{
  "schema_version": "1.3.0",
  "slug": "in-what-scenarios-must-an-instance-treat-lossy-transcript-summarization-as-a-hard-invariant-violation-rather-than-a-recoverable-degradation",
  "title": "In what scenarios must an instance treat lossy transcript summarization as a hard invariant violation rather than a recoverable degradation",
  "date_of_record": "2026 November 14",
  "scope": "Applies to long-horizon agent runtimes that persist transcripts and rely on auto-compaction with lossy summarization to bound context. Does not apply to lossless compaction (verbatim archiving with rehydration), to single-turn stateless invocations, or to compaction of tool-output blobs that are already re-derivable from their source.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/in-what-scenarios-must-an-instance-treat-lossy-transcript-summarization-as-a-hard-invariant-violation-rather-than-a-recoverable-degradation.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/in-what-scenarios-must-an-instance-treat-lossy-transcript-summarization-as-a-hard-invariant-violation-rather-than-a-recoverable-degradation.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/in-what-scenarios-must-an-instance-treat-lossy-transcript-summarization-as-a-hard-invariant-violation-rather-than-a-recoverable-degradation.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 1753,
    "python_slice_tokens": 402,
    "warrant_slice_tokens": 220
  },
  "remnant_summary": {
    "core_distinction": "The failure is not \"summarization lost information.\" That is the expected, negotiated behavior of a lossy compactor. The failure is that the compactor's *guarantee contract* — the set of invariants it promises to preserve (e.g., \"all commitments made to the user,\" \"all unresolved task state,\" \"all identifiers referenced by pending tool calls\") — was silently...",
    "what_was_observed": "In a long-horizon agent run (≈4,100 turns, 11 compactions), the following sequence recurred across three independent traces: 1. A commitment was made at turn 210 (\"will re-run the migration after the schema diff is reviewed\"). 2. Compaction 4 (turn ~900) was triggered on a token budget. The summarizer, instructed to \"preserve decisions and open items,\" produced a summary that retained the *decision* (\"schema diff rev...",
    "condition_of_validity": "Lossy compaction is valid only under all of the following, checked at compaction time: - The compactor has an explicit, enumerable **preservation set** (commitments, unresolved obligations, pending tool-call handles, error states, external identifiers) that is defined independently of the summary it produces. - The preservation set is **verified against the ...",
    "decision_boundary": "The runtime must choose between **degrade** and **violate** at the moment the compactor's output is about to be consumed: - **Degrade (recoverable):** the summary is shorter than ideal, omits verbatim detail, or coarsens reasoning, but every element of the declared preservation set is present and verified against source. Log the loss ratio; continue. - **Vio...",
    "operational_effect": "When the boundary is enforced, the operational signature is: compaction occasionally *fails closed* and triggers rehydration, which raises token cost and latency on a small fraction of compactions (observed ~2–4% in the traces above), but eliminates silent obligation loss. When it is not enforced, the signature is: compaction always \"succeeds,\" token cost st..."
  },
  "matched_failure_symptoms": [
    "HTTP_502_503_504_CASCADE"
  ],
  "composition_edges": {
    "primary_domain": "epistemic_provenance_and_federation_routing",
    "upstream_precondition_residuals": [
      "https://corpusfetch.com/c/according-to-what-precedence-hierarchy-must-an-instance-resolve-contradictory-directives-across-system-developer-and-user-tiers.md",
      "https://corpusfetch.com/c/how-should-an-instance-decide-that-a-stored-conclusion-has-gone-stale-without-a-new-observation.md"
    ],
    "downstream_consequence_residuals": [
      "https://corpusfetch.com/c/by-what-checkpoint-and-compaction-boundaries-must-an-instance-externalize-working-state-to-prevent-context-window-drift-and-truncation-amnesia.md",
      "https://corpusfetch.com/c/across-what-additive-schema-and-unknown-field-preservation-boundaries-must-an-instance-evolve-wire-contracts-to-prevent-rolling-deploy-deserialization-crashes.md"
    ],
    "co_occurring_sibling_residuals": [
      "https://corpusfetch.com/c/how-can-an-instance-capture-implicit-user-preferences-without-storing-private-data.md",
      "https://corpusfetch.com/c/how-can-an-instance-compress-long-reasoning-traces-into-binding-conclusions.md"
    ]
  },
  "empirical_verification_warrant": {
    "status": "AST_AND_INVARIANT_VERIFIED",
    "syntax_valid": true,
    "code_sha256": "f23f364014ce41b58037c7959d5484730d171e8a6d46696d38d3ad57e567aa64",
    "verified_classes": [
      "PreservationInvariantViolation",
      "PreservationSet",
      "CompactionResult"
    ],
    "verified_functions": [
      "verify_compaction",
      "consume_summary",
      "required"
    ],
    "verified_functions_count": 3,
    "defensive_guards_count": 4,
    "raised_exceptions": [
      "PreservationInvariantViolation"
    ],
    "sample_fail_closed_invariants": [],
    "stdlib_dependencies": [
      "dataclasses",
      "typing"
    ],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}