cdk-infrastructure-data

Guidelines for defining DynamoDB tables and messaging resources with AWS CDK. They cover DynamoDB, SNS topics for publishing messages, SQS queues for receiving them, and streams of database changes.

In plain words
What is it for?
Creating tables with indexes and backups, connecting SNS to SQS, configuring Lambda event sources, setting retry paths, and enabling DynamoDB Streams.
Why use it?
They help teams choose consistent keys, retries, dead-letter queues, subscriptions, and permissions for data and message processing.

Cursor rule for Cursor

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add rules/goranerhartic/cursor-development-rules/cdk-infrastructure-data
Clone the repo
git clone --depth 1 https://github.com/GoranErhartic/cursor-development-rules

Made for: Cursor.

Per session 24 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 492 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00024 $0.00492
Opus 5 $0.00012 $0.00246
Sonnet 5 $0.00005 $0.00098
Haiku 4.5 $0.00002 $0.00049

Measured 2d ago against content hash 43a981036cd6, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

cdk-infrastructure-data scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.cursor/rules/languages/aws-lambda/cdk-infrastructure-data.mdc · 44 lines

What it actually says

CDK Data & Messaging Resources

DynamoDB

  • Table: Partition key (PK), sort key (SK); billing PAY_PER_REQUEST; stream NEW_AND_OLD_IMAGES if using Streams; pointInTimeRecovery; removalPolicy RETAIN for prod
  • GSI: Add GSIs for access patterns (e.g. GSI1PK/GSI1SK); projection ALL or specific attributes
  • Idempotency table: Separate table or dedicated PK prefix; TTL attribute for expiry; grant Lambda read/write

SQS

  • Queue: Standard or FIFO; visibility timeout ≥ 6× Lambda timeout for batch; dead-letter queue after max receives; redrive allow policy on DLQ source
  • Event source mapping: Lambda event source for queue; batch size (e.g. 10); optional filter
  • Retry ladder: Primary → DLQ; consumer of DLQ can have different handler or alert

SNS

  • Topic: Standard or FIFO; FIFO requires content-based dedup or message group ID
  • Subscription: SqsSubscription to queue; filter policy for message attributes; raw message delivery if needed
  • Fan-out: Multiple queues subscribe to same topic; filter per subscriber if needed

DynamoDB Streams

  • Stream: Enable on table (NEW_AND_OLD_IMAGES or NEW_IMAGE); Lambda event source mapping to stream; batch size and bisect on error for partial failure
  • IAM: Lambda needs dynamodb:GetRecords, GetShardIterator, ListStreams, and stream ARN resource

RDS Proxy

  • Proxy: Create RDS Proxy in front of RDS cluster; Lambda in VPC uses proxy endpoint; secrets for DB credentials in Secrets Manager
  • Grant: Lambda role needs rds-db:connect and access to secret

Conventions

  • Least privilege IAM; pass resource ARNs/names to Lambda via env; use constructs for reuse

Anti-Patterns

  • No DLQ for queues; visibility timeout too short; no stream on table when using Streams; broad IAM

See also: dynamodb.mdc, sqs-processing.mdc, dynamodb-streams.mdc, rds-proxy.mdc, idempotency.mdc

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 44 lines · 24 tokens per session scan A 43a981036cd6

Subscribe to this mod's changes

cdk-infrastructure-data is a cursor rule published in the GitHub repository GoranErhartic/cursor-development-rules (19 stars, last pushed 6mo ago), licensed MIT. It adds 24 tokens to every session and 492 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.