feat(api): procurement-api read stack + OpenAPI docs (SHOC reconciliation path) (#127)

* feat(api): add procurement-api stack - read API + OpenAPI docs page

Third CDK stack: API Gateway REST API (IAM SigV4) over both pipelines'
tables, replacing SHOC's retired SyncController cross-account DynamoDB
scan as the reconciliation/backfill path.

- lambdas/api/: handler (healthcheck + docs-token gate + router dispatch),
  router (single route table), pagination (opaque cursor, hostile -> 400),
  Decimal-safe serialization, wo_repo/po_repo reads. No VendorReplies.
- OpenAPI 3.1 spec as source of truth incl. top-level webhooks section
  documenting the outbound SHOC feed; phase-2 write endpoints x-planned
  (router answers 501). Self-contained /docs page, no CDN.
- Auth: AWS_IAM on data routes + resource policy scoped to exactly
  arn:aws:iam::396287094661:role/shoc-backend-dev on GET/*; /docs and
  /openapi.json carve-out is token-gated in the Lambda via shared
  web_ui_auth (fail-closed, INFRA-74 posture).
- KMS: explicit Decrypt/DescribeKey on the DynamoDB CMK from SSM
  (name-imported table drops the key association - INFRA-104 class).
- Alarms: errors/throttles/duration(p99>=22.5s) + gateway 5xx, ALARM-only
  to site-alerts. No access logging in v1 (docs ?token= shim stays out of
  logs); cloud_watch_role=False.
- Tests: handler auth-seam + routing + Decimal round-trip; moto cursor
  pagination incl. hostile cursors; spec<->router drift gate; bundle
  AST pins for the api command; pytest.ini --cov + loader siblings.
- Deploy role: third stack DescribeStacks ARN + procurement-api smoke
  invoke ARN (re-run create-deploy-role.sh before merge).

* harden(api): apply sh-security-review findings to procurement-api

Fan-out (6 detectors) + review findings resolved:

Correctness / DoS:
- pagination: require EXACT key-set match (was subset) so a partial/foreign
  composite cursor can't reach DynamoDB as an inconsistent ExclusiveStartKey
  -> ValidationException -> 500; comments Query now pins the cursor's
  work_order_id to the path entity.
- handler: map botocore ValidationException to 400 (defense in depth) so a
  crafted cursor can't drive the zero-threshold 5xx alarm.
- web_ui_auth: compare tokens as bytes; a non-ASCII presented token now fails
  closed (401) instead of crashing hmac.compare_digest into a 500. Resolves the
  pre-existing xfail(strict) follow-up test; hardens the web UIs too.

Docs page:
- typeStr() now escapes the one spec-derived string that reached innerHTML.
- spec inlined into the docs <script> block escapes "<" -> < (</script>
  breakout guard); /openapi.json still served byte-faithful.
- Cache-Control: no-store + Referrer-Policy: no-referrer on docs responses so
  the ?token= URL stays out of caches/Referer.
- spec-drift test asserts the committed spec carries no "</" / "<!--".

IAM / IaC:
- resource policy enumerates the 7 data GET resources instead of GET/* so a
  future GET route can't silently inherit SHOC cross-account reach.
- kms:Decrypt grant gains a kms:ViaService=dynamodb condition.
- stage throttling (50 rps / 100 burst) bounds the unauthenticated /docs blast
  radius below the 10k account default.
- corrected the PATCH/POST comment (same-account callers aren't blocked by the
  resource policy; 501 handler + absent write grant are the gate).
- documented the RETAIN log-group first-deploy rollback trap and the
  resource-policy-needs-redeploy gotcha in-stack.

Mandatory GPT-4.1 cross-family review of the full policy surface: no BLOCK/FIX.
675 tests pass, ruff clean, cdk synth green.

README.md

@@ -86,9 +86,27 @@ Amazon APM work order emails (from Hexagon EAM / HxGN SmartCloud) are received a
 - `WorkOrders` (PK: `work_order_id`) — `site-code-index` and `status-index` GSIs removed 2026-06-03 (audit M-20)
 - `WorkOrderComments` (PK: `work_order_id`, SK: `comment_id`) — see the `comment_id` format note below
 
+### Procurement API (`procurement-api` stack)
+
+A read-only REST API (API Gateway + the `procurement-api` Lambda, `lambdas/api/`) over both pipelines' tables, plus a token-gated OpenAPI docs page. Primary consumer: the SHOC backend, for which this replaces the retired SyncController cross-account DynamoDB scan as the reconciliation/backfill path (and the initial-history load for the outbound work-order webhook, which starts at LATEST).
+
+| Method + path | Auth | Backing read |
+|---|---|---|
+| `GET /work-orders` · `/purchase-orders` · `/verified-sites` | IAM SigV4 | unordered paginated Scan (`limit` 1–500, opaque `cursor` = base64 `LastEvaluatedKey`; malformed cursor → 400) |
+| `GET /work-orders/{id}` · `/purchase-orders/{id}` · `/verified-sites/{siteCode}` | IAM SigV4 | GetItem (404 on miss) |
+| `GET /work-orders/{id}/comments` | IAM SigV4 | Query on the partition key, paginated |
+| `POST /work-orders/{id}/comments`, `PATCH /work-orders/{id}` | — | **phase-2 planned** (`x-planned` in the spec); handler answers 501 |
+| `GET /docs`, `GET /openapi.json` | shared docs token (`X-Auth-Token` header or `?token=` in a browser) | self-contained HTML reference page / the committed spec |
+
+- **Spec is source of truth:** `lambdas/api/openapi.json` (OpenAPI 3.1). Its top-level `webhooks` section documents the outbound SHOC work-order feed, so one page describes both directions (call + be-called). `tests/test_api_spec_drift.py` pins the spec's paths to the router table, so spec and implementation cannot drift.
+- **Auth:** data routes use API Gateway `AWS_IAM` (SigV4) plus a resource policy allowing exactly `arn:aws:iam::396287094661:role/shoc-backend-dev` on `GET/*`; same-account admin callers authorize via identity policy (Postman signs SigV4 natively). Docs routes are auth `NONE` at the gateway (resource-policy carve-out for exactly those two GETs) but the handler fails closed on the shared token (`lambdas/shared/web_ui_auth.py`, secret `procurement-ingest/web-ui-auth-token`) — not an unauthenticated data path (INFRA-74 posture).
+- **KMS:** `purchase-orders` is CMK-encrypted; the imported-by-name table doesn't carry the key association, so the stack grants `kms:Decrypt`/`DescribeKey` on the CMK from SSM `/seahaven/dynamodb/cmk-arn` explicitly (the INFRA-104 failure class).
+- **No access logging in v1** (keeps the `?token=` shim out of any log and avoids the account-level API Gateway CloudWatch role); rotate the docs token before ever enabling it. No CORS (server-to-server + Postman callers).
+- **Alarms:** `procurement-api-errors`/`-throttles`/`-duration` (p99 ≥ 22.5 s) + gateway `procurement-api-5xx`, all ALARM-only → `site-alerts`. No 4XX alarm (401/403/404 are expected traffic).
+
 ## Architecture
 
-**IaC:** AWS CDK (Python), two stacks in one app, region `us-east-1`. The `cdk.Environment` is deliberately **account-agnostic** (region-only, no `account=`): the stacks deploy to whichever account the deploy credentials target (`011934824531` seahaven-prod since the 2026-07 account migration; formerly mgmt `328440206208`), and every account-derived template value — bucket names, `Lambda::Permission` source account, the site-alerts SNS action ARN, the Bedrock ARN below — renders as the CloudFormation `AWS::AccountId` pseudo-parameter rather than a literal. Pinning `account=` was evaluated in Phase 4 and rejected: it would resolve those tokens to literals, and against the deployed (account-agnostic) templates CloudFormation flags the `RemovalPolicy.RETAIN` email buckets as requiring replacement — a data-loss risk — for no functional gain.
+**IaC:** AWS CDK (Python), three stacks in one app, region `us-east-1`. The `cdk.Environment` is deliberately **account-agnostic** (region-only, no `account=`): the stacks deploy to whichever account the deploy credentials target (`011934824531` seahaven-prod since the 2026-07 account migration; formerly mgmt `328440206208`), and every account-derived template value — bucket names, `Lambda::Permission` source account, the site-alerts SNS action ARN, the Bedrock ARN below — renders as the CloudFormation `AWS::AccountId` pseudo-parameter rather than a literal. Pinning `account=` was evaluated in Phase 4 and rejected: it would resolve those tokens to literals, and against the deployed (account-agnostic) templates CloudFormation flags the `RemovalPolicy.RETAIN` email buckets as requiring replacement — a data-loss risk — for no functional gain.
 
 All Lambdas: Python 3.12, ARM64, 60-day log retention.
 
@@ -179,7 +197,7 @@ if isinstance(event, dict) and event.get("healthcheck") is True:
 
 This placement is deliberate, not incidental: real mail always arrives as an S3 `ObjectCreated` event whose top-level keys (`Records`) AWS controls, so email content can never set a top-level `healthcheck` key — the branch creates no accept path for forged mail. It also emits **no EMF metric and no log line**, so it can never match the `sender_auth_rejected` log-metric-filter pattern that feeds the `<fn>-sender-auth-rejected` alarm (see [CloudWatch alarms](#cloudwatch-alarms)) — that alarm pages at ≥1 match in its window, so repeated healthcheck invokes across deploys (two deploys in ~30 min is routine) must never contribute to it. Unit coverage: `lambdas/po/email_processor/tests/test_po_healthcheck.py` and `lambdas/wo/email_processor/tests/test_healthcheck.py`.
 
-**Post-deploy smoke gate.** `scripts/post-deploy-smoke.sh` is wired into the CD workflow as `cd-cdk.yaml`'s `post-deploy-script` input (see [CI/CD](#cicd)) and runs synchronously after every deploy, before the workflow is considered green. It invokes both `po-email-processor` and `workorder-email-processor` with `aws lambda invoke --invocation-type RequestResponse --payload '{"healthcheck": true}'` (region `us-east-1`) and asserts, per function:
+**Post-deploy smoke gate.** `scripts/post-deploy-smoke.sh` is wired into the CD workflow as `cd-cdk.yaml`'s `post-deploy-script` input (see [CI/CD](#cicd)) and runs synchronously after every deploy, before the workflow is considered green. It invokes `po-email-processor`, `workorder-email-processor`, and `procurement-api` with `aws lambda invoke --invocation-type RequestResponse --payload '{"healthcheck": true}'` (region `us-east-1`) and asserts, per function:
 
 1. The invoke response's **`FunctionError` field is absent** — this is the load-bearing check. A broken bundle (e.g. an `ImportError` at module init from a missing sibling module) still returns HTTP 200 from the Lambda Invoke API with `FunctionError=Unhandled`; a bare exit-code check on `aws lambda invoke` would false-pass on exactly the failure this gate exists to catch.
 2. The returned payload is **exactly** `{"healthcheck": "ok"}`.
@@ -248,13 +266,13 @@ The `purchase-orders` DynamoDB table is **owned by this repo's `po-ingest` stack
 
 **Consumers (read-only):**
 
-| Repo | How it reads | Purpose |
+| Consumer | How it reads | Purpose |
 |---|---|---|
-| `seahaven-slack-bot` | `po-sync` (DynamoDB Streams + daily scan) and `wo-po-lookup` | Daily KB sync + Bedrock agent PO lookups |
+| `procurement-api` (this repo) | `Table.from_table_name` + `grant_read_data` | REST reads (`GET /purchase-orders*`) |
 
-The consumer imports the table via `Table.fromTableName(...)` and is granted read-only access (`grantReadData`); it does not own or define it.
+`seahaven-slack-bot`, the former external consumer, was decommissioned 2026-07-23 and its cross-account grants removed. External consumers now read through the `procurement-api` REST contract (`lambdas/api/openapi.json`), never by importing the table directly.
 
-**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.
+**Schema-coordination rule:** Any change to the `purchase-orders` schema (partition key, item shape, attribute names, streams view type) must be reflected in the API's OpenAPI schemas in the same PR (the spec-drift test pins paths, not item shapes — the schema fields are maintained by hand). Treat schema changes as a contract 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.
 
@@ -284,7 +302,7 @@ Both tables are **owned by this repo's `WorkorderIngestStack`** (`cdk/wo_stack.p
 
 Both currently use default DynamoDB encryption — they are **not** yet on the shared customer-managed CMK (`alias/seahaven-dynamodb`, INFRA-95 / M-3); that migration is tracked in INFRA-6. The `workorder-email-processor` role no longer holds a pre-emptive encrypt/decrypt grant on that CMK (removed in the 2026-06-17 security sweep — it was unused while the tables are unencrypted and extended the role's decrypt reach to the CMK protecting `purchase-orders`). Re-add the grant as part of the INFRA-6 migration, at which point `grant_read_write_data` on the then-encrypted tables propagates the needed key permissions automatically.
 
