httpx Raise dedicated exception in `.raise_from

The Fix

Upgrade to version 0.14.0 or later.

Based on closed encode/httpx issue #1067 · 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

@@ -267,9 +267,10 @@ We can raise an exception for any Client or Server error responses (4xx or 5xx s
 >>> not_found.raise_for_status()
 Traceback (most recent call last):
-  File "/Users/tomchristie/GitHub/encode/httpcore/httpx/models.py", line 776, in raise_for_status
-    raise HTTPError(message)
-httpx.HTTPError: 404 Not Found

fix.md

Option A — Upgrade to fixed release\nUpgrade to version 0.14.0 or later.\nWhen NOT to use: Do not use this fix if you require catching all HTTPError exceptions.\n\n

Why This Fix Works in Production

Trigger: Raise dedicated exception in `.raise_from_status()`
Mechanism: The generic HTTPError exception prevents separate handling of HTTP status errors
Why the fix works: Introduces a dedicated exception class, HTTPStatusError, to be raised in Response.raise_from_status(), addressing issue #1067. (first fixed release: 0.14.0).

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 generic HTTPError exception prevents separate handling of HTTP status errors
Production symptom (often without a traceback): Raise dedicated exception in `.raise_from_status()`

Proof / Evidence

GitHub issue: #1067
Fix PR: https://github.com/encode/httpx/pull/1072
First fixed release: 0.14.0
Reproduced locally: No (not executed)
Last verified: 2026-02-09
Confidence: 0.85
Did this fix it?: Yes (upstream fix exists)
Own content ratio: 0.71

Discussion

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

Jump to Sources Open on GitHub

“Hello there! Sounds like a good issue for starting contributing to httpx, so I'll work on it if you don't mind @florimondmanca 🙂”

@frankie567 · 2020-07-20 · source

Failure Signature (Search String)

Raise dedicated exception in `.raise_from_status()`
Currently `Response.raise_from_status()` raises a generic `HTTPError` exception.

Copy-friendly signature

signature.txt

Failure Signature
-----------------
Raise dedicated exception in `.raise_from_status()`
Currently `Response.raise_from_status()` raises a generic `HTTPError` exception.

Error Message

Signature-only (no traceback captured)

error.txt

Error Message
-------------
Raise dedicated exception in `.raise_from_status()`
Currently `Response.raise_from_status()` raises a generic `HTTPError` exception.

What Broke

Users cannot catch HTTP errors specifically, leading to unhandled exceptions.

Why It Broke

The generic HTTPError exception prevents separate handling of HTTP status errors

Fix Options (Details)

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

Upgrade to version 0.14.0 or later.

When NOT to use: Do not use this fix if you require catching all HTTPError exceptions.

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

Option D — Guard side-effects with OnceOnly Guardrail for side-effects

Mitigate duplicate external side-effects under retries/timeouts/agent loops by gating the operation before calling external systems.

Place OnceOnly between your code/agent and real side-effects (Stripe, emails, CRM, APIs).
Use a stable key per side-effect (e.g., customer_id + action + idempotency_key).
Fail-safe: configure fail-open vs fail-closed based on blast radius and spend risk.

Show example snippet (optional)

onceonly.py

from onceonly import OnceOnly
import os

once = OnceOnly(api_key=os.environ["ONCEONLY_API_KEY"], fail_open=True)

# Stable idempotency key per real side-effect.
# Use a request id / job id / webhook delivery id / Stripe event id, etc.
event_id = "evt_..."  # replace
key = f"stripe:webhook:{event_id}"

res = once.check_lock(key=key, ttl=3600)
if res.duplicate:
    return {"status": "already_processed"}

# Safe to execute the side-effect exactly once.
handle_event(event_id)

See OnceOnly SDK

When NOT to use: Do not use this to hide logic bugs or data corruption. Use it to block duplicate external side-effects and enforce tool permissions/spend caps.

Fix reference: https://github.com/encode/httpx/pull/1072

First fixed release: 0.14.0

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

When NOT to Use This Fix

Do not use this fix if you require catching all HTTPError exceptions.
Do not use this to hide logic bugs or data corruption. Use it to block duplicate external side-effects and enforce tool permissions/spend caps.

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
0.14.0	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.

httpx Raise dedicated exception in `.raise_from_status()` (Fix)