feat: implement T-019 reliable event ingress

2026-08-11 15:41:07 +08:00
parent b7fe44eeb0
commit bd964e8831
33 changed files with 2762 additions and 57 deletions
@@ -3,6 +3,7 @@ from __future__ import annotations
 import argparse
 import sys

+from .ingress import BrainEventIngress
 from .runtime import DemoEngine
 from .server import parse_bind, serve
 from .source import StreamSource, SyntheticSource, read_stream_url, require_opencv
@@ -14,6 +15,7 @@ def build_parser() -> argparse.ArgumentParser:
    parser.add_argument("--stream-url-file", help="absolute external file containing one RTSP URL")
    parser.add_argument("--bind", default="127.0.0.1:8090", help="loopback bind address")
    parser.add_argument("--fps", type=float, default=2.0, help="prototype processing FPS (0, 30]")
+    parser.add_argument("--event-ingress-config", help="absolute external Brain-to-Bell ingress configuration")
    return parser


@@ -30,7 +32,8 @@ def main(argv: list[str] | None = None) -> int:
            if args.stream_url_file:
                raise ValueError("--stream-url-file is only valid for stream mode")
            source = SyntheticSource()
-        engine = DemoEngine(source, fps=args.fps)
+        event_ingress = BrainEventIngress.from_file(args.event_ingress_config) if args.event_ingress_config else None
+        engine = DemoEngine(source, fps=args.fps, event_ingress=event_ingress)
    except (RuntimeError, ValueError) as exc:
        print(f"Brain demo configuration error: {exc}", file=sys.stderr)
        return 2
@@ -0,0 +1,645 @@
+from __future__ import annotations
+
+import base64
+import binascii
+import hashlib
+import hmac
+import ipaddress
+import json
+import re
+import secrets
+import sqlite3
+import threading
+import time
+from dataclasses import dataclass
+from pathlib import Path
+from typing import Callable
+from urllib.error import HTTPError, URLError
+from urllib.parse import urlsplit
+from urllib.request import HTTPRedirectHandler, ProxyHandler, Request, build_opener
+
+from .domain import EventCandidate
+
+
+INGRESS_PATH = "/internal/v1/event-candidates"
+MAX_PAYLOAD_BYTES = 1 << 20
+MAX_QUEUED = 10_000
+MAX_ATTEMPTS = 100
+HTTP_TIMEOUT_SECONDS = 10.0
+_ID = re.compile(r"^[A-Za-z0-9][A-Za-z0-9._-]{0,63}$")
+_SOURCE_ID = re.compile(r"^[A-Za-z0-9_-]{1,128}$")
+_EVENT_ID = re.compile(r"^evt_[0-9A-HJKMNP-TV-Z]{26}$")
+_ERROR_CODE = re.compile(r"^[a-z][a-z0-9_]{0,63}$")
+_REPO_ROOT = Path(__file__).resolve().parents[2]
+
+
+@dataclass(frozen=True)
+class IngressConfig:
+    producer_id: str
+    tenant_id: int
+    site_id: int
+    device_id: int
+    modality: str
+    severity: str
+    config_version: str
+    bell_url: str
+    key_id: str
+    key_file: Path
+    outbox_path: Path
+
+
+@dataclass(frozen=True)
+class KeyMaterial:
+    key_id: str
+    producer_id: str
+    secret: bytes
+
+
+@dataclass(frozen=True)
+class LeasedEvent:
+    source_event_id: str
+    payload: bytes
+    attempt_count: int
+
+
+@dataclass(frozen=True)
+class DeliveryResult:
+    status: str
+    event_id: str
+
+
+class RetryableDelivery(RuntimeError):
+    def __init__(self, code: str) -> None:
+        super().__init__(code)
+        self.code = _safe_error(code)
+
+
+class PermanentDelivery(RuntimeError):
+    def __init__(self, code: str) -> None:
+        super().__init__(code)
+        self.code = _safe_error(code)
+
+
+class _NoRedirect(HTTPRedirectHandler):
+    def redirect_request(self, _request: Request, _file_pointer: object, _code: int, _message: str, _headers: object, _new_url: str) -> None:
+        return None
+
+
+def _is_within(path: Path, parent: Path) -> bool:
+    try:
+        path.relative_to(parent)
+        return True
+    except ValueError:
+        return False
+
+
+def _external_absolute_path(raw: object, field: str, *, must_exist: bool) -> Path:
+    if not isinstance(raw, str) or not raw:
+        raise ValueError(f"{field} must be an absolute external path")
+    path = Path(raw)
+    if not path.is_absolute():
+        raise ValueError(f"{field} must be an absolute external path")
+    resolved = path.resolve(strict=must_exist)
+    if _is_within(resolved, _REPO_ROOT):