-**Consumer (read-only) — data contract:** `seahaven-slack-bot` imports both tables via `Table.fromTableName(...)` (`grantReadData`) and reads them from two Lambdas: `workorder-sync` (daily full-table scan into the Bedrock knowledge base) and `wo-po-lookup` (the Bedrock agent's direct WO lookup action group). The bot depends on the PK/SK schema above and these attributes: on `WorkOrders` — `description`, `wo_status`, `customer`, `site_code`, `building`, `address`, `severity`, `priority`, `assigned_to`, `date_reported`, `scheduled_start`, `due_date`, `updated_at`; on `WorkOrderComments` — `created_at` (used to sort comments), `commenter`, `text`. Any change to table name, key schema, these attribute names, or the encryption configuration (e.g. the INFRA-6 CMK migration) must be coordinated with `seahaven-slack-bot` before it ships, or the Bedrock agent breaks at runtime (not at deploy — the tables are imported by name, so there is no compile-time link).
+**Consumers (read-only) — data contract:** `seahaven-slack-bot` (the former external reader) was decommissioned 2026-07-23; its grants are gone. Current consumers: the `procurement-api` Lambda (this repo, `Table.from_table_name` + `grant_read_data`, serving `GET /work-orders*`), and — once the SHOC webhook ships — the `workorder-shoc-emitter` stream consumer. External readers (SHOC) consume through the REST contract (`lambdas/api/openapi.json`) and the webhook contract (`docs/shoc-webhook-contract.md`); both documents' field lists mirror `lambdas/wo/email_processor/persistence.py`. Any change to table name, key schema, attribute names, or encryption configuration (e.g. the INFRA-6 CMK migration) must update those two contracts in the same PR — the tables are imported by name, so there is no compile-time link and breakage surfaces at runtime.
 
 **Stream field contract (`site_code`).** Three definitions of "is this a valid site code" have existed in this repo at once. The canonical shape is `derived_fields._STRICT_CODE_RE` (`[A-Z][A-Z0-9]{2,4}`, `fullmatch`) plus its skip-list semantics (a code-shaped token is only a real site code if it is *not* skip-listed, e.g. `LLC`/`INC`/`CORP`/`LTD`/`ATTN`), used by `derive_site_code()` (the `enrich_parsed()` classifier, see the **Derived fields** note in the Purchase Orders flow above). Honestly noted, not papered over: `lambdas/po/site_extractor/handler.py`'s own `SITE_CODE_PATTERN` (`[A-Z]{2,4}\d{1,2}`, prefix-anchored `.match`, digit-requiring) still diverges from the canonical shape as of this phase — it rejects valid all-letter codes like `KLAL` (which surface as permanent `pending-site-review` rows) and accepts overlong junk like `DLI6X`/`SNY55` that the canonical `fullmatch` would not. Reconciling `po-ingest-site-extractor`'s direct-field validation onto the canonical `derived_fields` shape is Phase 6 scope, tracked separately — this paragraph will be updated when it lands.
 
@@ -292,9 +310,7 @@ Both currently use default DynamoDB encryption — they are **not** yet on the s
 
 Owned by this repo's `po-ingest` stack (`cdk/po_stack.py`). PK `siteCode` (S); default DynamoDB encryption (NOT the shared CMK).
 
-**Consumer (read-only) — data contract:** `seahaven-slack-bot`'s `wo-po-lookup` Lambda imports this table via `Table.fromTableName(...)` for the Bedrock agent's `lookup_site` action. It does point lookups by `siteCode` and reads `address`, `fullAddress`, `city`, `state`, `zip`, `latitude`, `longitude`, `notes`. Coordinate any change to the table name, key schema, or these attribute names with `seahaven-slack-bot`.
+**Consumer (read-only) — data contract:** `seahaven-slack-bot` (former reader, incl. the INFRA-138/INFRA-180 `by-state` GSI drift saga) was decommissioned 2026-07-23 — the GSI-drift issue died with it. Current consumer: the `procurement-api` Lambda (`GET /verified-sites*`). The API's `VerifiedSite` schema deliberately promises only pipeline-written fields (`siteCode`, `address`, `city`, `state`, `zip`, `fullAddress`, `locationCode`, `poCount`, `sourcePOs`) — `latitude`/`longitude`/`notes` were manually curated legacy attributes the extractor never writes, and are not part of the contract.
-
-> **GSI drift (INFRA-138):** the `by-state` GSI was removed here on 2026-06-03 (audit M-20, "0 reads in 30d"), but `seahaven-slack-bot` still queries `IndexName: 'by-state'` for its state-listing path, so that path fails at runtime today. Restoring the GSI or removing the consumer's state path needs to be reconciled cross-repo. This is the kind of silent owner-side lifecycle change this data-contract note exists to prevent.
 
 ## Documentation
 
@@ -306,7 +322,7 @@ The canonical map of Sea Haven's AWS infrastructure lives in Confluence. This pr
 
 GitHub Actions with reusable workflows from `Sea-Haven-Industries/.github` (all pinned to a commit SHA of `main`):
 - **CI** (`ci.yaml`, PR to `main`): linting + `cdk synth` via `ci-python-sam.yaml`. `cdk synth`'s Docker-bundled asset build for `po-email-processor` and `workorder-email-processor` mounts the widened `../lambdas` asset root (Phase 2, see [Deploy-Pipeline Guards](#deploy-pipeline-guards-phase-0)) as build context, not just each function's own subdirectory — the `exclude` list on both `from_asset` calls strips local-only `__pycache__`/`package/` (and `tests/`) cruft from that wider mount's source fingerprint, so CI's asset hash matches a clean local checkout, and each function's scoped `cp` glob copies only its own pipeline's `*.py` into the zip. (The exclude does not, and under `SOURCE` hashing cannot, keep the *other* pipeline's tracked source out of the fingerprint (see the PO bundling note above on `SOURCE` hashing) — but that source is identical in CI and local, so it does not cause hash divergence.)
-- **CD** (`deploy.yaml`, push to `main`): CDK deploy via `cd-cdk.yaml` (OIDC auth), followed by the synchronous `post-deploy-script: scripts/post-deploy-smoke.sh` healthcheck gate (see [Deploy-Pipeline Guards](#deploy-pipeline-guards-phase-0)) — `cd-cdk.yaml`'s `stack-name` input only accepts one stack, so the smoke script itself enumerates both `po-email-processor` and `workorder-email-processor`
+- **CD** (`deploy.yaml`, push to `main`): CDK deploy via `cd-cdk.yaml` (OIDC auth), followed by the synchronous `post-deploy-script: scripts/post-deploy-smoke.sh` healthcheck gate (see [Deploy-Pipeline Guards](#deploy-pipeline-guards-phase-0)) — `cd-cdk.yaml`'s `stack-name` input only accepts one stack, so the smoke script itself enumerates `po-email-processor`, `workorder-email-processor`, and `procurement-api`
 - Plus dependency review and PR labeler workflows on every PR
 
