fix: remove unused tests/validation and simplify enable flag for custom instructions

.env.template

@@ -113,7 +113,6 @@ LLM_OPENAI_API_KEY=your-api-key-here
 # DERIVER_MODEL_CONFIG__MAX_OUTPUT_TOKENS=4096
 # DERIVER_LOG_OBSERVATIONS=false
 # DERIVER_MAX_INPUT_TOKENS=25000
-# Required for non-blank reasoning.custom_instructions; unset disables non-blank custom instructions
 # DERIVER_MAX_CUSTOM_INSTRUCTIONS_TOKENS=2000
 # DERIVER_WORKING_REPRESENTATION_MAX_OBSERVATIONS=100
 # DERIVER_REPRESENTATION_BATCH_MAX_TOKENS=1024

config.toml.example

@@ -86,7 +86,7 @@ STALE_SESSION_TIMEOUT_MINUTES = 5
 DEDUPLICATE = true
 LOG_OBSERVATIONS = false
 MAX_INPUT_TOKENS = 25000
-MAX_CUSTOM_INSTRUCTIONS_TOKENS = 2000  # Required for non-blank reasoning.custom_instructions; max supported value is 2000
+MAX_CUSTOM_INSTRUCTIONS_TOKENS = 2000
 WORKING_REPRESENTATION_MAX_OBSERVATIONS = 100
 REPRESENTATION_BATCH_MAX_TOKENS = 1024
 FLUSH_ENABLED = false  # Bypass batch token threshold, process work immediately

src/config.py

@@ -732,10 +732,9 @@ class DeriverSettings(HonchoSettings):
     LOG_OBSERVATIONS: bool = False
 
     MAX_INPUT_TOKENS: Annotated[int, Field(default=25000, gt=0, le=25000)] = 25000
-    # Optional so deployments must opt in to accepting non-blank custom instructions.
     MAX_CUSTOM_INSTRUCTIONS_TOKENS: Annotated[
-        int | None, Field(default=None, gt=0, le=2000)
-    ] = None
+        int, Field(default=2000, ge=0, le=2000)
+    ] = 2000
 
     # Maximum number of observations to return in working representation
     # This is applied to both explicit and deductive observations
@@ -768,25 +767,8 @@ class DeriverSettings(HonchoSettings):
             raise ValueError(
                 f"REPRESENTATION_BATCH_MAX_TOKENS ({self.REPRESENTATION_BATCH_MAX_TOKENS}) cannot exceed max deriver input tokens ({self.MAX_INPUT_TOKENS})"
             )
-        if (
-            self.MAX_CUSTOM_INSTRUCTIONS_TOKENS is not None
-            and self.MAX_CUSTOM_INSTRUCTIONS_TOKENS > self.MAX_INPUT_TOKENS
-        ):
-            raise ValueError(
-                f"MAX_CUSTOM_INSTRUCTIONS_TOKENS ({self.MAX_CUSTOM_INSTRUCTIONS_TOKENS}) "
-                + f"cannot exceed max deriver input tokens ({self.MAX_INPUT_TOKENS})"
-            )
         return self
 
-    @property
-    def effective_max_custom_instructions_tokens(self) -> int:
-        if self.MAX_CUSTOM_INSTRUCTIONS_TOKENS is None:
-            raise ValueError(
-                "DERIVER.MAX_CUSTOM_INSTRUCTIONS_TOKENS is not set; set "
-                + "[deriver].MAX_CUSTOM_INSTRUCTIONS_TOKENS in config.toml"
-            )
-        return self.MAX_CUSTOM_INSTRUCTIONS_TOKENS
-
 
 class PeerCardSettings(HonchoSettings):
     model_config = SettingsConfigDict(env_prefix="PEER_CARD_", extra="ignore")  # pyright: ignore

src/schemas/configuration.py

@@ -26,7 +26,7 @@ class ReasoningConfiguration(BaseModel):
     )
     custom_instructions: str | None = Field(
         default=None,
-        description="Optional custom instructions for the reasoning system on this workspace/session/message. Non-blank values require an explicit deriver custom-instruction token cap and are rejected if they exceed it.",
+        description="Optional custom instructions for the reasoning system on this workspace/session/message. Rejected if they exceed the deriver custom-instruction token cap.",
     )
 
     @field_validator("custom_instructions")
@@ -92,7 +92,7 @@ def _validate_custom_instructions_budget(
         return custom_instructions
 
     max_tokens = settings.DERIVER.MAX_CUSTOM_INSTRUCTIONS_TOKENS
-    if max_tokens is None:
+    if max_tokens <= 0:
         raise ValueError("custom_instructions are not enabled for this deployment")
 
     if estimate_tokens(custom_instructions) > max_tokens:

tests/test_config.py

@@ -6,7 +6,7 @@ from src.config import ConfiguredModelSettings, DeriverSettings
 def _make_deriver_settings(
     *,
     MAX_INPUT_TOKENS: int = 25000,
-    MAX_CUSTOM_INSTRUCTIONS_TOKENS: int | None = None,
+    MAX_CUSTOM_INSTRUCTIONS_TOKENS: int = 2000,
     REPRESENTATION_BATCH_MAX_TOKENS: int = 1024,
 ) -> DeriverSettings:
     return DeriverSettings(
@@ -20,38 +20,17 @@ def _make_deriver_settings(
     )
 
