# NATS Subject Topology

All subjects are prefixed with `verae.zapier.` to isolate this platform from other Verae messaging.

## Streams

| Stream | Subjects | Retention | Purpose |
|--------|----------|-----------|---------|
| `ZAPIER_JOBS` | `verae.zapier.jobs.watch` | Work queue | Poll Verae for job status |
| `ZAPIER_EVENTS` | `verae.zapier.jobs.events` | Limits (time) | Terminal job outcomes |
| `ZAPIER_WEBHOOKS` | `verae.zapier.webhooks.deliver` | Work queue | POST to Zapier hook URLs |
| `ZAPIER_USAGE` (optional) | `verae.zapier.usage` | Limits | Billing export |

## Subjects

### `verae.zapier.jobs.watch`

**Published by:** HTTP edge after successful `POST /api/timestamp` (or batch item).  
**Consumed by:** `job-poller` durable consumer (queue group).

**Payload**

| Field | Type | Required | Description |
|-------|------|----------|-------------|
| `tenantId` | string | yes | Owning tenant |
| `jobId` | string | yes | Verae job id |
| `tokenRef` | string | preferred | Opaque ref to resolve Verae credentials (avoid raw JWT) |
| `veraeToken` | string | discouraged | Only if tokenRef unavailable; redacted in logs |
| `enqueuedAt` | ISO-8601 | yes | Enqueue time |
| `attempt` | number | yes | Delivery attempt (0-based) |
| `maxAttempts` | number | yes | Stop after this many polls |
| `intervalMs` | number | yes | Suggested delay between polls |
| `traceId` | string | yes | Correlation id for debug |

### `verae.zapier.jobs.events`

**Published by:** Job poller when status is `completed`, `failed`, or `timeout`.  
**Consumed by:** Event router → webhook enqueue; optional waiters on HTTP edge.

**Payload**

| Field | Type | Required | Description |
|-------|------|----------|-------------|
| `event` | string | yes | `timestamp.completed` \| `timestamp.failed` \| `timestamp.timeout` |
| `tenantId` | string | yes | Tenant id |
| `jobId` | string | yes | Job id |
| `status` | object | yes | Verae `StatusResponse` shape (or synthetic timeout) |
| `traceId` | string | yes | Correlation id |
| `emittedAt` | ISO-8601 | yes | Event time |

### `verae.zapier.webhooks.deliver`

**Published by:** Event router for each matching subscription.  
**Consumed by:** `webhook-deliver` queue group.

**Payload**

| Field | Type | Required | Description |
|-------|------|----------|-------------|
| `hookId` | string | yes | Stored subscription id |
| `tenantId` | string | yes | Tenant |
| `targetUrl` | string | yes | Zapier REST Hook URL |
| `event` | string | yes | Event name |
| `payload` | object | yes | Body POSTed to Zapier |
| `attempt` | number | yes | Attempt count |
| `traceId` | string | yes | Correlation id |

### `verae.zapier.usage` (optional)

| Field | Type | Description |
|-------|------|-------------|
| `tenantId` | string | Tenant |
| `action` | string | `timestamp` \| `verify` \| `status` \| … |
| `amount` | number | Increment |
| `at` | ISO-8601 | Timestamp |

## Consumers

| Name | Stream | Mode | Notes |
|------|--------|------|-------|
| `job-poller` | `ZAPIER_JOBS` | Pull, queue | Nak with delay when still pending |
| `event-webhook-router` | `ZAPIER_EVENTS` | Push/pull | Fan-out to deliver subjects |
| `webhook-deliver` | `ZAPIER_WEBHOOKS` | Pull, queue | HTTP POST with backoff |
| `usage-writer` | `ZAPIER_USAGE` | Optional | Persist metering |

## Ack semantics

| Situation | Action |
|-----------|--------|
| Job still `pending` | `Nak` with delay ≈ `intervalMs` or republish with `attempt+1` |
| Job terminal | Publish event, `Ack` watch message |
| Webhook HTTP 2xx | `Ack` |
| Webhook HTTP 5xx / network | `Nak` / redelivery until `max_deliver` |
| Poison message | Term after max_deliver; write DLQ log with `DEBUG_VERAE=webhooks` |

## Security rules

1. Prefer `tokenRef` over embedding Verae JWTs in messages.
2. NATS must use private network + auth (Phase 15: mTLS).
3. Debug logs must redact tokens and `targetUrl` query secrets if any.
4. Treat `targetUrl` as untrusted egress (timeouts, size limits, SSRF allowlist later).