 Branch protection on `main` — all changes through PR.
@@ -392,12 +408,13 @@ python scripts/backfill_sites.py
 
 ```
 cdk/
-  app.py               # Two stacks: po-ingest + WorkorderIngestStack (region-only env)
+  app.py               # Three stacks: po-ingest + WorkorderIngestStack + procurement-api (region-only env)
   common.py            # Phase 4: shared plain-function CDK helpers (alarms, Bedrock grant,
                         # email bucket, processor DLQ, fallback-rate alarm) -- called with
                         # each stack's own scope + literal construct ids, logical-ID-safe
   po_stack.py          # Purchase order pipeline resources
   wo_stack.py          # Work order pipeline resources
+  procurement_api_stack.py # REST API (IAM SigV4 + resource policy) over both pipelines' tables + token-gated /docs
 lambdas/               # Phase 2: shared Code.from_asset("../lambdas") bundling root for
                         # BOTH po-email-processor and workorder-email-processor (and, since
                         # Phase 3, both web_ui functions) -- each email-processor command
@@ -408,9 +425,18 @@ lambdas/               # Phase 2: shared Code.from_asset("../lambdas") bundling
   shared/              # Phase 3: single-sourced first-party modules, landed FLAT (no
                         # __init__.py -- bare-name imports) into each bundle by the cp above
     ses_auth.py          # fail-closed SES sender-auth (INFRA-107) -- one copy, one fix
-    web_ui_auth.py       # fail-closed X-Auth-Token gate + token cache (INFRA-74)
+    web_ui_auth.py       # fail-closed X-Auth-Token gate + token cache (INFRA-74; also gates the API /docs routes)
     email_parsing.py     # parse_raw_email (WO superset; returns cc unconditionally)
     emf.py               # generic CloudWatch EMF emitter (dimension-sets pinned once)
+  api/                 # procurement-api Lambda (REST reads over both pipelines' tables)
+    handler.py           # healthcheck early-return + docs-token gate + route dispatch + error mapping
+    router.py            # single route table (spec-drift test pins it to openapi.json)
+    pagination.py        # opaque base64(LastEvaluatedKey) cursor encode/validate (hostile cursor -> 400)
+    serialization.py     # Decimal-safe JSON responses
+    wo_repo.py           # WorkOrders/WorkOrderComments reads (paginated Scan / PK Query)
+    po_repo.py           # purchase-orders/verified-sites reads (no VendorReplies -- dead table)
+    openapi.json         # OpenAPI 3.1 source of truth (paths + outbound `webhooks` section)
+    docs.html            # self-contained reference page (spec inlined at request time; no CDN)
   po/                  # PO pipeline Lambdas
     email_processor/     # Phase 5: God-handler decomposed into flat siblings (bare-name
                          # imports; the Phase 0/2/3 `cp <pipeline>/email_processor/*.py`
@@ -460,7 +486,7 @@ lambdas/               # Phase 2: shared Code.from_asset("../lambdas") bundling
 scripts/
   reprocess.py
   backfill_sites.py
-  post-deploy-smoke.sh   # CD gate: synchronous healthcheck invoke of both processors, checks FunctionError
+  post-deploy-smoke.sh   # CD gate: synchronous healthcheck invoke of the three smoke-gated functions, checks FunctionError
 conftest.py             # Phase 8: THE repo-root session-invariant conftest. rootdir is pinned by
                         # pytest.ini at repo root, so this loads for every pytest invocation shape --
                         # including a standalone `pytest lambdas/po/email_processor/tests` -- before

cdk/app.py

@@ -1,6 +1,7 @@
 #!/usr/bin/env python3
 import aws_cdk as cdk
 from po_stack import PoIngestStack
+from procurement_api_stack import ProcurementApiStack
 from wo_stack import WorkorderIngestStack
 
 app = cdk.App()
@@ -19,4 +20,11 @@ WorkorderIngestStack(
     env=cdk.Environment(region="us-east-1"),
 )
 
+ProcurementApiStack(
+    app,
+    "procurement-api",
+    stack_name="procurement-api",
+    env=cdk.Environment(region="us-east-1"),
+)
+
 app.synth()

cdk/procurement_api_stack.py

@@ -0,0 +1,361 @@
+"""procurement-api stack: read-only REST API over both pipelines' tables.
+
+Third stack in the app. Serves work orders + comments (WO stack tables) and
+purchase orders + verified sites (PO stack tables) to SigV4 callers -- the
+primary consumer is the SHOC backend, for which this API replaces the retired
+SyncController cross-account DynamoDB scan as the reconciliation/backfill
+path. Also hosts the token-gated OpenAPI docs page (/docs, /openapi.json).
+
+Tables are imported by fixed physical name (Table.from_table_name), NOT
+passed as cross-stack objects: object passing would synthesize CFN Exports
+from the owning stacks and lock them against future changes to the tables.
+The one thing name-import does NOT carry is the purchase-orders CMK
+association -- see the explicit KMS grant below.
+"""
+
+import aws_cdk as cdk
+from aws_cdk import (
+    Duration,
+    Stack,
+    aws_apigateway as apigateway,
+    aws_cloudwatch as cloudwatch,
+    aws_cloudwatch_actions as cw_actions,
+    aws_dynamodb as dynamodb,
+    aws_iam as iam,
+    aws_kms as kms,
+    aws_lambda as lambda_,
+    aws_secretsmanager as secretsmanager,
+    aws_sns as sns,
+    aws_ssm as ssm,
+)
+from constructs import Construct
+
+import common
+
+# The only cross-account caller. Grants are to this exact role ARN -- future
+# shoc-backend-staging/-prod roles are each a deliberate, individually
+# cross-reviewed addition (no wildcard/prefix trust).
+SHOC_BACKEND_DEV_ROLE_ARN = "arn:aws:iam::396287094661:role/shoc-backend-dev"
+
+STAGE_NAME = "prod"
+
+
+class ProcurementApiStack(Stack):
+    def __init__(self, scope: Construct, construct_id: str, **kwargs) -> None:
+        super().__init__(scope, construct_id, **kwargs)
+
+        alarm_topic = sns.Topic.from_topic_arn(
+            self,
+            "SiteAlertsTopic",
+            f"arn:aws:sns:{self.region}:{self.account}:site-alerts",
+        )
+
+        work_orders_table = dynamodb.Table.from_table_name(
+            self, "WorkOrdersTable", "WorkOrders"
+        )
+        comments_table = dynamodb.Table.from_table_name(
+            self, "CommentsTable", "WorkOrderComments"
+        )
+        po_table = dynamodb.Table.from_table_name(
+            self, "PurchaseOrdersTable", "purchase-orders"
+        )
+        verified_sites_table = dynamodb.Table.from_table_name(
+            self, "VerifiedSitesTable", "verified-sites"
+        )
+
+        web_ui_auth_secret = secretsmanager.Secret.from_secret_name_v2(
+            self,
+            "WebUiAuthToken",
+            "procurement-ingest/web-ui-auth-token",
+        )
+
+        # purchase-orders is SSE-KMS encrypted with the org DynamoDB CMK. A
+        # name-imported Table has no encryption-key association, so
+        # grant_read_data alone leaves the reader without kms:Decrypt and every
+        # purchase-orders read AccessDenies at runtime (the INFRA-104 failure
+        # class). Import the key from the same SSM parameter po_stack uses and
+        # grant it explicitly.
+        dynamodb_cmk = kms.Key.from_key_arn(
+            self,
+            "DynamoDbCmk",
+            ssm.StringParameter.value_for_string_parameter(
+                self, "/seahaven/dynamodb/cmk-arn"
+            ),
+        )
+
+        # RETAIN log group (INFRA-114). This is the only stateful resource in
+        # this otherwise-stateless stack, so it carries the fresh-deploy
+        # rollback trap: if the FIRST create fails after the group exists,
+        # rollback deletes everything else but retains the group, and the retry
+        # CREATE then collides on "/aws/lambda/procurement-api already exists".
+        # Recovery: delete that log group before re-running a failed first
+        # deploy (same class as the RETAIN-orphan recovery in the deploy-role
+        # runbook / reference_cfn_deploy_role_gotchas).
+        api_log_group = common.make_function_log_group(
+            self, "ProcurementApi", "procurement-api"
+        )
+        api_fn = lambda_.Function(
+            self,
+            "ProcurementApi",
+            function_name="procurement-api",
+            runtime=lambda_.Runtime.PYTHON_3_12,
+            architecture=lambda_.Architecture.ARM_64,
+            handler="handler.handler",
+            code=lambda_.Code.from_asset(
+                "../lambdas",
+                exclude=["**/__pycache__/**"],
+                bundling=cdk.BundlingOptions(
+                    image=lambda_.Runtime.PYTHON_3_12.bundling_image,
+                    command=[
+                        "bash",
+                        "-c",
+                        # Non-recursive glob ships every api/ sibling (the
+                        # allowlist-omission trap from PR #105/PR #2); the spec
+                        # and docs page ride along because the handler serves
+                        # them from its own package dir. web_ui_auth.py must
+                        # land FLAT beside handler.py for the bare import.
+                        "cp api/*.py /asset-output/ && "
+                        "cp api/openapi.json /asset-output/ && "
+                        "cp api/docs.html /asset-output/ && "
+                        "cp shared/web_ui_auth.py /asset-output/ && "
+                        "rm -rf /asset-output/__pycache__",
+                    ],
+                ),
+            ),
+            timeout=Duration.seconds(30),
+            memory_size=256,
+            log_group=api_log_group,
+            environment={
+                "WORK_ORDERS_TABLE": work_orders_table.table_name,
+                "COMMENTS_TABLE": comments_table.table_name,
+                "PO_TABLE": po_table.table_name,
+                "VERIFIED_SITES_TABLE": verified_sites_table.table_name,
+                "WEB_UI_AUTH_TOKEN_SECRET_ARN": web_ui_auth_secret.secret_arn,
+            },
+        )
+
+        work_orders_table.grant_read_data(api_fn)
+        comments_table.grant_read_data(api_fn)
+        po_table.grant_read_data(api_fn)
+        verified_sites_table.grant_read_data(api_fn)
+        web_ui_auth_secret.grant_read(api_fn)
+        api_fn.add_to_role_policy(
+            iam.PolicyStatement(
+                actions=["kms:Decrypt", "kms:DescribeKey"],
+                resources=[dynamodb_cmk.key_arn],
+                # Scope the grant to the DynamoDB data path only: the role can
+                # decrypt purchase-orders items via DynamoDB, never call
+                # kms:Decrypt directly on arbitrary ciphertext under the shared
+                # org CMK.
+                conditions={
+                    "StringEquals": {
+                        "kms:ViaService": f"dynamodb.{self.region}.amazonaws.com"
+                    }
+                },
+            )
+        )
+
+        # Resource policy: once a REST API has one, anything not explicitly
+        # allowed is denied -- so the docs routes need their own Allow or the
+        # NONE-auth methods would be black-holed. The docs routes are still
+        # token-gated inside the Lambda (fail-closed), so this is not an
+        # unauthenticated data path (INFRA-74 posture).
+        #
+        # The SHOC data grant enumerates the exact GET resources rather than
+        # GET/*: adding a RESOURCE must be as reviewable as adding a PRINCIPAL,
+        # so a future GET route can't silently inherit cross-account reach
+        # without a policy diff. (Note: this resource policy binds CROSS-account
+        # callers only; a same-account principal holding execute-api:Invoke is
+        # authorized by its own identity policy under AWS union semantics -- it
+        # is NOT constrained here, including on the planned PATCH/POST methods,
+        # which is why those also rely on the 501 handler + absent write grant,
+        # not on this policy, until phase 2.)
+        shoc_data_resources = [
+            f"execute-api:/{STAGE_NAME}/GET/work-orders",
+            f"execute-api:/{STAGE_NAME}/GET/work-orders/*",
+            f"execute-api:/{STAGE_NAME}/GET/purchase-orders",
+            f"execute-api:/{STAGE_NAME}/GET/purchase-orders/*",
+            f"execute-api:/{STAGE_NAME}/GET/verified-sites",
+            f"execute-api:/{STAGE_NAME}/GET/verified-sites/*",
+        ]
+        api_policy = iam.PolicyDocument(
+            statements=[
+                iam.PolicyStatement(
+                    sid="ShocBackendDevDataRead",
+                    principals=[iam.ArnPrincipal(SHOC_BACKEND_DEV_ROLE_ARN)],
+                    actions=["execute-api:Invoke"],
+                    resources=shoc_data_resources,
+                ),
+                # SECURITY INVARIANT: this AnyPrincipal allow is safe only
+                # while /docs//openapi.json serve static docs (handler
+                # enforces the shared token, fail-closed). Widening these
+                # routes to dynamic data, or enabling access logging (which
+                # would record the docs ?token= shim), requires a security
+                # re-review + docs-token rotation.
+                iam.PolicyStatement(
+                    sid="DocsTokenGatedRoutes",
+                    principals=[iam.AnyPrincipal()],
+                    actions=["execute-api:Invoke"],
+                    resources=[
+                        f"execute-api:/{STAGE_NAME}/GET/docs",
+                        f"execute-api:/{STAGE_NAME}/GET/openapi.json",
+                    ],
+                ),
+            ]
+        )
+
+        # OPERATIONAL NOTE: API Gateway serves the resource policy from the
+        # deployed stage snapshot, and CDK's Deployment hash is computed from
+        # resources/methods, not the RestApi Policy. A later policy-ONLY change
+        # (e.g. revoking the SHOC role) will UPDATE the RestApi but keep serving
+        # the old policy until a new Deployment is forced (any method/resource
+        # change, or a salted deployment). When tightening this policy, force a
