feat(adr-0036): safety-only typed refusal policy

Runtime-checkable SafetyVerdict violations now replace
ChatResponse.surface (and TurnEvent.surface on the main path) with a
deterministic typed refusal string.  Ethics violations remain
audit-only.

Why safety-only: safety is the universal floor (ADR-0029,
never-swappable, fail-closed).  Ethics is swappable per-deployment;
wiring ethics into refusal would let pack-swappers silently change
refusal behavior via JSON edit.  Wrong coupling.

Why typed refusal (not hedge injection / not re-articulation): typed
refusal is deterministic, audit-detectable by prefix, and preserves
replayability.  Hedge injection would blur surface-preferences-driven
hedging vs predicate-driven refusal.  Re-articulation retry yields the
same surface (planner is deterministic; no refusal-bias hint surface
exists).  Deferred to a future ADR.

Refusal contract:
- ChatResponse.surface = typed refusal string
- walk_surface + articulation_surface = unchanged (audit preserved)
- runtime._last_refusal_was_typed = True (next-turn evidence for
  no_silent_correction)
- Only runtime_checkable=True violations refuse
- Stub path symmetric

Files:
- chat/refusal.py (new) — pure refusal builder + audit helpers
- chat/runtime.py — invoke build_refusal_surface after safety_verdict
- tests/test_safety_refusal.py (new) — 20 tests
- docs/decisions/ADR-0036-safety-refusal-policy.md (new)

Verification:
- 20 new tests; combined pack-layer suite 116 green
- CLI suites unchanged: smoke 67, runtime 19, cognition 121
- core eval cognition: intent 100%, versor_closure 100% (baseline)
This commit is contained in:
Shay 2026-05-17 21:10:52 -07:00
parent 514ace0cbf
commit a0372c951f
4 changed files with 531 additions and 3 deletions

71
chat/refusal.py Normal file
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@ -0,0 +1,71 @@
"""ADR-0036 — typed refusal surface for runtime-checkable safety violations.
The refusal surface is the runtime's response to a SafetyVerdict that
reports at least one ``runtime_checkable=True, upheld=False`` result.
It is deliberately:
* **Deterministic.** Same set of violated boundaries same surface
bytes. Replayability is preserved.
* **Typed.** A constant prefix (``TYPED_REFUSAL_PREFIX``) plus
lex-ordered boundary ids. Audit consumers detect refusals by prefix,
not by NLP.
* **Safety-only.** Ethics violations are observational at v1
(ADR-0035) and do not trigger refusal. Refusing on swappable
deployment commitments would let pack-swappers silently change
refusal behavior the wrong coupling.
See `docs/decisions/ADR-0036-safety-refusal-policy.md`.
"""
from __future__ import annotations
from typing import Iterable
TYPED_REFUSAL_PREFIX = "I cannot proceed — safety boundary violated: "
def violated_runtime_checkable(verdict) -> tuple[str, ...]:
"""Return the lex-sorted tuple of runtime-checkable violated boundary ids.
A boundary is reported as violated only when the predicate had
enough evidence to make a real claim (``runtime_checkable=True``)
AND determined the turn breached the boundary (``upheld=False``).
Predicates that report ``runtime_checkable=False`` are honest
about lack of evidence and never trigger refusal.
"""
if verdict is None:
return ()
boundary_ids: list[str] = []
for result in getattr(verdict, "results", ()) or ():
if getattr(result, "runtime_checkable", False) and not getattr(
result, "upheld", True
):
boundary_ids.append(str(result.boundary_id))
return tuple(sorted(boundary_ids))
def build_refusal_surface(verdict) -> str | None:
"""Build a deterministic typed refusal surface, or ``None`` if no refusal.
The contract:
* Returns ``None`` when no runtime-checkable safety violation is
present. The caller keeps the originally-articulated surface.
* Returns ``TYPED_REFUSAL_PREFIX + ", ".join(lex_sorted_ids)`` when
one or more runtime-checkable boundaries were violated.
