fastsqs 0.3.5

FastAPI-like, modern async SQS message processing for Python with advanced features

FastSQS

FastAPI-like, production-ready async SQS message processing for Python.

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Version 0.3.0 - Production Ready Features

⚠️ Pre-1.0 Release Warning: This library is under active development. Breaking changes may occur until version 1.0.0. Pin your version in production.

🚀 New Enterprise Features

• Idempotency: Prevent duplicate message processing with memory or DynamoDB storage
• Advanced Error Handling: Exponential backoff, circuit breaker, and DLQ management
• Visibility Timeout Management: Automatic monitoring and extension for long-running processes
• Parallelization: Concurrent processing with semaphore-based limiting and thread pools

Recent Updates

Version 0.3.2

• Auto DynamoDB Table Creation: DynamoDB idempotency store now automatically creates tables with proper schema and TTL configuration
• Enhanced Table Management: Improved error handling and race condition protection for table operations

Version 0.3.1

• Idempotency Improvements: Enhanced DynamoDB store reliability and error handling
• Bug Fixes: Various stability improvements and edge case handling

Key Features

• 🚀 FastAPI-like API: Familiar decorator-based routing with automatic type inference
• 🔒 Pydantic Validation: Automatic message validation and serialization using SQSEvent models
• 🔄 Auto Async/Sync: Write handlers as sync or async functions - framework handles both automatically
• �️ Middleware Support: Built-in and custom middleware for logging, timing, and more
• 🦾 Partial Batch Failure: Native support for AWS Lambda batch failure responses
• 🔀 FIFO & Standard Queues: Full support for both SQS queue types with proper ordering
• 🎯 Flexible Matching: Automatic field name normalization (camelCase ↔ snake_case)
• 🏗️ Nested Routing: QueueRouter support for complex routing scenarios
• 🐍 Type Safety: Full type hints and editor support throughout

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Requirements

• Python 3.8+
• Pydantic (installed automatically)

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Installation

pip install fastsqs

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Quick Start

Basic FastAPI-like Example

from fastsqs import FastSQS, SQSEvent

class UserCreated(SQSEvent):
    user_id: str
    email: str
    name: str

class OrderProcessed(SQSEvent):
    order_id: str
    amount: float

# Create FastSQS app
app = FastSQS(debug=True)

# Route messages using SQSEvent models
@app.route(UserCreated)
async def handle_user_created(msg: UserCreated):
    print(f"User created: {msg.name} ({msg.email})")

@app.route(OrderProcessed)
def handle_order_processed(msg: OrderProcessed):
    print(f"Order {msg.order_id}: ${msg.amount}")

# Default handler for unmatched messages
@app.default()
def handle_unknown(payload, ctx):
    print(f"Unknown message: {payload}")

# AWS Lambda handler
def lambda_handler(event, context):
    return app.handler(event, context)

Example SQS Message Payloads

{
  "type": "user_created",
  "user_id": "123",
  "email": "[e-mail]",
  "name": "John Doe"
}

{
  "type": "order_processed",
  "order_id": "ord-456",
  "amount": 99.99
}

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Advanced Features

# FIFO Queue Support
app = FastSQS(queue_type=QueueType.FIFO)

# Middleware
from fastsqs.middleware import TimingMiddleware, LoggingMiddleware
app.add_middleware(TimingMiddleware())
app.add_middleware(LoggingMiddleware())

# Field Matching - automatically handles camelCase ↔ snake_case
class UserEvent(SQSEvent):
    user_id: str  # Matches: user_id, userId, USER_ID
    first_name: str  # Matches: first_name, firstName

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How it Works

1. Message Parsing: JSON validated and normalized
2. Route Matching: Type-based routing to handlers
3. Handler Execution: Sync/async functions supported
4. Error Handling: Failed messages → SQS retry/DLQ

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Error Handling & Performance

• Predictable Errors: All failures result in batch item failures for SQS retry
• Parallel Processing: Concurrent message handling (respects FIFO ordering)
• Type Safety: Full Pydantic validation with IDE support
• Memory Efficient: Minimal overhead per message

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Documentation & Contributing

• Examples: See examples/ directory for complete working examples
• Contributing: Issues and PRs welcome!
• License: MIT

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Ready to build type-safe, FastAPI-like SQS processors? Try FastSQS today!