+        # redeploy and verify the effective policy post-deploy.
+        api = apigateway.RestApi(
+            self,
+            "ProcurementRestApi",
+            rest_api_name="procurement-api",
+            description=(
+                "Read API over procurement-ingest work orders + purchase "
+                "orders; token-gated OpenAPI docs at /docs"
+            ),
+            endpoint_types=[apigateway.EndpointType.REGIONAL],
+            policy=api_policy,
+            deploy_options=apigateway.StageOptions(
+                stage_name=STAGE_NAME,
+                # Bound the blast radius of the unauthenticated /docs routes
+                # (and the whole API) below the 10k rps account default -- this
+                # is a low-volume reconciliation/backfill API, not a hot path.
+                throttling_rate_limit=50,
+                throttling_burst_limit=100,
+            ),
+            # No access/execution logging in v1: avoids the account-level API
+            # Gateway CloudWatch role prerequisite AND keeps the docs ?token=
+            # query shim out of any log. Rotate the docs token before ever
+            # enabling access logging here.
+            cloud_watch_role=False,
+        )
+
+        integration = apigateway.LambdaIntegration(api_fn)
+        iam_auth = {"authorization_type": apigateway.AuthorizationType.IAM}
+
+        work_orders = api.root.add_resource("work-orders")
+        work_orders.add_method("GET", integration, **iam_auth)
+        wo_by_id = work_orders.add_resource("{workOrderId}")
+        wo_by_id.add_method("GET", integration, **iam_auth)
+        # Phase-2 planned write endpoints: deployed but the handler answers 501
+        # and the role holds no DynamoDB write grant. The resource policy denies
+        # these to the cross-account SHOC role (GET-only enumeration above); a
+        # same-account caller is NOT blocked by the resource policy, so the 501
+        # handler + absent write grant are the real gate until phase 2 lands the
+        # deliberate policy + handler + write-grant change with its own review.
+        wo_by_id.add_method("PATCH", integration, **iam_auth)
+        wo_comments = wo_by_id.add_resource("comments")
+        wo_comments.add_method("GET", integration, **iam_auth)
+        wo_comments.add_method("POST", integration, **iam_auth)
+
+        purchase_orders = api.root.add_resource("purchase-orders")
+        purchase_orders.add_method("GET", integration, **iam_auth)
+        purchase_orders.add_resource("{poNumber}").add_method(
+            "GET", integration, **iam_auth
+        )
+
+        verified_sites = api.root.add_resource("verified-sites")
+        verified_sites.add_method("GET", integration, **iam_auth)
+        verified_sites.add_resource("{siteCode}").add_method(
+            "GET", integration, **iam_auth
+        )
+
+        api.root.add_resource("docs").add_method(
+            "GET",
+            integration,
+            authorization_type=apigateway.AuthorizationType.NONE,
+        )
+        api.root.add_resource("openapi.json").add_method(
+            "GET",
+            integration,
+            authorization_type=apigateway.AuthorizationType.NONE,
+        )
+
+        # --- Alarms (ALARM-only -> site-alerts, NOT_BREACHING) ---
+        # common.add_standard_lambda_alarms is NOT used here: its duration
+        # threshold is a fixed 45000 ms (75% of the processors' 60 s timeout),
+        # which this function's 30 s timeout can never reach. Same idiom,
+        # right-sized thresholds.
+        api_fn.metric_errors(period=Duration.minutes(5), statistic="Sum").create_alarm(
+            self,
+            "ProcurementApiErrorsAlarm",
+            alarm_name="procurement-api-errors",
+            alarm_description=(
+                "procurement-api Lambda raised (bundle/init failures; the "
+                "handler catches request errors, so any signal here is "
+                "structural)"
+            ),
+            threshold=0,
+            evaluation_periods=1,
+            comparison_operator=cloudwatch.ComparisonOperator.GREATER_THAN_THRESHOLD,
+            treat_missing_data=cloudwatch.TreatMissingData.NOT_BREACHING,
+        ).add_alarm_action(cw_actions.SnsAction(alarm_topic))
+
+        api_fn.metric_throttles(
+            period=Duration.minutes(5), statistic="Sum"
+        ).create_alarm(
+            self,
+            "ProcurementApiThrottlesAlarm",
+            alarm_name="procurement-api-throttles",
+            alarm_description="procurement-api Lambda throttled",
+            threshold=0,
+            evaluation_periods=1,
+            comparison_operator=cloudwatch.ComparisonOperator.GREATER_THAN_THRESHOLD,
+            treat_missing_data=cloudwatch.TreatMissingData.NOT_BREACHING,
+        ).add_alarm_action(cw_actions.SnsAction(alarm_topic))
+
+        api_fn.metric_duration(
+            period=Duration.minutes(5), statistic="p99"
+        ).create_alarm(
+            self,
+            "ProcurementApiDurationAlarm",
+            alarm_name="procurement-api-duration",
+            alarm_description=(
+                "procurement-api p99 duration >= 22.5s (75% of the 30s "
+                "timeout; scans degrading toward timeout)"
+            ),
+            threshold=22500,
+            evaluation_periods=3,
+            datapoints_to_alarm=2,
+            comparison_operator=cloudwatch.ComparisonOperator.GREATER_THAN_OR_EQUAL_TO_THRESHOLD,
+            treat_missing_data=cloudwatch.TreatMissingData.NOT_BREACHING,
+        ).add_alarm_action(cw_actions.SnsAction(alarm_topic))
+
+        # Gateway-side 5xx: catches what the Lambda's own Errors metric can't
+        # (the handler returns clean 500s; integration faults surface here).
+        # No 4XX alarm -- 401/403/404 are expected traffic.
+        cloudwatch.Metric(
+            namespace="AWS/ApiGateway",
+            metric_name="5XXError",
+            dimensions_map={"ApiName": "procurement-api", "Stage": STAGE_NAME},
+            period=Duration.minutes(5),
+            statistic="Sum",
+        ).create_alarm(
+            self,
+            "ProcurementApi5xxAlarm",
+            alarm_name="procurement-api-5xx",
+            alarm_description="procurement-api gateway 5XX responses",
+            threshold=0,
+            evaluation_periods=1,
+            comparison_operator=cloudwatch.ComparisonOperator.GREATER_THAN_THRESHOLD,
+            treat_missing_data=cloudwatch.TreatMissingData.NOT_BREACHING,
+        ).add_alarm_action(cw_actions.SnsAction(alarm_topic))
+
+        cdk.CfnOutput(
+            self,
+            "ApiEndpointUrl",
+            value=api.url,
+            description="procurement-api invoke URL (stage prod)",
+        )
+        cdk.CfnOutput(
+            self,
+            "ProcurementApiFunctionArn",
+            value=api_fn.function_arn,
+            description="ARN of the procurement-api Lambda",
+        )

infra/deploy-role/README.md

@@ -10,19 +10,20 @@ stays untouched until decommission as the emergency mgmt deploy path.
 | File | Purpose |
 |---|---|
 | `trust-policy.json` | OIDC trust: `repo:Sea-Haven-Industries/procurement-ingest:ref:refs/heads/main` only |
-| `permissions-policy.json` | `sts:AssumeRole` on the four `cdk-hnb659fds-*` bootstrap roles, `cloudformation:DescribeStacks` scoped to this repo's stacks + `CDKToolkit` (cd-cdk health check), and `lambda:InvokeFunction` on exactly the two email-processor function ARNs (post-deploy smoke gate) |
+| `permissions-policy.json` | `sts:AssumeRole` on the four `cdk-hnb659fds-*` bootstrap roles, `cloudformation:DescribeStacks` scoped to this repo's stacks + `CDKToolkit` (cd-cdk health check), and `lambda:InvokeFunction` on exactly the three smoke-gated function ARNs (post-deploy smoke gate) |
 | `create-deploy-role.sh` | Idempotent create-or-update from the two JSON files, profile `seahaven-prod` |
 
-> **Maintenance note:** `DescribeStacks` is scoped to `stack/po-ingest/*`, `stack/WorkorderIngestStack/*`, and `stack/CDKToolkit/*`. If a third stack is ever added to this CDK app, add its ARN pattern here and re-run the review-then-apply flow — otherwise the cd-cdk health check on the new stack will `AccessDenied`.
+> **Maintenance note:** `DescribeStacks` is scoped to `stack/po-ingest/*`, `stack/WorkorderIngestStack/*`, `stack/procurement-api/*` (added with the procurement-api stack), and `stack/CDKToolkit/*`. If another stack is ever added to this CDK app, add its ARN pattern here and re-run the review-then-apply flow — otherwise the cd-cdk health check on the new stack will `AccessDenied`.
 
 ## Why the SmokeInvokeLambda statement exists
 
 `deploy.yaml` runs `scripts/post-deploy-smoke.sh` under the deploy role's own
 session, not the assumed `cdk-*` roles. Without `lambda:InvokeFunction` on the
-two function ARNs the smoke gate hits AccessDenied and every deploy fails
+smoke-gated function ARNs (the two email processors + `procurement-api`) the
-closed. The mgmt-era grant was applied out-of-band and undocumented; keeping
+smoke gate hits AccessDenied and every deploy fails closed. The mgmt-era grant
-it in these reviewed artifacts closes that gap. Scope it to exactly the two
+was applied out-of-band and undocumented; keeping it in these reviewed
-ARNs, never `Resource: "*"`.
+artifacts closes that gap. Scope it to exactly the named ARNs, never
+`Resource: "*"`.
 
 ## Change process
 

infra/deploy-role/permissions-policy.json

@@ -19,6 +19,7 @@
             "Resource": [
                 "arn:aws:cloudformation:us-east-1:011934824531:stack/po-ingest/*",
                 "arn:aws:cloudformation:us-east-1:011934824531:stack/WorkorderIngestStack/*",
+                "arn:aws:cloudformation:us-east-1:011934824531:stack/procurement-api/*",
                 "arn:aws:cloudformation:us-east-1:011934824531:stack/CDKToolkit/*"
             ],
             "Condition": {
@@ -33,7 +34,8 @@
             "Action": "lambda:InvokeFunction",
             "Resource": [
                 "arn:aws:lambda:us-east-1:011934824531:function:po-email-processor",
-                "arn:aws:lambda:us-east-1:011934824531:function:workorder-email-processor"
+                "arn:aws:lambda:us-east-1:011934824531:function:workorder-email-processor",
+                "arn:aws:lambda:us-east-1:011934824531:function:procurement-api"
             ]
         }
     ]

lambdas/api/docs.html

@@ -0,0 +1,229 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+<meta charset="UTF-8">
+<meta name="viewport" content="width=device-width, initial-scale=1.0">
+<title>Procurement Ingest API</title>
+<style>
+  * { margin: 0; padding: 0; box-sizing: border-box; }
+  body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif; background: #f1f5f9; color: #1e293b; line-height: 1.55; }
+  .wrap { max-width: 960px; margin: 0 auto; padding: 24px 20px 80px; }
+  h1 { font-size: 24px; margin-bottom: 4px; }
+  h2 { font-size: 18px; margin: 36px 0 14px; padding-bottom: 6px; border-bottom: 2px solid #e2e8f0; }
+  .muted { color: #64748b; font-size: 14px; }
+  .desc { margin: 14px 0; font-size: 14px; color: #334155; }
+  .desc p { margin-bottom: 8px; }
+  code { background: #e2e8f0; border-radius: 4px; padding: 1px 5px; font-size: 12.5px; font-family: ui-monospace, SFMono-Regular, Menlo, monospace; }
+  .card { background: #fff; border-radius: 10px; box-shadow: 0 1px 3px rgba(0,0,0,0.08); margin-bottom: 12px; overflow: hidden; }
+  .op-head { display: flex; align-items: center; gap: 12px; padding: 12px 16px; cursor: pointer; }
+  .op-head:hover { background: #f8fafc; }
+  .method { font-size: 12px; font-weight: 700; padding: 3px 10px; border-radius: 6px; color: #fff; min-width: 58px; text-align: center; }
+  .m-get { background: #10b981; } .m-post { background: #f59e0b; } .m-patch { background: #8b5cf6; }
+  .m-webhook { background: #3b82f6; }
+  .path { font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: 14px; font-weight: 600; }
+  .summary { color: #64748b; font-size: 13px; flex: 1; }
+  .planned { background: #fef3c7; color: #92400e; font-size: 11px; font-weight: 700; padding: 2px 8px; border-radius: 10px; }
+  .op-body { display: none; padding: 4px 16px 16px; border-top: 1px solid #f1f5f9; }
+  .open .op-body { display: block; }
+  table { width: 100%; border-collapse: collapse; margin: 8px 0 14px; font-size: 13px; }
+  th { text-align: left; padding: 6px 8px; color: #64748b; font-size: 11px; text-transform: uppercase; border-bottom: 2px solid #e2e8f0; }
+  td { padding: 6px 8px; border-bottom: 1px solid #f1f5f9; vertical-align: top; }
+  .sec-label { font-size: 12px; font-weight: 700; color: #64748b; text-transform: uppercase; margin: 14px 0 4px; }
+  .schema-name { font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-weight: 600; }
+  .type { color: #7c3aed; font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: 12px; }
+  .req { color: #dc2626; font-size: 11px; font-weight: 700; }
+  .badge-auth { background: #dbeafe; color: #1d4ed8; font-size: 11px; font-weight: 600; padding: 2px 8px; border-radius: 10px; }
+  a { color: #3b82f6; text-decoration: none; }
+  .enum { color: #0f766e; font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: 12px; }
+</style>
+</head>
+<body>
+<div class="wrap" id="app"><p class="muted">Loading spec…</p></div>
+<script id="spec" type="application/json">__OPENAPI_SPEC_JSON__</script>
+<script>
+"use strict";
+const spec = JSON.parse(document.getElementById("spec").textContent);
+const el = (tag, cls, html) => {
+  const node = document.createElement(tag);
+  if (cls) node.className = cls;
+  if (html !== undefined) node.innerHTML = html;
+  return node;
+};
+const escapeHtml = s => String(s).replace(/[&<>"']/g,
+  c => ({"&":"&amp;","<":"&lt;",">":"&gt;",'"':"&quot;","'":"&#39;"}[c]));
+const md = s => escapeHtml(s || "")
+  .replace(/\*\*([^*]+)\*\*/g, "<strong>$1</strong>")
+  .replace(/`([^`]+)`/g, "<code>$1</code>")
+  .split(/\n\n+/).map(p => `<p>${p.replace(/\n/g, "<br>")}</p>`).join("");
+
+function deref(node) {
+  if (node && node.$ref) {
