add_argument("--base-directory", type=str, default=None, help="Set the ComfyUI base directory for models, custom_nodes, input, output, temp, and user directories.")
parser.add_argument("--extra-model-paths-config", type=str, default=None, metavar="PATH", nargs='+', action='append', help="Load one or more extra_model_paths.yaml files.")
diff --git a/server.py b/server.py
index c9ffcaa0d..b8f7378d5 100644
--- a/server.py
+++ b/server.py
@@ -42,6 +42,7 @@ from comfy_api import feature_flags
from comfy.comfy_api_env import get_environment_overrides
import node_helpers
from comfyui_version import __version__
+from app.api_docs import add_api_docs_routes
from app.frontend_management import FrontendManager, parse_version
from comfy_api.internal import _ComfyNodeInternal
from app.assets.seeder import asset_seeder
@@ -1223,6 +1224,8 @@ class PromptServer():
self.custom_node_manager.add_routes(self.routes, self.app, nodes.LOADED_MODULE_DIRS.items())
self.subgraph_manager.add_routes(self.routes, nodes.LOADED_MODULE_DIRS.items())
self.node_replace_manager.add_routes(self.routes)
+ if args.enable_api_docs:
+ add_api_docs_routes(self.routes)
self.app.add_subapp('/internal', self.internal_routes.get_app())
# Prefix every route with /api for easier matching for delegation.
diff --git a/tests-unit/server_test/test_api_docs.py b/tests-unit/server_test/test_api_docs.py
new file mode 100644
index 000000000..42d7f0dd6
--- /dev/null
+++ b/tests-unit/server_test/test_api_docs.py
@@ -0,0 +1,144 @@
+"""Tests for the OpenAPI spec and API docs routes."""
+
+import os
+
+import pytest
+import pytest_asyncio
+import yaml
+from aiohttp import web
+
+from app.api_docs import SPEC_PATH, SPEC_URL, add_api_docs_routes
+
+pytestmark = pytest.mark.asyncio
+
+
+def _build_app():
+ """Mirror how PromptServer mounts these routes, including the /api prefix.
+
+ add_routes() walks the route table and re-registers every RouteDef under an
+ /api prefix, so both the bare and prefixed forms are served. Reproducing
+ that here keeps the prefix behaviour covered by tests.
+ """
+ app = web.Application()
+ routes = web.RouteTableDef()
+ add_api_docs_routes(routes)
+
+ api_routes = web.RouteTableDef()
+ for route in routes:
+ if isinstance(route, web.RouteDef):
+ api_routes.route(route.method, "/api" + route.path)(
+ route.handler, **route.kwargs
+ )
+ app.add_routes(api_routes)
+ app.add_routes(routes)
+ return app
+
+
+@pytest_asyncio.fixture
+async def client(aiohttp_client):
+ return await aiohttp_client(_build_app())
+
+
+async def test_spec_path_points_at_the_repo_spec():
+ """SPEC_PATH must resolve from __file__, not the cwd."""
+ assert os.path.isfile(SPEC_PATH)
+ assert os.path.basename(SPEC_PATH) == "openapi.yaml"
+
+
+async def test_get_spec_returns_yaml(client):
+ resp = await client.get("/openapi.yaml")
+ assert resp.status == 200
+ assert resp.headers["Content-Type"] == "application/yaml"
+ assert resp.headers["Cache-Control"] == "no-store, must-revalidate"
+
+
+async def test_spec_body_is_valid_openapi_3(client):
+ resp = await client.get("/openapi.yaml")
+ spec = yaml.safe_load(await resp.text())
+ assert spec["openapi"].startswith("3.")
+ assert spec["paths"]
+
+
+async def test_spec_is_also_served_under_the_api_prefix(client):
+ """Documents the prefix duplication so a refactor cannot silently break it."""
+ resp = await client.get("/api/openapi.yaml")
+ assert resp.status == 200
+ assert resp.headers["Content-Type"] == "application/yaml"
+
+
+async def test_missing_spec_returns_404(client, monkeypatch):
+ monkeypatch.setattr("app.api_docs.SPEC_PATH", "/nonexistent/openapi.yaml")
+ resp = await client.get("/openapi.yaml")
+ assert resp.status == 404
+
+
+async def test_docs_page_returns_html_referencing_the_spec(client):
+ resp = await client.get("/api-docs")
+ assert resp.status == 200
+ assert resp.content_type == "text/html"
+ body = await resp.text()
+ assert SPEC_URL in body
+
+
+async def test_docs_page_spec_url_is_relative(client):
+ """A relative URL resolves correctly from both /api-docs and /api/api-docs."""
+ assert not SPEC_URL.startswith("/")
+ resp = await client.get("/api/api-docs")
+ assert resp.status == 200
+
+
+async def test_docs_page_cannot_execute_requests(client):
+ """The local server is unauthenticated, so the docs UI must not fire requests.
+
+ Redoc has no request execution at all. Guard against a swap to Swagger UI,
+ whose "Try it out" would give one-click access to destructive endpoints.
+ """
+ body = (await (await client.get("/api-docs")).text()).lower()
+ assert "' in body
+
+
+async def test_routes_survive_the_static_catch_all(aiohttp_client, tmp_path):
+ """web.static('/') is registered last and matches everything.
+
+ Registering on PromptServer's route table is what keeps these paths
+ reachable; this fails if they are ever moved after the catch-all.
+ """
+ (tmp_path / "index.html").write_text("frontend")
+ (tmp_path / "docs").mkdir()
+ (tmp_path / "docs" / "node.json").write_text("{}")
+
+ app = _build_app()
+ app.add_routes([web.static("/docs", tmp_path / "docs")])
+ app.add_routes([web.static("/", tmp_path)])
+ client = await aiohttp_client(app)
+
+ assert (await client.get("/openapi.yaml")).headers["Content-Type"] == (
+ "application/yaml"
+ )
+ assert (await client.get("/api-docs")).content_type == "text/html"
+ # Embedded node docs and the frontend bundle are untouched.
+ assert await (await client.get("/docs/node.json")).text() == "{}"
+ assert await (await client.get("/index.html")).text() == "frontend"
+
+
+async def test_api_docs_flag_is_off_by_default():
+ """Both routes are gated on this flag in PromptServer.add_routes()."""
+ from comfy.cli_args import parser
+
+ assert parser.parse_args([]).enable_api_docs is False
+ assert parser.parse_args(["--enable-api-docs"]).enable_api_docs is True