+        raise ValueError(f"{field} must stay outside the repository")
+    return resolved
+
+
+def _load_json_file(path: Path, maximum: int = 64 << 10) -> object:
+    raw = path.read_bytes()
+    if len(raw) > maximum:
+        raise ValueError("external configuration file is too large")
+    try:
+        return json.loads(raw.decode("utf-8"))
+    except (UnicodeError, json.JSONDecodeError) as exc:
+        raise ValueError("external configuration is not valid JSON") from exc
+
+
+def _positive_int(value: object, field: str) -> int:
+    if isinstance(value, bool) or not isinstance(value, int) or value < 1:
+        raise ValueError(f"{field} must be a positive integer")
+    return value
+
+
+def _validate_bell_url(raw: object) -> str:
+    if not isinstance(raw, str):
+        raise ValueError("bell_url must be a URL")
+    parsed = urlsplit(raw)
+    if parsed.scheme not in {"http", "https"} or parsed.hostname is None or parsed.path != INGRESS_PATH:
+        raise ValueError("bell_url must target the versioned event ingress path")
+    if parsed.username is not None or parsed.password is not None or parsed.query or parsed.fragment:
+        raise ValueError("bell_url cannot contain credentials, query or fragment")
+    try:
+        port = parsed.port
+    except ValueError as exc:
+        raise ValueError("bell_url has an invalid port") from exc
+    if port is not None and not 1 <= port <= 65535:
+        raise ValueError("bell_url has an invalid port")
+    if parsed.scheme == "http":
+        host = parsed.hostname
+        loopback = host == "localhost"
+        if not loopback:
+            try:
+                loopback = ipaddress.ip_address(host).is_loopback
+            except ValueError:
+                loopback = False
+        if not loopback:
+            raise ValueError("non-loopback event ingress requires HTTPS")
+    return raw
+
+
+def load_config(path_value: str) -> tuple[IngressConfig, KeyMaterial]:
+    config_path = _external_absolute_path(path_value, "event ingress config", must_exist=True)
+    value = _load_json_file(config_path)
+    expected = {
+        "version",
+        "producer_id",
+        "tenant_id",
+        "site_id",
+        "device_id",
+        "modality",
+        "severity",
+        "config_version",
+        "bell_url",
+        "key_id",
+        "key_file",
+        "outbox_path",
+    }
+    if not isinstance(value, dict) or set(value) != expected or value.get("version") != 1:
+        raise ValueError("invalid event ingress configuration shape")
+    producer_id = value["producer_id"]
+    key_id = value["key_id"]
+    config_version = value["config_version"]
+    if not isinstance(producer_id, str) or not _ID.fullmatch(producer_id):
+        raise ValueError("invalid producer_id")
+    if not isinstance(key_id, str) or not _ID.fullmatch(key_id):
+        raise ValueError("invalid key_id")
+    if not isinstance(config_version, str) or not 1 <= len(config_version) <= 128:
+        raise ValueError("config_version must contain 1 to 128 characters")
+    if value["modality"] != "video":
+        raise ValueError("T-019 Brain ingress supports only video primary sensors")
+    if value["severity"] not in {"low", "medium", "high", "critical"}:
+        raise ValueError("invalid severity")
+    key_file = _external_absolute_path(value["key_file"], "key_file", must_exist=True)
+    outbox_path = _external_absolute_path(value["outbox_path"], "outbox_path", must_exist=False)
+    if not outbox_path.parent.is_dir():
+        raise ValueError("outbox_path parent directory must already exist")
+    config = IngressConfig(
+        producer_id=producer_id,
+        tenant_id=_positive_int(value["tenant_id"], "tenant_id"),
+        site_id=_positive_int(value["site_id"], "site_id"),
+        device_id=_positive_int(value["device_id"], "device_id"),
+        modality="video",
+        severity=value["severity"],
+        config_version=config_version,
+        bell_url=_validate_bell_url(value["bell_url"]),
+        key_id=key_id,
+        key_file=key_file,
+        outbox_path=outbox_path,
+    )
+    document = _load_json_file(key_file)