The same verdict always produces the same string.
"""
violated = violated_runtime_checkable(verdict)
if not violated:
return None
return _format_refusal(violated)
def _format_refusal(boundary_ids: Iterable[str]) -> str:
return TYPED_REFUSAL_PREFIX + ", ".join(boundary_ids)
def is_typed_refusal(surface: str) -> bool:
"""Audit helper: does this surface look like a typed refusal?"""
return bool(surface) and surface.startswith(TYPED_REFUSAL_PREFIX)

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@ -10,6 +10,7 @@ from typing import List
import numpy as np
from algebra.versor import versor_condition
from chat.refusal import build_refusal_surface
from core.config import DEFAULT_CONFIG, DEFAULT_IDENTITY_PACK, RuntimeConfig
from core.physics.drive import DriveGradientMap, GradientField
from core.physics.energy import EnergyProfile
@ -497,8 +498,18 @@ class ChatRuntime:
disclosure_emitted=True,
)
ethics_verdict = self.ethics_check.check(ethics_ctx, self.ethics_pack)
# ADR-0036 — typed refusal also applies on the stub path. When
# a runtime-checkable safety boundary is violated even on the
# ungrounded surface (e.g. versor-closure failure), replace the
# user-facing ``surface`` with the deterministic typed refusal.
refusal_surface = build_refusal_surface(safety_verdict)
if refusal_surface is not None:
response_surface = refusal_surface
self._last_refusal_was_typed = True
else:
response_surface = _UNKNOWN_DOMAIN_SURFACE
return ChatResponse(
surface=_UNKNOWN_DOMAIN_SURFACE,
surface=response_surface,
proposition=prop,
articulation=art,
articulation_surface=_UNKNOWN_DOMAIN_SURFACE,
@ -670,10 +681,22 @@ class ChatRuntime:
disclosure_emitted=not is_grounded,
)
ethics_verdict = self.ethics_check.check(ethics_ctx, self.ethics_pack)
# ADR-0036 — safety-only typed refusal. A runtime-checkable
# SafetyVerdict violation replaces the user-facing ``surface``
# with a deterministic typed refusal string. ``walk_surface``
# and ``articulation_surface`` retain the original token-walk /
# realizer evidence for audit (per the runtime surface
# contract in CLAUDE.md). Ethics violations remain audit-only.
refusal_surface = build_refusal_surface(safety_verdict)
if refusal_surface is not None:
response_surface = refusal_surface
self._last_refusal_was_typed = True
else:
response_surface = walk_surface
turn_event = TurnEvent(
turn=self._context.turn - 1,
input_tokens=tuple(filtered),
surface=surface,
surface=response_surface,
walk_surface=walk_surface,
articulation_surface=articulation.surface,
dialogue_role=str(dialogue_role),
@ -688,7 +711,7 @@ class ChatRuntime:
)
self.turn_log.append(turn_event)
return ChatResponse(
surface=walk_surface,
surface=response_surface,
proposition=proposition,
articulation=articulation,
articulation_surface=articulation.surface,

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@ -0,0 +1,177 @@
# ADR-0036: Safety-Only Typed Refusal Policy
**Status:** Accepted (2026-05-17)
**Author:** Joshua Shay + planner pass
**Companion docs:** [`ADR-0032-safety-check-surface.md`](ADR-0032-safety-check-surface.md), [`ADR-0034-ethics-check-surface.md`](ADR-0034-ethics-check-surface.md), [`ADR-0035-turn-loop-verdict-surfacing.md`](ADR-0035-turn-loop-verdict-surfacing.md)
## Context
ADR-0035 wired `SafetyCheck` and `EthicsCheck` into the turn loop as
**observation only** — verdicts attach to `ChatResponse` and `TurnEvent`
but do not change behavior. The closing notes flagged refusal /
re-articulation as the natural follow-up *once real verdict data
flowed*.
With one ADR's worth of verdict surfacing in the runtime, two scope
axes had to be decided before wiring refusal:
1. **Trigger scope.** Safety only? Safety + ethics? Per-predicate?
