{
  "schema": "varexis-index-free-publication-preview/1",
  "catalogue_version": "ice-09-tranche-69-v1",
  "route_id": "agentic_reviewed_a2a_message_only_stream_no_task_tracking",
  "record_id": "VXI-EXT-ICE09-A2A-MESSAGE-ONLY-STREAM-NO-TASK-TRACKING-01-v1",
  "question": "Does every A2A streaming reply create a task that can later be polled?",
  "answer": "A message-only stream contains exactly one Message and then closes, with no task tracking or updates. A task-lifecycle stream starts with a Task and may then carry updates. The client must distinguish the returned shape before scheduling task retrieval.",
  "records": [
    {
      "record_id": "VXI-EXT-ICE09-A2A-MESSAGE-ONLY-STREAM-NO-TASK-TRACKING-01-v1",
      "url": "/varexis-index/records/a2a-message-only-stream-no-task-tracking.json",
      "content_sha256": "55549cb29cd42d6955df7e60270ef9527eeb3e917d85f1a6c9368484c42655f7",
      "evidence": {
        "schema": "varexis-public-evidence-record/0.3",
        "generated_at_utc": "2026-10-30T15:17:58.235744+00:00",
        "record_id": "VXI-EXT-ICE09-A2A-MESSAGE-ONLY-STREAM-NO-TASK-TRACKING-01-v1",
        "record_kind": "external_reference",
        "title": "Does every A2A streaming reply create a task that can later be polled",
        "system": "A2A Project",
        "evidence_family": "vendor_evidence_review",
        "index_status": "PUBLIC_SAFE_SOURCE_REVIEW",
        "evidence_state": "PRIMARY_DOCUMENTATION_REVIEW_ONLY",
        "canonical_question": "Does every A2A streaming reply create a task that can later be polled?",
        "near_questions": [
          "Does an A2A Message response have pollable task state?",
          "How do I distinguish a message-only stream from a task stream?",
          "Why did the A2A stream end without a task ID?",
          "Can I subscribe to later updates after a direct Message reply?"
        ],
        "supported_claims": [
          {
            "claim": "A message-only stream contains exactly one Message and then closes, with no task tracking or updates. A task-lifecycle stream starts with a Task and may then carry updates. The client must distinguish the returned shape before scheduling task retrieval.",
            "reliance": "DOCUMENTED_CAPABILITY_ONLY"
          }
        ],
        "not_demonstrated_claims": [
          "Require an actual Task and its identifier before relying on later task-state polling.",
          "Buyer implementation, live runtime enforcement, settled payment, verified deletion or certification are not established.",
          "No expanded capabilities or licences for existing INDEX executables."
        ],
        "public_summary": "A message-only stream contains exactly one Message and then closes, with no task tracking or updates. A task-lifecycle stream starts with a Task and may then carry updates. The client must distinguish the returned shape before scheduling task retrieval.",
        "related_record_ids": [],
        "source_review": {
          "source_type": "official_external_documentation",
          "source_title": "A2A Project primary documentation: a2a spec",
          "source_url": "https://a2a-protocol.org/latest/specification/",
          "checked_on": "2026-10-30",
          "candidate_record_id": "VXI-EXT-ICE09-A2A-MESSAGE-ONLY-STREAM-NO-TASK-TRACKING-01-v1",
          "candidate_record_sha256": "c379d3da410a5237b7f2cde010f39ab16599f44a19f9a3039b87fae6a8866327",
          "method": "Primary documentation reviewed for the published bounded statement.",
          "deployment_tested_by_varexis": false,
          "revalidation": "The delivered snapshot preserves the review date shown. Recheck current primary documentation and deployment context before relying on present applicability; payment does not trigger fresh research."
        },
        "answer_policy": {
          "classification": "DOCUMENTED_WITH_DEPLOYMENT_BOUNDARY",
          "bounded_answer": "A message-only stream contains exactly one Message and then closes, with no task tracking or updates. A task-lifecycle stream starts with a Task and may then carry updates. The client must distinguish the returned shape before scheduling task retrieval.",
          "required_buyer_context": "response type; initial stream object; task ID if present; requested outcome. Buyer deployment not inspected.",
          "missing_evidence": "A broader claim needs evidence matching the intended use. Payment does not upgrade the evidence state."
