The Fix
Upgrade to version 0.14.0 or later.
Based on closed encode/httpx issue #1039 · 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%.
@@ -89,10 +89,10 @@ def trust_env(self) -> bool:
def _get_proxy_map(
- self, proxies: typing.Optional[ProxiesTypes], trust_env: bool,
+ self, proxies: typing.Optional[ProxiesTypes], allow_env_proxies: bool,
) -> typing.Dict[str, typing.Optional[Proxy]]:
repro.py
import asyncio
import os
import httpx
async def hello_world(scope, receive, send):
status = 200
output = b"Hello, World!"
headers = [(b"content-type", "text/plain"), (b"content-length", str(len(output)))]
await send({"type": "http.response.start", "status": status, "headers": headers})
await send({"type": "http.response.body", "body": output})
async def test_asgi_with_env():
os.environ["http_proxy"] = "http://localhost:1111"
client = httpx.AsyncClient(app=hello_world)
response = await client.get("http://www.example.org/")
assert response.status_code == 200
assert response.text == "Hello, World!"
asyncio.run(test_asgi_with_env())
verify
Re-run the minimal reproduction on your broken version, then apply the fix and re-run.
fix.md
Option A — Upgrade to fixed release\nUpgrade to version 0.14.0 or later.\nWhen NOT to use: This fix should not be used if environment proxies are required for other requests.\n\n
Why This Fix Works in Production
- Trigger: httpcore._exceptions.ConnectError: Multiple exceptions: [Errno 61] Connect call failed ('::1', 1111, 0, 0), [Errno 61] Connect call failed ('127.0.0.1', 1111
- Mechanism: The AsyncClient was incorrectly using environment proxies when an ASGI app was specified
- Why the fix works: Ensures that when an app or transport is specified, environment proxies are bypassed, resolving the issue of unintended proxy usage. (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 AsyncClient was incorrectly using environment proxies when an ASGI app was specified
- Surfaces as: httpcore._exceptions.ConnectError: Multiple exceptions: [Errno 61] Connect call failed ('::1', 1111, 0, 0), [Errno 61] Connect call failed ('127.0.0.1', 1111
Proof / Evidence
- GitHub issue: #1039
- Fix PR: https://github.com/encode/httpx/pull/1122
- 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: 0.56
Verified Execution
We executed the runnable minimal repro in a temporary environment and captured exit codes + logs.
- Status: PASS
- Ran: 2026-02-11T16:52:29Z
- Package: httpx
- Fixed: 0.14.0
- Mode: fixed_only
- Outcome: ok
Logs
affected (exit=None)
fixed (exit=0)
Discussion
High-signal excerpts from the issue thread (symptoms, repros, edge-cases).
“> on a smaller scope, we can look at the auto proxies setup code, see if it makes sense to bypass it if an app…”
“Cool, looks like the resolution path is all rounded there, up for grabs…”
“Might be worth looking if there’s any past discussion about whether we should make trust_env default to False..”
Failure Signature (Search String)
- httpcore._exceptions.ConnectError: Multiple exceptions: [Errno 61] Connect call failed ('::1', 1111, 0, 0), [Errno 61] Connect call failed ('127.0.0.1', 1111
Error Message
Stack trace
error.txt
Error Message
-------------
httpcore._exceptions.ConnectError: Multiple exceptions: [Errno 61] Connect call failed ('::1', 1111, 0, 0), [Errno 61] Connect call failed ('127.0.0.1', 1111
Minimal Reproduction
repro.py
import asyncio
import os
import httpx
async def hello_world(scope, receive, send):
status = 200
output = b"Hello, World!"
headers = [(b"content-type", "text/plain"), (b"content-length", str(len(output)))]
await send({"type": "http.response.start", "status": status, "headers": headers})
await send({"type": "http.response.body", "body": output})
async def test_asgi_with_env():
os.environ["http_proxy"] = "http://localhost:1111"
client = httpx.AsyncClient(app=hello_world)
response = await client.get("http://www.example.org/")
assert response.status_code == 200
assert response.text == "Hello, World!"
asyncio.run(test_asgi_with_env())
What Broke
Requests routed through the proxy caused connection errors and unexpected behavior.
Why It Broke
The AsyncClient was incorrectly using environment proxies when an ASGI app was specified
Fix Options (Details)
Option A — Upgrade to fixed release Safe default (recommended)
Upgrade to version 0.14.0 or later.
When NOT to use: This fix should not be used if environment proxies are required for other requests.
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/1122
First fixed release: 0.14.0
Last verified: 2026-02-09. Validate in your environment.
When NOT to Use This Fix
- This fix should not be used if environment proxies are required for other requests.
Verify Fix
verify
Re-run the minimal reproduction on your broken version, then apply the fix and re-run.
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.
- Add a TLS smoke test that performs a real handshake in CI (include CA bundle validation and hostname checks).
- Alert on handshake failures by error string and endpoint to catch cert/CA changes quickly.
Version Compatibility Table
| Version | Status |
|---|---|
| 0.14.0 | Fixed |
Related Issues
No related fixes found.
Sources
We don’t republish the full GitHub discussion text. Use the links above for context.