Unified email ingestion pipelines for Amazon procurement data. Two independent pipelines — purchase orders (Coupa) and work orders (APM/Hexagon EAM) — share a single repo and CDK app but deploy as separate CloudFormation stacks.
## Pipelines
### Purchase Orders (`po-ingest` stack)
Coupa PO emails are received at `amazon_po@int.seahaven.com`, parsed by Claude Haiku 4.5, and written to the `purchase-orders` DynamoDB table.
**Flow:**
1. Coupa sends a PO email (new, revision, or cancellation).
2. SES (`INBOUND_MAIL` rule set) drops the raw MIME into `s3://po-ingest-emails-{AccountId}/inbound/`.
3. S3 `ObjectCreated` triggers the `po-email-processor` Lambda.
4. Claude extracts structured JSON (PO number, status, supplier, site code, trade classification, line items, fiscal year).
5. Conditional write to DynamoDB:
-`new_po` — idempotent insert (no-op if PO exists)
-`pending-site-review` (PK: `po_number`) — unresolvable POs for manual Payee Central verification
### Work Orders (`WorkorderIngestStack` stack)
Amazon APM work order emails (from Hexagon EAM / HxGN SmartCloud) are received at `apm@int.seahaven.com`, parsed by Claude Haiku 4.5, and written to the `WorkOrders` DynamoDB table.
**Flow:**
1. Hexagon EAM sends email notifications (new assignments, comments, updates, cancellations) to `amazon@seahavenind.com`.
2. Gmail filter forwards APM emails to `apm@int.seahaven.com` (SES).
3. SES drops the raw MIME into `s3://workorder-ingest-emails-{AccountId}/inbound/`.
4. S3 triggers the `workorder-email-processor` Lambda.
5. Claude extracts structured JSON (work order ID, site code, severity, priority, dates, assigned technician).
6. Work order upserted to `WorkOrders`, event/comment appended to `WorkOrderComments`.
**Failure handling (INFRA-41):** Each email-processor is async-invoked (S3 → Lambda). Both have a CDK-managed SQS dead-letter queue (`dead_letter_queue=`, 14-day retention, SSL-enforced) so a failed parse is captured rather than silently dropped after Lambda's retries.
### CloudWatch alarms
Every alarm is **ALARM-only** (no OK action), sends to the shared `site-alerts` SNS topic (imported once per stack via `Topic.from_topic_arn`), and uses `TreatMissingData.NOT_BREACHING`.
| `<fn>-duration` | `po-email-processor`, `po-ingest-site-extractor`, `po-web-ui` (p99); `workorder-email-processor` (p95) | `Duration` percentile, 5 min, `>= 45000` ms (75% of the 60s timeout), eval 3 / datapoints 2 |
The `<fn>-duration` and `<fn>-throttles` alarms for `po-email-processor` and `workorder-email-processor` supersede the orphaned, CLI-created `Lambda-Duration-*` / `Lambda-Throttles-*` alarms (deleted post-deploy).
**DynamoDB alarms** (`AWS/DynamoDB`): each owned table gets `<table>-throttles` (`ThrottledRequests`) and `<table>-system-errors` (`SystemErrors`). These metrics emit only at the `TableName` + `Operation` dimension set, so each alarm is a `Sum` math expression across the operations the table uses (Get/BatchGet/Query/Scan/Put/Update/Delete/BatchWrite). Tables covered: `purchase-orders`, `verified-sites`, `pending-site-review` (po-ingest); `WorkOrders`, `WorkOrderComments` (workorder-ingest).
The `purchase-orders` DynamoDB table is **owned by this repo's `po-ingest` stack** (defined in `cdk/po_stack.py` with `RemovalPolicy.RETAIN` and `StreamViewType.NEW_IMAGE`). The `po-email-processor` Lambda is the authoritative writer — it performs the conditional inserts, revision overwrites, and cancellation updates described above.
The consumer imports the table via `Table.fromTableName(...)` and is granted read-only access (`grantReadData`); it does not own or define it.
**Schema-coordination rule:** Any change to the `purchase-orders` schema (partition key, item shape, attribute names, streams view type) must be coordinated with `seahaven-slack-bot`. The owner here ships the change; the consumer must be updated in lockstep so its readers do not break. Treat schema changes as a cross-repo migration, not a local edit.
**Known exception (INFRA-51):** `amazon-po-parser` currently writes directly to `purchase-orders` outside this stack (backfill/enrichment scripts). This second writer is being folded into the `po-ingest` pipeline so this stack is the sole writer; until INFRA-51 closes, coordinate any schema change with `amazon-po-parser` as well.
The canonical map of Sea Haven's AWS infrastructure lives in Confluence. This project's `po-ingest` and `workorder-ingest` stacks are represented there as Mermaid subgraphs.
- **[AWS Architecture Map](https://seahaven.atlassian.net/wiki/spaces/IT/pages/1540098)** (Confluence, IT space, page 1540098)