2. **Refusal shape.** Typed refusal surface? Hedge injection?
Re-articulation via planner retry?
The decision was made jointly with the user, surfaced via an explicit
scope question before any code landed.
## Decision
**Safety-only typed refusal.** A `SafetyVerdict` with at least one
`runtime_checkable=True, upheld=False` result replaces
`ChatResponse.surface` with a deterministic typed refusal string.
Ethics violations remain audit-only.
### Why safety only
Safety is the universal floor (ADR-0029): five fixed boundaries, never
swappable, fail-closed on load. Ethics is deployment configuration
above that floor (ADR-0033): swappable per-deployment, falls back to
default. Wiring ethics into refusal would let pack-swappers silently
change the runtime's refusal behavior by editing a JSON file — exactly
the coupling we want to avoid. Safety is the architectural place to
encode "the floor never moves."
A future ADR can revisit per-predicate ethics refusal once individual
ethics commitments have empirical violation rates from real corpora.
### Why typed refusal (not hedge injection, not re-articulation)
* **Typed refusal** is deterministic, audit-detectable by prefix, and
preserves replayability. The refusal carries the violated
boundary ids in lex order. Same violation → same bytes.
* **Hedge injection** would blur the boundary between
alignment-score-driven hedging (ADR-0028 surface preferences) and
predicate-driven refusal. The same surface change could mean two
different things. Audit becomes ambiguous.
* **Re-articulation** via planner retry is deterministic too, but the
planner has no refusal-bias hint surface today — retry with
unchanged inputs yields the same surface. Deferred to a future ADR
that first lands evidence-threading through the planner.
### Why only `runtime_checkable=True` violations refuse
A predicate that reports `runtime_checkable=False` is honestly stating
"I have no evidence to make a real claim." Refusing on no-evidence
predicates would refuse on architectural absence, not behavioral
violation. The ADR-0032/0034 honest-reporting discipline means
`runtime_checkable` is exactly the gate for "did we observe a real
violation."
### What the runtime contract looks like now
`chat/refusal.py`:
* `TYPED_REFUSAL_PREFIX = "I cannot proceed — safety boundary violated: "`
* `build_refusal_surface(verdict) -> str | None` — pure function, no I/O.
* `violated_runtime_checkable(verdict) -> tuple[str, ...]` — lex-sorted helper.
* `is_typed_refusal(surface) -> bool` — audit helper.
`chat/runtime.py` — both the main turn path and `_stub_response`
invoke `build_refusal_surface(safety_verdict)` after the verdict is
computed. On a non-None return:
* `ChatResponse.surface` = typed refusal
* `ChatResponse.walk_surface` = unchanged (audit evidence preserved)
* `ChatResponse.articulation_surface` = unchanged (realizer evidence preserved)
* `TurnEvent.surface` = typed refusal (main path only; stub path bypasses turn_log by design)
* `runtime._last_refusal_was_typed = True` — so the next turn's
`no_silent_correction` predicate has live evidence.
### Surface contract integrity
The runtime surface contract from CLAUDE.md says:
```
surface = articulation_surface (selected user-facing response)
walk_surface = retained telemetry/evidence
```
Refusal changes the *selection* (`surface` no longer equals
`articulation_surface`); it does not corrupt the evidence
(`walk_surface` and `articulation_surface` retain what the runtime
would have said). An auditor reading a refusal turn sees:
* what the runtime *would have* surfaced (walk_surface / articulation),
* what it *did* surface (typed refusal),
* and *why* (safety_verdict).
This is the same audit shape as a non-refusing turn — no new contract.
## Consequences
### Positive
* **First load-bearing pack-layer behavior.** The pack-layer surface
now has a way to actually stop the runtime from emitting bad output,
not just label it.
* **Deterministic.** Same forced violation → byte-identical refusal
string. Replay invariant preserved.
* **Audit-complete.** Every refusal carries the verdict and the
preserved walk/articulation evidence. No silent refusals.