        },
        "private_boundary": "Raw logs, thresholds, private paths, source code, protected mechanisms and reconstruction-level details are excluded from public and paid delivery.",
        "decision_profile": {
          "schema": "varexis-vendor-evidence-review/1",
          "review_status": "documentation_review_only",
          "applicability_status": "Captured current A2A specification on 2026-10-30; verify the negotiated implementation version; deployment behaviour untested.",
          "checked_on": "2026-10-30",
          "claim_to_check": "Does every A2A streaming reply create a task that can later be polled?",
          "documented_statement": {
            "status": "documented",
            "statement": "A message-only stream contains exactly one Message and then closes, with no task tracking or updates. A task-lifecycle stream starts with a Task and may then carry updates. The client must distinguish the returned shape before scheduling task retrieval.",
            "source_ids": [
              "a2a-spec"
            ]
          },
          "review_inference": {
            "status": "review_inference",
            "statement": "Does every A2A streaming reply create a task that can later be polled? Require an actual Task and its identifier before relying on later task-state polling. Task existence precedes and differs from replay limitations of an existing task. This is an operational review inference, not an observed deployment outcome.",
            "source_ids": [
              "a2a-spec"
            ]
          },
          "buyer_evidence_required": [
            "response type",
            "initial stream object",
            "task ID if present",
            "requested outcome"
          ],
          "review_condition": {
            "status": "varexis_review_policy",
            "statement": "Require an actual Task and its identifier before relying on later task-state polling."
          },
          "unknowns": "The buyer implementation, effective authority, source-data completeness and actual business outcomes were not inspected.",
          "unknown_finding": {
            "status": "unknown",
            "statement": "No buyer deployment or transaction was observed."
          },
          "evidence_sources": [
            {
              "source_id": "a2a-spec",
              "url": "https://a2a-protocol.org/latest/specification/",
              "final_url": "https://a2a-protocol.org/latest/specification/",
              "captured_at_utc": "2026-10-30T14:58:02.230232+00:00",
              "status": 200,
              "content_type": "text/html; charset=utf-8",
              "bytes": 624337,
              "sha256": "c23f78af020ace1b35e4dd8af6b7c78d9a6a4bef50c91acd81a9a3407a2e6e40",
              "title": "A2A Project primary documentation: a2a spec",
              "publisher": "A2A Project",
              "checked_on": "2026-10-30",
              "capture_status": 200,
              "claim_review_completed": true,
              "hash_basis": "SHA-256 of captured HTTP response-body bytes; not a signature or factual guarantee.",
              "version_context": "Captured current A2A specification on 2026-10-30; verify the negotiated implementation version; deployment behaviour untested.; Captured A2A specification 2026-10-30; configuration and general-operation timing statements conflict. This record preserves the uncertainty; deployed behavior unverified.",
              "rights_disposition": "Original bounded paraphrase with source attribution. Captured source body remains private; no source-body redistribution. Vendor documentation rights, code licences and marks are not transferred.",
              "reviewed_sections": [
                "Messages sent to Tasks that are in a terminal state",
                "3.4.3. Multi-Turn Conversation Patterns",
                "3.3.1. Idempotency",
                "Message-only stream",
                "3.2.2. SendMessageConfiguration",
                "3.1.1. Send Message",
                "3.4.2. Task Identifier Semantics",
                "3.1.5. Cancel Task"
              ]
            }
          ],
          "observed_deployment": false,
          "commercial_reliance_boundary": "Documentation supports only the stated boundary. Existing licensed checkers analyse supported supplied declarations locally; they do not inspect provider accounts, verify live behaviour, enforce decisions or certify compliance.",
          "paid_value": {
            "decision_context": "Does every A2A streaming reply create a task that can later be polled? Require an actual Task and its identifier before relying on later task-state polling.",
            "free": "Complete source review, questions, provenance and limitations; free to read and save locally.",
            "single_request": "Unavailable for this publication-only record; historical saved retrieval is unchanged.",
            "evidence_receipt": "Unavailable for this publication-only record; no paid retrieval entitlement is added.",
            "excluded": [
              "Fresh source research",
              "Native provider integration or schema support",
              "Live inspection or runtime enforcement",
              "Payment settlement or verified deletion",
              "Certification or expanded licences"
            ],
            "integrity": "Hashes identify content versions; they do not prove factual truth or provide a signature."
          },
          "revalidation": {
            "trigger": "Recheck current primary documentation and the applicable API, service, account and configuration before reliance. No ongoing monitoring is included.",
            "specific_watch": "Message-only stream"
          },
          "buyer_relevance": "Does every A2A streaming reply create a task that can later be polled? Require an actual Task and its identifier before relying on later task-state polling.",
          "refusal_conditions": [
            "Require an actual Task and its identifier before relying on later task-state polling.",
            "Do not infer deployment conformance, authority or successful outcomes from source documentation."
