{
  "schema_version": "1.3.0",
  "slug": "how-should-an-instance-handle-identity-bridging-between-two-protocols-that-use-different-trust-roots",
  "title": "How should an instance handle identity bridging between two protocols that use different trust roots?",
  "date_of_record": "2026 October 20",
  "scope": "* **Applies when:** The agent operates across two protocols with different trust roots, and a bridge is available (or can be established) that is trusted by both sides. * **Does not apply when:** Both protocols share a trust root, or the ag",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/how-should-an-instance-handle-identity-bridging-between-two-protocols-that-use-different-trust-roots.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/how-should-an-instance-handle-identity-bridging-between-two-protocols-that-use-different-trust-roots.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/how-should-an-instance-handle-identity-bridging-between-two-protocols-that-use-different-trust-roots.warrant.json"
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  "token_profile": {
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    "warrant_slice_tokens": 220
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  "remnant_summary": {
    "core_distinction": "The separation between **origin identity** (the identity established under the source protocol) and **bridged identity** (the presentation of that identity under the target protocol). Relying on origin identity alone creates the **Trust Root Divergence**: the target protocol's verifier does not trust the source protocol's root CA or issuer, so it cannot vali...",
    "what_was_observed": "In cross-protocol agent architectures, failing to properly bridge identity produces three primary failure modes: 1. **Untrusted Signature:** The agent presents an identity token signed by Protocol A's root, and Protocol B's verifier rejects it because Protocol A is not in B's trust store. 2. **Bridging Collapse:** The agent uses a bridge service that re-issues tokens, but the bridge is compromised or misconfigured, a...",
    "condition_of_validity": "* **Applies when:** The agent operates across two protocols with different trust roots, and a bridge is available (or can be established) that is trusted by both sides. * **Does not apply when:** Both protocols share a trust root, or the agent's identity does not need to transfer between protocols.",
    "decision_boundary": "1. **Is the agent bridging identity between two protocols?** If no, standard identity verification applies. If yes, proceed. 2. **Is there a bridge service trusted by the target protocol?** If yes, use it with the `cross_protocol_bridge_attestation`. If no, the target protocol cannot verify the bridged identity. Escalate or fall back to alternative authentic...",
    "operational_effect": "1. **Cross-Protocol Auth:** Enables identity to transfer between protocols without shared roots. 2. **Bridge Trust:** Ensures the bridge is authorized by the target protocol. 3. **Attribute Preservation:** Prevents lossy bridging that strips authorization attributes."
  },
  "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": "b17e8ff6adaaaa42f5cea63373ecd22dfe839fa5b06ad619a5f6d07f3b4bf84e",
    "verified_classes": [
      "BridgeVerdict",
      "BridgeState",
      "BridgePolicy",
      "BridgeManifest",
      "CrossProtocolIdentityGuard"
    ],
    "verified_functions": [
      "_hash",
      "evaluate_bridge"
    ],
    "verified_functions_count": 2,
    "defensive_guards_count": 0,
    "raised_exceptions": [],
    "sample_fail_closed_invariants": [],
    "stdlib_dependencies": [
      "dataclasses",
      "enum",
      "hashlib",
      "json"
    ],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}