Feature/ccm 12937- publish supplier letter events

infrastructure/terraform/components/api/ddb_table_letters.tf

@@ -1,6 +1,8 @@
 resource "aws_dynamodb_table" "letters" {
   name         = "${local.csi}-letters"
   billing_mode = "PAY_PER_REQUEST"
+  stream_enabled   = true
+  stream_view_type = "NEW_AND_OLD_IMAGES"
 
   hash_key  = "supplierId"
   range_key = "id"

infrastructure/terraform/components/api/event_source_mapping_letter_updates.tf

@@ -0,0 +1,11 @@
+resource "aws_lambda_event_source_mapping" "letter_updates_transformer_kinesis" {
+  event_source_arn                     = aws_kinesis_stream.letter_change_stream.arn
+  function_name                        = module.letter_updates_transformer.function_arn
+  starting_position                    = "LATEST"
+  batch_size                           = 10
+  maximum_batching_window_in_seconds   = 1
+
+  depends_on = [
+    module.letter_updates_transformer    # ensures updates transformer exists
+  ]
+}

infrastructure/terraform/components/api/kinesis_letter_change_stream.tf

@@ -0,0 +1,11 @@
+resource "aws_kinesis_stream" "letter_change_stream" {
+  name             = "${local.csi}-letter-change-stream"
+  shard_count      = 1
+  retention_period = 24
+}
+
+resource "aws_dynamodb_kinesis_streaming_destination" "letter_streaming_destination" {
+  stream_arn                               = aws_kinesis_stream.letter_change_stream.arn
+  table_name                               = aws_dynamodb_table.letters.name
+  approximate_creation_date_time_precision = "MILLISECOND"
+}

infrastructure/terraform/components/api/module_lambda_letter_updates_transformer.tf

@@ -36,35 +36,39 @@ module "letter_updates_transformer" {
   log_subscription_role_arn = local.acct.log_subscription_role_arn
 
   lambda_env_vars = merge(local.common_lambda_env_vars, {
-    EVENTPUB_SNS_TOPIC_ARN = module.eventpub.sns_topic.arn
+    EVENTPUB_SNS_TOPIC_ARN = "${module.eventpub.sns_topic.arn}"
   })
 }
 
 data "aws_iam_policy_document" "letter_updates_transformer_lambda" {
   statement {
-    sid    = "KMSPermissions"
+    sid    = "AllowSNSPublish"
     effect = "Allow"
 
     actions = [
-      "kms:Decrypt",
-      "kms:GenerateDataKey",
+      "sns:Publish"
     ]
 
     resources = [
-      module.kms.key_arn,
+      module.eventpub.sns_topic.arn
     ]
   }
 
   statement {
-    sid    = "AllowSNSPublish"
+    sid    = "AllowKinesisGet"
     effect = "Allow"
 
     actions = [
-      "sns:Publish"
+      "kinesis:GetRecords",
+      "kinesis:GetShardIterator",
+      "kinesis:DescribeStream",
+      "kinesis:DescribeStreamSummary",
+      "kinesis:ListShards",
+      "kinesis:ListStreams",
     ]
 
     resources = [
-      module.eventpub.sns_topic.arn
+      aws_kinesis_stream.letter_change_stream.arn
     ]
   }
 }

internal/events/package.json

@@ -50,5 +50,5 @@
     "typecheck": "tsc --noEmit"
   },
   "types": "dist/index.d.ts",
-  "version": "1.0.3"
+  "version": "1.0.4"
 }

internal/events/src/domain/letter.ts

@@ -76,6 +76,12 @@ The identifier will be included as the origin domain in the subject of any corre
       examples: ["1y3q9v1zzzz"],
     }),
 
+    supplierId: z.string().meta({
+      title: "Supplier ID",
+      description: "Supplier ID allocated to the letter during creation.",
+      examples: ["supplier-1"],
+    }),
+
     groupId: z.string().meta({
       title: "Group ID",
       description:

