[
  {
    "protocol": "bpa.browser/2",
    "version": "2.0.0",
    "message_id": "message-hello",
    "session_id": "new",
    "seq": 0,
    "sent_at": "2026-07-27T06:00:00.000Z",
    "type": "session.hello",
    "trace_id": "trace-session",
    "payload": {
      "browser_instance_id": "browser-example-01",
      "extension_id": "bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb",
      "extension_version": "0.4.0",
      "bridge_build_id": "v0.4.0-example.node24.18.0",
      "supported_protocols": ["bpa.browser/2"],
      "features": [
        "page_observation_v2",
        "exact_tab_binding_v2",
        "active_page_probe_v1"
      ],
      "last_acked_command_seq": 0
    }
  },
  {
    "protocol": "bpa.browser/2",
    "version": "2.0.0",
    "message_id": "message-welcome",
    "session_id": "session-01",
    "seq": 1,
    "sent_at": "2026-07-27T06:00:00.010Z",
    "type": "session.welcome",
    "trace_id": "trace-session",
    "payload": {
      "selected_protocol": "bpa.browser/2",
      "heartbeat_ms": 20000,
      "resume_token": "resume-token-01",
      "resume_token_expires_at": "2026-07-28T06:00:00.010Z",
      "core_signing_key": {
        "key_id": "core-key-01",
        "algorithm": "Ed25519",
        "public_key_spki_base64": "MCowBQYDK2VwAyEAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=="
      },
      "max_message_bytes": 524288
    }
  },
  {
    "protocol": "bpa.browser/2",
    "version": "2.0.0",
    "message_id": "message-capabilities",
    "session_id": "session-01",
    "seq": 1,
    "sent_at": "2026-07-27T06:00:00.020Z",
    "type": "capability.report",
    "trace_id": "trace-session",
    "payload": {
      "capabilities": [
        {
          "node_id": "browser.page.context.read",
          "versions": ["1.0.0", "1.1.0", "1.2.0"],
          "risk_level": "R0",
          "permissions": ["browser.dom.read", "browser.tabs.read"],
          "routes": [
            {
              "origin": "https://example.com",
              "pathname_prefixes": ["/"],
              "observer_capability_id": "example.page"
            }
          ],
          "adapter_id": "example",
          "adapter_version": "1.1.0"
        }
      ],
      "features": [
        "page_observation_v2",
        "exact_tab_binding_v2",
        "active_page_probe_v1"
      ],
      "manifest_digest": "sha256:aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
    }
  },
  {
    "protocol": "bpa.browser/2",
    "version": "2.0.0",
    "message_id": "message-command",
    "session_id": "session-01",
    "seq": 2,
    "sent_at": "2026-07-27T06:00:01.000Z",
    "type": "command.dispatch",
    "trace_id": "trace-run-01",
    "payload": {
      "command_seq": 1,
      "run_id": "run-01",
      "workflow_id": "example.page-context-observe",
      "workflow_version": "1.2.0",
      "node_execution_id": "node-execution-01",
      "command_id": "command-01",
      "idempotency_key": "idempotency-01",
      "fencing_token": 1,
      "attempt": 1,
      "node": {
        "id": "browser.page.context.read",
        "version": "1.2.0"
      },
      "input": {},
      "timing_policy": {
        "readiness": {
          "timeoutMs": 8000,
          "stableForMs": 300,
          "pollIntervalMs": 200
        },
        "dispatchJitter": {
          "minMs": 100,
          "maxMs": 500,
          "distribution": "uniform"
        },
        "retryBackoff": {
          "strategy": "exponential",
          "baseMs": 1000,
          "maxMs": 5000,
          "jitterRatio": 0.2
        },
        "rateLimit": {
          "scope": "tab",
          "minIntervalMs": 350,
          "maxQueueMs": 3000
        }
      },
      "permission_grant": {
        "grant_id": "grant-01",
        "permissions": ["browser.dom.read", "browser.tabs.read"],
        "domains": ["https://example.com"],
        "risk_level": "R0",
        "expires_at": "2026-07-27T06:05:00.000Z",
        "run_id": "run-01",
        "node_execution_id": "node-execution-01",
        "node_id": "browser.page.context.read",
        "node_version": "1.2.0",
        "fencing_token": 1,
        "key_id": "core-key-01",
        "grant_digest": "sha256:aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
        "authorization_tag": "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=="
      },
      "deadline": "2026-07-27T06:00:11.000Z",
      "tab_ref": {
