diff --git a/strategy/README.md b/strategy/README.md
index d48a448..57d6c43 100644
--- a/strategy/README.md
+++ b/strategy/README.md
@@ -51,9 +51,12 @@ from strategy import Transform, register_transform, subspace_matmul, Config
 
 class MyTransform(Transform):
     name = "mine"
-    def basis(self, n, m, backend, dtype, A=None, B=None):
+    def basis(self, n, m, backend, dtype, A=None, B=None, frac=None):
         Q = ...                     # (n, m), ORTHONORMAL columns, on backend.xp
-        return Q
+        return Q                    # frac = the run's --vram-fraction; forward it
+                                    # to any stream_gemm_* helper you call. Declare
+                                    # it even if unused: multiply_subspace only
+                                    # passes the budget to a basis() that does.
 
 register_transform("mine", MyTransform)
 C = subspace_matmul(A, B, config=Config(transform="mine", rank_m=256))
diff --git a/tests/test_contributor_docs_basis_signature.py b/tests/test_contributor_docs_basis_signature.py
index 2f62413..75ccce7 100644
--- a/tests/test_contributor_docs_basis_signature.py
+++ b/tests/test_contributor_docs_basis_signature.py
@@ -6,14 +6,17 @@
 in the legacy branch and silently streams its basis at the default fraction
 instead of Config.vram_fraction (the bug #211 fixed for rsvd).
 
-The template was brought in line already; these tests cover the two remaining
-copies contributors actually read:
+The template was brought in line already; these tests cover every other copy a
+contributor actually reads:
 
   * CONTRIBUTING.md's "What you actually change" snippet -- the canonical
     "that is enough to be scored" example.
+  * strategy/README.md's "Register your own (the updatable hook)" -- the copy a
+    contributor meets first, and the one this file used to leave uncovered, which
+    is how it stayed on the old signature (#274).
   * strategy/examples/run_example.py's FirstAxes -- the worked custom transform.
 
-Both are parsed as text/AST rather than imported: run_example.py runs a real
+All are parsed as text/AST rather than imported: run_example.py runs a real
 subspace_matmul at module scope, which needs a GPU. Pure parsing; no GPU needed.
 
 Run:  python tests/test_contributor_docs_basis_signature.py
@@ -24,14 +27,21 @@
 import re
 import sys
 
+import pytest
+
 sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
 
 from strategy.transforms import Transform
 
 _ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
 _CONTRIBUTING = os.path.join(_ROOT, "CONTRIBUTING.md")
+_README = os.path.join(_ROOT, "strategy", "README.md")
 _RUN_EXAMPLE = os.path.join(_ROOT, "strategy", "examples", "run_example.py")
 
+# Every prose copy of the hook. Driven through one table so a new doc cannot be
+# added -- or an existing one silently rolled back -- without being checked.
+_MARKDOWN_SNIPPETS = ((_CONTRIBUTING, "CONTRIBUTING.md"), (_README, "strategy/README.md"))
+
 
 def _read(path: str) -> str:
     with open(path, encoding="utf-8") as fh:
@@ -52,12 +62,27 @@ def _basis_defs(source: str) -> list:
     return out
 
 
-def test_contributing_snippet_declares_frac():
-    """CONTRIBUTING.md's transform snippet is the contract contributors copy."""
-    snippets = re.findall(r"def basis\(([^)]*)\)", _read(_CONTRIBUTING))
-    assert snippets, "no `def basis(...)` snippet found in CONTRIBUTING.md"
+@pytest.mark.parametrize("path,label", _MARKDOWN_SNIPPETS, ids=[s[1] for s in _MARKDOWN_SNIPPETS])
+def test_markdown_snippet_declares_frac(path, label):
+    """Every prose basis() a contributor copies must show the real signature."""
+    snippets = re.findall(r"def basis\(([^)]*)\)", _read(path))
+    assert snippets, f"no `def basis(...)` snippet found in {label}"
     for sig in snippets:
-        assert "frac" in sig, f"CONTRIBUTING.md basis() snippet omits frac: def basis({sig})"
+        assert "frac" in sig, f"{label} basis() snippet omits frac: def basis({sig})"
+
+
+@pytest.mark.parametrize("path,label", _MARKDOWN_SNIPPETS, ids=[s[1] for s in _MARKDOWN_SNIPPETS])
+def test_markdown_snippet_matches_the_base_class_contract(path, label):
+    """Not just frac: the whole parameter list must match Transform.basis, so a
+    snippet cannot drift on any other argument either. Defaults are stripped --
+    the snippets legitimately show `A=None`, the contract is the parameter names
+    and their order."""
+    for sig in re.findall(r"def basis\(([^)]*)\)", _read(path)):
+        got = [p.strip().split("=")[0].strip() for p in sig.split(",")]
+        assert got == _base_params(), (
+            f"{label}: def basis({', '.join(got)}) does not match "
+            f"Transform.basis({', '.join(_base_params())})"
+        )
 
 
 def test_run_example_custom_transform_declares_frac():
@@ -74,14 +99,4 @@ def test_run_example_basis_matches_the_base_class_contract():
 
 
 if __name__ == "__main__":
-    fns = [v for k, v in sorted(globals().items()) if k.startswith("test_")]
-    failed = 0
-    for fn in fns:
-        try:
-            fn()
-            print(f"PASS  {fn.__name__}")
-        except AssertionError as e:
-            failed += 1
-            print(f"FAIL  {fn.__name__}: {e}")
-    print(f"\n{len(fns) - failed}/{len(fns)} passed")
-    sys.exit(1 if failed else 0)
+    sys.exit(pytest.main([__file__, "-q"]))