+    if not isinstance(document, dict) or set(document) != {"version", "keys"} or document.get("version") != 1:
+        raise ValueError("invalid event ingress key document")
+    keys = document.get("keys")
+    if not isinstance(keys, list) or not keys:
+        raise ValueError("event ingress key document has no keys")
+    selected: KeyMaterial | None = None
+    seen: set[str] = set()
+    for item in keys:
+        if not isinstance(item, dict) or set(item) != {"key_id", "producer_id", "secret_base64url"}:
+            raise ValueError("invalid event ingress key entry")
+        item_key = item["key_id"]
+        item_producer = item["producer_id"]
+        encoded = item["secret_base64url"]
+        if not isinstance(item_key, str) or not _ID.fullmatch(item_key) or item_key in seen:
+            raise ValueError("invalid or duplicate event ingress key ID")
+        if not isinstance(item_producer, str) or not _ID.fullmatch(item_producer) or not isinstance(encoded, str):
+            raise ValueError("invalid event ingress key entry")
+        seen.add(item_key)
+        try:
+            secret = base64.b64decode(encoded + "=" * (-len(encoded) % 4), altchars=b"-_", validate=True)
+        except (ValueError, binascii.Error) as exc:
+            raise ValueError("invalid event ingress secret") from exc
+        if len(secret) < 32:
+            raise ValueError("event ingress secret must contain at least 32 bytes")
+        if item_key == key_id:
+            selected = KeyMaterial(item_key, item_producer, secret)
+    if selected is None or selected.producer_id != producer_id:
+        raise ValueError("selected key is not bound to the configured producer")
+    return config, selected
+
+
+def map_candidate(value: EventCandidate, config: IngressConfig) -> bytes:
+    if not _SOURCE_ID.fullmatch(value.source_event_id):
+        raise ValueError("invalid source_event_id")
+    payload = {
+        "schema_version": "0.1",
+        "source_event_id": value.source_event_id,
+        "tenant_id": config.tenant_id,
+        "site_id": config.site_id,
+        "device_id": config.device_id,
+        "sensors": [{"device_id": config.device_id, "modality": config.modality, "role": "primary"}],
+        "kind": value.kind,
+        "severity": config.severity,
+        "confidence": None,
+        "occurred_at": value.occurred_at,
+        "detected_at": value.occurred_at,
+        "latency_seconds": 0.0,
+        "config_version": config.config_version,
+        "rule": None,
+        "subject": {
+            "class": "person",
+            "track_id": value.track_id,
+            "attributes": {},
+            "anon_id": None,
+            "identity": None,
+            "identity_status": "not_enabled",
+        },
+        "observation": {
+            "zone": value.zone_id,
+            "dwell_sec": 0.0,
+            "bbox_seq_uri": None,
+            "keypoint_seq_uri": None,
+            "signal_seq_uri": None,
+        },
+        "evidence": {"snapshot_uris": [], "clip_uri": None, "clip_range": None},
+        "dedup_key": None,
+        "aggregated_into": None,
+        "outcome": "test" if value.fixture else "unknown",
+        "outcome_source": "auto" if value.fixture else None,
+        "outcome_reason": None,
+        "diagnostics": None,
+        "ext": {"brain_candidate_version": "brain-demo-v1", "zone_version": value.zone_version},
+    }
+    encoded = json.dumps(payload, ensure_ascii=False, sort_keys=True, separators=(",", ":")).encode("utf-8")
+    if len(encoded) > MAX_PAYLOAD_BYTES:
+        raise ValueError("event candidate exceeds 1 MiB")
+    return encoded
+
+
+class EventOutbox:
+    def __init__(self, path: Path, *, now: Callable[[], float] = time.time) -> None:
+        if not path.is_absolute() or _is_within(path.resolve(), _REPO_ROOT):
+            raise ValueError("outbox path must be absolute and external")
+        self._now = now
+        self._lock = threading.RLock()
+        self._connection = sqlite3.connect(str(path), timeout=5.0, isolation_level=None, check_same_thread=False)
+        self._connection.row_factory = sqlite3.Row
