fix(auth): add User-Agent header to bypass Cloudflare 403 (closes #41)#42
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alexandrosh8 wants to merge 5 commits intoPolymarket:mainfrom
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fix(auth): add User-Agent header to bypass Cloudflare 403 (closes #41)#42alexandrosh8 wants to merge 5 commits intoPolymarket:mainfrom
alexandrosh8 wants to merge 5 commits intoPolymarket:mainfrom
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…loses Polymarket#41, Polymarket#38) - Add DEFAULT_USER_AGENT = "polymarket-clob-client-v2/{version}" to constants.py, resolved at import time via importlib.metadata with a setup.py fallback. - Replace the unversioned "py_clob_client_v2" UA in _overload_headers() with _resolve_user_agent(), which reads POLY_USER_AGENT env var first (operator override), then falls back to DEFAULT_USER_AGENT. - Add 17 regression tests in tests/test_user_agent_header.py covering the constant shape, env-var override, and every HTTP method path.
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I set os.environ["POLY_USER_AGENT"] = "polymarket-clob-client-v2/1.0.1rc1" but still same error. Should i wait for new version puhlish? |
…e 2 of UA-bypass) Community evidence on Polymarket#41 (copperhuh, Zero-Ace5, lakeswimmer; calrde on this PR) confirmed that User-Agent header alone is insufficient against the Cloudflare WAF guarding /auth/api-key. Cloudflare scores TLS JA3, HTTP/2 frames, header order, and IP reputation alongside the UA — a clean UA on a datacenter IP still hits 403. This commit expands the original UA fix into a three-layer mitigation: 1. Versioned UA (already shipped in 6fedd7f). 2. Full browser-header bundle (Accept-*, sec-ch-ua-*, sec-fetch-*) on every request via _overload_headers, set with dict.setdefault so caller-supplied headers still win. 3. Opt-in residential-proxy support via POLY_AUTH_PROXY for the L1 /auth/api-key call ONLY (no order-path latency hit). Wired through a new build_auth_http_client(timeout_s) helper that returns an httpx.Client with proxies={"https://": url, "http://": url} when the env var is set; direct client otherwise. Tested against IPRoyal. Test count: 17 -> 26. New cases cover the browser bundle (sec-ch-ua, sec-fetch-*, Accept-Language, caller-override-wins) and the proxy support (env unset/whitespace/value; client built without proxies when unset; client built with proxies when set). PR description updated with the community evidence chain + IPRoyal as a tested provider. Refs: Polymarket#38, Polymarket#41, Polymarket#43; community-fix discovery 2026-05-02.
![cursor[bot]](https://avatars.githubusercontent.com/in/1210556?s=60&v=4){kind=small}
Cursor Bugbot review on PR Polymarket#42 commit ba44d13 surfaced 4 real bugs in the residential-proxy + browser-header bundle. All four are now fixed and covered by regression tests (32 → all green; 164 SDK tests overall pass with zero regressions). 1. HIGH — `str | None` (PEP 604) crashed Python 3.9 at import ---------------------------------------------------------- The project declares ``python_requires=">=3.9.10"`` but ``get_auth_proxy_url() -> str | None`` requires runtime PEP 604 support (Python 3.10+). On 3.9 it raised ``TypeError: unsupported operand type(s) for |`` at import time, taking the entire SDK down (client.py imports from this module). Fix: add ``from __future__ import annotations`` AND switch to ``Optional[str]`` (belt-and-braces — survives a future maintainer removing the future import). 2. MED — ``proxies={...}`` kwarg removed in httpx 0.28+ ---------------------------------------------------- The original ``httpx.Client(proxies={"https://": url, "http://": url})`` call raised ``TypeError: Client.__init__() got an unexpected keyword argument 'proxies'`` on httpx >=0.28 (Nov 2024). setup.py pins ``httpx[http2]>=0.27.0`` with no upper bound. Fix: switch to the new single-URL ``proxy=<url>`` kwarg, which is forward-compatible with httpx >=0.28 and back-compatible with httpx >=0.27. 