+    const parts = node.$ref.replace("#/", "").split("/");
+    let cur = spec;
+    for (const p of parts) cur = cur[p];
+    return { name: node.$ref.split("/").pop(), ...cur };
+  }
+  return node;
+}
+const typeStr = schema => {
+  // Returns an HTML-escaped fragment: this is the one spec-derived string
+  // that reaches innerHTML (the type cells), so it must escape like every
+  // other renderer here. The array<...> wrapper composes already-escaped
+  // pieces, so its literal &lt;/&gt; are safe.
+  if (!schema) return "";
+  if (schema.$ref) return escapeHtml(schema.$ref.split("/").pop());
+  if (Array.isArray(schema.type) && schema.type.includes("array") && schema.items)
+    return `array&lt;${typeStr(schema.items)}&gt;`;
+  if (schema.type === "array" && schema.items) return `array&lt;${typeStr(schema.items)}&gt;`;
+  const t = Array.isArray(schema.type) ? schema.type.join(" | ") : (schema.type || "");
+  return escapeHtml(t);
+};
+
+function schemaTable(schema, depth = 0) {
+  schema = deref(schema);
+  if (schema.allOf) {
+    const merged = { properties: {}, required: [] };
+    for (const part of schema.allOf.map(deref)) {
+      Object.assign(merged.properties, part.properties || {});
+      merged.required.push(...(part.required || []));
+    }
+    schema = merged;
+  }
+  if (!schema.properties) return null;
+  const table = el("table");
+  table.appendChild(el("tr", "", "<th>Field</th><th>Type</th><th>Description</th>"));
+  for (const [name, raw] of Object.entries(schema.properties)) {
+    const prop = raw.$ref ? deref(raw) : raw;
+    const required = (schema.required || []).includes(name);
+    let desc = md(prop.description);
+    if (prop.enum) desc += `<div class="enum">${prop.enum.filter(v => v !== null).map(escapeHtml).join(" | ")}</div>`;
+    const tr = el("tr", "", `
+      <td><span class="schema-name">${escapeHtml(name)}</span>${required ? ' <span class="req">required</span>' : ""}</td>
+      <td><span class="type">${typeStr(raw)}</span></td>
+      <td>${desc}</td>`);
+    table.appendChild(tr);
+    const inner = prop.type === "object" || (Array.isArray(prop.type) && prop.type.includes("object"));
+    if (inner && prop.properties && depth < 2) {
+      const cell = el("td", "", "");
+      cell.colSpan = 3;
+      cell.style.paddingLeft = "24px";
+      cell.appendChild(schemaTable(prop, depth + 1));
+      const row = el("tr");
+      row.appendChild(cell);
+      table.appendChild(row);
+    }
+  }
+  return table;
+}
+
+function opCard(method, path, op, isWebhook) {
+  const card = el("div", "card");
+  const head = el("div", "op-head");
+  const cls = isWebhook ? "m-webhook" : `m-${method.toLowerCase()}`;
+  head.appendChild(el("span", `method ${cls}`, isWebhook ? "EVENT" : method.toUpperCase()));
+  head.appendChild(el("span", "path", escapeHtml(path)));
+  head.appendChild(el("span", "summary", escapeHtml(op.summary || "")));
+  if (op["x-planned"]) head.appendChild(el("span", "planned", "PLANNED"));
+  const secSchemes = op.security || spec.security || [];
+  const secName = secSchemes.length ? Object.keys(secSchemes[0])[0] : null;
+  if (!isWebhook && secName) head.appendChild(el("span", "badge-auth", escapeHtml(secName)));
+  const body = el("div", "op-body");
+  if (op.description) body.appendChild(el("div", "desc", md(op.description)));
+
+  const params = (op.parameters || []).map(deref);
+  if (params.length) {
+    body.appendChild(el("div", "sec-label", "Parameters"));
+    const table = el("table");
+    table.appendChild(el("tr", "", "<th>Name</th><th>In</th><th>Type</th><th>Description</th>"));
+    for (const p of params) {
+      table.appendChild(el("tr", "", `
+        <td><span class="schema-name">${escapeHtml(p.name)}</span>${p.required ? ' <span class="req">required</span>' : ""}</td>
+        <td>${escapeHtml(p.in)}</td>
+        <td><span class="type">${typeStr(p.schema)}</span></td>
+        <td>${md(p.description)}</td>`));
+    }
+    body.appendChild(table);
+  }
+
+  const reqSchema = op.requestBody && op.requestBody.content &&
+    op.requestBody.content["application/json"] && op.requestBody.content["application/json"].schema;
+  if (reqSchema) {
+    body.appendChild(el("div", "sec-label", `Payload (${typeStr(reqSchema)})`));
+    const table = schemaTable(reqSchema);
+    if (table) body.appendChild(table);
+  }
+
+  body.appendChild(el("div", "sec-label", "Responses"));
+  const rtable = el("table");
+  rtable.appendChild(el("tr", "", "<th>Status</th><th>Description</th><th>Schema</th>"));
+  for (const [code, raw] of Object.entries(op.responses || {})) {
+    const resp = deref(raw);
+    const schema = resp.content && resp.content["application/json"] && resp.content["application/json"].schema;
+    rtable.appendChild(el("tr", "", `
+      <td><span class="schema-name">${escapeHtml(code)}</span></td>
+      <td>${md(resp.description)}</td>
+      <td><span class="type">${schema ? typeStr(schema) : ""}</span></td>`));
+    if (code.startsWith("2") && schema) {
+      const cell = el("td", "", "");
+      cell.colSpan = 3;
+      cell.style.paddingLeft = "24px";
+      const table = schemaTable(schema);
+      if (table) cell.appendChild(table);
+      const row = el("tr");
+      row.appendChild(cell);
+      rtable.appendChild(row);
+    }
+  }
+  body.appendChild(rtable);
+  head.addEventListener("click", () => card.classList.toggle("open"));
+  card.appendChild(head);
+  card.appendChild(body);
+  return card;
+}
+
+const app = document.getElementById("app");
+app.innerHTML = "";
+app.appendChild(el("h1", "", escapeHtml(spec.info.title)));
+app.appendChild(el("div", "muted", `v${escapeHtml(spec.info.version)} &middot; ${escapeHtml((spec.servers && spec.servers[0] && spec.servers[0].url) || "")}`));
+app.appendChild(el("div", "desc", md(spec.info.description)));
+
+app.appendChild(el("h2", "", "Authentication"));
+for (const [name, scheme] of Object.entries((spec.components || {}).securitySchemes || {})) {
+  const card = el("div", "card");
+  card.appendChild(el("div", "op-head",
+    `<span class="badge-auth">${escapeHtml(name)}</span>
+     <span class="summary">${escapeHtml(scheme.name)} (${escapeHtml(scheme.in)}) &mdash; ${md(scheme.description)}</span>`));
+  app.appendChild(card);
+}
+
+app.appendChild(el("h2", "", "Endpoints (this API can be called)"));
+for (const [path, ops] of Object.entries(spec.paths || {})) {
+  for (const [method, op] of Object.entries(ops)) {
+    app.appendChild(opCard(method, path, op, false));
+  }
+}
+
+app.appendChild(el("h2", "", "Outbound webhooks (this API calls you)"));
+for (const [name, ops] of Object.entries(spec.webhooks || {})) {
+  for (const [method, op] of Object.entries(ops)) {
+    app.appendChild(opCard(method, name, op, true));
+  }
+}
+
+app.appendChild(el("h2", "", "Schemas"));
+for (const [name, schema] of Object.entries((spec.components || {}).schemas || {})) {
+  const card = el("div", "card open");
+  const head = el("div", "op-head");
+  head.appendChild(el("span", "schema-name", escapeHtml(name)));
+  head.appendChild(el("span", "summary", escapeHtml(schema.description || "")));
+  card.appendChild(head);
+  const body = el("div", "op-body");
+  const table = schemaTable(schema);
+  if (table) body.appendChild(table);
+  card.appendChild(body);
+  head.addEventListener("click", () => card.classList.toggle("open"));
+  app.appendChild(card);
+}
+</script>
+</body>
+</html>

lambdas/api/handler.py

@@ -0,0 +1,193 @@
+"""Procurement API Lambda (API Gateway REST proxy integration).
+
+Auth is split by route class and enforced at two layers:
+- Data routes: AWS_IAM at the gateway (SigV4; cross-account callers allowed by
+  the API resource policy). The handler does NOT re-check a token there --
+  authorization is API Gateway's job on those routes.
+- Docs routes (/docs, /openapi.json): reachable at the gateway (auth NONE +
+  resource-policy carve-out) but the handler fails closed on the shared
+  header token via web_ui_auth (same secret + constant-time compare as the
+  web UIs), so they are never an unauthenticated data path (INFRA-74).
+"""
+
+import logging
+from pathlib import Path
+
+import po_repo
+import wo_repo
+from botocore.exceptions import ClientError
+from pagination import BadCursor, clamp_limit
+from router import DATA_ROUTES, DOCS_ROUTES, PLANNED_ROUTES
+from serialization import error_response, json_response
+from web_ui_auth import is_authenticated
+
+logger = logging.getLogger()
+logger.setLevel(logging.INFO)
+
+_MODULE_DIR = Path(__file__).resolve().parent
+_SPEC_PATH = _MODULE_DIR / "openapi.json"
+_DOCS_PATH = _MODULE_DIR / "docs.html"
+# The docs page template carries this placeholder where the spec JSON is
+# inlined, so /docs is a single token-gated request (a browser can't attach
+# the auth header to a follow-up asset fetch).
+_SPEC_PLACEHOLDER = "__OPENAPI_SPEC_JSON__"
+
+_spec_cache = None
+_docs_cache = None
+
+_REPO_FUNCS = {
+    "list_work_orders": wo_repo.list_work_orders,
+    "get_work_order": wo_repo.get_work_order,
+    "list_comments": wo_repo.list_comments,
+    "list_purchase_orders": po_repo.list_purchase_orders,
+    "get_purchase_order": po_repo.get_purchase_order,
+    "list_verified_sites": po_repo.list_verified_sites,
+    "get_verified_site": po_repo.get_verified_site,
+}
+
+_PATH_PARAM_BY_RESOURCE = {
+    "/work-orders/{workOrderId}": "workOrderId",
+    "/work-orders/{workOrderId}/comments": "workOrderId",
+    "/purchase-orders/{poNumber}": "poNumber",
+    "/verified-sites/{siteCode}": "siteCode",
+}
+
+
+# Headers on the docs responses: the token rides in the ?token= query shim,
+# so keep the token-keyed URL and page out of shared/browser caches and out of
+# any Referer sent to a followed link.
+_DOCS_SECURITY_HEADERS = {
+    "Cache-Control": "no-store",
+    "Referrer-Policy": "no-referrer",
+}
+
+
+def _load_spec() -> str:
+    """Raw spec bytes, served verbatim at /openapi.json (byte-faithful JSON)."""
+    global _spec_cache
+    if _spec_cache is None:
+        _spec_cache = _SPEC_PATH.read_text(encoding="utf-8")
+    return _spec_cache
+
+
+def _load_docs_html() -> str:
+    global _docs_cache
+    if _docs_cache is None:
+        # Neutralize any "</script"/"<!--" a future spec edit could introduce:
+        # the spec is spliced into a <script type="application/json"> block
+        # where the HTML parser ends the element at the first literal "<"
+        # sequence regardless of JSON quoting. "<" is the same JSON
+        # string value ("<") to JSON.parse but can never close the script tag.
+        inlined_spec = _load_spec().replace("<", "\\u003c")
+        _docs_cache = _DOCS_PATH.read_text(encoding="utf-8").replace(
+            _SPEC_PLACEHOLDER, inlined_spec
+        )
+    return _docs_cache
+
+
+def _with_token_shim(event: dict) -> dict:
+    """Copy a ?token= query parameter into an x-auth-token header.
+
+    Browsers can't set headers on plain navigation, so /docs accepts the
+    shared token as a query parameter too. The constant-time compare still
+    happens inside web_ui_auth -- this only synthesizes the header on a
+    shallow copy. Acceptable only while API Gateway access logging stays off
+    (nothing at the gateway records the query string); rotate the token if
+    access logging is ever enabled.
+    """
+    qs = event.get("queryStringParameters") or {}
+    token = qs.get("token")
+    if not token:
+        return event
+    shimmed = dict(event)
+    headers = dict(event.get("headers") or {})
+    headers["x-auth-token"] = token
+    shimmed["headers"] = headers
+    return shimmed
+
+
+def _docs_response(resource: str, event: dict) -> dict:
+    # SECURITY INVARIANT: these routes serve ONLY the committed spec and the
+    # static docs page -- never table data. The gateway resource policy allows
+    # Principal "*" on exactly these two GETs on the strength of that; serving
+    # anything dynamic here requires a resource-policy + security re-review.
+    if not is_authenticated(_with_token_shim(event)):
+        return error_response(401, "unauthorized")
+    if resource == "/openapi.json":
+        return {
+            "statusCode": 200,
+            "headers": {"Content-Type": "application/json", **_DOCS_SECURITY_HEADERS},
+            "body": _load_spec(),
+        }
+    return {
+        "statusCode": 200,
+        "headers": {
+            "Content-Type": "text/html; charset=utf-8",
+            **_DOCS_SECURITY_HEADERS,
+        },
+        "body": _load_docs_html(),
+    }
+
+
+def _data_response(route_key: tuple, event: dict) -> dict:
+    method, resource = route_key
+    func = _REPO_FUNCS[DATA_ROUTES[route_key]]
+    qs = event.get("queryStringParameters") or {}
+    path_params = event.get("pathParameters") or {}
+
+    if DATA_ROUTES[route_key].startswith("list_"):
+        limit = clamp_limit(qs.get("limit"))
+        cursor = qs.get("cursor")
+        if resource in _PATH_PARAM_BY_RESOURCE:
+            entity_id = path_params.get(_PATH_PARAM_BY_RESOURCE[resource], "")
+            items, next_cursor = func(entity_id, limit, cursor)
+        else:
+            items, next_cursor = func(limit, cursor)
+        return json_response(200, {"items": items, "next_cursor": next_cursor})
+
+    entity_id = path_params.get(_PATH_PARAM_BY_RESOURCE[resource], "")
+    item = func(entity_id)
+    if item is None:
+        return error_response(404, "not found")
+    return json_response(200, item)
+
+
+def _dispatch(route_key: tuple, event: dict) -> dict:
+    if route_key in PLANNED_ROUTES:
+        return error_response(501, "planned endpoint - not implemented (phase 2)")
+    if route_key in DOCS_ROUTES:
+        return _docs_response(route_key[1], event)
+    if route_key in DATA_ROUTES:
+        return _data_response(route_key, event)
+    return error_response(404, "not found")
+
+
+def handler(event, context):
+    # Deploy-guard healthcheck: a direct-invoke {"healthcheck": true} probe
+    # returns before any routing/auth so the post-deploy smoke gate can verify
