BLOCK-01: Add API Gateway JWT authorizer with Cognito, route internal Lambda calls through Function URL to bypass gateway auth BLOCK-02/03: Prevent proposal number race condition with pg_advisory_xact_lock and filter revision numbers from max-number query BLOCK-04: Restrict VendorProposals and GeneratedPdfs to admins/sysadmins BLOCK-05: Sum all vendor costs instead of overwriting with single vendor BLOCK-06: Enable ValidateAudience on JWT, add Auth env vars to API Lambda BLOCK-07: Validate ID token signature in AuthController via OIDC discovery BLOCK-08: Use batchItemFailures in all Lambda SQS handlers BLOCK-09: Increase SQS visibility timeout from 180s to 720s FIX-10: Scope dispatcher queries to own proposals (IDOR fix)
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Proposal System
Internal proposal management platform for Sea Haven Industries. Dispatchers submit proposal requests, AI generates draft line items from historical data via Bedrock RAG, admins review and approve in a pricing workspace, and the system produces branded PDFs for delivery.
Architecture Overview
Monorepo with five primary services:
- .NET 8 API -- Clean Architecture REST API hosted on Lambda behind API Gateway (JWT-authorized) with Function URL for internal access
- React 19 Web -- MUI v7 admin/dispatcher workspace served via CloudFront + S3
- React Native Mobile -- iOS-first field app for dispatchers (offline-capable)
- Python Lambdas -- PDF extraction, PDF generation, library ingestion, AI suggestions, AOSS index provisioning
- CDK Infrastructure -- Three TypeScript stacks managing all AWS resources
Repository Structure
proposal-system/
├── api/ .NET 8 Web API (Lambda-hosted, EF Core + PostgreSQL)
├── web/ React 19 + MUI v7 + Vite frontend
├── mobile/ React Native 0.85 iOS app
├── lambdas/ Python 3.12 processing functions (arm64)
├── infra/ CDK TypeScript (3 stacks)
├── shared/ TypeScript API contracts (shared between web + mobile)
├── scripts/ Post-deploy and utility scripts
├── .github/ CI/CD workflows
└── docker-compose.yml
Tech Stack
| Component | Technologies |
|---|---|
| API | .NET 8, ASP.NET Core, EF Core + Npgsql, FluentValidation, Cognito JWT, Amazon.Lambda.AspNetCoreServer |
| Web | React 19, TypeScript, MUI v7, Vite, Redux Toolkit, TanStack Query, axios |
| Mobile | React Native CLI 0.85, React 19, React Native Paper, React Navigation, react-native-app-auth (PKCE), amazon-cognito-identity-js (SRP), Keychain, offline draft queue |
| Lambdas | Python 3.12, arm64, pdfplumber, reportlab, httpx, boto3 |
| Infrastructure | CDK TypeScript (aws-cdk-lib 2.253.1) |
| AI/RAG | Bedrock Knowledge Base (Titan Embeddings v2), OpenSearch Serverless, Claude via Bedrock Runtime |
| Auth | Cognito User Pool + Google OAuth IdP (groups: dispatchers, admins, sysadmins) |
AWS Resources
All resources are in us-east-1 (account 328440206208).
| CDK Stack | Key Resources |
|---|---|
proposal-system-foundation |
RDS PostgreSQL 15 (t4g.small), S3 buckets, SQS queue + DLQ, Cognito user pool, Secrets Manager |
proposal-system-compute |
API Gateway HTTP API (JWT authorizer), .NET 8 API Lambda + Function URL, Python Lambdas (pdf-extract, pdf-generate, library-ingest, suggestions, oss-index-creator), OpenSearch Serverless collection, Bedrock KB |
proposal-system-frontend |
CloudFront distribution (S3 OAC) |
| Resource Type | Names |
|---|---|
| S3 Buckets | proposal-system-uploads, proposal-system-generated, proposal-system-library, seahaven-ios-certificates |
| SQS | proposal-system-jobs (720s visibility, reportBatchItemFailures) + proposal-system-jobs-dlq (message body filtering by jobType) |
| Secrets | proposal-system/db-credentials, proposal-system/internal-api-key |
Local Development
Prerequisites
- .NET 8 SDK
- Node.js 24+
- Python 3.12
- PostgreSQL 16 (via docker-compose or native)
Database
docker compose up -d # starts PostgreSQL on port 5432
# database: proposalsystem, password: localdev
API
cd api
dotnet restore
dotnet run --project src/ProposalSystem.Api
# runs on http://localhost:5000
In development mode (DevMode=true in appsettings.Development.json):
- JWT auth uses a local symmetric HMAC key (no Cognito required)
- S3 service returns fake presigned URLs
- SQS publisher logs messages without sending
Web Frontend
cd web
npm install
npm run dev
# runs on http://localhost:5173, proxies /api to localhost:5000
When VITE_COGNITO_CLIENT_ID is not set, the login screen shows role-selector buttons for local development.
