diff --git a/.gitignore b/.gitignore
index e2fb743..7bb8506 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,6 +6,8 @@ __pycache__/
 *.egg
 dist/
 build/
+!build/Dockerfile.tools
+!build/*.py
 *.whl
 
 # Virtual environments
diff --git a/Makefile b/Makefile
index d249f53..ce49ba2 100644
--- a/Makefile
+++ b/Makefile
@@ -6,7 +6,7 @@ DOCKER_RUN_ROOT := docker run --rm -v $(CURDIR):/workspace -v $(CURDIR)/../decre
 PROTO_DIR := /proto
 GEN_DIR   := sdk/src/opendecree/_generated
 
-.PHONY: all generate lint format typecheck test integration build clean tools docs pre-commit help
+.PHONY: all generate gen-constants lint format typecheck test integration build clean tools docs pre-commit help
 
 all: generate lint typecheck test
 
@@ -19,8 +19,12 @@ $(TOOLS_SENTINEL): build/Dockerfile.tools
 	docker build -t $(TOOLS_IMAGE) -f build/Dockerfile.tools build/
 	@touch $(TOOLS_SENTINEL)
 
-## generate: Generate Python proto stubs from proto definitions
-generate: $(TOOLS_SENTINEL)
+## gen-constants: Generate _constants.py from pyproject.toml [tool.opendecree]
+gen-constants:
+	python3 build/gen-constants.py
+
+## generate: Generate Python proto stubs and package constants
+generate: $(TOOLS_SENTINEL) gen-constants
 	$(DOCKER_RUN) sh -c '\
 		SITE=$$(python -c "import site; print(site.getsitepackages()[0])") && \
 		GRPC_PROTO=$$(python -c "import grpc_tools; import os; print(os.path.join(os.path.dirname(grpc_tools.__file__), \"_proto\"))") && \
diff --git a/build/gen-constants.py b/build/gen-constants.py
new file mode 100644
index 0000000..7884656
--- /dev/null
+++ b/build/gen-constants.py
@@ -0,0 +1,20 @@
+#!/usr/bin/env python3
+"""Generate sdk/src/opendecree/_constants.py from pyproject.toml [tool.opendecree]."""
+
+import tomllib
+from pathlib import Path
+
+ROOT = Path(__file__).parent.parent
+PYPROJECT = ROOT / "sdk" / "pyproject.toml"
+OUT = ROOT / "sdk" / "src" / "opendecree" / "_constants.py"
+
+with PYPROJECT.open("rb") as f:
+    config = tomllib.load(f)
+
+supported = config["tool"]["opendecree"]["supported_server_version"]
+
+OUT.write_text(
+    "# Generated by build/gen-constants.py — do not edit manually.\n"
+    f'SUPPORTED_SERVER_VERSION = "{supported}"\n'
+)
+print(f"Written {OUT.relative_to(ROOT)}")
diff --git a/sdk/pyproject.toml b/sdk/pyproject.toml
index 7fd242f..cae4ce4 100644
--- a/sdk/pyproject.toml
+++ b/sdk/pyproject.toml
@@ -93,3 +93,6 @@ omit = ["src/opendecree/_generated/*"]
 
 [tool.coverage.report]
 fail_under = 95
+
+[tool.opendecree]
+supported_server_version = ">=0.3.0,<1.0.0"
diff --git a/sdk/src/opendecree/__init__.py b/sdk/src/opendecree/__init__.py
index 8b4978b..b82cdaa 100644
--- a/sdk/src/opendecree/__init__.py
+++ b/sdk/src/opendecree/__init__.py
@@ -4,7 +4,8 @@
 
 __version__ = _pkg_version("opendecree")
 
-SUPPORTED_SERVER_VERSION = ">=0.3.0,<1.0.0"
+from opendecree._constants import SUPPORTED_SERVER_VERSION
+
 PROTO_VERSION = "v1"
 
 from opendecree._convert import URL
diff --git a/sdk/src/opendecree/_constants.py b/sdk/src/opendecree/_constants.py
new file mode 100644
index 0000000..bdb571c
--- /dev/null
+++ b/sdk/src/opendecree/_constants.py
@@ -0,0 +1,2 @@
+# Generated by build/gen-constants.py — do not edit manually.
+SUPPORTED_SERVER_VERSION = ">=0.3.0,<1.0.0"