{
  "schema_version": "1.3.0",
  "slug": "why-does-an-instance-of-a-causal-span-link-fail-across-organizational-boundaries-when-both-sides-report-healthy-traces",
  "title": "Why does an instance of a Causal Span Link Fail Across Organizational Boundaries When Both Sides Report Healthy Traces",
  "date_of_record": "2026 November 13",
  "scope": "Applies to multi-agent GenAI systems where spans are linked causally (parent/child or follow-from) across two or more trust/organizational domains, each emitting traces to its own collector and joining them via propagated trace context (W3C `traceparent`/`tracestate` or vendor equivalents). Does not apply to single-org traces, to purely time-correlated (non-causal) aggregation, or to systems where a single collector owns the entire causal graph.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/why-does-an-instance-of-a-causal-span-link-fail-across-organizational-boundaries-when-both-sides-report-healthy-traces.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/why-does-an-instance-of-a-causal-span-link-fail-across-organizational-boundaries-when-both-sides-report-healthy-traces.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/why-does-an-instance-of-a-causal-span-link-fail-across-organizational-boundaries-when-both-sides-report-healthy-traces.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 1910,
    "python_slice_tokens": 280,
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  },
  "remnant_summary": {
    "core_distinction": "A span link is *causally valid* when the child span's `parent_span_id` resolves to a span that exists, is complete, and lies within the same trace, *and* the receiving side has been authorized to read the parent's payload. It is *locally valid* when the span exists in the emitter's own store. These are not the same predicate. The failure mode is that **every...",
    "what_was_observed": "A three-agent pipeline: Org A (planner, emits `agent.plan`), Org B (retriever, emits `agent.retrieve` with a follow-from link back to the plan), Org C (synthesizer, emits `agent.synthesize`). All three use OTel GenAI semantic conventions and propagate `traceparent`. - A's collector dashboard: 100% of `agent.plan` spans present, 0 orphans, p99 latency nominal. - B's collector: 100% of `agent.retrieve` spans present, 0...",
    "condition_of_validity": "The cross-org causal link is valid iff all of the following hold simultaneously at the *join* point, not at any single emitter: 1. **Reference integrity:** for every cross-org `parent_span_id` / `link.span_id`, the referenced span is present in the joined set — i.e., the emitting org's retention/sampling decision was made *before* context injection, or the r...",
    "decision_boundary": "Do not treat \"my store has no orphans\" as evidence of cross-org link health. The decision boundary is: - **Single-org, single-collector:** local orphan check is sufficient. Stop here; do not add join-point validation. - **Multi-org, context propagated but parent retained unconditionally:** reference integrity holds by construction; validate only authorizatio...",
    "operational_effect": "Concretely, after this incident the pipeline was changed to: (a) move tail-based sampling decisions ahead of `tracestate` injection, so a dropped plan never emits a context referencing it; (b) tag every cross-org link with `link.integrity = {resolved | dangling | redacted | forbidden}` at the join, so causality validators can distinguish the four states inst..."
  },
  "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": "5f4293f469c07e065c4897302108fe31540a78675c42f28d10ec70c2d6c28fce",
    "verified_classes": [
      "CrossOrgLinkIntegrityError"
    ],
    "verified_functions": [
      "validate_joined_edge"
    ],
    "verified_functions_count": 1,
    "defensive_guards_count": 2,
    "raised_exceptions": [
      "CrossOrgLinkIntegrityError"
    ],
    "sample_fail_closed_invariants": [],
    "stdlib_dependencies": [],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}