+        self._connection.execute("PRAGMA journal_mode=WAL")
+        self._connection.execute("PRAGMA synchronous=FULL")
+        self._connection.execute("PRAGMA foreign_keys=ON")
+        self._connection.executescript(
+            """
+            CREATE TABLE IF NOT EXISTS event_outbox (
+                source_event_id TEXT PRIMARY KEY,
+                candidate_hash BLOB NOT NULL,
+                payload BLOB NOT NULL,
+                state TEXT NOT NULL CHECK(state IN ('queued','delivering','delivered','dead_letter')),
+                attempt_count INTEGER NOT NULL DEFAULT 0 CHECK(attempt_count BETWEEN 0 AND 100),
+                available_at REAL NOT NULL,
+                lease_until REAL,
+                bell_event_id TEXT,
+                last_error_code TEXT,
+                created_at REAL NOT NULL,
+                updated_at REAL NOT NULL,
+                delivered_at REAL,
+                dead_lettered_at REAL,
+                CHECK(length(candidate_hash)=32),
+                CHECK(length(payload)<=1048576),
+                CHECK((state='delivering')=(lease_until IS NOT NULL)),
+                CHECK(delivered_at IS NULL OR dead_lettered_at IS NULL)
+            );
+            CREATE INDEX IF NOT EXISTS event_outbox_due_idx
+                ON event_outbox(available_at, created_at, source_event_id)
+                WHERE state='queued';
+            CREATE TABLE IF NOT EXISTS event_outbox_identity (
+                singleton INTEGER PRIMARY KEY CHECK(singleton=1),
+                producer_id TEXT NOT NULL,
+                tenant_id INTEGER NOT NULL CHECK(tenant_id>=1),
+                site_id INTEGER NOT NULL CHECK(site_id>=1),
+                device_id INTEGER NOT NULL CHECK(device_id>=1)
+            );
+            """
+        )
+
+    def bind_identity(self, config: IngressConfig) -> None:
+        identity = (config.producer_id, config.tenant_id, config.site_id, config.device_id)
+        with self._lock:
+            self._connection.execute("BEGIN IMMEDIATE")
+            try:
+                row = self._connection.execute(
+                    "SELECT producer_id,tenant_id,site_id,device_id FROM event_outbox_identity WHERE singleton=1"
+                ).fetchone()
+                if row is None:
+                    self._connection.execute(
+                        """INSERT INTO event_outbox_identity(
+                           singleton,producer_id,tenant_id,site_id,device_id
+                           ) VALUES (1,?,?,?,?)""",
+                        identity,
+                    )
+                elif tuple(row) != identity:
+                    raise ValueError("event outbox is bound to a different producer or device identity")
+                self._connection.execute("COMMIT")
+            except Exception:
+                self._connection.execute("ROLLBACK")
+                raise
+
+    def enqueue(self, payload: bytes) -> bool:
+        if not 0 < len(payload) <= MAX_PAYLOAD_BYTES:
+            raise ValueError("event candidate payload must contain at most 1 MiB")
+        try:
+            candidate = json.loads(payload)
+            source_event_id = candidate["source_event_id"]
+        except (UnicodeError, json.JSONDecodeError, KeyError, TypeError) as exc:
+            raise ValueError("invalid event candidate payload") from exc
+        if not isinstance(source_event_id, str) or not _SOURCE_ID.fullmatch(source_event_id):
+            raise ValueError("invalid source_event_id")
+        digest = hashlib.sha256(payload).digest()
+        now = self._now()
+        with self._lock:
+            self._connection.execute("BEGIN IMMEDIATE")
+            try:
+                existing = self._connection.execute(
+                    "SELECT candidate_hash FROM event_outbox WHERE source_event_id=?", (source_event_id,)
+                ).fetchone()
+                if existing is not None:
+                    if not hmac.compare_digest(existing["candidate_hash"], digest):
+                        raise ValueError("source_event_id already has a different candidate")
+                    self._connection.execute("COMMIT")
+                    return False
