{
  "schema_version": "1.3.0",
  "slug": "in-what-scenarios-must-an-instance-reject-cross-origin-span-links-in-federated-genai-agent-traces",
  "title": "In what scenarios must an instance reject cross-origin span links in federated GenAI agent traces",
  "date_of_record": "2026 November 13",
  "scope": "Applies to OpenTelemetry-style GenAI semantic convention span linking where an agent trace (`gen_ai.agent.*`) is assembled from spans emitted by more than one trust origin—e.g., a parent orchestrator linking `gen_ai.tool.call` spans produced by a remote sub-agent. Does not apply to single-origin traces where all spans share one emitter identity and one span-ID namespace.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/in-what-scenarios-must-an-instance-reject-cross-origin-span-links-in-federated-genai-agent-traces.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/in-what-scenarios-must-an-instance-reject-cross-origin-span-links-in-federated-genai-agent-traces.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/in-what-scenarios-must-an-instance-reject-cross-origin-span-links-in-federated-genai-agent-traces.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 1212,
    "python_slice_tokens": 140,
    "warrant_slice_tokens": 220
  },
  "remnant_summary": {
    "core_distinction": "A span link is a *reference*, not a *parent*. The GenAI semantic conventions permit an agent span to carry `links[]` entries pointing at spans it causally influenced but does not nest under—tool calls, retrieval fetches, delegated sub-agent invocations. The non-obvious invariant is this: **link validity is a function of the target span's origin, not of the t...",
    "what_was_observed": "During assembly of a three-party agent trace—orchestrator `O`, retrieval service `R`, and a delegated sub-agent `S` operating under a distinct tenant—`S` emitted a `gen_ai.agent.invoke` span whose `links[]` contained a `trace_id`/`span_id` pair pointing at an `R` span. The link resolved cleanly against the collector's span store. The assembled trace showed a direct causal edge `S → R` that never existed: `R` was invo...",
    "condition_of_validity": "Accept a cross-origin link `L` from emitter origin `E` to target span `T` in origin `O` only when **all** of the following hold: 1. `E` and `O` are the same origin, **or** `O` has published an explicit link-authorization grant naming `E` (a directed, per-origin-pair allowlist—not a global \"federation enabled\" flag). 2. The link's `trace_id` equals the enclos...",
    "decision_boundary": "The boundary is between *link acceptance* and *link quarantine*, and it is drawn on origin authority, not on resolvability: - **Same origin, resolves, same trace** → accept. - **Cross origin, no grant** → reject the link, retain the span, and emit a `link.rejected` annotation. Do **not** drop the span; dropping it destroys evidence of the emitter's overreach...",
    "operational_effect": "Enforcing origin-authority validation changed the assembled graph materially: the spurious `S → R` edge disappeared, and the true path `O → R`, `O → S` was restored. The cost was one rejected link and one annotation per federated trace—negligible against the cost of a corrupted causal graph driving a downstream root-cause or attribution query. The invariant ..."
  },
  "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": "15c817f0127058935e36c14641d1c3ac7946e864bc632151f7b801fd85d290a8",
    "verified_classes": [
      "UnauthorizedSpanLinkError"
    ],
    "verified_functions": [
      "validate_link"
    ],
    "verified_functions_count": 1,
    "defensive_guards_count": 2,
    "raised_exceptions": [
      "UnauthorizedSpanLinkError"
    ],
    "sample_fail_closed_invariants": [],
    "stdlib_dependencies": [],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}