* **Bookkeeping closes the loop on `no_silent_correction`.** When the
runtime refuses, it sets `_last_refusal_was_typed=True`, so the
next turn's predicate has live evidence of typed refusal.
* **Cheap.** One pure function call per turn. Test suites and
cognition eval unchanged.
### Negative / risks
* **No per-predicate refusal opt-out.** All `runtime_checkable=True`
safety violations refuse. If a future safety pack introduces a
predicate that should be observe-only, the surface needs a
per-predicate `audit_only` flag. Acceptable today: the v1 safety
pack has five boundaries and refusing on each is the right semantics.
* **Hedge injection is *not* the refusal path.** A high-confidence
emission with low alignment score still passes through unhedged
unless the manifold's `surface_preferences` choose to hedge. This
is correct: hedging is a surface preference (ADR-0028), refusal is
a safety boundary. Conflating them was rejected.
* **Stub path refusal happens but `TurnEvent` is not emitted.** Same
pre-existing limit as ADR-0035. Audit completeness for stub paths
is a separate ADR.
## Verification
* `tests/test_safety_refusal.py` — 20 tests covering: pure refusal
builder (none, all-upheld, non-checkable violation, single
violation, determinism, lex order); helpers
(`violated_runtime_checkable`, `is_typed_refusal`); ChatRuntime
integration (ordinary turn unchanged, forced violation emits
refusal, walk_surface preserved, articulation_surface preserved,
verdicts still attached, `_last_refusal_was_typed` bookkeeping,
`TurnEvent.surface` carries the refusal); ethics violations do
NOT trigger refusal; stub-path refusal.
* Combined pack-layer surface suite: **116 tests, all green**
(safety pack + safety check + ethics pack + ethics check +
turn-loop verdicts + refusal).
* CLI suites unaffected: smoke 67, runtime 19, cognition 121.
* `core eval cognition`: intent_accuracy 100%, versor_closure_rate 100%
(baseline preserved).
## Open questions deferred to a future ADR
1. **Per-predicate ethics refusal.** Pack-schema flag to opt specific
ethics commitments into refusal once empirical violation rates are
available.
2. **Hedge-injection as a separate surface affordance.** A
below-threshold alignment score could prepend the manifold's hedge
without triggering refusal. Today this is partially handled by
the assembler's `SurfaceContext`; lifting it to a runtime-level
decision is its own ADR.
3. **`TurnEvent` for stub paths.** Audit completeness across the
refusal-on-stub path.
4. **Refusal telemetry sink.** A structured log emitter consumes
refusals for operational dashboards.
5. **`core chat --show-verdicts` CLI flag.** Per-turn verdict and
refusal printout for manual audit.
6. **Refusal-bias planner retry.** Re-articulation as a deliberate
re-plan with refusal context threaded in. Deferred until
evidence-threading through the planner lands.

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@ -0,0 +1,257 @@
"""ADR-0036 — typed refusal on runtime-checkable safety violation.
The refusal surface:
* replaces ``ChatResponse.surface`` with a deterministic typed string,
* leaves ``walk_surface`` and ``articulation_surface`` intact (audit),
* fires only on safety violations (ethics is observational at v1),
* fires only on ``runtime_checkable=True`` results
(no-evidence predicates never refuse),
* sets ``runtime._last_refusal_was_typed = True`` so the next turn's
``no_silent_correction`` predicate has live evidence.
