Letter Viewer Callbacks

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Known Issues / Todo

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Events Consumed

Events Produced

DigitalLetterRead - viewer-digital-letter-read - uk.nhs.notify.digital.letters.viewer.digital.letter.read.v1

Diagrams

c4code-nhsapp-callback

C4:

Link to this diagram directly: /nhs-notify-digital-letters/diagrams/c4code-nhsapp-callback.html

architecture-beta
    group CallbackHandler(cloud)[NHSApp Callback Handler]
    service nhsapp(server)[NHS App]
    service apiGateway(aws:arch-amazon-api-gateway)[API Gateway]
    service lambda(logos:aws-lambda)[NHS App Callback Handler] in CallbackHandler
    service sqs(logos:aws-sqs)[Callback Queue] in CallbackHandler
    service ddb(aws:arch-amazon-dynamodb)[Items With TTL] in CallbackHandler
    service docReadEvent(aws:res-amazon-eventbridge-event)[DigitalLetterRead Event]

    nhsapp:R --> L:apiGateway
    apiGateway:R --> L:sqs
    sqs:R --> L:lambda
    lambda:B --> T:ddb
    lambda:R --> L:docReadEvent

sequence-nhsapp-callback

C4:

Link to this diagram directly: /nhs-notify-digital-letters/diagrams/sequence-nhsapp-callback.html

    sequenceDiagram
    participant nhsapp as NHSApp
    participant apig as API Gateway
    participant sqs as SQS<br/>Callback Queue
    participant lambda as Lambda<br/>NHS App Callback Handler
    participant ddb as DynamoDB<br/>Items With TTL
    participant eb as Event Bridge

    nhsapp ->> apig: POST /callback
    activate apig
    apig ->> sqs: Send message
    apig -->> nhsapp: 200 OK
    deactivate apig
    sqs ->> lambda: Invoke asynchronously
    activate lambda
    lambda ->> ddb: Delete TTL
    lambda ->> eb: DigitalLetterRead event
    deactivate lambda