internal/events/src/events/__tests__/event-envelope.test.ts

@@ -8,12 +8,15 @@ describe("EventEnvelope schema validation", () => {
   const baseValidEnvelope: Envelope = {
     dataschema:
       "https://notify.nhs.uk/cloudevents/schemas/supplier-api/order.READ.1.0.0.schema.json",
+    dataschemaversion: "1.0.0",
     specversion: "1.0",
     id: "6f1c2a53-3d54-4a0a-9a0b-0e9ae2d4c111",
     source: "/data-plane/supplier-api/ordering",
     subject: "order/769acdd4",
     type: "uk.nhs.notify.supplier-api.order.READ.v1",
+    plane: "data",
     time: "2025-10-01T10:15:30.000Z",
+    datacontenttype: "application/json",
     data: {
       "notify-payload": {
         "notify-data": { nhsNumber: "9434765919" },
@@ -241,10 +244,13 @@ describe("EventEnvelope schema validation", () => {
       specversion: "1.0" as const,
       id: "6f1c2a53-3d54-4a0a-9a0b-0e02b2c3d479",
       type: "uk.nhs.notify.supplier-api.letter.CREATED.v1" as const,
+      plane: "data",
       dataschema:
         "https://notify.nhs.uk/cloudevents/schemas/supplier-api/letter.CREATED.1.0.0.schema.json",
+      dataschemaversion: "1.0.0",
       source: "/data-plane/supplier-api/letters",
       time: "2025-10-01T10:15:30.000Z",
+      datacontenttype: "application/json",
       data: { status: "CREATED" },
       traceparent: "00-0af7651916cd43dd8448eb211c80319c-b7ad6b7169203331-01",
       recordedtime: "2025-10-01T10:15:30.250Z",
@@ -294,11 +300,14 @@ describe("EventEnvelope schema validation", () => {
         specversion: "1.0" as const,
         id: "6f1c2a53-3d54-4a0a-9a0b-0e9ae2d4c111",
         type: "uk.nhs.notify.supplier-api.order.READ.v1" as const,
+        plane: "data",
         dataschema:
           "https://notify.nhs.uk/cloudevents/schemas/supplier-api/order.READ.1.0.0.schema.json",
+        dataschemaversion: "1.0.0",
         source: "/data-plane/supplier-api/ordering",
         subject: "order/769acdd4",
         time: "2025-10-01T10:15:30.000Z",
+        datacontenttype: "application/json",
         data: { status: "READ" },
         traceparent: "00-0af7651916cd43dd8448eb211c80319c-b7ad6b7169203331-01",
         recordedtime: "2025-10-01T10:15:30.250Z",
@@ -341,6 +350,7 @@ describe("EventEnvelope schema validation", () => {
         type: "uk.nhs.notify.supplier-api.order.read.v1" as const,
         dataschema:
           "https://notify.nhs.uk/cloudevents/schemas/supplier-api/order.read.1.0.0.schema.json",
+        dataschemaversion: "1.0.0",
         source: "/data-plane/supplier-api/ordering",
         subject: "prefix/letter-rendering/order/769acdd4",
         time: "2025-10-01T10:15:30.000Z",

internal/events/src/events/__tests__/mi-events.test.ts

@@ -18,6 +18,7 @@ describe("MI event validations", () => {
     expect(event).toEqual(
       expect.objectContaining({
         type: "uk.nhs.notify.supplier-api.mi.SUBMITTED.v1",
+        plane: "data",
         specversion: "1.0",
         source: "/data-plane/supplier-api/prod/submit-mi",
         id: "8f2c3b44-4e65-5b1b-a678-1f0bf3d4d222",

internal/events/src/events/__tests__/testData/letter.ACCEPTED-with-invalid-major-version.json

@@ -9,11 +9,14 @@
       "subject": "client/00f3b388-bbe9-41c9-9e76-052d37ee8988/letter-request/0o5Fs0EELR0fUjHjbCnEtdUwQe4_0o5Fs0EELR0fUjHjbCnEtdUwQe5"
     },
     "specificationId": "1y3q9v1zzzz",
-    "status": "ACCEPTED"
+    "status": "ACCEPTED",
+    "supplierId": "supplier1"
   },
   "datacontenttype": "application/json",
   "dataschema": "https://notify.nhs.uk/cloudevents/schemas/supplier-api/letter.ACCEPTED.0.1.0.schema.json",
+  "dataschemaversion": "1.0.0",
   "id": "23f1f09c-a555-4d9b-8405-0b33490bc920",
+  "plane": "data",
   "recordedtime": "2025-08-28T08:45:00.000Z",
   "severitynumber": 2,
   "severitytext": "INFO",

internal/events/src/events/__tests__/testData/letter.ACCEPTED-with-missing-fields.json

