docs: Update CHANGELOG for v7.7.1

.cz.toml

@@ -1,7 +1,7 @@
 [tool.commitizen]
 name = "cz_customize"
 tag_format = "v$version"
-version = "7.7.0"
+version = "7.7.1"
 version_scheme = "semver"
 version_files = [
     "pyproject.toml:version",

CHANGELOG.md

@@ -1,3 +1,11 @@
+## 7.7.1 (2026-04-23)
+
+
+### Fixed
+
+- Make max_batch_cost optional with default none, and a float.
+
+
 ## 7.7.0 (2026-04-17)
 
 

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "quantinuum-schemas"
-version = "7.7.0"
+version = "7.7.1"
 description = "Shared data models for Quantinuum."
 authors = [
     {name = "Matthew Burke", email = "matthew.burke@quantinuum.com"},

quantinuum_schemas/models/backend_config.py

@@ -212,6 +212,7 @@ class Batchable(Protocol):
 
     batch_id: UUID | None
     attempt_batching: bool
+    max_batch_cost: float | None
     targets_hardware_device: Callable[..., bool]
 
 
@@ -242,6 +243,17 @@ def warn_if_backend_doesnt_support_batching(self: BatchableT) -> BatchableT:
             )
         return self
 
+    @model_validator(mode="after")
+    def warn_if_max_batch_cost_is_unset(self: BatchableT) -> BatchableT:
+        """Warns if attempt_batching is true and batch_max_hqc is unset"""
+
+        if self.attempt_batching and self.max_batch_cost is None:
+            warnings.warn(
+                "max_batch_cost is unset. Your organisation's value will be used instead.",
+                RuntimeWarning,
+            )
+        return self
+
 
 class QuantinuumConfig(BaseBackendConfig, BatchingValidationMixin):
     """Runs circuits on Quantinuum's quantum devices and simulators.
@@ -287,7 +299,7 @@ class QuantinuumConfig(BaseBackendConfig, BatchingValidationMixin):
     noisy_simulation: bool = True
     target_2qb_gate: Optional[str] = None
     user_group: Optional[str] = None
-    max_batch_cost: int = 2000
+    max_batch_cost: Optional[float] = None
     compiler_options: Optional[QuantinuumCompilerOptions] = None
     no_opt: bool = True
     allow_2q_gate_rebase: bool = False
@@ -523,7 +535,7 @@ class HeliosConfig(BaseBackendConfig, BatchingValidationMixin):
 
     attempt_batching: bool = False
     batch_id: Optional[UUID] = None
-    max_batch_cost: float = 2000.0
+    max_batch_cost: Optional[float] = None
 
     options: QuantinuumOptions | None = None
 

tests/models/test_backend_config.py

@@ -186,23 +186,60 @@ def test_attempt_batching_against_simulators() -> None:
             system_name="Helios-1E",
             emulator_config=HeliosEmulatorConfig(),
             attempt_batching=True,
+            max_batch_cost=2000.0,
+        )
+        HeliosConfig(
+            system_name="Helios-1SC", attempt_batching=True, max_batch_cost=2000.0
+        )
+        QuantinuumConfig(
+            device_name="H2-1E", attempt_batching=True, max_batch_cost=2000.0
+        )
+        QuantinuumConfig(
+            device_name="H1-Emulator", attempt_batching=True, max_batch_cost=2000.0
+        )
+        QuantinuumConfig(
+            device_name="H2-1SC", attempt_batching=True, max_batch_cost=2000.0
         )
-        HeliosConfig(system_name="Helios-1SC", attempt_batching=True)
-        QuantinuumConfig(device_name="H2-1E", attempt_batching=True)
-        QuantinuumConfig(device_name="H1-Emulator", attempt_batching=True)
-        QuantinuumConfig(device_name="H2-1SC", attempt_batching=True)
 
     assert len(record) == 5, record
     assert all([error_string in str(i.message) for i in record]), record
 
     with warnings.catch_warnings(record=True) as captured_warnings:
         # test valid configs don't throw warning.
-        HeliosConfig(system_name="Helios-1", attempt_batching=True)
-        QuantinuumConfig(device_name="H2-2", attempt_batching=True)
+        HeliosConfig(
+            system_name="Helios-1", attempt_batching=True, max_batch_cost=2000.0
+        )
+        QuantinuumConfig(
+            device_name="H2-2", attempt_batching=True, max_batch_cost=2000.0
+        )
         # if attempt batching is false, no warning is throw
         HeliosConfig(system_name="Helios-1E", emulator_config=HeliosEmulatorConfig())
         HeliosConfig(system_name="Helios-1SC")
         QuantinuumConfig(device_name="H2-1E")
         QuantinuumConfig(device_name="H1-Emulator")
         QuantinuumConfig(device_name="H2-1SC")
     assert not captured_warnings
+
+
+def test_match_batch_cost_warns_if_needed() -> None:
+    """Test warning if attempt_batching is True and max_batch_cost is unset."""
+    error_string = (
+        "max_batch_cost is unset. Your organisation's value will be used instead."
+    )
+    with pytest.warns(RuntimeWarning) as record:
+        # test warning if max_batch_cost is unset.
+        HeliosConfig(system_name="Helios-1", attempt_batching=True)
+        QuantinuumConfig(device_name="H2-2", attempt_batching=True)
+
+    assert len(record) == 2, record
+    assert all([error_string in str(i.message) for i in record]), record
+
+    with warnings.catch_warnings(record=True) as captured_warnings:
+        # test warning isn't thrown when max_batch_cost is set.
+        HeliosConfig(
+            system_name="Helios-1", attempt_batching=True, max_batch_cost=2000.0
+        )
+        QuantinuumConfig(
+            device_name="H2-2", attempt_batching=True, max_batch_cost=2000.0
+        )
+    assert not captured_warnings