httpx Stricter typing. (Fix)

The Fix

Upgrade to version 0.23.2 or later.

Based on closed encode/httpx issue #2436 · PR/commit linked

Production note: Most teams hit this during upgrades or environment changes. Roll out with a canary and smoke critical endpoints (health, OpenAPI/docs) before 100%.

Open PR/Commit

@@ -3,22 +3,8 @@ ignore = W503, E203, B305, PIE801
 
 [mypy]
-disallow_untyped_defs = True
-disallow_any_generics = True
 ignore_missing_imports = True

fix.md

Option A — Upgrade to fixed release\nUpgrade to version 0.23.2 or later.\nWhen NOT to use: This fix is not suitable if existing code relies on dynamic typing without type hints.\n\n

Why This Fix Works in Production

Trigger: * Individually targeted pull requests which turn on a *single* `mypy` flag, and make the required changes to keep the tests passing.
Mechanism: The project lacked stricter typing checks, leading to potential type-related issues
Why the fix works: Enables the 'disallow_untyped_calls' flag in mypy, improving type checking in the project. (first fixed release: 0.23.2).

Production impact:

If left unfixed, the same config can fail only in production (env differences), causing startup failures or partial feature outages.

Why This Breaks in Prod

The project lacked stricter typing checks, leading to potential type-related issues
Production symptom (often without a traceback): * Individually targeted pull requests which turn on a *single* `mypy` flag, and make the required changes to keep the tests passing.

Proof / Evidence

GitHub issue: #2436
Fix PR: https://github.com/encode/httpx/pull/2479
First fixed release: 0.23.2
Reproduced locally: No (not executed)
Last verified: 2026-02-09
Confidence: 0.75
Did this fix it?: Yes (upstream fix exists)
Own content ratio: 0.77

Discussion

High-signal excerpts from the issue thread (symptoms, repros, edge-cases).

Jump to Sources Open on GitHub

“> [ ] no_implicit_reexport = True - 36 errors The error count here is misleading, actually”

@mjpieters · 2022-11-11 · source

“There is a minor typo in the diff: s/brotly/brotli/”

@pmav99 · 2022-11-12 · source

“> There is a minor typo in the diff: s/brotly/brotli/ Well spotted! On my mac, the import brotli as brotli import was being used so…”

@mjpieters · 2022-11-12 · source

“Okay, since https://github.com/encode/httpx/pull/2479 we've now got mypy --strict passing”

@lovelydinosaur · 2022-12-02 · source

Failure Signature (Search String)

* Individually targeted pull requests which turn on a *single* `mypy` flag, and make the required changes to keep the tests passing.
and `scripts/check` passes cleanly with no other changes required.

Copy-friendly signature

signature.txt

Failure Signature
-----------------
* Individually targeted pull requests which turn on a *single* `mypy` flag, and make the required changes to keep the tests passing.
and `scripts/check` passes cleanly with no other changes required.

Error Message

Signature-only (no traceback captured)

error.txt

Error Message
-------------
* Individually targeted pull requests which turn on a *single* `mypy` flag, and make the required changes to keep the tests passing.
and `scripts/check` passes cleanly with no other changes required.

What Broke

Users experienced type-related errors when using tools with stricter type checking.

Why It Broke

The project lacked stricter typing checks, leading to potential type-related issues

Fix Options (Details)

Option A — Upgrade to fixed release Safe default (recommended)

Upgrade to version 0.23.2 or later.

When NOT to use: This fix is not suitable if existing code relies on dynamic typing without type hints.

Use when you can deploy the upstream fix. It is usually lower-risk than long-lived workarounds.

Fix reference: https://github.com/encode/httpx/pull/2479

First fixed release: 0.23.2

Last verified: 2026-02-09. Validate in your environment.

When NOT to Use This Fix

This fix is not suitable if existing code relies on dynamic typing without type hints.

Did This Fix Work in Your Case?

Quick signal helps us prioritize which fixes to verify and improve.

Prevention

Add a CI check that diffs key outputs after upgrades (OpenAPI schema snapshots, JSON payload shapes, CLI output).
Upgrade behind a canary and run integration tests against the canary before 100% rollout.

Version Compatibility Table

Version	Status
0.23.2	Fixed

Related Issues

No related fixes found.

Cluster: httpx:configuration-error All hubs All clusters

Related clusters: Data consistency Other Timeout

Sources

We don’t republish the full GitHub discussion text. Use the links above for context.