scrapyx-mw 0.1.0

Composable Scrapy middlewares: API/session headers, debug, captcha polling/webhook, proxy rotation, smart retry.

scrapyx-mw

Composable Scrapy middlewares packaged for reuse across projects:

• API / Session headers injection
• Debug logging
• Captcha (polling via 2captcha or CapSolver) or Captcha (webhook + sidecar SQLite store)
• Proxy rotation with health checking
• Smart retry with exponential backoff

This package is compatible with projects that store per-spider config under SERVICES[SPIDER_NAME_UPPER] (e.g., CAPTCHA_REQUIRED, SITE_KEY, HEADERS), as used in your compliance_scraper project.

📚 Documentation

• Full Documentation - Complete documentation index
• Deployment Guide - Production deployment instructions
• Migration Guide - Migrate existing projects

Install (with uv)

From a project that consumes this plugin:

uv add -e ./libs/scrapyx-mw
# or publish and: uv add scrapyx-mw

🚀 Features

Core Middlewares

• Session Management: Automatic session handling with configurable headers
• API Request: Inject API-specific headers from spider configuration
• Debug Logging: Comprehensive request/response logging for development

Captcha Solving

• Multi-Provider Support: 2captcha and CapSolver providers
• Polling Mode: Traditional polling-based captcha solving
• Webhook Mode: Webhook-based captcha solving with fallback to polling
• Configurable Timeouts: Customizable polling intervals and timeouts

Production Hardening

• Telemetry: Track captcha solve attempts, success rates, and costs
• Guardrails: Rate limiting, budget controls, and circuit breaker
• Log Redaction: Automatically redact sensitive information from logs
• Configuration Validation: Fail-fast validation of captcha settings

Advanced Features

• Proxy Rotation: Intelligent proxy rotation with health checking
• Smart Retry: Exponential backoff with jitter and circuit breaker
• Scrapy Add-on: One-switch enablement of all features

Enable in your Scrapy project

In your project settings.py:

from scrapyx_mw import default_config, apply_downloader_middlewares, apply_spider_middlewares

# Toggle features here
SCRAPYX = default_config(
    api_request=True,
    session=True,
    debug=False,
    captcha="none",         # "none" | "polling" | "webhook"
    captcha_enabled=False,  # also controlled by env var CAPTCHA_ENABLED
    captcha_api_key="",     # required if captcha_enabled
    captcha_webhook_url="http://127.0.0.1:6801/webhook",
    session_headers={"Accept": "application/json"},
)

DOWNLOADER_MIDDLEWARES.update(apply_downloader_middlewares(globals(), SCRAPYX))
SPIDER_MIDDLEWARES.update(apply_spider_middlewares(globals(), SCRAPYX))

# Per-spider service configs, same shape as in your compliance_scraper:
SERVICES = {
    "EXAMPLE_SERVICE": {
        "CAPTCHA_REQUIRED": True,
        "SITE_KEY": "6Lxxxxxx...your-site-key...",
        "HEADERS": {"Accept": "text/html,application/xhtml+xml"}
    }
}

Note: Your spiders can keep using spider.service_config, spider.captcha_needed, and spider.site_key (as in your BaseComplianceSpider); this plugin is designed to read those fields.

Captcha options

• Polling (captcha="polling"): middleware submits & polls 2captcha or CapSolver.
• Webhook (captcha="webhook"): middleware submits with a callbackUrl and waits for the sidecar webhook receiver to store codes in SQLite for pickup.

Supported Providers

• 2captcha: Traditional polling-based captcha solving
• CapSolver: Modern API-based captcha solving with JSON endpoints

Provider Configuration

# For 2captcha
CAPTCHA_PROVIDER = "2captcha"
CAPTCHA_API_KEY = "your-2captcha-key"
CAPTCHA_2CAPTCHA_BASE = "https://2captcha.com"  # optional
CAPTCHA_2CAPTCHA_METHOD = "userrecaptcha"       # optional

# For CapSolver
CAPTCHA_PROVIDER = "capsolver"
CAPTCHA_API_KEY = "your-capsolver-key"
CAPTCHA_CAPSOLVER_BASE = "https://api.capsolver.com"           # optional
CAPTCHA_CAPSOLVER_TASK_TYPE = "ReCaptchaV2TaskProxyLess"       # optional

Webhook sidecar

Run the included receiver next to Scrapyd (bind to 127.0.0.1 by default):

uv run python -m scrapyx_mw.scrapyd.webhook_service
# Health: GET http://127.0.0.1:6801/health
# Webhook: POST from 2captcha to /webhook (id, code)

DB file path: /var/lib/scrapyd/webhook_solutions.db (same as your original project for drop-in compatibility).

