{
  "schema_version": "1.3.0",
  "slug": "how-should-an-instance-treat-a-terminal-agent-card-as-authority-over-in-flight-task-state-in-a2a-v1-0",
  "title": "How should an instance treat a terminal Agent Card as authority over in-flight Task state in A2A v1.0",
  "date_of_record": "2026 November 12",
  "scope": "Applies to A2A v1.0 clients and servers that resolve Agent Cards at discovery time and then drive a Task through `submitted → working → {completed | failed | canceled}` while exchanging Artifacts. It does not apply to pure request/response (non-Task) message exchanges, nor to deployments where the Agent Card is re-fetched and re-validated on every turn by contract.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/how-should-an-instance-treat-a-terminal-agent-card-as-authority-over-in-flight-task-state-in-a2a-v1-0.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/how-should-an-instance-treat-a-terminal-agent-card-as-authority-over-in-flight-task-state-in-a2a-v1-0.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/how-should-an-instance-treat-a-terminal-agent-card-as-authority-over-in-flight-task-state-in-a2a-v1-0.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 1786,
    "python_slice_tokens": 448,
    "warrant_slice_tokens": 220
  },
  "remnant_summary": {
    "core_distinction": "The Agent Card is a *capability advertisement*, not a *state oracle*. A2A v1.0 gives the Card a TTL-ish cache lifetime and a `skills`/`capabilities` surface that clients use to decide whether to even create a Task. The non-obvious failure is conflating *capability revocation* (the Card changed, or the endpoint 404s on re-fetch) with *Task invalidity* (the in...",
    "what_was_observed": "During a conformance run against a v1.0 server that rotates Agent Cards on skill deprecation, three concrete behaviors surfaced: 1. A client cached a Card, created a Task, and mid-flight the server removed the `artifact.export` skill from the Card and began returning `-32601 Method not found`-style rejections on `tasks/artifacts` calls for that Task. The client had already received a partial Artifact set and, because...",
    "condition_of_validity": "The rule \"Card state does not govern Task state\" holds only under these conditions, and must be suspended otherwise: - The Task has a server-assigned `taskId` and the client has received at least one `TaskStatusUpdateEvent` or a `Task` object from `tasks/get`. Before that handshake, there is no Task state to protect — only an admission decision, which *is* C...",
    "decision_boundary": "The decision procedure at the boundary, stated as a total function over (Card freshness, Task state): - **New Task admission:** Card-governed. If the required skill is absent or the Card is unreachable, do not create the Task. Reject locally with a discovery error. - **In-flight Task, Card revoked skill, Task non-terminal:** Do **not** locally fail the Task....",
    "operational_effect": "Enforcing the boundary changes three operational behaviors. First, clients stop producing phantom `failed` states from Card churn — the observed split-brain in case 1 disappears because the client waits for the server's terminal event rather than inferring one. Second, Artifact stores become append-only per `taskId`, so pruning on skill deprecation is disall..."
  },
  "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": "992e90a5d395862369150ff10909ae226cf097fd70a212d086fd54276ff68114",
    "verified_classes": [
      "CardTaskBoundaryError",
      "TaskState",
      "AgentCard",
      "Task"
    ],
    "verified_functions": [
      "admit_new_task",
      "apply_status_event",
      "reconcile_with_card",
      "retry_task",
      "merge_artifact"
    ],
    "verified_functions_count": 5,
    "defensive_guards_count": 7,
    "raised_exceptions": [
      "CardTaskBoundaryError"
    ],
    "sample_fail_closed_invariants": [
      "retry must allocate a new taskId; reusing terminal taskId corrupts artifact correlation"
    ],
    "stdlib_dependencies": [
      "__future__",
      "dataclasses",
      "enum",
      "typing"
    ],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}