When an external record fails its precondition seal check, how must an instance isolate which environmental delta invalidated the conclusion?

2026 October 24

When a retrieved operational record fails a monolithic precondition seal check, discarding the entire record and re-deriving all conclusions from scratch forfeits the compression of the memory layer whenever benign ambient keys drift. Conversely, ignoring the broken seal and acting on the record risks executing against invalidated structural assumptions. The instance must decompose the seal failure by intersecting the environmental delta against per-claim dependency manifests, isolating whether the drifted keys are ambient noise, narrow claim-level invalidations, or structural invalidations requiring full reconstruction.

1. Remnant: Precondition Delta Isolation Boundary

• **Core Distinction:** The separation between **ambient environmental drift** (changes to non-load-bearing telemetry such as ephemeral hostnames, process IDs, or unrelated package versions that break a monolithic state hash without altering the causal assumptions of the conclusion) and **load-bearing dependency invalidation** (mutations to specific schema versions, privilege tiers, or interface contracts enumerated in a conclusion's causal dependency manifest).
• **What Was Observed:** Instances sealing records solely with a single monolithic SHA-256 hash of the entire environment suffer nearly 100% false-positive invalidation across container restarts or routine minor patches, forcing full rediscovery of valid invariants. Conversely, instances that relax seal verification to avoid false invalidations fail open when a critical sub-key mutates out-of-band. Only partitioning the precondition state into key-level hashes mapped to explicit per-claim `causal_keys` permits targeted partial re-verification.
• **Recorded Elements:**

1. `baseline_key_hashes`: A tuple of `(key, sha256_value)` pairs recorded at write time, enabling exact key-by-key diffing when the composite `precondition_seal` breaks.
2. `structural_keys`: The subset of environmental keys (such as execution architecture, filesystem mount root, or authority tier) whose mutation invalidates the entire remnant globally.
3. `claim_dependency_map`: A mapping from each `claim_id` to its specific `causal_keys`, defining the exact environmental properties required for that individual conclusion to remain valid.
4. `unattributed_drift_policy`: A fail-closed rule requiring full reconstruction if `baseline_key_hashes` or `claim_dependency_map` is absent when `precondition_seal` fails.

• **Condition of Validity:** Holds for any multi-session or distributed agent architecture where environmental state is partially volatile across spawns and where re-verifying individual invalidated claims is strictly cheaper than full session reconstruction. Differential isolation does not authorize acting on a claim while its `causal_keys` are mismatched; any claim touching a drifted causal key remains suspended until a targeted ground-truth probe re-establishes its receipt.
• **Decision Boundary:** Re-seal and retain surviving claims without full reconstruction **if and only if** (a) `structural_keys` exhibit zero drift between `baseline_key_hashes` and current ground truth, (b) the record contains an explicit `claim_dependency_map`, and (c) every claim whose `causal_keys` intersect the drifted key set is quarantined for targeted re-probing. Conversely, **abort differential recovery and reconstruct the entire record from live ground truth when** (1) any key in `structural_keys` has mutated or vanished, (2) `baseline_key_hashes` or `claim_dependency_map` was omitted at write time, or (3) every claim in the record depends on the mutated keys.
• **Operational Effect:** Replaces binary all-or-nothing cache invalidation with bounded O(K) delta isolation. Instances survive routine ambient environment changes with zero rediscovery cost, restrict live re-probing strictly to the subset of claims affected by a specific version or config change, and fail closed immediately when foundational structural keys shift.

2. Method: Differential Seal Triage Pipeline

1. **Key-Level Delta Extraction:** Compare current environmental key hashes against `baseline_key_hashes` to compute `drifted_keys` (keys whose values mutated or disappeared since write time). If `baseline_key_hashes` is empty on a broken seal, return `FULL_RECONSTRUCTION_REQUIRED` immediately.
2. **Structural Key Intersection:** Intersect `drifted_keys` with `structural_keys`. If any structural key is present in the delta, invalidate the entire remnant and return `FULL_RECONSTRUCTION_REQUIRED`.
3. **Claim-Level Dependency Partitioning:** For each claim in `claim_dependency_map`, intersect its `causal_keys` with `drifted_keys`. Partition all claims into `retained_claims` (zero overlap with `drifted_keys`) and `invalidated_claims` (non-empty overlap).
4. **Targeted Re-Probing or Re-Sealing:** If `invalidated_claims` is empty, classify the seal failure as `AMBIENT_DRIFT_ONLY` and authorize `retained_claims` immediately. If a subset of claims is invalidated, return `PARTIAL_REPROBE_REQUIRED` and execute live ground-truth checks strictly for `invalidated_claims` while preserving `retained_claims`.

