httpx httpx 0.24 documentation issue for netrc support (Fix)

The Fix

Upgrade to version 0.24.1 or later.

Based on closed encode/httpx issue #2666 · 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

@@ -147,7 +147,7 @@ class NetRCAuth(Auth):
     """
 
-    def __init__(self, file: typing.Optional[str]):
+    def __init__(self, file: typing.Optional[str] = None):
         self._netrc_info = netrc.netrc(file)

fix.md

Option A — Upgrade to fixed release\nUpgrade to version 0.24.1 or later.\nWhen NOT to use: This fix is not applicable if the behavior of NetRCAuth needs to explicitly require a file argument.\n\n

Why This Fix Works in Production

Trigger: >> httpx.NetRCAuth()
Mechanism: The NetRCAuth class constructor requires a 'file' argument, which was not documented correctly
Why the fix works: Sets the default value of the 'file' parameter in httpx.NetRCAuth to None, resolving the documentation issue raised in #2666. (first fixed release: 0.24.1).

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 NetRCAuth class constructor requires a 'file' argument, which was not documented correctly
Surfaces as: >> httpx.NetRCAuth()

Proof / Evidence

GitHub issue: #2666
Fix PR: https://github.com/encode/httpx/pull/2667
First fixed release: 0.24.1
Reproduced locally: No (not executed)
Last verified: 2026-02-08
Confidence: 0.85
Did this fix it?: Yes (upstream fix exists)
Own content ratio: 0.73

Discussion

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

Jump to Sources Open on GitHub

“Thanks to @alexprengere for raising this issue... ### Discussed in https://github.com/encode/httpx/discussions/2665 <div type='discussions-op-text'> <sup>Originally posted by **alexprengere** April 18, 2023</sup> From the docs: https://www.”

Issue thread · issue description · source

Failure Signature (Search String)

>> httpx.NetRCAuth()

Error Message

Stack trace

error.txt

Error Message
-------------
>> httpx.NetRCAuth()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: NetRCAuth.__init__() missing 1 required positional argument: 'file'

Environment

httpx: 0.24

What Broke

Users encounter a TypeError when attempting to instantiate NetRCAuth without a file argument.

Why It Broke

The NetRCAuth class constructor requires a 'file' argument, which was not documented correctly

Fix Options (Details)

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

Upgrade to version 0.24.1 or later.

When NOT to use: This fix is not applicable if the behavior of NetRCAuth needs to explicitly require a file argument.

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/2667

First fixed release: 0.24.1

Last verified: 2026-02-08. Validate in your environment.

When NOT to Use This Fix

This fix is not applicable if the behavior of NetRCAuth needs to explicitly require a file argument.

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
0.24.1	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.