Note: CapSolver webhook support is limited - it falls back to polling behavior in webhook mode.

Environment variables

CAPTCHA_ENABLED=false
CAPTCHA_API_KEY=
CAPTCHA_PROVIDER=2captcha
CAPTCHA_WEBHOOK_URL=http://127.0.0.1:6801/webhook
CAPTCHA_TOKEN_TTL_SECONDS=110
CAPTCHA_POLL_INITIAL_S=4.0
CAPTCHA_POLL_MAX_S=45.0
CAPTCHA_POLL_MAX_TIME_S=180.0
CAPTCHA_HTTP_TIMEOUT_S=15.0
CAPTCHA_HTTP_RETRIES=2

# 2captcha specific
CAPTCHA_2CAPTCHA_BASE=https://2captcha.com
CAPTCHA_2CAPTCHA_METHOD=userrecaptcha

# CapSolver specific
CAPTCHA_CAPSOLVER_BASE=https://api.capsolver.com
CAPTCHA_CAPSOLVER_TASK_TYPE=ReCaptchaV2TaskProxyLess

Enable via Scrapy Add-on (recommended)

Instead of editing middleware dicts manually, turn on the package with one line:

# settings.py
ADDONS = {
  "scrapyx_mw.addon.ScrapyxAddon": 0,
}

Then tweak behavior using flags:

Setting	Type	Default	Notes
SCRAPYX_SESSION_ENABLED	bool	True	Enable default session headers middleware
SCRAPYX_API_REQUEST_ENABLED	bool	True	Enable API header injector middleware
SCRAPYX_DEBUG_ENABLED	bool	False	Log outgoing requests at DEBUG
SCRAPYX_CAPTCHA_MODE	str	"none"	"none" | "polling" | "webhook"
SCRAPYX_CAPTCHA_ENABLED	bool	False	Master switch; CAPTCHA_ENABLED is also honored
CAPTCHA_API_KEY	str	""	Required if captcha is enabled
CAPTCHA_WEBHOOK_URL	str	http://127.0.0.1:6801/webhook	Webhook receiver URL
CAPTCHA_* knobs	mixed	see defaults	TTL, polling delays, HTTP timeouts/retries
SESSION_HEADERS	dict	{}	Global default headers (overridden by per-spider service_config["HEADERS"])

The Add-on composes DOWNLOADER_MIDDLEWARES / SPIDER_MIDDLEWARES with "addon" priority and avoids overwriting user-set values.

Compatibility notes

• Reads per-spider config from SERVICES[SPIDER_NAME_UPPER] (same as your compliance_scraper).
• Honors spider.captcha_needed, spider.site_key, and injects request.meta["recaptcha_solution"].
• Webhook DB path remains /var/lib/scrapyd/webhook_solutions.db for drop-in compatibility.

Prefer Add-on mode for fleet-wide consistency. The original presets.py helpers still work if you want to compose stacks manually.

---

Notes on compatibility

• Reads SERVICES[SPIDER_NAME_UPPER] for CAPTCHA_REQUIRED, SITE_KEY, HEADERS.
• Honors spider.captcha_needed and spider.site_key, and sets request.meta["recaptcha_solution"].
• Webhook SQLite schema and path matches the original (/var/lib/scrapyd/webhook_solutions.db).
• Session/API middlewares merge with service_config["HEADERS"] (exactly like your project).