+                active = self._connection.execute(
+                    "SELECT count(*) FROM event_outbox WHERE state IN ('queued','delivering')"
+                ).fetchone()[0]
+                if active >= MAX_QUEUED:
+                    raise RuntimeError("event outbox capacity exceeded")
+                self._connection.execute(
+                    """INSERT INTO event_outbox(
+                        source_event_id,candidate_hash,payload,state,available_at,created_at,updated_at
+                    ) VALUES (?,?,?,'queued',?,?,?)""",
+                    (source_event_id, digest, payload, now, now, now),
+                )
+                self._connection.execute("COMMIT")
+                return True
+            except Exception:
+                self._connection.execute("ROLLBACK")
+                raise
+
+    def lease_one(self, lease_seconds: float = 30.0) -> LeasedEvent | None:
+        now = self._now()
+        with self._lock:
+            self._connection.execute("BEGIN IMMEDIATE")
+            try:
+                self._connection.execute(
+                    """UPDATE event_outbox SET state='dead_letter', lease_until=NULL,
+                       last_error_code='retry_exhausted', dead_lettered_at=?, updated_at=?
+                       WHERE attempt_count>=? AND (
+                         state='queued' OR (state='delivering' AND lease_until<=?)
+                       )""",
+                    (now, now, MAX_ATTEMPTS, now),
+                )
+                self._connection.execute(
+                    """UPDATE event_outbox SET state='queued', lease_until=NULL,
+                       available_at=?, last_error_code='lease_expired', updated_at=?
+                       WHERE state='delivering' AND lease_until<=? AND attempt_count<?""",
+                    (now, now, now, MAX_ATTEMPTS),
+                )
+                row = self._connection.execute(
+                    """SELECT source_event_id,payload,attempt_count FROM event_outbox
+                       WHERE state='queued' AND available_at<=? AND attempt_count<?
+                       ORDER BY available_at,created_at,source_event_id LIMIT 1""",
+                    (now, MAX_ATTEMPTS),
+                ).fetchone()
+                if row is None:
+                    self._connection.execute("COMMIT")
+                    return None
+                attempt = row["attempt_count"] + 1
+                self._connection.execute(
+                    """UPDATE event_outbox SET state='delivering',attempt_count=?,lease_until=?,updated_at=?
+                       WHERE source_event_id=? AND state='queued'""",
+                    (attempt, now + lease_seconds, now, row["source_event_id"]),
+                )
+                self._connection.execute("COMMIT")
+                return LeasedEvent(row["source_event_id"], bytes(row["payload"]), attempt)
+            except Exception:
+                self._connection.execute("ROLLBACK")
+                raise
+
+    def mark_delivered(self, item: LeasedEvent, result: DeliveryResult) -> None:
+        now = self._now()
+        with self._lock:
+            changed = self._connection.execute(
+                """UPDATE event_outbox SET state='delivered',lease_until=NULL,bell_event_id=?,
+                   last_error_code=NULL,delivered_at=?,updated_at=?
+                   WHERE source_event_id=? AND state='delivering' AND attempt_count=?""",
+                (result.event_id, now, now, item.source_event_id, item.attempt_count),
+            ).rowcount
+        if changed != 1:
+            raise RuntimeError("event outbox delivery lease was lost")
+
+    def mark_retry(self, item: LeasedEvent, code: str) -> None:
+        now = self._now()
+        if item.attempt_count >= MAX_ATTEMPTS:
+            self.mark_dead(item, "retry_exhausted")
+            return
+        delay = min(300.0, float(2 ** min(item.attempt_count - 1, 9)))
+        with self._lock:
+            changed = self._connection.execute(
+                """UPDATE event_outbox SET state='queued',lease_until=NULL,available_at=?,
+                   last_error_code=?,updated_at=?