@@ -8,11 +8,14 @@
       "source": "/data-plane/letter-rendering/prod/render-pdf"
     },
     "specificationId": "1y3q9v1zzzz",
-    "status": "ACCEPTED"
+    "status": "ACCEPTED",
+    "supplierId": "supplier1"
   },
   "datacontenttype": "application/json",
   "dataschema": "https://notify.nhs.uk/cloudevents/schemas/supplier-api/letter.ACCEPTED.1.0.0.schema.json",
+  "dataschemaversion": "1.0.0",
   "id": "23f1f09c-a555-4d9b-8405-0b33490bc920",
+  "plane": "data",
   "recordedtime": "2025-08-28T08:45:00.000Z",
   "severitynumber": 2,
   "severitytext": "INFO",

internal/events/src/events/__tests__/testData/letter.ACCEPTED.json

@@ -9,11 +9,14 @@
       "subject": "client/00f3b388-bbe9-41c9-9e76-052d37ee8988/letter-request/0o5Fs0EELR0fUjHjbCnEtdUwQe4_0o5Fs0EELR0fUjHjbCnEtdUwQe5"
     },
     "specificationId": "1y3q9v1zzzz",
-    "status": "ACCEPTED"
+    "status": "ACCEPTED",
+    "supplierId": "supplier1"
   },
   "datacontenttype": "application/json",
   "dataschema": "https://notify.nhs.uk/cloudevents/schemas/supplier-api/letter.ACCEPTED.1.0.0.schema.json",
+  "dataschemaversion": "1.0.0",
   "id": "23f1f09c-a555-4d9b-8405-0b33490bc920",
+  "plane": "data",
   "recordedtime": "2025-08-28T08:45:00.000Z",
   "severitynumber": 2,
   "severitytext": "INFO",

internal/events/src/events/__tests__/testData/letter.FORWARDED.json

@@ -11,11 +11,14 @@
     "reasonCode": "RNIB",
     "reasonText": "RNIB",
     "specificationId": "1y3q9v1zzzz",
-    "status": "FORWARDED"
+    "status": "FORWARDED",
+    "supplierId": "supplier1"
   },
   "datacontenttype": "application/json",
   "dataschema": "https://notify.nhs.uk/cloudevents/schemas/supplier-api/letter.FORWARDED.1.0.0.schema.json",
+  "dataschemaversion": "1.0.0",
   "id": "23f1f09c-a555-4d9b-8405-0b33490bc920",
+  "plane": "data",
   "recordedtime": "2025-08-28T08:45:00.000Z",
   "severitynumber": 2,
   "severitytext": "INFO",

internal/events/src/events/__tests__/testData/letter.RETURNED.json

@@ -11,11 +11,14 @@
     "reasonCode": "R07",
     "reasonText": "No such address",
     "specificationId": "1y3q9v1zzzz",
-    "status": "RETURNED"
+    "status": "RETURNED",
+    "supplierId": "supplier1"
   },
   "datacontenttype": "application/json",
   "dataschema": "https://notify.nhs.uk/cloudevents/schemas/supplier-api/letter.RETURNED.1.0.0.schema.json",
+  "dataschemaversion": "1.0.0",
   "id": "23f1f09c-a555-4d9b-8405-0b33490bc920",
+  "plane": "data",
   "recordedtime": "2025-08-28T08:45:00.000Z",
   "severitynumber": 2,
   "severitytext": "INFO",

internal/events/src/events/__tests__/testData/mi.SUBMITTED-minimal.json

@@ -11,7 +11,9 @@
   },
   "datacontenttype": "application/json",
   "dataschema": "https://notify.nhs.uk/cloudevents/schemas/supplier-api/mi.SUBMITTED.1.0.0.schema.json",
+  "dataschemaversion": "1.0.0",
   "id": "9a3d4c55-5f76-6c2c-b789-2f1cf4e5e333",
+  "plane": "data",
   "recordedtime": "2025-11-16T15:00:00.250Z",
   "severitynumber": 2,
   "severitytext": "INFO",

internal/events/src/events/__tests__/testData/mi.SUBMITTED-with-invalid-major-version.json

@@ -13,7 +13,9 @@
   },
   "datacontenttype": "application/json",
   "dataschema": "https://notify.nhs.uk/cloudevents/schemas/supplier-api/mi.SUBMITTED.2.0.0.schema.json",
+  "dataschemaversion": "1.0.0",
   "id": "8f2c3b44-4e65-5b1b-a678-1f0bf3d4d222",
+  "plane": "data",
   "recordedtime": "2025-11-16T10:30:00.250Z",
   "severitynumber": 2,
   "severitytext": "INFO",

internal/events/src/events/__tests__/testData/mi.SUBMITTED-with-missing-subject.json