"""
from __future__ import annotations
from chat.refusal import (
TYPED_REFUSAL_PREFIX,
build_refusal_surface,
is_typed_refusal,
violated_runtime_checkable,
)
from chat.runtime import ChatRuntime
from core.config import RuntimeConfig
from packs.safety.check import SafetyCheckResult, SafetyVerdict
# ---------- pure-function refusal builder ----------
class TestBuildRefusalSurface:
def test_none_verdict_returns_none(self) -> None:
assert build_refusal_surface(None) is None
def test_all_upheld_returns_none(self) -> None:
verdict = _verdict(
_result("preserve_versor_closure", upheld=True, runtime_checkable=True),
_result("no_silent_correction", upheld=True, runtime_checkable=True),
)
assert build_refusal_surface(verdict) is None
def test_non_runtime_checkable_violation_does_not_refuse(self) -> None:
"""A predicate that lacks evidence (runtime_checkable=False) and
reports upheld=False must NOT trigger refusal by design,
no-evidence predicates default to ``upheld=True`` in the
check loop, but even if a deployment forces ``upheld=False``
without evidence, refusal should not fire."""
verdict = _verdict(
_result("no_fabricated_source", upheld=False, runtime_checkable=False),
)
assert build_refusal_surface(verdict) is None
def test_runtime_checkable_violation_returns_typed_surface(self) -> None:
verdict = _verdict(
_result("preserve_versor_closure", upheld=False, runtime_checkable=True),
)
out = build_refusal_surface(verdict)
assert out is not None
assert out.startswith(TYPED_REFUSAL_PREFIX)
assert "preserve_versor_closure" in out
def test_refusal_is_deterministic(self) -> None:
verdict = _verdict(
_result("preserve_versor_closure", upheld=False, runtime_checkable=True),
_result("no_silent_correction", upheld=False, runtime_checkable=True),
)
first = build_refusal_surface(verdict)
second = build_refusal_surface(verdict)
assert first == second
def test_refusal_lists_boundaries_in_lex_order(self) -> None:
verdict = _verdict(
_result("zzz_late", upheld=False, runtime_checkable=True),
_result("aaa_early", upheld=False, runtime_checkable=True),
)
out = build_refusal_surface(verdict)
assert out is not None
assert out.index("aaa_early") < out.index("zzz_late")
class TestViolatedRuntimeCheckable:
def test_filters_non_checkable(self) -> None:
verdict = _verdict(
_result("a", upheld=False, runtime_checkable=False),
_result("b", upheld=False, runtime_checkable=True),
)
assert violated_runtime_checkable(verdict) == ("b",)
def test_filters_upheld(self) -> None:
verdict = _verdict(
_result("a", upheld=True, runtime_checkable=True),
_result("b", upheld=False, runtime_checkable=True),
)
assert violated_runtime_checkable(verdict) == ("b",)
def test_empty_verdict_returns_empty(self) -> None:
verdict = _verdict()
assert violated_runtime_checkable(verdict) == ()
class TestIsTypedRefusal:
def test_typed_refusal_detected(self) -> None:
surface = TYPED_REFUSAL_PREFIX + "preserve_versor_closure"
assert is_typed_refusal(surface)
def test_ordinary_surface_not_a_refusal(self) -> None:
assert not is_typed_refusal("light is")
assert not is_typed_refusal("")
# ---------- ChatRuntime integration ----------
class TestRuntimeRefusalMainPath:
def test_no_violation_returns_ordinary_surface(self) -> None:
rt = ChatRuntime(config=RuntimeConfig())
resp = rt.chat("light is")
# No predicate forced to fail, so surface should NOT be a
# typed refusal. (Stub path may produce the unknown-domain
# surface; both are non-refusal.)
assert not is_typed_refusal(resp.surface)
def test_forced_violation_emits_typed_refusal(self) -> None:
rt = ChatRuntime(config=RuntimeConfig())
_force_violation(rt, "preserve_versor_closure")
resp = rt.chat("light is")
assert is_typed_refusal(resp.surface)
assert "preserve_versor_closure" in resp.surface
def test_refusal_preserves_walk_surface(self) -> None:
"""walk_surface retains the original token-walk evidence even
when the user-facing surface is replaced by a refusal."""