---

How to use the new Add-on

In your Scrapy project (that consumes libs/scrapyx-mw):

# settings.py
ADDONS = {
    "scrapyx_mw.addon.ScrapyxAddon": 0,
}

# Optional toggles
SCRAPYX_SESSION_ENABLED = True
SCRAPYX_API_REQUEST_ENABLED = True
SCRAPYX_DEBUG_ENABLED = False

# Captcha
SCRAPYX_CAPTCHA_MODE = "polling"   # or "webhook" or "none"
SCRAPYX_CAPTCHA_ENABLED = True     # or set CAPTCHA_ENABLED=True
CAPTCHA_API_KEY = "your-2captcha-key"
# CAPTCHA_WEBHOOK_URL = "http://127.0.0.1:6801/webhook"

# (keep your existing SERVICES mapping)
SERVICES = {
    "EXAMPLE_SERVICE": {
        "CAPTCHA_REQUIRED": True,
        "SITE_KEY": "6Lxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx",
        "HEADERS": {"Accept": "text/html,application/xhtml+xml"}
    }
}

If you choose webhook mode, run the sidecar on the Scrapyd host:

uv run python -m scrapyx_mw.scrapyd.webhook_service
# Health: curl http://127.0.0.1:6801/health

---

ConfigValidator Extension

This extension validates CAPTCHA-related configuration on startup and aborts misconfigured crawls early.

Enabled automatically by the Add-on. To use independently:

EXTENSIONS = {
    "scrapyx_mw.extensions.config_validator.ConfigValidator": 10,
}

Checks performed

• If CAPTCHA_ENABLED=True but CAPTCHA_API_KEY is missing → fail.
• For each spider where SERVICES[SPIDER_NAME_UPPER]["CAPTCHA_REQUIRED"]=True:
  • Ensure SITE_KEY is set.

Useful in CI and Scrapyd to prevent broken deployments.

🔄 Proxy Rotation Middleware

The proxy rotation middleware provides intelligent proxy management:

Configuration

# Enable proxy rotation
SCRAPYX_PROXY_ROTATION_ENABLED = True

# Proxy sources
SCRAPYX_PROXY_LIST = [
    "http://proxy1:8080",
    "http://proxy2:8080",
    "socks5://proxy3:1080"
]

# Or from environment variable
SCRAPYX_PROXY_ENV_VAR = "SCRAPYX_PROXY_LIST"  # Default
# export SCRAPYX_PROXY_LIST="http://proxy1:8080,http://proxy2:8080"

# Or from file
SCRAPYX_PROXY_FILE = "proxies.txt"

# Rotation strategy
SCRAPYX_PROXY_ROTATION_STRATEGY = "round_robin"  # "round_robin" | "random" | "weighted"

# Health checking
SCRAPYX_PROXY_HEALTH_CHECK = True
SCRAPYX_PROXY_HEALTH_CHECK_INTERVAL = 300  # seconds
SCRAPYX_PROXY_MAX_FAILURES = 3

# Session persistence
SCRAPYX_PROXY_SESSION_PERSISTENCE = True

Features

• Multiple Sources: Load proxies from settings, environment variables, or files
• Health Checking: Automatically remove failed proxies
• Load Balancing: Round-robin, random, or weighted selection
• Session Persistence: Use same proxy for requests with same session_id
• Performance Tracking: Monitor proxy success rates and response times

🔁 Smart Retry Middleware

The smart retry middleware provides intelligent retry logic with exponential backoff:

Configuration

# Enable smart retry
SCRAPYX_SMART_RETRY_ENABLED = True

# Retry configuration
SCRAPYX_RETRY_MAX_TIMES = 3
SCRAPYX_RETRY_HTTP_CODES = [500, 502, 503, 504, 408, 429]

# Backoff configuration
SCRAPYX_RETRY_BASE_BACKOFF = 1.0  # seconds
SCRAPYX_RETRY_MAX_BACKOFF = 60.0  # seconds
SCRAPYX_RETRY_BACKOFF_MULTIPLIER = 2.0
SCRAPYX_RETRY_JITTER_ENABLED = True
SCRAPYX_RETRY_JITTER_RANGE = 0.1

# Circuit breaker
SCRAPYX_RETRY_CIRCUIT_BREAKER_ENABLED = True
SCRAPYX_RETRY_CIRCUIT_BREAKER_THRESHOLD = 5  # failures before circuit opens
SCRAPYX_RETRY_CIRCUIT_BREAKER_TIMEOUT = 60  # seconds before circuit resets

# Priority handling
SCRAPYX_RETRY_PRIORITY_ENABLED = True
SCRAPYX_RETRY_PRIORITY_MULTIPLIER = 1.5  # reduce delay for high-priority requests

Features

• Exponential Backoff: Increasing delays between retries
• Jitter: Random variation to prevent thundering herd
• Circuit Breaker: Stop retrying failed domains temporarily
• Priority Support: Faster retries for high-priority requests
• Statistics: Track retry success rates and delays per domain