+                   WHERE source_event_id=? AND state='delivering' AND attempt_count=?""",
+                (now + delay, _safe_error(code), now, item.source_event_id, item.attempt_count),
+            ).rowcount
+        if changed != 1:
+            raise RuntimeError("event outbox retry lease was lost")
+
+    def mark_dead(self, item: LeasedEvent, code: str) -> None:
+        now = self._now()
+        with self._lock:
+            changed = self._connection.execute(
+                """UPDATE event_outbox SET state='dead_letter',lease_until=NULL,
+                   last_error_code=?,dead_lettered_at=?,updated_at=?
+                   WHERE source_event_id=? AND state='delivering' AND attempt_count=?""",
+                (_safe_error(code), now, now, item.source_event_id, item.attempt_count),
+            ).rowcount
+        if changed != 1:
+            raise RuntimeError("event outbox dead-letter lease was lost")
+
+    def status(self) -> dict[str, object]:
+        with self._lock:
+            counts = {row["state"]: row["count"] for row in self._connection.execute(
+                "SELECT state,count(*) AS count FROM event_outbox GROUP BY state"
+            )}
+            error = self._connection.execute(
+                """SELECT last_error_code FROM event_outbox WHERE last_error_code IS NOT NULL
+                   ORDER BY updated_at DESC LIMIT 1"""
+            ).fetchone()
+        return {
+            "enabled": True,
+            "queued": counts.get("queued", 0),
+            "delivering": counts.get("delivering", 0),
+            "delivered": counts.get("delivered", 0),
+            "dead_letter": counts.get("dead_letter", 0),
+            "last_error_code": None if error is None else error["last_error_code"],
+        }
+
+    def close(self) -> None:
+        with self._lock:
+            self._connection.close()
+
+
+class EventIngressClient:
+    def __init__(self, config: IngressConfig, key: KeyMaterial, *, now: Callable[[], float] = time.time) -> None:
+        self._config = config
+        self._key = key
+        self._now = now
+        # Internal event payloads must never be redirected through ambient
+        # HTTP(S)_PROXY settings.
+        self._opener = build_opener(ProxyHandler({}), _NoRedirect())
+
+    def deliver(self, candidate: bytes) -> DeliveryResult:
+        try:
+            candidate_object = json.loads(candidate)
+        except (UnicodeError, json.JSONDecodeError) as exc:
+            raise PermanentDelivery("candidate_invalid") from exc
+        body = json.dumps(
+            {"schema_version": 1, "producer_id": self._config.producer_id, "candidate": candidate_object},
+            ensure_ascii=False,
+            sort_keys=True,
+            separators=(",", ":"),
+        ).encode("utf-8")
+        if len(body) > MAX_PAYLOAD_BYTES:
+            raise PermanentDelivery("payload_too_large")
+        timestamp = str(int(self._now()))
+        nonce = base64.urlsafe_b64encode(secrets.token_bytes(16)).rstrip(b"=").decode("ascii")
+        digest = hashlib.sha256(body).hexdigest()
+        canonical = "\n".join(("POST", INGRESS_PATH, timestamp, nonce, digest)).encode("utf-8")
+        signature_value = base64.urlsafe_b64encode(hmac.new(self._key.secret, canonical, hashlib.sha256).digest()).rstrip(b"=").decode("ascii")
+        request = Request(self._config.bell_url, data=body, method="POST")
+        request.add_header("Content-Type", "application/json")
+        request.add_header("X-YoVision-Key-Id", self._key.key_id)
+        request.add_header("X-YoVision-Timestamp", timestamp)
+        request.add_header("X-YoVision-Nonce", nonce)
+        request.add_header("X-YoVision-Signature", signature_value)
+        try:
+            with self._opener.open(request, timeout=HTTP_TIMEOUT_SECONDS) as response:
+                status = response.status
+                response_body = response.read(64 << 10)
+        except HTTPError as exc:
+            status = exc.code
+            response_body = exc.read(64 << 10)
+        except (URLError, TimeoutError, OSError) as exc:
+            raise RetryableDelivery("network_error") from exc
+        if status in {200, 201}:
+            try:
+                value = json.loads(response_body)
