[HTTPXodus] Consider migrating from `httpx` to `httpx2` (the actively maintained fork)

[ProgrammerPlus1998]

Background — what happened to httpx

httpx is one of the most important HTTP clients in the Python ecosystem (370k+ dependent repositories). However:

• The last stable release is 0.28.1 (December 2024) — over 20 months ago.
• For most of 2025 the repository was dormant.
• 1.0.dev4–dev6 shipped between 2026-08-19 and 2026-08-31. No committed date for stable 1.0.

Meanwhile, httpx2 is the actively maintained fork by Pydantic Services (with original httpx author Tom Christie involved). It is a drop-in replacement for the public API used here.

What migration could look like

httpx is a direct, declared runtime dependency of the published replicate package. Direct usage is well-contained — 5 files (replicate/webhook.py, replicate/client.py, replicate/stream.py, replicate/prediction.py, replicate/exceptions.py).

Two viable paths:

Option A — dual support (recommended for libraries): prefer httpx2 when available, fall back to httpx:

try:
    import httpx2 as httpx
except ImportError:
    import httpx

with httpx2>=2.12.0; python_version >= "3.10" added as an extra/optional dependency. The public API surface is identical, so no call-site changes are needed beyond the import.

Option B — hard switch: replace the dependency outright. Requires Python ≥ 3.10.

Risks of staying on httpx

• Security exposure: no stable-line releases means no stable-line security fixes.
• Compounding migration cost: the gap between 0.28.x and whatever 1.0 becomes keeps growing.

Happy to open a PR for either option if the maintainers are interested. 🙏