Debug requests with Smello

The requests library is Python's most popular HTTP client. When you're integrating with a REST API, the most common frustration is not seeing what your code actually sent: wrong headers, malformed JSON, unexpected redirects. Smello captures every requests call automatically.

Setup

pip install smello smello-server
smello-server  # start the dashboard

Then run your script with smello run:

smello run my_app.py

Every call through requests.get(), requests.post(), or Session.send() is now captured. No proxy configuration, no code changes.

Example script: basic_requests.py

Scenario: debugging a 401 from a REST API

You're calling a third-party API and getting 401 Unauthorized, but you're sure you set the token. Is it a typo? Wrong header name? Expired token?

session = requests.Session()
session.headers["X-Auth-Token"] = get_api_token()

resp = session.get("https://api.acme.com/v1/users")
# 401: why?

Debug in the dashboard

Open the Smello dashboard at http://localhost:5110. Click the failed request to see the full detail view:

• Request headers: verify the exact header name and value that was sent. Maybe the API expects Authorization: Bearer ... but you sent X-Auth-Token.
• Request URL: check for typos, wrong base URL, or missing path segments.
• Response body: many APIs include a helpful error message in the 401 response that resp.status_code alone doesn't show you.
• Remote host group: wraps adjacent loaded calls to the same destination while preserving runtime parenthood and record order.

Debug with an AI agent

If you use Claude Code or another AI coding tool, the /smello skill can query captured events and cross-reference them with your source code. Install it once:

npx skills add smelloscope/smello --skill smello

Then ask your agent:

/smello
Why am I getting 401 from api.acme.com?

The skill is also invoked automatically when your agent recognizes a debugging question, but calling /smello explicitly gives the best results. See AI Agent Skills for compatible tools.

Tips

• Redirects: requests follows redirects by default. If your request is being redirected before hitting the API, you'll see multiple captured requests: the original and each redirect hop.
• Session reuse: Smello captures at the Session.send() level, so it works whether you use requests.get() (which creates a temporary session) or a long-lived Session object.
• Raised calls: Connection failures and timeouts produce failed operations with typed error details before Requests raises the original exception.
• Binary responses: Non-JSON response bodies are shown as raw text. Large binary responses are truncated with a size indicator.
• Header redaction: Authorization and cookie headers are redacted by default. Configure redact_headers to add more.

Next step: follow the getting started guide for installation, configuration, and more.