Resilient HTTP client delivery sample

A dependency-free Python sample demonstrating bounded retries, Retry-After handling, deterministic tests, and atomic output replacement for scheduled API collectors.

Acceptance criteria

• HTTP 429, selected 5xx, timeouts, transport failures, and malformed JSON can be retried.
• Non-transient 4xx failures are raised immediately.
• Exponential backoff is capped and supports bounded jitter.
• Numeric Retry-After takes precedence over calculated backoff.
• The previous output file survives an interrupted replacement.
• Tests never call the network or actually sleep.

Verify

python3 -m unittest discover -v

Expected result: eight tests pass.

Integration sketch

import json
from src import JsonHttpClient, atomic_write_text

client = JsonHttpClient()
data = client.get_json("https://api.example.test/data")
atomic_write_text("daily.txt", json.dumps(data, indent=2))

See DELIVERY_REPORT.md for the verification and handoff format. A ready-to-copy GitHub Actions workflow is included at ci/python-tests.yml.example.

Commercial scope

This repository is a public capability sample, not customer code. Fixed-scope API reliability, CI, and QA engagements are available through LaborX escrow.