        "browser_instance_id": "browser-example-01",
        "tab_id": 100,
        "origin": "https://example.com"
      },
      "page_epoch": "page-epoch-01",
      "observation_revision": 1,
      "authentication_context_ref": "auth-context-example-01"
    }
  },
  {
    "protocol": "bpa.browser/2",
    "version": "2.0.0",
    "message_id": "message-command-ack",
    "session_id": "session-01",
    "seq": 2,
    "sent_at": "2026-07-27T06:00:01.010Z",
    "type": "command.ack",
    "trace_id": "trace-run-01",
    "payload": {
      "command_seq": 1,
      "command_id": "command-01",
      "node_execution_id": "node-execution-01",
      "accepted": true,
      "fencing_token": 1
    }
  },
  {
    "protocol": "bpa.browser/2",
    "version": "2.0.0",
    "message_id": "message-result",
    "session_id": "session-01",
    "seq": 3,
    "sent_at": "2026-07-27T06:00:02.000Z",
    "type": "command.result",
    "trace_id": "trace-run-01",
    "payload": {
      "command_seq": 1,
      "command_id": "command-01",
      "node_execution_id": "node-execution-01",
      "idempotency_key": "idempotency-01",
      "fencing_token": 1,
      "status": "succeeded",
      "output": {
        "supported": true,
        "page": {
          "id": "page-01",
          "title": "Example Console"
        },
        "tab_ref": {
          "browser_instance_id": "browser-example-01",
          "tab_id": 100,
          "origin": "https://example.com"
        },
        "page_epoch": "page-epoch-01"
      },
      "evidence_refs": [],
      "page_epoch": "page-epoch-01",
      "risk_signals": [],
      "timing_observation": {
        "rate_limit_wait_ms": 0,
        "readiness_wait_ms": 420,
        "stable_for_ms": 300
      }
    }
  },
  {
    "protocol": "bpa.browser/2",
    "version": "2.0.0",
    "message_id": "message-result-ack",
    "session_id": "session-01",
    "seq": 3,
    "sent_at": "2026-07-27T06:00:02.010Z",
    "type": "result.ack",
    "trace_id": "trace-run-01",
    "payload": {
      "command_id": "command-01",
      "node_execution_id": "node-execution-01",
      "accepted": true
    }
  },
  {
    "protocol": "bpa.browser/2",
    "version": "2.0.0",
    "message_id": "message-heartbeat",
    "session_id": "session-01",
    "seq": 4,
    "sent_at": "2026-07-27T06:00:20.000Z",
    "type": "heartbeat.ping",
    "trace_id": "trace-session",
    "payload": {
      "nonce": "heartbeat-01"
    }
  },
  {
    "protocol": "bpa.browser/2",
    "version": "2.0.0",
    "message_id": "message-heartbeat-pong",
    "session_id": "session-01",
    "seq": 4,
    "sent_at": "2026-07-27T06:00:20.010Z",
    "type": "heartbeat.pong",
    "trace_id": "trace-session",
    "payload": {
      "nonce": "heartbeat-01"
    }
  },
  {
    "protocol": "bpa.browser/2",
    "version": "2.0.0",
    "message_id": "message-cancel-request",
    "session_id": "session-01",
    "seq": 5,
    "sent_at": "2026-07-27T06:01:00.000Z",
    "type": "cancel.request",
    "trace_id": "trace-run-02",
    "payload": {
      "command_id": "command-02",
      "node_execution_id": "node-execution-02",
      "fencing_token": 2,
      "reason_code": "USER_REQUESTED"
    }
  },
  {
    "protocol": "bpa.browser/2",
    "version": "2.0.0",
    "message_id": "message-cancel-ack",
    "session_id": "session-01",
    "seq": 5,
    "sent_at": "2026-07-27T06:01:00.010Z",
    "type": "cancel.ack",
    "trace_id": "trace-run-02",
    "payload": {
      "command_id": "command-02",
      "node_execution_id": "node-execution-02",
      "fencing_token": 2,
      "acknowledged": true,
      "action_started": true
    }
  },
  {
    "protocol": "bpa.browser/2",
    "version": "2.0.0",
    "message_id": "message-cancel-effective",
    "session_id": "session-01",
    "seq": 6,
    "sent_at": "2026-07-27T06:01:01.000Z",
    "type": "cancel.effective",
    "trace_id": "trace-run-02",
    "payload": {
      "command_id": "command-02",
      "node_execution_id": "node-execution-02",
      "fencing_token": 2,
      "status": "uncertain",
      "safe_stop": false
    }
  },
  {
    "protocol": "bpa.browser/2",
    "version": "2.0.0",
    "message_id": "message-evidence-begin",
    "session_id": "session-01",
    "seq": 7,
    "sent_at": "2026-07-27T06:02:00.000Z",
    "type": "evidence.begin",
    "trace_id": "trace-run-03",
    "payload": {
      "evidence_id": "evidence-01",
      "run_id": "run-03",