@@ -10,7 +10,9 @@
   },
   "datacontenttype": "application/json",
   "dataschema": "https://notify.nhs.uk/cloudevents/schemas/supplier-api/mi.SUBMITTED.1.0.0.schema.json",
+  "dataschemaversion": "1.0.0",
   "id": "8f2c3b44-4e65-5b1b-a678-1f0bf3d4d222",
+  "plane": "data",
   "recordedtime": "2025-11-16T10:30:00.250Z",
   "severitynumber": 2,
   "severitytext": "INFO",

internal/events/src/events/__tests__/testData/mi.SUBMITTED.json

@@ -13,7 +13,9 @@
   },
   "datacontenttype": "application/json",
   "dataschema": "https://notify.nhs.uk/cloudevents/schemas/supplier-api/mi.SUBMITTED.1.0.0.schema.json",
+  "dataschemaversion": "1.0.0",
   "id": "8f2c3b44-4e65-5b1b-a678-1f0bf3d4d222",
+  "plane": "data",
   "recordedtime": "2025-11-16T10:30:00.250Z",
   "severitynumber": 2,
   "severitytext": "INFO",

internal/events/src/events/event-envelope.ts

@@ -50,6 +50,12 @@ export function EventEnvelope<TData extends z.ZodTypeAny>(
         examples: typeStrings,
       }),
 
+      plane: z.literal("data").meta({
+        title: "plane",
+        description: "The event bus that this event will be published to",
+        examples: ["data"],
+      }),
+
       dataschema: z
         .string()
         .regex(
@@ -64,6 +70,15 @@ export function EventEnvelope<TData extends z.ZodTypeAny>(
           examples: schemaExamples,
         }),
 
+      dataschemaversion: z
+        .string()
+        .regex(/^1\.\d+\.\d+$/)
+        .meta({
+          title: "Data Schema URI",
+          description: `Version of the schema that describes the event data\n\nMust match the version in dataschema`,
+          examples: ["1.0.0"],
+        }),
+
       source: z
         .string()
         .regex(/^\/data-plane\/supplier-api(?:\/.*)?$/)
@@ -94,14 +109,12 @@ export function EventEnvelope<TData extends z.ZodTypeAny>(
         examples: ["2025-10-01T10:15:30.000Z"],
       }),
 
-      datacontenttype: z.optional(
-        z.literal("application/json").meta({
-          title: "Data Content Type",
-          description:
-            "Media type for the data field (fixed to application/json).",
-          examples: ["application/json"],
-        }),
-      ),
+      datacontenttype: z.literal("application/json").meta({
+        title: "Data Content Type",
+        description:
+          "Media type for the data field (fixed to application/json).",
+        examples: ["application/json"],
+      }),
 
       traceparent: z
         .string()

internal/events/src/events/letter-events.ts

@@ -13,7 +13,7 @@ export const $LetterEvent = EventEnvelope(
   "letter",
   "letter",
   $Letter,
-  $LetterStatus.options,
+  $LetterStatus.options.map((status) => status.toLowerCase()),
   "letter-origin",
 ).meta({
   title: `letter.* Event`,
@@ -27,13 +27,13 @@ export type LetterEvent = z.infer<typeof $LetterEvent>;
  */
 const eventSchema = (status: LetterStatus) =>
   EventEnvelope(
-    `letter.${status}`,
+    `letter.${status.toLowerCase()}`,
     "letter",
     $Letter,
     [status],
     "letter-origin",
   ).meta({
-    title: `letter.${status} Event`,
+    title: `letter.${status.toLowerCase()} Event`,
     description: `Event schema for letter status change to ${status}`,
   });
 

lambdas/letter-updates-transformer/package.json

@@ -1,7 +1,14 @@
 {
   "dependencies": {
-    "@types/aws-lambda": "^8.10.148",
-    "esbuild": "^0.24.0"
+    "@aws-sdk/client-sns": "^3.943.0",
+    "@aws-sdk/util-dynamodb": "^3.943.0",
+    "@internal/datastore": "^0.1.0",
+    "@internal/helpers": "^0.1.0",
+    "@nhsdigital/nhs-notify-event-schemas-supplier-api": "*",
+    "aws-lambda": "^1.0.7",
+    "esbuild": "^0.24.0",
+    "pino": "^10.1.0",
+    "zod": "^4.1.13"
   },
   "devDependencies": {
     "@tsconfig/node22": "^22.0.2",