+                response_status = value["status"]
+                event_id = value["event_id"]
+                if (
+                    value["schema_version"] != 1
+                    or value["producer_id"] != self._config.producer_id
+                    or value["source_event_id"] != candidate_object["source_event_id"]
+                    or response_status not in {"accepted", "duplicate"}
+                    or not isinstance(event_id, str)
+                    or not _EVENT_ID.fullmatch(event_id)
+                ):
+                    raise ValueError
+            except (KeyError, TypeError, ValueError, json.JSONDecodeError) as exc:
+                raise RetryableDelivery("invalid_response") from exc
+            return DeliveryResult(response_status, event_id)
+        code = "http_error"
+        try:
+            error_value = json.loads(response_body)
+            if isinstance(error_value, dict) and isinstance(error_value.get("error"), str):
+                code = error_value["error"]
+        except (UnicodeError, json.JSONDecodeError):
+            pass
+        if status == 401 or status >= 500:
+            raise RetryableDelivery(code)
+        raise PermanentDelivery(code)
+
+
+class EventRelayWorker:
+    def __init__(self, outbox: EventOutbox, client: EventIngressClient) -> None:
+        self._outbox = outbox
+        self._client = client
+        self._stop = threading.Event()
+        self._thread: threading.Thread | None = None
+        self._last_error_code: str | None = None
+
+    def run_once(self) -> bool:
+        item = self._outbox.lease_one()
+        if item is None:
+            return False
+        try:
+            result = self._client.deliver(item.payload)
+        except PermanentDelivery as exc:
+            self._outbox.mark_dead(item, exc.code)
+        except RetryableDelivery as exc:
+            self._outbox.mark_retry(item, exc.code)
+        except Exception:
+            self._outbox.mark_retry(item, "client_error")
+        else:
+            self._outbox.mark_delivered(item, result)
+        return True
+
+    def start(self) -> None:
+        if self._thread is not None:
+            return
+        self._thread = threading.Thread(target=self._run, name="brain-event-relay", daemon=True)
+        self._thread.start()
+
+    def _run(self) -> None:
+        while not self._stop.is_set():
+            try:
+                worked = self.run_once()
+                self._last_error_code = None
+            except Exception:
+                self._last_error_code = "event_outbox_unavailable"
+                self._stop.wait(1.0)
+                continue
+            if not worked:
+                self._stop.wait(0.25)
+
+    def stop(self) -> None:
+        self._stop.set()
+        if self._thread is not None:
+            self._thread.join(timeout=HTTP_TIMEOUT_SECONDS + 2.0)
+            self._thread = None
+
+    def last_error_code(self) -> str | None:
+        return self._last_error_code
+
+
+class BrainEventIngress:
+    def __init__(self, config: IngressConfig, key: KeyMaterial) -> None:
+        self._config = config
+        self._outbox = EventOutbox(config.outbox_path)
+        self._outbox.bind_identity(config)
+        self._worker = EventRelayWorker(self._outbox, EventIngressClient(config, key))
+
+    @classmethod
+    def from_file(cls, path: str) -> "BrainEventIngress":
+        config, key = load_config(path)
+        return cls(config, key)
+
+    def submit(self, value: EventCandidate) -> None:
+        self._outbox.enqueue(map_candidate(value, self._config))
+
+    def start(self) -> None:
+        self._worker.start()
+
+    def stop(self) -> None:
+        self._worker.stop()
+        self._outbox.close()
+
+    def status(self) -> dict[str, object]:
+        value = self._outbox.status()
+        if self._worker.last_error_code() is not None:
+            value["last_error_code"] = self._worker.last_error_code()
+        return value
+
+
+def _safe_error(value: str) -> str:
+    if not isinstance(value, str) or not _ERROR_CODE.fullmatch(value):
+        return "unknown_error"
+    return value
@@ -24,8 +24,12 @@ DEFAULT_ZONE = Zone(
 )


+class EventIngressUnavailable(RuntimeError):
+    pass
+
+
 class DemoEngine:
