aws-blocks

Guidance for building full-stack applications with AWS Blocks, a framework whose building blocks provide backend features such as storage, authentication, jobs, files, and real-time communication. The same blocks can run locally with mocks and later be deployed to AWS.

In plain words
What is it for?
Use it to create or extend AWS Blocks applications, select building blocks, run local development and testing environments, and deploy them with least-privilege credentials.
Why use it?
It gives a consistent way to develop and test backend features locally before deploying them, without needing AWS credentials during local work.

Skill for Claude CodeCodex

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 skills/xyruscode/ai-sync/aws-blocks
Any agent
npx skills add XyrusCode/ai-sync --skill aws-blocks
Clone the repo
git clone --depth 1 https://github.com/XyrusCode/ai-sync

Made for: Claude Code, Codex.

Per session 105 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,077 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 98% copy Near-identical to another mod 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 $0.00105 $0.01077
Opus 5 $0.00053 $0.00539
Sonnet 5 $0.00021 $0.00215
Haiku 4.5 $0.00011 $0.00108

Measured yesterday against content hash e945a00c4601, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

aws-blocks 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 yesterday.

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.

Origin

This is a copy

98% identical to aws-blocks — 13 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

skills/aws-blocks/SKILL.md · 94 lines

How it starts

The opening of the file, as written. The whole thing — 94 lines — stays where its author put it; the contents beside it link to each section on GitHub.

AWS Blocks Application Development

Package naming: All packages are published under the @aws-blocks scope (e.g., @aws-blocks/core, @aws-blocks/blocks, @aws-blocks/bb-kv-store).

Overview

AWS Blocks is an Infrastructure-from-Code framework where Building Blocks bundle CDK, SDK, and local mocks into a single API. It provides 18+ Building Blocks covering storage, authentication, real-time communication, background jobs, file management, AI/search, email, and observability — all working locally without AWS credentials.

Key characteristics:

  • One aws-blocks/ directory defines the entire backend
  • Frontend imports are fully typed — no client generation needed
  • All Building Blocks work locally without AWS (mocks persist to .bb-data/)
  • Deploy ephemeral, individual testing environments with npm run sandbox and long-lived environments with npm run deploy using least-privilege credentials

Scaffolding a New Project

npx @aws-blocks/create-blocks-app my-app
cd my-app

To add AWS Blocks to an existing project:

npx @aws-blocks/create-blocks-app .

This detects the existing project and adds an aws-blocks/ workspace alongside your code.

To add AWS Blocks to an Amplify Gen 2 project:

npx @aws-blocks/create-blocks-app .

When the CLI detects amplify/backend.ts, it automatically integrates AWS Blocks with your Amplify backend.

With a specific template:

npx @aws-blocks/create-blocks-app my-app --template demo
cd my-app

Available Templates

Template Description
default Vite + lit-html starter app with basic authentication, data persistence, and realtime to help demonstrate basic app architecture and patterns (used when --template is omitted)
bare Vite + lit-html starter with a single "hello world" API method and a bare frontend
react React + Vite starter with a single API endpoint and typed React frontend
backend Backend-only — no frontend, just the AWS Blocks API with a single endpoint
demo Todo app with AuthBasic, KVStore, DistributedTable, Zod schemas, indexes, and auth-protected CRUD
auth-cognito Full AuthCognito passwordless email-OTP with roles, device management, and Authenticator UI
nextjs Next.js + React starter with AWS Blocks backend integration (SSR + Server Components)

Read the full file on GitHub · 94 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. yesterday First seen · 94 lines · 105 tokens per session scan A e945a00c4601

Subscribe to this mod's changes

aws-blocks is a skill published in the GitHub repository XyrusCode/ai-sync (2 stars, last pushed yesterday), licensed MIT. It adds 105 tokens to every session and 1,077 once invoked, about $0.0005 per session on Opus 5. A static security scan graded it A with 0 findings. It is 98% identical to aws-blocks, differing in 13 lines, and is treated as a copy.

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