+    # the bundle imports and the runtime boots.
+    if isinstance(event, dict) and event.get("healthcheck") is True:
+        return {"healthcheck": "ok"}
+
+    method = (event.get("httpMethod") or "").upper()
+    resource = event.get("resource") or ""
+
+    try:
+        return _dispatch((method, resource), event)
+    except BadCursor as exc:
+        return error_response(400, str(exc))
+    except ClientError as exc:
+        # A client-supplied cursor that survives validation but is still
+        # inconsistent at the data layer makes DynamoDB raise
+        # ValidationException; map it to 400, not 500, so a crafted cursor
+        # can't drive the 5xx alarm. Any other AWS error is a real 500.
+        if exc.response.get("Error", {}).get("Code") == "ValidationException":
+            return error_response(400, "cursor is not valid")
+        logger.exception("AWS error serving %s %s", method, resource)
+        return error_response(500, "internal error")
+    except Exception:
+        # A raised exception would surface as an opaque 502 from the proxy
+        # integration; return a clean 500 instead. The API Gateway 5XX alarm
+        # pages on these; the exception (never the request token) is logged.
+        logger.exception("Unhandled error serving %s %s", method, resource)
+        return error_response(500, "internal error")

lambdas/api/pagination.py

@@ -0,0 +1,62 @@
+"""Opaque cursor pagination over DynamoDB ``LastEvaluatedKey``.
+
+The cursor is base64url(JSON(LastEvaluatedKey)). It is untrusted client input:
+``decode_cursor`` validates shape strictly (a flat dict whose keys are exactly
+a subset of the table's key attributes and whose values are non-empty strings)
+and raises ``BadCursor`` -- mapped to HTTP 400 by the handler -- on anything
+else, so a malformed or tampered cursor can never reach DynamoDB as an
+arbitrary ``ExclusiveStartKey`` or surface as a 500.
+"""
+
+import base64
+import binascii
+import json
+
+DEFAULT_LIMIT = 100
+MAX_LIMIT = 500
+_MAX_CURSOR_CHARS = 2048
+
+
+class BadCursor(ValueError):
+    pass
+
+
+def clamp_limit(raw) -> int:
+    if raw is None or raw == "":
+        return DEFAULT_LIMIT
+    try:
+        value = int(raw)
+    except (TypeError, ValueError):
+        raise BadCursor("limit must be an integer") from None
+    return max(1, min(MAX_LIMIT, value))
+
+
+def encode_cursor(last_evaluated_key: dict) -> str:
+    raw = json.dumps(last_evaluated_key, default=str, sort_keys=True)
+    return base64.urlsafe_b64encode(raw.encode()).decode()
+
+
+def decode_cursor(cursor: str, key_attrs: frozenset) -> dict:
+    """Decode a cursor and require it to be EXACTLY the table's key attributes.
+
+    ``key_attrs`` is the full key schema of the operation the cursor feeds
+    (e.g. ``{work_order_id, comment_id}`` for the comments Query). An exact
+    match -- not a subset -- is required: a partial composite key or a cursor
+    minted for a different endpoint would otherwise pass a subset check, reach
+    DynamoDB as an incomplete/inconsistent ``ExclusiveStartKey``, and raise a
+    ValidationException that surfaces as a 500 (and pages the 5xx alarm). Here
+    it fails closed as a 400 instead. Callers additionally pin the
+    partition-key value to the request path (see ``wo_repo.list_comments``).
+    """
+    if len(cursor) > _MAX_CURSOR_CHARS:
+        raise BadCursor("cursor too long")
+    try:
+        decoded = json.loads(base64.urlsafe_b64decode(cursor.encode()))
+    except (binascii.Error, UnicodeDecodeError, json.JSONDecodeError, ValueError):
+        raise BadCursor("cursor is not valid") from None
+    if not isinstance(decoded, dict) or set(decoded) != key_attrs:
+        raise BadCursor("cursor is not valid")
+    for value in decoded.values():
+        if not isinstance(value, str) or not value:
+            raise BadCursor("cursor is not valid")
+    return decoded

lambdas/api/po_repo.py

@@ -0,0 +1,53 @@
+"""Read access to the purchase-order tables for the procurement API.
+
+Same unordered cursor-paginated Scan pattern as wo_repo (no GSIs; listing
+serves reconciliation, not ranked queries). VendorReplies is deliberately
+absent: the table is dead (its writer was deleted) and must not gain new
+consumers.
+"""
+
+import os
+
+import boto3
+
+from pagination import decode_cursor, encode_cursor
+
+dynamodb = boto3.resource("dynamodb")
+
+PO_TABLE = os.environ.get("PO_TABLE", "purchase-orders")
+VERIFIED_SITES_TABLE = os.environ.get("VERIFIED_SITES_TABLE", "verified-sites")
+
+PO_KEY_ATTRS = frozenset({"po_number"})
+SITE_KEY_ATTRS = frozenset({"siteCode"})
+
+
+def _page(response) -> tuple[list, str | None]:
+    items = response.get("Items", [])
+    lek = response.get("LastEvaluatedKey")
+    return items, (encode_cursor(lek) if lek else None)
+
+
+def list_purchase_orders(limit: int, cursor: str | None) -> tuple[list, str | None]:
+    table = dynamodb.Table(PO_TABLE)
+    kwargs = {"Limit": limit}
+    if cursor:
+        kwargs["ExclusiveStartKey"] = decode_cursor(cursor, PO_KEY_ATTRS)
+    return _page(table.scan(**kwargs))
+
+
+def get_purchase_order(po_number: str) -> dict | None:
+    table = dynamodb.Table(PO_TABLE)
+    return table.get_item(Key={"po_number": po_number}).get("Item")
+
+
+def list_verified_sites(limit: int, cursor: str | None) -> tuple[list, str | None]:
+    table = dynamodb.Table(VERIFIED_SITES_TABLE)
+    kwargs = {"Limit": limit}
+    if cursor:
+        kwargs["ExclusiveStartKey"] = decode_cursor(cursor, SITE_KEY_ATTRS)
+    return _page(table.scan(**kwargs))
+
+
+def get_verified_site(site_code: str) -> dict | None:
+    table = dynamodb.Table(VERIFIED_SITES_TABLE)
+    return table.get_item(Key={"siteCode": site_code}).get("Item")

lambdas/api/requirements.txt

@@ -0,0 +1 @@
+# Dependabot anchor only. The procurement-api Lambda is stdlib+boto3 (provided by the runtime); nothing is pip-installed into the bundle.

lambdas/api/router.py

@@ -0,0 +1,33 @@
+"""Route tables for the procurement API.
+
+Single source of truth for what the API implements: the spec-drift test
+(tests/test_api_spec_drift.py) asserts these tables match lambdas/api/
+openapi.json exactly, so an endpoint can't be added, removed, or renamed on
+one side without failing CI. Keys are (httpMethod, resource) as API Gateway's
+Lambda-proxy event presents them (resource = the templated path).
+
+DATA_ROUTES values are handler-module attribute names resolved by handler.py.
+PLANNED_ROUTES are phase-2 write endpoints: present in the spec (x-planned)
+and at the gateway, but the handler answers 501 until they ship with their
+own IAM diff + cross-family review.
+"""
+
+DATA_ROUTES = {
+    ("GET", "/work-orders"): "list_work_orders",
+    ("GET", "/work-orders/{workOrderId}"): "get_work_order",
+    ("GET", "/work-orders/{workOrderId}/comments"): "list_comments",
+    ("GET", "/purchase-orders"): "list_purchase_orders",
+    ("GET", "/purchase-orders/{poNumber}"): "get_purchase_order",
+    ("GET", "/verified-sites"): "list_verified_sites",
+    ("GET", "/verified-sites/{siteCode}"): "get_verified_site",
+}
+
+DOCS_ROUTES = {
+    ("GET", "/docs"),
+    ("GET", "/openapi.json"),
+}
+
+PLANNED_ROUTES = {
+    ("POST", "/work-orders/{workOrderId}/comments"),
+    ("PATCH", "/work-orders/{workOrderId}"),
+}

lambdas/api/serialization.py

@@ -0,0 +1,43 @@
+"""JSON response helpers for the procurement API.
+
+DynamoDB items come back through boto3 with numeric attributes as
+``decimal.Decimal`` (e.g. purchase-orders ``total_amount``/``line_items``
+prices), which ``json.dumps`` rejects. The encoder below renders integral
+Decimals as JSON integers (exact) and non-integral Decimals as floats. For the
+values this API serves -- currency amounts at PO magnitudes, well under ~15
+significant digits -- the shortest-float repr round-trips the original digits
+exactly. A Decimal carrying more precision than a float can hold (DynamoDB
+Number supports 38 digits) would be truncated silently; the pipeline never
+writes such values, but if that ever changes, switch non-integral Decimals to
+``str(o)`` and update the OpenAPI number types.
+"""
+
+import decimal
+import json
+
+
+class _DecimalSafeEncoder(json.JSONEncoder):
+    def default(self, o):
+        if isinstance(o, decimal.Decimal):
+            if o == o.to_integral_value():
+                return int(o)
+            return float(o)
+        if isinstance(o, set):
+            return sorted(o)
+        return super().default(o)
+
+
+def dumps(payload) -> str:
+    return json.dumps(payload, cls=_DecimalSafeEncoder)
+
+
+def json_response(status_code: int, payload) -> dict:
+    return {
+        "statusCode": status_code,
+        "headers": {"Content-Type": "application/json"},
+        "body": dumps(payload),
+    }
+
+
+def error_response(status_code: int, message: str) -> dict:
+    return json_response(status_code, {"error": message})

lambdas/api/wo_repo.py

@@ -0,0 +1,62 @@
+"""Read access to the work-order tables for the procurement API.
+
+Listing is a cursor-paginated Scan -- deliberately: the WO tables carry no
+GSIs (removed 2026-06-03 for zero reads), and the API's list consumers
+(SHOC reconciliation/backfill) walk the full table anyway, which is exactly
+the access pattern SHOC's retired SyncController used. Listings are therefore
+UNORDERED across pages; per-work-order comment listing is a cheap Query on
+the partition key.
+"""
+
+import os
+
+import boto3
+from boto3.dynamodb.conditions import Key
+
+from pagination import BadCursor, decode_cursor, encode_cursor
+
+dynamodb = boto3.resource("dynamodb")
+
+WORK_ORDERS_TABLE = os.environ.get("WORK_ORDERS_TABLE", "WorkOrders")
+COMMENTS_TABLE = os.environ.get("COMMENTS_TABLE", "WorkOrderComments")
+
+WO_KEY_ATTRS = frozenset({"work_order_id"})
+COMMENT_KEY_ATTRS = frozenset({"work_order_id", "comment_id"})
+
+
+def _page(response) -> tuple[list, str | None]:
+    items = response.get("Items", [])
+    lek = response.get("LastEvaluatedKey")
+    return items, (encode_cursor(lek) if lek else None)
+
+
+def list_work_orders(limit: int, cursor: str | None) -> tuple[list, str | None]:
+    table = dynamodb.Table(WORK_ORDERS_TABLE)
+    kwargs = {"Limit": limit}
+    if cursor:
+        kwargs["ExclusiveStartKey"] = decode_cursor(cursor, WO_KEY_ATTRS)
+    return _page(table.scan(**kwargs))
+
+
+def get_work_order(work_order_id: str) -> dict | None:
+    table = dynamodb.Table(WORK_ORDERS_TABLE)
+    return table.get_item(Key={"work_order_id": work_order_id}).get("Item")
+
+
+def list_comments(
+    work_order_id: str, limit: int, cursor: str | None
+) -> tuple[list, str | None]:
+    table = dynamodb.Table(COMMENTS_TABLE)
+    kwargs = {
+        "KeyConditionExpression": Key("work_order_id").eq(work_order_id),
+        "Limit": limit,
+    }
+    if cursor:
+        start_key = decode_cursor(cursor, COMMENT_KEY_ATTRS)
+        # Pin the cursor's partition to the path entity: a cursor minted for
+        # WO A must never resume WO B's Query (DynamoDB would reject the
+        # partition mismatch as a 500; reject it as a 400 here instead).
+        if start_key["work_order_id"] != work_order_id:
+            raise BadCursor("cursor is not valid")
+        kwargs["ExclusiveStartKey"] = start_key
+    return _page(table.query(**kwargs))

lambdas/shared/web_ui_auth.py

@@ -74,4 +74,8 @@ def is_authenticated(event: dict) -> bool:
             presented = auth[7:].strip()
     if not presented:
         return False
-    return hmac.compare_digest(presented, token)
+    # Compare as bytes: hmac.compare_digest raises TypeError on non-ASCII str
+    # operands, which a crafted token (?token=%C3%A9 or a non-ASCII header)
+    # would otherwise turn into an uncaught 500. Bytes always compare in
+    # constant time, so a non-matching token fails closed (401) instead.
+    return hmac.compare_digest(presented.encode("utf-8"), token.encode("utf-8"))

pytest.ini

@@ -12,6 +12,7 @@ addopts =
     --cov=lambdas/po/web_ui
     --cov=lambdas/wo/web_ui
     --cov=lambdas/po/site_extractor
+    --cov=lambdas/api
     --cov=lambdas/shared
     --cov-report=term-missing
     --cov-fail-under=80

scripts/post-deploy-smoke.sh

@@ -14,7 +14,7 @@
 set -euo pipefail
 
 REGION="us-east-1"
-FUNCTION_NAMES=("po-email-processor" "workorder-email-processor")
+FUNCTION_NAMES=("po-email-processor" "workorder-email-processor" "procurement-api")
 HEALTHCHECK_PAYLOAD='{"healthcheck": true}'
 
 work_dir="$(mktemp -d)"

tests/support/loader.py

@@ -50,6 +50,15 @@ _SIBLING_MODULES = (
     "email_parsing",
     "emf",
     "web_ui_auth",
+    # procurement-api siblings (lambdas/api/): pagination/serialization/router
+    # have no sibling deps; wo_repo/po_repo import pagination, so they follow
+    # it. These names exist only under lambdas/api/, so the po/wo handler
+    # loads skip them via the exists() check.
+    "pagination",
+    "serialization",
+    "router",
+    "wo_repo",
+    "po_repo",
     "prompts",
     "template_parser",
     "derived_fields",

tests/test_api_handlers.py

@@ -0,0 +1,271 @@
+"""procurement-api handler tests (offline, fake Dynamo).
+
+Pins the auth seam both ways: docs routes fail closed on the shared token
+(including the browser ?token= shim), while data routes must NOT consult the
+token at all -- SigV4 authorization is API Gateway's job upstream, and a
+handler-side token check there would break every legitimate SigV4 caller.
+Also pins routing, 404/501/400 mapping, Decimal-safe serialization, and limit
+clamping.
+"""
+
+import json
+from decimal import Decimal
+
+import pytest
+
+from tests.support import load_lambda_module
+
+
+class _FakeTable:
+    def __init__(self, items):
+        self._items = items
+        self.last_kwargs = None
+
+    def scan(self, **kwargs):
+        self.last_kwargs = kwargs
+        return {"Items": list(self._items)}
+
+    def query(self, **kwargs):
+        self.last_kwargs = kwargs
+        return {"Items": list(self._items)}
+
+    def get_item(self, Key):  # noqa: N803 (boto3 kwarg name)
+        pk_attr, pk_val = next(iter(Key.items()))