      "node_execution_id": "node-execution-03",
      "kind": "verification",
      "media_type": "text/plain",
      "size": 1,
      "digest": "sha256:2d711642b726b04401627ca9fbac32f5c8530fb1903cc4db02258717921a4881",
      "chunk_size": 262144,
      "chunk_count": 1
    }
  },
  {
    "protocol": "bpa.browser/2",
    "version": "2.0.0",
    "message_id": "message-evidence-chunk",
    "session_id": "session-01",
    "seq": 8,
    "sent_at": "2026-07-27T06:02:00.010Z",
    "type": "evidence.chunk",
    "trace_id": "trace-run-03",
    "payload": {
      "evidence_id": "evidence-01",
      "index": 0,
      "data_base64": "eA==",
      "chunk_digest": "sha256:2d711642b726b04401627ca9fbac32f5c8530fb1903cc4db02258717921a4881"
    }
  },
  {
    "protocol": "bpa.browser/2",
    "version": "2.0.0",
    "message_id": "message-evidence-complete",
    "session_id": "session-01",
    "seq": 9,
    "sent_at": "2026-07-27T06:02:00.020Z",
    "type": "evidence.complete",
    "trace_id": "trace-run-03",
    "payload": {
      "evidence_id": "evidence-01",
      "digest": "sha256:2d711642b726b04401627ca9fbac32f5c8530fb1903cc4db02258717921a4881",
      "chunk_count": 1
    }
  },
  {
    "protocol": "bpa.browser/2",
    "version": "2.0.0",
    "message_id": "message-page-observation",
    "session_id": "session-01",
    "seq": 10,
    "sent_at": "2026-07-27T06:02:00.025Z",
    "type": "page.observation",
    "trace_id": "trace-page-observation",
    "payload": {
      "tab_ref": {
        "browser_instance_id": "browser-example-01",
        "tab_id": 42,
        "window_id": 7,
        "origin": "https://merchant.example.com"
      },
      "pathname": "/products",
      "content_script_ready": true,
      "authentication": {
        "state": "authenticated",
        "context_ref": "auth-context-example-shop"
      },
      "observation_state": "ready",
      "page_epoch": "tab-42:1722059999000:example",
      "observation_revision": 1,
      "observer_capability_id": "example.page",
      "observed_at": "2026-07-27T06:02:00.025Z",
      "reason_code": "PAGE_READY"
    }
  },
  {
    "protocol": "bpa.browser/2",
    "version": "2.0.0",
    "message_id": "message-page-probe-request",
    "session_id": "session-01",
    "seq": 6,
    "sent_at": "2026-07-27T06:02:00.026Z",
    "type": "page.probe.request",
    "trace_id": "trace-page-probe",
    "payload": {
      "request_id": "probe-request-01",
      "tab_ref": {
        "browser_instance_id": "browser-example-01",
        "tab_id": 42,
        "window_id": 7,
        "origin": "https://merchant.example.com"
      },
      "deadline": "2026-07-27T06:02:05.026Z"
    }
  },
  {
    "protocol": "bpa.browser/2",
    "version": "2.0.0",
    "message_id": "message-page-probe-result",
    "session_id": "session-01",
    "seq": 11,
    "sent_at": "2026-07-27T06:02:00.027Z",
    "type": "page.probe.result",
    "trace_id": "trace-page-probe",
    "payload": {
      "request_id": "probe-request-01",
      "tab_ref": {
        "browser_instance_id": "browser-example-01",
        "tab_id": 42,
        "window_id": 7,
        "origin": "https://merchant.example.com"
      },
      "accepted": true,
      "observation_revision": 1
    }
  },
  {
    "protocol": "bpa.browser/2",
    "version": "2.0.0",
    "message_id": "message-evidence-ack",
    "session_id": "session-01",
    "seq": 7,
    "sent_at": "2026-07-27T06:02:00.030Z",
    "type": "evidence.ack",
    "trace_id": "trace-run-03",
    "payload": {
      "evidence_id": "evidence-01",
      "accepted": true,
      "next_chunk_index": 1
    }
  },
  {
    "protocol": "bpa.browser/2",
    "version": "2.0.0",
    "message_id": "message-session-resume",
    "session_id": "session-01",
    "seq": 8,
    "sent_at": "2026-07-27T06:03:00.000Z",
    "type": "session.resume",
    "trace_id": "trace-session",
    "payload": {
      "accepted": true,
      "replay_from_command_seq": 2
    }
  },
  {
    "protocol": "bpa.browser/2",
    "version": "2.0.0",
    "message_id": "message-session-error",
    "session_id": "session-01",
    "seq": 9,
    "sent_at": "2026-07-27T06:04:00.000Z",
    "type": "session.error",
    "trace_id": "trace-session",
    "payload": {
      "code": "CAPABILITY_MISMATCH",
      "message": "Requested node version is unavailable.",
      "fatal": false,
      "related_message_id": "message-command"
    }
  }
]