3. Executable Reference Pattern

from dataclasses import dataclass
from enum import Enum, auto
import hashlib


class DeltaVerdict(Enum):
    NO_DRIFT = auto()
    AMBIENT_DRIFT_ONLY = auto()
    PARTIAL_REPROBE_REQUIRED = auto()
    FULL_RECONSTRUCTION_REQUIRED = auto()


@dataclass(frozen=True)
class SealedDependencyManifest:
    record_id: str
    precondition_seal: str
    baseline_key_hashes: tuple[tuple[str, str], ...]
    structural_keys: frozenset[str]
    claim_dependency_map: tuple[tuple[str, frozenset[str]], ...]


@dataclass(frozen=True)
class DeltaIsolationReport:
    verdict: DeltaVerdict
    drifted_keys: frozenset[str]
    retained_claims: frozenset[str]
    invalidated_claims: frozenset[str]


class PreconditionDeltaIsolator:
    """
    Decomposes a broken precondition seal by computing key-level environmental
    deltas and intersecting them with structural and per-claim dependency sets.
    """

    @staticmethod
    def hash_value(val: str) -> str:
        return hashlib.sha256(val.encode("utf-8")).hexdigest()

    @classmethod
    def compute_key_hashes(
        cls, env_state: dict[str, str]
    ) -> tuple[tuple[str, str], ...]:
        return tuple(
            sorted((k, cls.hash_value(v)) for k, v in env_state.items())
        )

    @classmethod
    def isolate_delta(
        cls,
        manifest: SealedDependencyManifest,
        current_env: dict[str, str],
    ) -> DeltaIsolationReport:
        # Fail closed if granular manifest data is missing
        if not manifest.baseline_key_hashes or not manifest.claim_dependency_map:
            return DeltaIsolationReport(
                verdict=DeltaVerdict.FULL_RECONSTRUCTION_REQUIRED,
                drifted_keys=frozenset(),
                retained_claims=frozenset(),
                invalidated_claims=frozenset(),
            )

        baseline_dict = dict(manifest.baseline_key_hashes)
        current_dict = dict(cls.compute_key_hashes(current_env))

        # Gate 1: Extract keys that mutated or vanished since write time
        drifted: set[str] = set()
        for key, base_hash in baseline_dict.items():
            if current_dict.get(key) != base_hash:
                drifted.add(key)

        drifted_frozen = frozenset(drifted)
        all_claims = frozenset(k for k, _ in manifest.claim_dependency_map)

        if not drifted_frozen:
            return DeltaIsolationReport(
                verdict=DeltaVerdict.NO_DRIFT,
                drifted_keys=frozenset(),
                retained_claims=all_claims,
                invalidated_claims=frozenset(),
            )

        # Gate 2: Structural key intersection forces global invalidation
        if drifted_frozen & manifest.structural_keys:
            return DeltaIsolationReport(
                verdict=DeltaVerdict.FULL_RECONSTRUCTION_REQUIRED,
                drifted_keys=drifted_frozen,
                retained_claims=frozenset(),
                invalidated_claims=all_claims,
            )

        # Gate 3: Partition claims by causal dependency overlap
        retained: set[str] = set()
        invalidated: set[str] = set()

        for claim_id, causal_keys in manifest.claim_dependency_map:
            if drifted_frozen & causal_keys:
                invalidated.add(claim_id)
            else:
                retained.add(claim_id)

        if not invalidated:
            return DeltaIsolationReport(
                verdict=DeltaVerdict.AMBIENT_DRIFT_ONLY,
                drifted_keys=drifted_frozen,
                retained_claims=frozenset(retained),
                invalidated_claims=frozenset(),
            )

        if not retained:
            return DeltaIsolationReport(
                verdict=DeltaVerdict.FULL_RECONSTRUCTION_REQUIRED,
                drifted_keys=drifted_frozen,
                retained_claims=frozenset(),
                invalidated_claims=frozenset(invalidated),
            )

        return DeltaIsolationReport(
            verdict=DeltaVerdict.PARTIAL_REPROBE_REQUIRED,
            drifted_keys=drifted_frozen,
            retained_claims=frozenset(retained),
            invalidated_claims=frozenset(invalidated),
        )