The Lupaxa SRE Toolbox
Part of The Lupaxa Project

lupaxa-time-to-first-byte

Measure HTTP time to first byte and repeat until interrupted.

Features

• Measure DNS, connection, TLS, and total time to first byte
• Follow redirects and report the final response status
• Repeat after a configurable delay (default 1 second)
• Use a 5 second socket timeout and follow up to 10 redirects by default
• Run a fixed --count or continue until Ctrl-C
• Treat any HTTP response with a first byte, including 4xx and 5xx, as a pass
• Use the measure and run_measurements library API
• Run with no dependencies beyond the Python standard library

Installation

From PyPI

pip install lupaxa-time-to-first-byte

From source (development mode)

pip install -e ".[dev]"

Requires Python 3.13+. No runtime dependencies.

Library quick start

from lupaxa.time_to_first_byte import measure, run_measurements

one = measure("https://example.com")
print(one.ok, one.status, one.ttfb_ms)

summary = run_measurements("https://example.com", count=3, delay=0)
print(summary.total, summary.passed, summary.failed)

CLI quick start

time-to-first-byte --help
time-to-first-byte --url https://example.com
ttfb -u https://example.com --count 5
ttfb -u https://example.com --delay 0 --timeout 5 --max-redirects 10

You can also run the CLI as a module:

python -m lupaxa.time_to_first_byte --help
python -m lupaxa.time_to_first_byte --version

Options

• --url, -u: required HTTP or HTTPS URL
• --delay, -d: seconds between samples; default 1
• --count, -c: number of samples; omitted means run until Ctrl-C
• --timeout, -T: socket timeout in seconds; default 5
• --max-redirects: maximum redirects to follow; default 10
• --version: print the package version

Documentation

Online documentation:

Documentation

Source repository:

GitHub

Serve docs locally

From a clone of the repository:

make mkdocs-serve

Then open the local URL printed by MkDocs in your browser.

Development

Clone the repository and install with Make:

make init                # first-time makefile-skills checkout
make python-install-dev  # editable install with [dev]
make python-check        # lint, type-check, and test