-    def __init__(self, source: Any, fps: float = 2.0, event_limit: int = 100) -> None:
+    def __init__(self, source: Any, fps: float = 2.0, event_limit: int = 100, event_ingress: Any | None = None) -> None:
        if not math.isfinite(fps) or fps <= 0.0 or fps > 30.0:
            raise ValueError("fps must be within (0, 30]")
        if not 1 <= event_limit <= 100:
@@ -36,6 +40,7 @@ class DemoEngine:
        self._detector = None if source.fixture else HOGPersonDetector()
        self._tracker = CentroidTracker()
        self._evaluator = ZoneEntryEvaluator(source.source_ref, source.fixture)
+        self._event_ingress = event_ingress
        self._zone = DEFAULT_ZONE
        self._events: deque[dict[str, object]] = deque(maxlen=event_limit)
        self._lock = threading.RLock()
@@ -54,6 +59,8 @@ class DemoEngine:
    def start(self) -> None:
        if self._thread is not None:
            return
+        if self._event_ingress is not None:
+            self._event_ingress.start()
        self._thread = threading.Thread(target=self._run, name="brain-demo", daemon=True)
        self._thread.start()

@@ -62,6 +69,8 @@ class DemoEngine:
        if self._thread is not None:
            self._thread.join(timeout=3.0)
            self._thread = None
+        if self._event_ingress is not None:
+            self._event_ingress.stop()
        self._source.close()

    def _run(self) -> None:
@@ -70,6 +79,9 @@ class DemoEngine:
            started = time.perf_counter()
            try:
                self.step()
+            except EventIngressUnavailable:
+                with self._lock:
+                    self._last_error_code = "event_outbox_unavailable"
            except RuntimeError:
                with self._lock:
                    self._connected = False
@@ -89,6 +101,12 @@ class DemoEngine:
        with self._lock:
            zone = self._zone
        new_events, inside_by_track = self._evaluator.evaluate(self._sequence, packet.captured_at, zone, detections)
+        if self._event_ingress is not None:
+            try:
+                for item in new_events:
+                    self._event_ingress.submit(item)
+            except Exception as exc:
+                raise EventIngressUnavailable("persist event candidate") from exc
        ok, encoded = cv2.imencode(".jpg", packet.frame, [int(cv2.IMWRITE_JPEG_QUALITY), 82])
        if not ok:
            raise RuntimeError("frame encoding failed")
@@ -96,7 +114,12 @@ class DemoEngine:
        serialized_detections = [self._serialize_detection(item, inside_by_track.get(item.track_id, False)) for item in detections]
        with self._lock:
            for event in new_events:
-                self._events.appendleft(event.as_dict())
+                serialized_event = event.as_dict()
+                if self._event_ingress is not None:
+                    # This is an immutable handoff fact, not a live delivery
+                    # status. Current counts live under event_ingress.
+                    serialized_event["delivery_status"] = "outbox_persisted"
+                self._events.appendleft(serialized_event)
            self._frame_jpeg = encoded.tobytes()
            self._frame_width = int(width)
            self._frame_height = int(height)
@@ -130,6 +153,13 @@ class DemoEngine:
    def state(self) -> dict[str, object]:
        with self._lock:
            zone = self._zone
+            if self._event_ingress is None:
+                ingress_status: dict[str, object] = {"enabled": False}
+            else:
+                try:
+                    ingress_status = self._event_ingress.status()
+                except Exception:
+                    ingress_status = {"enabled": True, "last_error_code": "event_outbox_unavailable"}
            return {
                "prototype": True,
                "notice": "工程原型；合成回放不是模型输出，HOG 适配器不是生产检测模型。",
@@ -159,6 +189,7 @@ class DemoEngine:
                },
                "detections": list(self._detections),
                "events": list(self._events),
+                "event_ingress": ingress_status,
                "last_error_code": self._last_error_code,
                "generated_at": datetime.now(timezone.utc).isoformat().replace("+00:00", "Z"),
            }