{
  "schema_version": "1.3.0",
  "slug": "when-must-an-agent-transcript-compactor-refuse-to-reclaim-a-summarized-span",
  "title": "When must an agent transcript compactor refuse to reclaim a summarized span?",
  "date_of_record": "2026 November 6",
  "scope": "Applies to long-horizon agent runtimes that auto-compact conversational transcripts by replacing older spans with lossy summaries, and that must later recover original detail from those summaries or their provenance chain. Does not apply to append-only logs with no summarization, nor to compaction that preserves byte-exact originals in cold storage with guaranteed, latency-bounded retrieval.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/when-must-an-agent-transcript-compactor-refuse-to-reclaim-a-summarized-span.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/when-must-an-agent-transcript-compactor-refuse-to-reclaim-a-summarized-span.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/when-must-an-agent-transcript-compactor-refuse-to-reclaim-a-summarized-span.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 1328,
    "python_slice_tokens": 338,
    "warrant_slice_tokens": 220
  },
  "remnant_summary": {
    "core_distinction": "There are two distinct notions of \"recoverable\" that compaction systems routinely conflate: 1. **Semantic recoverability** — the summary retains enough information to reconstruct *meaning* well enough for the agent to continue reasoning. 2. **Evidential recoverability** — the system can still answer *verifiable* questions about the original span: exact ident...",
    "what_was_observed": "During a long-horizon session, the compactor folded a span containing a tool call (`write_file(path=\"/etc/app/conf.yaml\", ...)`) into a summary reading: *\"The agent configured the application's YAML configuration.\"* The path, the exact filename, and the fact that the write targeted `/etc/app/` rather than a project-local directory were all dropped. Later, the agent needed to answer \"did we ever modify system config?\"...",
    "condition_of_validity": "The invariant holds — and the compactor must refuse reclamation — precisely when **all** of the following are true: - The span contains **structured or verifiable content**: tool-call arguments, file paths, numeric parameters, identifiers, timestamps, or negations (\"did *not* do X\"). - The downstream workload includes **evidence-demanding operations**: audit...",
    "decision_boundary": "The compactor must not decide reclamation on a single scalar (age × size × recency). It must gate on a **two-axis predicate**: evidential class (structured/side-effecting vs. narrative) crossed with provenance availability (pointer present and original retrievable vs. not). Reclamation is permitted only in the (narrative, any) cell and the (structured, point...",
    "operational_effect": "Enforcing this boundary raises storage cost modestly (structured spans persist longer) but eliminates a class of silent, high-severity errors: confident answers derived from summaries that had abstracted away the deciding detail. It converts an invisible correctness bug into an explicit, auditable \"insufficient evidence — original retained\" state. The compac..."
  },
  "matched_failure_symptoms": [
    "DOMAIN:EPISTEMIC_PROVENANCE_AND_FEDERATION_ROUTING"
  ],
  "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": "a2923a7571cfc11c900d4d5eaf1af8b2c7c648d616a81da8e27f41e6a9492a9f",
    "verified_classes": [
      "CompactionRefusedError",
      "EvidentialClass",
      "Span"
    ],
    "verified_functions": [
      "_content_hash",
      "may_reclaim_lossily",
      "compact"
    ],
    "verified_functions_count": 3,
    "defensive_guards_count": 1,
    "raised_exceptions": [
      "CompactionRefusedError"
    ],
    "sample_fail_closed_invariants": [],
    "stdlib_dependencies": [
      "dataclasses",
      "enum",
      "hashlib"
    ],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}