+        for item in self._items:
+            if item.get(pk_attr) == pk_val:
+                return {"Item": item}
+        return {}
+
+
+class _FakeDynamo:
+    def __init__(self, tables):
+        self.tables = tables
+
+    def Table(self, name):  # noqa: N802 (boto3 method name)
+        return self.tables[name]
+
+
+def _event(method, resource, path_params=None, qs=None, headers=None):
+    return {
+        "httpMethod": method,
+        "resource": resource,
+        "pathParameters": path_params or {},
+        "queryStringParameters": qs or {},
+        "headers": headers or {},
+    }
+
+
+@pytest.fixture()
+def api(monkeypatch):
+    mod = load_lambda_module("api", "handler")
+    wo_items = [
+        {
+            "work_order_id": "11144580730",
+            "wo_status": "assigned",
+            "description": "Dock door 14",
+        }
+    ]
+    comment_items = [
+        {
+            "work_order_id": "11144580730",
+            "comment_id": "11144580730#2026-01-01T00:00:00#abc123def456",
+            "text": "Vendor dispatched",
+        }
+    ]
+    po_items = [
+        {
+            "po_number": "2D-22030794",
+            "total_amount": Decimal("123.45"),
+            "line_items": [{"quantity": Decimal("5"), "price": Decimal("24.69")}],
+        }
+    ]
+    site_items = [{"siteCode": "JFK8", "state": "NY", "poCount": Decimal("7")}]
+
+    tables = {
+        mod.wo_repo.WORK_ORDERS_TABLE: _FakeTable(wo_items),
+        mod.wo_repo.COMMENTS_TABLE: _FakeTable(comment_items),
+        mod.po_repo.PO_TABLE: _FakeTable(po_items),
+        mod.po_repo.VERIFIED_SITES_TABLE: _FakeTable(site_items),
+    }
+    fake = _FakeDynamo(tables)
+    monkeypatch.setattr(mod.wo_repo, "dynamodb", fake)
+    monkeypatch.setattr(mod.po_repo, "dynamodb", fake)
+    return mod, fake
+
+
+def test_healthcheck_short_circuits(api):
+    mod, _ = api
+    assert mod.handler({"healthcheck": True}, None) == {"healthcheck": "ok"}
+
+
+def test_docs_fail_closed_without_token(api):
+    # No WEB_UI_AUTH_TOKEN_SECRET_ARN configured -> web_ui_auth returns None
+    # -> the docs routes must 401, not serve the spec.
+    mod, _ = api
+    for resource in ("/docs", "/openapi.json"):
+        response = mod.handler(_event("GET", resource), None)
+        assert response["statusCode"] == 401
+
+
+def test_docs_served_when_authenticated(api, monkeypatch):
+    mod, _ = api
+    monkeypatch.setattr(mod, "is_authenticated", lambda event: True)
+    docs = mod.handler(_event("GET", "/docs"), None)
+    assert docs["statusCode"] == 200
+    assert docs["headers"]["Content-Type"].startswith("text/html")
+    assert "Procurement Ingest API" in docs["body"]
+    assert mod._SPEC_PLACEHOLDER not in docs["body"]
+
+    spec = mod.handler(_event("GET", "/openapi.json"), None)
+    assert spec["statusCode"] == 200
+    assert json.loads(spec["body"])["openapi"] == "3.1.0"
+
+
+def test_token_query_shim_synthesizes_header(api, monkeypatch):
+    mod, _ = api
+    seen = {}
+
+    def capture(event):
+        seen.update(event.get("headers") or {})
+        return False
+
+    monkeypatch.setattr(mod, "is_authenticated", capture)
+    original = _event("GET", "/docs", qs={"token": "sekrit"})
+    mod.handler(original, None)
+    assert seen.get("x-auth-token") == "sekrit"
+    # The shim must not mutate the caller's event in place.
+    assert "x-auth-token" not in original["headers"]
+
+
+def test_non_ascii_token_fails_closed_not_500(api):
+    # A non-ASCII presented token must 401 (fail closed), not crash
+    # hmac.compare_digest into a 500 that pages the 5xx alarm. Reach the
+    # web_ui_auth module namespace through the imported is_authenticated's
+    # globals and seed a valid cached token.
+    mod, _ = api
+    auth_globals = mod.is_authenticated.__globals__
+    auth_globals["_auth_token_cache"] = "correct-token"
+    auth_globals["_auth_token_cached_at"] = float("inf")
+    try:
+        response = mod.handler(
+            _event("GET", "/docs", headers={"x-auth-token": "é"}), None
+        )
+        assert response["statusCode"] == 401
+    finally:
+        auth_globals["_auth_token_cache"] = None
+        auth_globals["_auth_token_cached_at"] = 0.0
+
+
+def test_data_routes_never_consult_docs_token(api, monkeypatch):
+    mod, _ = api
+
+    def explode(event):
+        raise AssertionError("data routes must not consult the docs token")
+
+    monkeypatch.setattr(mod, "is_authenticated", explode)
+    response = mod.handler(_event("GET", "/work-orders"), None)
+    assert response["statusCode"] == 200
+
+
+def test_list_and_get_routing(api):
+    mod, _ = api
+    listing = mod.handler(_event("GET", "/work-orders"), None)
+    body = json.loads(listing["body"])
+    assert body["items"][0]["work_order_id"] == "11144580730"
+    assert body["next_cursor"] is None
+
+    hit = mod.handler(
+        _event(
+            "GET",
+            "/work-orders/{workOrderId}",
+            path_params={"workOrderId": "11144580730"},
+        ),
+        None,
+    )
+    assert json.loads(hit["body"])["wo_status"] == "assigned"
+
+    miss = mod.handler(
+        _event(
+            "GET",
+            "/work-orders/{workOrderId}",
+            path_params={"workOrderId": "999"},
+        ),
+        None,
+    )
+    assert miss["statusCode"] == 404
+
+    comments = mod.handler(
+        _event(
+            "GET",
+            "/work-orders/{workOrderId}/comments",
+            path_params={"workOrderId": "11144580730"},
+        ),
+        None,
+    )
+    assert json.loads(comments["body"])["items"][0]["text"] == "Vendor dispatched"
+
+    sites = mod.handler(
+        _event(
+            "GET",
+            "/verified-sites/{siteCode}",
+            path_params={"siteCode": "JFK8"},
+        ),
+        None,
+    )
+    assert json.loads(sites["body"])["state"] == "NY"
+
+
+def test_decimal_serialization_round_trips(api):
+    mod, _ = api
+    response = mod.handler(
+        _event(
+            "GET",
+            "/purchase-orders/{poNumber}",
+            path_params={"poNumber": "2D-22030794"},
+        ),
+        None,
+    )
+    body = json.loads(response["body"])
+    assert body["total_amount"] == 123.45
+    assert body["line_items"][0]["quantity"] == 5
+    assert isinstance(body["line_items"][0]["quantity"], int)
+    assert "Decimal" not in response["body"]
+
+
+def test_limit_clamped_to_bounds(api):
+    mod, fake = api
+    mod.handler(_event("GET", "/work-orders", qs={"limit": "9999"}), None)
+    assert fake.tables[mod.wo_repo.WORK_ORDERS_TABLE].last_kwargs["Limit"] == 500
+    mod.handler(_event("GET", "/work-orders", qs={"limit": "0"}), None)
+    assert fake.tables[mod.wo_repo.WORK_ORDERS_TABLE].last_kwargs["Limit"] == 1
+
+
+def test_non_integer_limit_is_400(api):
+    mod, _ = api
+    response = mod.handler(_event("GET", "/work-orders", qs={"limit": "abc"}), None)
+    assert response["statusCode"] == 400
+
+
+def test_planned_routes_return_501(api):
+    mod, _ = api
+    for method, resource in mod.PLANNED_ROUTES:
+        response = mod.handler(_event(method, resource), None)
+        assert response["statusCode"] == 501, (method, resource)
+
+
+def test_unknown_route_is_404(api):
+    mod, _ = api
+    response = mod.handler(_event("GET", "/nope"), None)
+    assert response["statusCode"] == 404
+
+
+def test_unexpected_error_maps_to_clean_500(api, monkeypatch):
+    mod, fake = api
+
+    def boom(**kwargs):
+        raise RuntimeError("dynamo fell over")
+
+    monkeypatch.setattr(fake.tables[mod.wo_repo.WORK_ORDERS_TABLE], "scan", boom)
+    response = mod.handler(_event("GET", "/work-orders"), None)
+    assert response["statusCode"] == 500
+    assert json.loads(response["body"]) == {"error": "internal error"}

tests/test_api_pagination_moto.py

@@ -0,0 +1,232 @@
+"""Cursor pagination against real DynamoDB semantics (moto).
+
+The offline handler tests fake Dynamo, which can't exercise real
+LastEvaluatedKey behavior. Here moto-backed tables with the production key
+schemas prove: pages are disjoint and complete, the final page's next_cursor
+is null, comment Query pagination respects the composite key, and hostile
+cursors (garbage, wrong key attrs, huge) map to 400 -- never 500, never a raw
+ExclusiveStartKey error.
+
+The repo modules build their boto3 resource at import time; a resource created
+before mock_aws starts is NOT intercepted, so each test rebinds the modules'
+``dynamodb`` to a fresh resource inside the mock (same trap as test_po_merge's
+moto-before-handler ordering).
+"""
+
+import base64
+import json
+
+import boto3
+import pytest
+from moto import mock_aws
+
+from tests.support import load_lambda_module
+
+
+def _event(method, resource, path_params=None, qs=None):
+    return {
+        "httpMethod": method,
+        "resource": resource,
+        "pathParameters": path_params or {},
+        "queryStringParameters": qs or {},
+        "headers": {},
+    }
+
+
+@pytest.fixture()
+def api(monkeypatch):
+    with mock_aws():
+        mod = load_lambda_module("api", "handler")
+        resource = boto3.resource("dynamodb", region_name="us-east-1")
+        monkeypatch.setattr(mod.wo_repo, "dynamodb", resource)
+        monkeypatch.setattr(mod.po_repo, "dynamodb", resource)
+
+        resource.create_table(
+            TableName=mod.wo_repo.WORK_ORDERS_TABLE,
+            KeySchema=[{"AttributeName": "work_order_id", "KeyType": "HASH"}],
+            AttributeDefinitions=[
+                {"AttributeName": "work_order_id", "AttributeType": "S"}
+            ],
+            BillingMode="PAY_PER_REQUEST",
+        )
+        resource.create_table(
+            TableName=mod.wo_repo.COMMENTS_TABLE,
+            KeySchema=[
+                {"AttributeName": "work_order_id", "KeyType": "HASH"},
+                {"AttributeName": "comment_id", "KeyType": "RANGE"},
+            ],
+            AttributeDefinitions=[
+                {"AttributeName": "work_order_id", "AttributeType": "S"},
+                {"AttributeName": "comment_id", "AttributeType": "S"},
+            ],
+            BillingMode="PAY_PER_REQUEST",
+        )
+        resource.create_table(
+            TableName=mod.po_repo.PO_TABLE,
+            KeySchema=[{"AttributeName": "po_number", "KeyType": "HASH"}],
+            AttributeDefinitions=[{"AttributeName": "po_number", "AttributeType": "S"}],
+            BillingMode="PAY_PER_REQUEST",
+        )
+        resource.create_table(
+            TableName=mod.po_repo.VERIFIED_SITES_TABLE,
+            KeySchema=[{"AttributeName": "siteCode", "KeyType": "HASH"}],
+            AttributeDefinitions=[{"AttributeName": "siteCode", "AttributeType": "S"}],
+            BillingMode="PAY_PER_REQUEST",
+        )
+        yield mod, resource
+
+
+def _walk_pages(mod, resource_path, qs_extra=None, path_params=None, limit=5):
+    seen, pages = [], 0
+    cursor = None
+    while True:
+        qs = {"limit": str(limit), **(qs_extra or {})}
+        if cursor:
+            qs["cursor"] = cursor
+        response = mod.handler(
+            _event("GET", resource_path, path_params=path_params, qs=qs), None
+        )
+        assert response["statusCode"] == 200
+        body = json.loads(response["body"])
+        seen.extend(body["items"])
+        pages += 1
+        cursor = body["next_cursor"]
+        assert pages < 50, "pagination failed to terminate"
+        if cursor is None:
+            return seen, pages
+
+
+def test_work_order_scan_pages_are_disjoint_and_complete(api):
+    mod, resource = api
+    table = resource.Table(mod.wo_repo.WORK_ORDERS_TABLE)
+    for i in range(12):
+        table.put_item(Item={"work_order_id": str(10000 + i), "wo_status": "new"})
+
+    items, pages = _walk_pages(mod, "/work-orders", limit=5)
+    ids = [item["work_order_id"] for item in items]
+    assert len(ids) == 12
+    assert len(set(ids)) == 12
+    assert pages >= 3
+
+
+def test_comment_query_pagination_composite_key(api):
+    mod, resource = api
+    table = resource.Table(mod.wo_repo.COMMENTS_TABLE)
+    for i in range(7):
+        table.put_item(
+            Item={
+                "work_order_id": "555",
+                "comment_id": f"555#2026-01-0{i + 1}T00:00:00#{i:012d}",
+                "text": f"comment {i}",
+            }
+        )
+    # A second work order's comments must never bleed into the page.
+    table.put_item(
+        Item={"work_order_id": "666", "comment_id": "666#x#0", "text": "other"}
+    )
+
+    items, _ = _walk_pages(
+        mod,
+        "/work-orders/{workOrderId}/comments",
+        path_params={"workOrderId": "555"},
+        limit=3,
+    )
+    assert len(items) == 7
+    assert {item["work_order_id"] for item in items} == {"555"}
+
+
+def test_purchase_order_and_site_pagination(api):
+    mod, resource = api
+    po_table = resource.Table(mod.po_repo.PO_TABLE)
+    for i in range(6):
+        po_table.put_item(Item={"po_number": f"2D-{i:08d}"})
+    sites_table = resource.Table(mod.po_repo.VERIFIED_SITES_TABLE)
+    for code in ("JFK8", "WNY2", "UVA5"):
+        sites_table.put_item(Item={"siteCode": code})
+
+    po_items, _ = _walk_pages(mod, "/purchase-orders", limit=4)
+    assert len(po_items) == 6
+    site_items, _ = _walk_pages(mod, "/verified-sites", limit=2)
+    assert {item["siteCode"] for item in site_items} == {"JFK8", "WNY2", "UVA5"}
+
+
+@pytest.mark.parametrize(
+    "cursor",
+    [
+        "not-base64!!!",
+        "aGVsbG8=",  # base64("hello") -- not JSON-dict
+        "e30=",  # base64("{}") -- empty dict
+        # base64 of {"evil_attr": "x"} -- key attr not allowed for this table
+        "eyJldmlsX2F0dHIiOiAieCJ9",
+        "A" * 3000,  # oversized
+    ],
+)
+def test_hostile_cursor_is_400_not_500(api, cursor):
+    mod, resource = api
+    resource.Table(mod.wo_repo.WORK_ORDERS_TABLE).put_item(Item={"work_order_id": "1"})
+    response = mod.handler(_event("GET", "/work-orders", qs={"cursor": cursor}), None)
+    assert response["statusCode"] == 400