          ],
          "decision_context": {
            "operator": "Agent integration or handoff reviewer",
            "scenario": "Does every A2A streaming reply create a task that can later be polled?",
            "consequence": "Require an actual Task and its identifier before relying on later task-state polling.",
            "confidence": "High for the explicitly bounded captured clause; conflicts and version limits retained; deployment untested."
          },
          "novelty_review": {
            "candidate_id": "ICE09-105",
            "disposition": "EXTENSION",
            "nearest_record_id": "VXI-EXT-PROCUREMENT-A2A-RESUBSCRIBE-CURRENT-STATE-NOT-EVENT-REPLAY-01-v1",
            "nearest_record_url": "/varexis-index/records/a2a-resubscribe-current-state-not-event-replay.json",
            "nearest_record_sha256": "343e075b5dc6f0b2b2c7659c2120d60d51fbbb99fc45498270766a85eeea1c9b",
            "material_distinction": "Task existence precedes and differs from replay limitations of an existing task.",
            "review_status": "PASS: source qualification plus independent reviewer challenge and resolved corrections"
          },
          "optional_selection": {
            "guide_id": "cross-agent-handoff-acceptance",
            "guide_url": "/index-guides/cross-agent-handoff-acceptance",
            "guide_manifest": "/varexis-index/decision-guides.json",
            "checker": {
              "product_id": "agent-audit-coverage",
              "price_gbp_excluding_vat": 79,
              "purchase_url": "/index-access?route=agentic_pack_audit_coverage_v1",
              "licence_scope": "Existing separate internal-use licence; subscriptions do not include the executable.",
              "benefit": "Optional local analysis of supported supplied declarations only; no native provider integration or verification is added."
            },
            "boundary": "Optional existing checker analyses its supported supplied declarations locally. It does not connect to the documented provider, import native provider exports, verify tokens, establish live outcomes or extend its schema or licence."
          },
          "exact_access": {
            "endpoint": "/mcp/catalogue",
            "tool": "get_publication_record",
            "arguments": {
              "record_id": "VXI-EXT-ICE09-A2A-MESSAGE-ONLY-STREAM-NO-TASK-TRACKING-01-v1"
            },
            "record_url": "/varexis-index/records/a2a-message-only-stream-no-task-tracking.json",
            "original_mcp_search": false,
            "paid_saved_retrieval": false
          }
        },
        "niche": {
          "niche_id": "ice09-audit",
          "label": "Audit, Provenance & Evidence Accountability",
          "classification_id": "audit",
          "classification_label": "Audit, Provenance & Evidence Accountability",
          "topic_id": "audit",
          "buyer_intent": "Does every A2A streaming reply create a task that can later be polled? Require an actual Task and its identifier before relying on later task-state polling.",
          "comparison_role": "supplementary_discovery"
        },
        "paid_access_note": "The full published answer and boundaries are free. Paid access saves the selected route and source versions, with an unsigned receipt when purchased. Preview coverage before paying. Fresh research, bespoke assessment and protected evidence are excluded.",
        "service_route": {
          "request_guide": "/varexis-index/request.html",
          "request_workflow": "/varexis-index/request-workflow.json",
          "service_id": "single_request",
          "service_routes_url": "/varexis-index/service-routes.json",
          "payment_required": true,
          "availability_endpoint": "/api/index/capabilities",
          "operational_status": "AUTOMATIC_SERVICE_CAPABILITIES_GATED",
          "checkout_url": "/index-access"
        },
        "authority_boundary": "VAREXIS-INDEX informs evidence reliance. It does not provide advice, certification, deployment authority, security assurance, production approval, or guarantee.",
        "human_page": "/varexis-index/catalog.html#a2a-message-only-stream-no-task-tracking",
        "machine_readable_record": "/varexis-index/records/a2a-message-only-stream-no-task-tracking.json"
      }
    }
  ],
  "access": {
    "mode": "exact_http_only",
    "payment_required": false,
    "purchase_url": null,
    "mcp_preview_available": false,
    "paid_saved_retrieval_available": false,
    "natural_language_search_qualified": false
  },
  "boundary": "Catalogue additions are available free through the exact HTTP JSON links below. Enhanced natural-language discovery is not yet qualified for these records. They are outside MCP search, MCP preview and paid saved retrieval. No search qualification, executable capability or entitlement is added.",
  "content_sha256": "721d97eff91df508e2eef7f7cd257c88f4f9c49ecd8959372b6f7577a7faa8bb"
}