Infrastructure
cd infra
npm install
npx cdk synth
CI/CD
CI (on pull request to main)
Five parallel jobs calling org reusable workflows:
| Job | Workflow | What it checks |
|---|---|---|
| .NET Build & Test | ci-dotnet.yaml |
Restore, build, test the API solution |
| Web Frontend Check | ci-typescript-cdk.yaml |
TypeScript typecheck for web |
| Mobile Typecheck | ci-typescript-cdk.yaml |
TypeScript typecheck for mobile |
| Python Lint | ci-python-sam.yaml |
ruff check + format on lambdas/ |
| CDK Synth | ci-typescript-cdk.yaml |
Synthesize CDK stacks (includes .NET publish) |
Deploy (on push to main)
Calls cd-cdk.yaml reusable workflow:
- Publishes .NET 8 API and Python Lambdas
- Runs
cdk deploy --all - Executes
scripts/post-deploy.sh(builds web, syncs to S3, invalidates CloudFront)
Deploy uses OIDC role githubdeploy-proposal-system. Concurrency group prevents parallel deploys.
Mobile Deploy
Workflow: deploy-mobile.yaml -- builds and uploads to TestFlight via cd-mobile-ios.yaml reusable workflow on macos-26.
Triggers:
- Automatic: push to
mainwith changes inmobile/** - Manual:
workflow_dispatchfor on-demand builds
Mobile iOS
The iOS app uses Fastlane with match for code signing. Certificates and profiles are stored in the seahaven-ios-certificates S3 bucket (versioning enabled, public access blocked).
Build and upload to TestFlight is handled by the cd-mobile-ios.yaml reusable workflow. Required secrets:
| Secret | Purpose |
|---|---|
AWS_DEPLOY_ROLE_ARN |
OIDC role for match S3 access |
MATCH_PASSWORD |
Decryption passphrase for signing assets |
ASC_KEY_ID |
App Store Connect API key ID |
ASC_ISSUER_ID |
App Store Connect issuer |
ASC_KEY_CONTENT |
App Store Connect API key (base64) |
Authentication & Authorization
Two-layer auth architecture with defense-in-depth:
| Path | Authorizer | Authentication |
|---|---|---|
External clients → API Gateway /{proxy+} |
Cognito JWT authorizer (web + mobile client IDs) | .NET JWT middleware (ValidateAudience=true) |
/api/health |
None (public) | None |
/api/auth/callback, /api/auth/dev-login |
None (unauthenticated) | None (pre-auth endpoints) |
| Internal Lambdas → Function URL | None (NONE auth type) | Internal API key (X-Internal-Api-Key header, value from Secrets Manager) |
Role-based access: Cognito groups (dispatchers, admins, sysadmins) map to API roles via cognito:groups claim. Dispatchers can only see their own proposals (ownership enforced in service layer). VendorProposals and GeneratedPdfs endpoints restricted to admins/sysadmins.
Internal API key: Python Lambdas call the .NET API via a Lambda Function URL (bypasses API Gateway JWT check). The InternalApiKeyMiddleware validates the key and assigns the admins role to the synthetic identity.
Data Flow
- Dispatcher submits proposal request (web or mobile)
- API creates proposal record (with advisory-locked number generation), publishes SQS message
- If vendor PDF attached:
pdf-extractLambda parses and structures data - Suggestions Lambda queries Bedrock KB for similar proposals, generates line items via Claude
- Admin reviews/edits line items in pricing workspace
- On approval:
pdf-generateLambda creates branded PDF - On send:
library-ingestLambda adds approved proposal to KB for future matching
Failed SQS messages are reported via batchItemFailures and retried up to 3 times before moving to the DLQ.