+    assert "error" in json.loads(response["body"])
+
+
+def _cursor(payload):
+    return base64.urlsafe_b64encode(json.dumps(payload).encode()).decode()
+
+
+def test_partial_composite_cursor_is_400_not_500(api):
+    # A work-orders-shaped cursor {work_order_id} is a partial key for the
+    # comments Query (needs work_order_id+comment_id). Exact-key match rejects
+    # it as 400 rather than letting DynamoDB ValidationException -> 500.
+    mod, resource = api
+    resource.Table(mod.wo_repo.COMMENTS_TABLE).put_item(
+        Item={"work_order_id": "555", "comment_id": "555#x#0"}
+    )
+    response = mod.handler(
+        _event(
+            "GET",
+            "/work-orders/{workOrderId}/comments",
+            path_params={"workOrderId": "555"},
+            qs={"cursor": _cursor({"work_order_id": "555"})},
+        ),
+        None,
+    )
+    assert response["statusCode"] == 400
+
+
+def test_cross_work_order_comment_cursor_is_400(api):
+    # A full comments cursor minted for WO A must not resume WO B's Query.
+    mod, resource = api
+    response = mod.handler(
+        _event(
+            "GET",
+            "/work-orders/{workOrderId}/comments",
+            path_params={"workOrderId": "B"},
+            qs={"cursor": _cursor({"work_order_id": "A", "comment_id": "A#x#0"})},
+        ),
+        None,
+    )
+    assert response["statusCode"] == 400
+
+
+def test_dynamodb_validation_error_maps_to_400(api, monkeypatch):
+    # Defense in depth: even if some crafted-but-valid cursor reached DynamoDB
+    # and raised ValidationException, the handler maps it to 400, not a 500
+    # that would page the zero-threshold 5xx alarm.
+    from botocore.exceptions import ClientError
+
+    mod, _ = api
+
+    class _RaisingTable:
+        def scan(self, **kwargs):
+            raise ClientError(
+                {"Error": {"Code": "ValidationException", "Message": "bad key"}},
+                "Scan",
+            )
+
+    monkeypatch.setattr(
+        mod.wo_repo,
+        "dynamodb",
+        type("D", (), {"Table": lambda self, n: _RaisingTable()})(),
+    )
+    response = mod.handler(_event("GET", "/work-orders"), None)
+    assert response["statusCode"] == 400

tests/test_api_spec_drift.py

@@ -0,0 +1,114 @@
+"""Spec <-> implementation drift gate.
+
+lambdas/api/openapi.json is the published contract; lambdas/api/router.py is
+what the Lambda actually serves. This test makes them the SAME set: an
+endpoint added/removed/renamed on one side without the other fails CI here,
+so the docs page can never silently lie. Also pins the phase-2 x-planned
+markers, the four outbound webhook events, and the enum values the spec
+promises against the WO extraction contract (prompts.py).
+"""
+
+import json
+from pathlib import Path
+
+from tests.support import REPO_ROOT, load_lambda_module
+
+_SPEC_PATH = Path(REPO_ROOT) / "lambdas" / "api" / "openapi.json"
+
+_HTTP_METHODS = {"get", "put", "post", "patch", "delete", "head", "options"}
+
+
+def _spec():
+    return json.loads(_SPEC_PATH.read_text(encoding="utf-8"))
+
+
+def _spec_routes(spec):
+    implemented, planned = set(), set()
+    for path, ops in spec["paths"].items():
+        for method, op in ops.items():
+            if method not in _HTTP_METHODS:
+                continue
+            key = (method.upper(), path)
+            if op.get("x-planned"):
+                planned.add(key)
+            else:
+                implemented.add(key)
+    return implemented, planned
+
+
+def test_spec_is_openapi_31():
+    assert _spec()["openapi"] == "3.1.0"
+
+
+def test_implemented_routes_match_router_exactly():
+    router = load_lambda_module("api", "router")
+    implemented, planned = _spec_routes(_spec())
+    assert implemented == set(router.DATA_ROUTES) | set(router.DOCS_ROUTES)
+    assert planned == set(router.PLANNED_ROUTES)
+
+
+def test_every_data_route_has_a_repo_function():
+    router = load_lambda_module("api", "router")
+    handler = load_lambda_module("api", "handler")
+    assert set(router.DATA_ROUTES.values()) == set(handler._REPO_FUNCS)
+
+
+def test_webhooks_section_documents_all_four_events():
+    spec = _spec()
+    assert set(spec["webhooks"]) == {
+        "work_order.created",
+        "work_order.updated",
+        "work_order.cancelled",
+        "work_order.comment_added",
+    }
+    for ops in spec["webhooks"].values():
+        assert "post" in ops
+
+
+def test_spec_enums_match_wo_extraction_contract():
+    # The WO pipeline's prompts.py is the enum source of truth (the webhook
+    # contract pins it too). If the pipeline ever widens wo_status or
+    # record_type, the published spec must move in the same PR.
+    prompts = load_lambda_module("wo", "email_processor/prompts")
+    prompt_text = prompts.EXTRACTION_PROMPT
+    spec = _spec()
+    schemas = spec["components"]["schemas"]
+
+    wo_status_enum = {
+        value
+        for value in schemas["WorkOrder"]["properties"]["wo_status"]["enum"]
+        if value is not None
+    }
+    record_type_enum = {
+        value
+        for value in schemas["WorkOrder"]["properties"]["record_type"]["enum"]
+        if value is not None
+    }
+    for value in wo_status_enum - {"unknown"}:
+        assert value in prompt_text, f"wo_status {value!r} not in extraction prompt"
+    for value in record_type_enum:
+        assert value in prompt_text, f"record_type {value!r} not in extraction prompt"
+
+    event_data = schemas["WorkOrderEventData"]["properties"]
+    assert set(event_data["wo_status"]["enum"]) == set(
+        schemas["WorkOrder"]["properties"]["wo_status"]["enum"]
+    )
+
+
+def test_spec_has_no_script_breakout_sequence():
+    # The spec is inlined into a <script type="application/json"> block on the
+    # docs page. The handler escapes "<" -> < defensively, but keep the
+    # committed spec itself clean so the raw /openapi.json is also breakout-safe
+    # and a reviewer sees the invariant here.
+    raw = _SPEC_PATH.read_text(encoding="utf-8")
+    assert "</" not in raw and "<!--" not in raw
+
+
+def test_docs_and_spec_files_ship_with_the_handler():
+    # The handler serves these from its own package dir; if either file is
+    # missing from lambdas/api/ the bundle would 500 at runtime.
+    api_dir = Path(REPO_ROOT) / "lambdas" / "api"
+    assert (api_dir / "openapi.json").is_file()
+    assert (api_dir / "docs.html").is_file()
+    docs = (api_dir / "docs.html").read_text(encoding="utf-8")
+    assert "__OPENAPI_SPEC_JSON__" in docs

tests/test_bundle_consistency.py

@@ -21,8 +21,10 @@ REPO_ROOT = Path(__file__).resolve().parents[1]
 
 PO_HANDLER = REPO_ROOT / "lambdas" / "po" / "email_processor" / "handler.py"
 WO_HANDLER = REPO_ROOT / "lambdas" / "wo" / "email_processor" / "handler.py"
+API_HANDLER = REPO_ROOT / "lambdas" / "api" / "handler.py"
 PO_STACK = REPO_ROOT / "cdk" / "po_stack.py"
 WO_STACK = REPO_ROOT / "cdk" / "wo_stack.py"
+API_STACK = REPO_ROOT / "cdk" / "procurement_api_stack.py"
 # Phase 3: ses_auth/web_ui_auth/email_parsing/emf are single-sourced here and
 # shipped into the email-processor bundles via `cp shared/*.py`.
 SHARED_DIR = REPO_ROOT / "lambdas" / "shared"
@@ -90,6 +92,28 @@ WO_PIPELINE_MODULES = frozenset(
 PO_EXPECTED_TOP_LEVEL_MODULES = PO_PIPELINE_MODULES | SHARED_MODULES
 WO_EXPECTED_TOP_LEVEL_MODULES = WO_PIPELINE_MODULES | SHARED_MODULES
 
+# procurement-api (lambdas/api/): a fourth bundled function, in its own stack.
+# Same exact-set discipline as the pipeline dirs -- `cp api/*.py` ships every
+# top-level .py here (untracked strays included), so any new module is a
+# deliberate addition to this pin.
+API_PIPELINE_MODULES = frozenset(
+    {
+        "handler",
+        "router",
+        "pagination",
+        "serialization",
+        "wo_repo",
+        "po_repo",
+    }
+)
+# Non-.py files the api bundle must also EXECUTE cps for: the handler serves
+# the spec and docs page from its own package dir, so dropping either cp
+# 500s /docs at runtime with green CI.
+API_DATA_FILES_CP_RES = (
+    r"(?:^|\s)api/openapi\.json(?:\s|$)",
+    r"(?:^|\s)api/docs\.html(?:\s|$)",
+)
+
 # Pipeline-scoped glob shapes the per-stack ships-all pins accept. Phase 2
 # widened the bundling cwd to the shared ../lambdas asset root, so the executed
 # glob carries its own pipeline's path prefix (`po/email_processor/*.py`); a
@@ -652,3 +676,93 @@ def test_detection_logic_rejects_commented_out_web_ui_auth_cp():
     )
     executed = _executed_cp_commands(commented_out_command)
     assert not any(re.search(WEB_UI_AUTH_CP_RE, cp) for cp in executed)
+
+
+def _extract_api_command(stack_path: Path) -> str:
+    """Extract the procurement-api function's bash -c bundling command string.
+
+    Mirrors _extract_bundling_command but selects the command whose text
+    mentions ``api/`` (its first cp is ``cp api/*.py``). procurement_api_stack
+    has exactly one bundled function today; the exactly-one demand makes any
+    future second bundle in that stack surface loudly instead of silently
+    checking the wrong command.
+    """
+    tree = ast.parse(stack_path.read_text())
+    commands: list[str] = []
+    for node in ast.walk(tree):
+        if isinstance(node, ast.keyword) and node.arg == "command":
+            list_node = node.value
+            if isinstance(list_node, ast.List) and list_node.elts:
+                last = list_node.elts[-1]
+                if isinstance(last, ast.Constant) and isinstance(last.value, str):
+                    commands.append(last.value)
+    api_cmds = [c for c in commands if "api/" in c]
+    if len(api_cmds) != 1:
+        raise AssertionError(
+            f"expected exactly one api bundling command=[...] list in "
+            f"{stack_path}, found {len(api_cmds)} (of {len(commands)} total "
+            "command lists) — update this test to select the intended bundling "
+            "command explicitly"
+        )
+    return api_cmds[0]
+
+
+def test_api_bundling_ships_all_first_party_siblings():
+    """The procurement-api bundle must ship every sibling handler.py imports.
+
+    Same PR #105 ImportError class as the email processors: the api handler
+    imports router/pagination/serialization/wo_repo/po_repo (next to it) and
+    web_ui_auth (lambdas/shared/); a narrowed glob or dropped shared cp would
+    cold-start ImportError with green CI.
+    """
+    required = _first_party_sibling_imports(API_HANDLER)
+    assert required, "expected api/handler.py to import first-party siblings"
+    command = _extract_api_command(API_STACK)
+    assert _bundling_ships_all(command, required), (
+        f"cdk/procurement_api_stack.py bundling does not ship all first-party "
+        f"siblings {sorted(required)}. Executed cp commands: "
+        f"{_executed_cp_commands(command)}"
+    )
+
+
+def test_api_dir_ships_no_unexpected_top_level_modules():
+    """Exact-set pin on lambdas/api/*.py -- both bounds.
+
+    `cp api/*.py` ships every top-level .py in the dir (untracked strays
+    included, since Code.from_asset does not honor .gitignore), so a stray
+    scratch/secrets module would silently ship into the production zip. Any
+    new module must be deliberately added to API_PIPELINE_MODULES.
+    """
+    api_dir = REPO_ROOT / "lambdas" / "api"
+    top_level = {p.stem for p in api_dir.glob("*.py")}
+    assert top_level == set(API_PIPELINE_MODULES), (
+        f"lambdas/api/ top-level modules {sorted(top_level)} != pinned "
+        f"{sorted(API_PIPELINE_MODULES)}. If a new module is intended, add it "
+        "to API_PIPELINE_MODULES."
+    )
+
+
+def test_api_bundle_stages_shared_auth_module():
+    """The api bundle must EXECUTE `cp shared/web_ui_auth.py` (docs-token gate)."""
+    command = _extract_api_command(API_STACK)
+    executed_cps = _executed_cp_commands(command)
+    assert any(re.search(WEB_UI_AUTH_CP_RE, cp) for cp in executed_cps), (
+        "cdk/procurement_api_stack.py bundling command must EXECUTE "
+        "'cp shared/web_ui_auth.py /asset-output/' so the docs-token gate "
+        f"resolves at cold start. Executed cp commands: {executed_cps}"
+    )
+
+
+def test_api_bundle_stages_spec_and_docs_page():
+    """The api bundle must EXECUTE cps for openapi.json and docs.html.
+
+    The handler serves both from its package dir; the .py glob does not cover
+    them, so each needs its own executed cp or /docs 500s at runtime.
+    """
+    command = _extract_api_command(API_STACK)
+    executed_cps = _executed_cp_commands(command)
+    for pattern in API_DATA_FILES_CP_RES:
+        assert any(re.search(pattern, cp) for cp in executed_cps), (
+            f"cdk/procurement_api_stack.py bundling command must EXECUTE a cp "
+            f"matching {pattern!r}. Executed cp commands: {executed_cps}"
+        )

tests/test_web_ui_auth.py

@@ -105,16 +105,12 @@ def test_header_matrix(load_auth, monkeypatch, headers, expected):
     assert mod.is_authenticated(_evt(**headers)) is expected
 
 
-@pytest.mark.xfail(
-    strict=True,
-    reason="web_ui_auth is frozen this phase: is_authenticated raises TypeError on "
-    "a non-ASCII presented token (hmac.compare_digest is ASCII-only) and surfaces "
-    "as a 500 instead of failing closed to False. Asserting the DESIRED behavior "
-    "under xfail(strict) documents the intended fix and auto-fails (xpass) the moment "
-    "the module is corrected, forcing the marker's removal. Tracked as a follow-up.",
-    raises=TypeError,
-)
 def test_non_ascii_token_should_fail_closed(load_auth, monkeypatch):
+    # Fixed 2026-07-23 (procurement-api security review): is_authenticated now
+    # compares tokens as bytes, so a non-ASCII presented token fails closed to
+    # False instead of raising TypeError (which surfaced as a 500 that would
+    # page the API's zero-threshold 5xx alarm). Was xfail(strict) while
+    # web_ui_auth was frozen; the fix landed with the shared bytes-compare.
     mod = load_auth()
     monkeypatch.setattr(mod, "_get_auth_token", lambda: "SECRET")
     assert mod.is_authenticated(_evt(**{"x-auth-token": "SÉCRET"})) is False