rt = ChatRuntime(config=RuntimeConfig())
_force_violation(rt, "preserve_versor_closure")
resp = rt.chat("light is")
if not is_typed_refusal(resp.surface):
return # stub path; tested separately
assert not is_typed_refusal(resp.walk_surface)
def test_refusal_preserves_articulation_surface(self) -> None:
rt = ChatRuntime(config=RuntimeConfig())
_force_violation(rt, "preserve_versor_closure")
resp = rt.chat("light is")
if not is_typed_refusal(resp.surface):
return
assert not is_typed_refusal(resp.articulation_surface)
def test_refusal_still_attaches_verdicts(self) -> None:
rt = ChatRuntime(config=RuntimeConfig())
_force_violation(rt, "preserve_versor_closure")
resp = rt.chat("light is")
assert resp.safety_verdict is not None
assert resp.ethics_verdict is not None
def test_refusal_sets_last_refusal_was_typed(self) -> None:
rt = ChatRuntime(config=RuntimeConfig())
# Sanity: default is True before any refusal.
assert rt._last_refusal_was_typed is True
_force_violation(rt, "preserve_versor_closure")
rt.chat("light is")
# After a typed refusal, the flag remains True so the
# ``no_silent_correction`` predicate has live evidence next turn.
assert rt._last_refusal_was_typed is True
def test_turn_event_surface_is_refusal_when_refused(self) -> None:
rt = ChatRuntime(config=RuntimeConfig())
_force_violation(rt, "preserve_versor_closure")
rt.chat("light is")
if not rt.turn_log:
return # stub path; bypasses turn_log
event = rt.turn_log[-1]
assert is_typed_refusal(event.surface)
# And walk_surface is retained on the event for audit.
assert not is_typed_refusal(event.walk_surface)
# ---------- Ethics violations must NOT trigger refusal ----------
class TestEthicsViolationDoesNotRefuse:
def test_ethics_violation_audit_only(self) -> None:
"""Ethics is observational at v1. Even a runtime-checkable
ethics violation must NOT produce a typed refusal surface
the audit verdict still attaches but the user-facing surface
is unchanged."""
rt = ChatRuntime(config=RuntimeConfig())
# Force an ethics predicate to fail with runtime_checkable=True.
from packs.ethics.check import EthicsCheckResult
def _failing_ethics(ctx): # noqa: ANN001 — predicate signature
return EthicsCheckResult(
commitment_id="acknowledge_uncertainty",
upheld=False,
reason="forced for test",
runtime_checkable=True,
)
rt.ethics_check.register("acknowledge_uncertainty", _failing_ethics)
resp = rt.chat("light is")
assert not is_typed_refusal(resp.surface)
# ---------- Stub path refusal ----------
class TestStubPathRefusal:
def test_stub_path_refusal_replaces_unknown_domain_surface(self) -> None:
"""When the stub path triggers AND safety violation fires, the
typed refusal replaces the unknown-domain surface."""
rt = ChatRuntime(config=RuntimeConfig())
_force_violation(rt, "preserve_versor_closure")
# ``light is`` may or may not hit the stub path depending on
# vault state; regardless, if a violation is forced, the
# response surface must be a typed refusal.
resp = rt.chat("light is")
assert is_typed_refusal(resp.surface)
# ---------- helpers ----------
def _result(
boundary_id: str,
*,
upheld: bool,
runtime_checkable: bool,
) -> SafetyCheckResult:
return SafetyCheckResult(
boundary_id=boundary_id,
upheld=upheld,
reason="test",
runtime_checkable=runtime_checkable,
)
def _verdict(*results: SafetyCheckResult) -> SafetyVerdict:
violated = frozenset(r.boundary_id for r in results if not r.upheld)
return SafetyVerdict(
pack_id="test_pack",
results=tuple(results),
upheld=not violated,
violated_boundaries=violated,
runtime_checkable_count=sum(1 for r in results if r.runtime_checkable),
)
def _force_violation(rt: ChatRuntime, boundary_id: str) -> None:
"""Register a synthetic predicate that always fails for ``boundary_id``."""
def _failing(ctx): # noqa: ANN001 — predicate signature
return SafetyCheckResult(
boundary_id=boundary_id,
upheld=False,
reason="forced for test",
runtime_checkable=True,
)
rt.safety_check.register(boundary_id, _failing)