[omerbek]

Problem

Coingecko.copy() and AsyncCoingecko.copy() always pass the original base_url to the constructor, even when environment is explicitly overridden. Since an explicit URL takes precedence over environment selection, client.with_options(environment="demo") created from a Pro client continues sending requests to pro-api.coingecko.com. The reverse switch has the same problem.

Change

Only inherit the original URL when no environment override is supplied. An explicitly supplied base_url still wins, and ordinary copies preserve their current URL. Apply the same behavior to both clients; add Pro→Demo, Demo→Pro, and explicit-custom-URL precedence regressions plus a README example.

This is an independent finding, not work taken from an existing issue. Searches for environment, with_options, base_url, and copy did not identify a matching issue/PR; #34 is an unrelated response-model issue. CONTRIBUTING.md explicitly describes how manual generated-file patches persist across regeneration; no generator files were invented or changed here.

Verification

Windows / supported Python 3.11.5, httpx 0.28.1, pydantic 2.12.5:

• Added regressions before the fix: 4 failed / 2 passed.
• Copy-focused tests after the fix: 16 passed / 2 skipped.
• Standalone sync/async smoke called the public simple.price.get() resource through httpx.MockTransport; observed request hosts switched to api.coingecko.com and pro-api.coingecko.com respectively while the original clients retained their URL. No live API request or real key was used.
• Ruff check passed; Ruff formatter applied to the test file.
• Full tests/test_client.py: 149 passed / 2 skipped / 2 failed. The failures are the untouched sync/async proxy-environment tests (len(client._mounts) == 1, observed 0). On Windows environment names are case-insensitive; these tests set HTTPS_PROXY and subsequently delete https_proxy. No test suppression/change is included, and I did not establish a clean baseline.

The pinned Rye development Python is 3.9.18. The full lock could not install under 3.11 because its backports-asyncio-runner==1.2.0 requires Python <3.11; I used a supported 3.11 venv with the test-tool versions above instead. The Prism-backed resource suite and pinned-3.9 development environment were not run.

AI-assisted implementation and investigation; the regression failures, offline SDK smoke, and verification results above were exercised locally.

Upstream CI approval gate

The upstream workflow API now reports three runs as completed / action_required, rather than a test result: CI, Release Doctor, and Trunk sync lock. This is an external-contributor workflow approval gate (author association NONE); no successful CI is claimed. A maintainer with repository write permissions needs to approve the permitted fork workflows. No empty commit, duplicate PR, or workflow bypass was added.