The Fix
Upgrade to version 0.23.0 or later.
Based on closed encode/httpx issue #2124 · 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%.
@@ -69,7 +69,7 @@ def print_help() -> None:
table.add_row(
- "--proxy [cyan]URL",
+ "--proxies [cyan]URL",
"Send the request via a proxy. Should be the URL giving the proxy address.",
Option A — Upgrade to fixed release\nUpgrade to version 0.23.0 or later.\nWhen NOT to use: This fix is not applicable if the CLI is expected to support the `--proxy` option.\n\n
Why This Fix Works in Production
- Trigger: Which is correct? Is there an undocumented change from`--proxy` to `--proxies`?
- Mechanism: The CLI documentation incorrectly referenced the `--proxy` option instead of the correct `--proxies` option
- Why the fix works: Updates the CLI documentation to reflect the correct option for proxies. (first fixed release: 0.23.0).
- 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 CLI documentation incorrectly referenced the `--proxy` option instead of the correct `--proxies` option
- Production symptom (often without a traceback): Which is correct? Is there an undocumented change from`--proxy` to `--proxies`?
Proof / Evidence
- GitHub issue: #2124
- Fix PR: https://github.com/encode/httpx/pull/2125
- First fixed release: 0.23.0
- Reproduced locally: No (not executed)
- Last verified: 2026-02-09
- Confidence: 0.85
- 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).
“And is there a standalone repo of httpx cli in the history? I remember I submitted an issue but can not find it.”
“@guyskk AFAIK, no, httpx-cli is now integrated into this repository, with code in httpx/_main.py. I assume the correct option is proxies, since that is what…”
“@florimondmanca Thank you! PR submitted #2125 .”
Failure Signature (Search String)
- Which is correct? Is there an undocumented change from`--proxy` to `--proxies`?
Copy-friendly signature
Failure Signature
-----------------
Which is correct? Is there an undocumented change from`--proxy` to `--proxies`?
Error Message
Signature-only (no traceback captured)
Error Message
-------------
Which is correct? Is there an undocumented change from`--proxy` to `--proxies`?
What Broke
Users were confused by incorrect CLI documentation leading to failed proxy configurations.
Why It Broke
The CLI documentation incorrectly referenced the `--proxy` option instead of the correct `--proxies` option
Fix Options (Details)
Option A — Upgrade to fixed release Safe default (recommended)
Upgrade to version 0.23.0 or later.
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/2125
First fixed release: 0.23.0
Last verified: 2026-02-09. Validate in your environment.
When NOT to Use This Fix
- This fix is not applicable if the CLI is expected to support the `--proxy` option.
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 |
|---|---|
| 0.23.0 | Fixed |
Related Issues
No related fixes found.
Sources
We don’t republish the full GitHub discussion text. Use the links above for context.