 
-def test_effective_custom_instructions_tokens_requires_explicit_limit() -> None:
-    settings = _make_deriver_settings()
-
-    with pytest.raises(
-        ValueError,
-        match=r"set \[deriver\]\.MAX_CUSTOM_INSTRUCTIONS_TOKENS in config\.toml",
-    ):
-        _ = settings.effective_max_custom_instructions_tokens
-
-
-def test_effective_custom_instructions_tokens_uses_explicit_limit() -> None:
-    settings = _make_deriver_settings(MAX_CUSTOM_INSTRUCTIONS_TOKENS=2000)
-
-    assert settings.effective_max_custom_instructions_tokens == 2000
-
-
-def test_deriver_default_input_budget_accommodates_custom_instruction_cap() -> None:
+def test_deriver_defaults_enable_custom_instructions_at_supported_cap() -> None:
     settings = _make_deriver_settings()
 
     assert settings.MAX_INPUT_TOKENS == 25000
+    assert settings.MAX_CUSTOM_INSTRUCTIONS_TOKENS == 2000
 
 
-def test_custom_instructions_tokens_cannot_exceed_input_budget() -> None:
-    with pytest.raises(
-        ValueError,
-        match=r"MAX_CUSTOM_INSTRUCTIONS_TOKENS.*cannot exceed max deriver input tokens",
-    ):
-        _make_deriver_settings(
-            MAX_INPUT_TOKENS=400,
-            MAX_CUSTOM_INSTRUCTIONS_TOKENS=500,
-            REPRESENTATION_BATCH_MAX_TOKENS=128,
-        )
+def test_custom_instructions_tokens_can_be_disabled_with_zero() -> None:
+    settings = _make_deriver_settings(MAX_CUSTOM_INSTRUCTIONS_TOKENS=0)
+
+    assert settings.MAX_CUSTOM_INSTRUCTIONS_TOKENS == 0
 
 
 def test_custom_instructions_tokens_cannot_exceed_supported_cap() -> None:

tests/test_schema_validations.py

@@ -208,12 +208,10 @@ class TestResolvedConfigurationMigration:
 
 
 class TestReasoningCustomInstructionsValidation:
-    def test_nonblank_custom_instructions_require_enabled_deployment_cap(
+    def test_nonblank_custom_instructions_rejected_when_cap_is_zero(
         self, monkeypatch: pytest.MonkeyPatch
     ) -> None:
-        monkeypatch.setattr(
-            settings.DERIVER, "MAX_CUSTOM_INSTRUCTIONS_TOKENS", None, raising=False
-        )
+        monkeypatch.setattr(settings.DERIVER, "MAX_CUSTOM_INSTRUCTIONS_TOKENS", 0)
 
         with pytest.raises(ValidationError) as exc_info:
             ReasoningConfiguration(custom_instructions="Prefer concrete facts.")
@@ -225,14 +223,11 @@ class TestReasoningCustomInstructionsValidation:
             in error["msg"]
             for error in errors
         )
-        assert "[deriver].MAX_CUSTOM_INSTRUCTIONS_TOKENS" not in str(exc_info.value)
 
     def test_reasoning_configuration_rejects_oversized_custom_instructions(
         self, monkeypatch: pytest.MonkeyPatch
     ) -> None:
-        monkeypatch.setattr(
-            settings.DERIVER, "MAX_CUSTOM_INSTRUCTIONS_TOKENS", 1, raising=False
-        )
+        monkeypatch.setattr(settings.DERIVER, "MAX_CUSTOM_INSTRUCTIONS_TOKENS", 1)
 
         with pytest.raises(ValidationError) as exc_info:
             ReasoningConfiguration(
@@ -247,9 +242,7 @@ class TestReasoningCustomInstructionsValidation:
     def test_oversized_custom_instructions_are_rejected(
         self, monkeypatch: pytest.MonkeyPatch
     ) -> None:
-        monkeypatch.setattr(
-            settings.DERIVER, "MAX_CUSTOM_INSTRUCTIONS_TOKENS", 1, raising=False
-        )
+        monkeypatch.setattr(settings.DERIVER, "MAX_CUSTOM_INSTRUCTIONS_TOKENS", 1)
 
         payload = {
             "reasoning": {
@@ -277,12 +270,8 @@ class TestReasoningCustomInstructionsValidation:
     def test_blank_custom_instructions_do_not_require_token_cap(
         self, monkeypatch: pytest.MonkeyPatch, custom_instructions: str
     ) -> None:
-        monkeypatch.setattr(
-            settings.DERIVER, "MAX_CUSTOM_INSTRUCTIONS_TOKENS", None, raising=False
-        )
+        monkeypatch.setattr(settings.DERIVER, "MAX_CUSTOM_INSTRUCTIONS_TOKENS", 0)
 
-        configuration = ReasoningConfiguration(
-            custom_instructions=custom_instructions
-        )
+        configuration = ReasoningConfiguration(custom_instructions=custom_instructions)
 
         assert configuration.custom_instructions == custom_instructions