3. MED — ``build_auth_http_client`` was dead code ---------------------------------------------- The proxy-aware client builder existed but was never called from ``create_api_key`` / ``derive_api_key``, so ``POLY_AUTH_PROXY`` had no effect. The PR claimed Layer 3 of the bypass was wired; in fact it was completely inert. Fix: introduce ``auth_request`` / ``auth_get`` / ``auth_post`` in helpers.py that build a per-call ``httpx.Client`` via ``build_auth_http_client()`` (proxy-aware, honours UA + browser headers). Wire ``ClobClient.create_api_key`` to ``auth_post`` and ``ClobClient.derive_api_key`` to ``auth_get`` — these are the only two surfaces Cloudflare 403's against datacenter IPs (Polymarket#38 / Polymarket#41 / Polymarket#43). Every other call still flows through the long-lived shared ``_http_client`` to amortise connection setup. Also export the new helpers from ``http_helpers/__init__.py`` so they appear in the public API surface. 4. MED — Brotli advertised without ``brotli`` dependency ----------------------------------------------------- ``Accept-Encoding: gzip, deflate, br`` told Cloudflare we accept Brotli, but ``brotli`` / ``brotlicffi`` is NOT in install_requires (httpx[http2] only). Cloudflare commonly responds with ``Content-Encoding: br`` when the client advertises support, and httpx then fails to decode the body (ImportError or UnicodeDecodeError). Fix: drop ``br`` from the advertised set. ``gzip, deflate`` is sufficient to look like a modern client without introducing a new mandatory dependency. (Operators who want Brotli can install the ``brotli`` extra themselves and patch the header.) New tests --------- - ``TestPython39Compat`` — pins ``from __future__ import annotations`` + ``Optional[str]`` annotation in helpers.py source. - ``test_get_does_not_advertise_brotli_without_dep`` — pins the ``Accept-Encoding`` value to ``gzip, deflate`` (no ``br``). - ``TestAuthRequestRoutesThroughProxy`` — three tests proving ``auth_post`` / ``auth_get`` actually invoke ``build_auth_http_client`` and inject the browser-header bundle. - Updated ``test_build_auth_http_client_uses_proxy_when_set`` to assert the new ``proxy=<url>`` kwarg (not the removed ``proxies={...}``). Test results: 32/32 in test_user_agent_header.py, 164 SDK tests pass. 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Author
Bugbot fixes (commit
|
| # | Sev | Bug | Fix |
|---|---|---|---|
| 1 | HIGH | str | None (PEP 604) crashed Python 3.9 at import — python_requires=">=3.9.10" |
Added from __future__ import annotations + switched to Optional[str] (belt-and-braces) |
| 2 | MED | proxies={...} kwarg removed in httpx 0.28+ (no upper bound on httpx pin) |
Switched to proxy=<single url> kwarg (forward-compat 0.28+, back-compat 0.27+) |
| 3 | MED | build_auth_http_client defined but never called — Layer 3 was dead code |
Added auth_request / auth_post / auth_get in helpers.py and wired create_api_key → auth_post, derive_api_key → auth_get. Exported from __init__.py. |
| 4 | MED | Accept-Encoding: ..., br advertised Brotli without brotli in install_requires |
Dropped br; kept gzip, deflate (httpx ships built-in support) |
Tests
- 32/32 in
test_user_agent_header.py(addedTestPython39Compat,TestAuthRequestRoutesThroughProxy, plus the Brotli + newproxy=assertions) - 164/164 in the broader SDK test suite — zero regressions
Bypass surface now correctly assembled
- Layer 1 — versioned UA (
polymarket-clob-client-v2/{version}) - Layer 2 — full Chrome 124 browser-header bundle (
Accept,Accept-Language,sec-ch-ua*,sec-fetch-*,gzip+deflatefor GETs) - Layer 3 — opt-in residential proxy via
POLY_AUTH_PROXY(now actually wired intocreate_api_key/derive_api_key, the only two surfaces Cloudflare 403's against datacenter IPs per Cloudflare 403 on auth/api-key #38 / Cloudflare blocks API key creation (403) with py_clob_client_v2 #41 / signature_type=2 (POLY_GNOSIS_SAFE) — POST /order returns 401 with valid credentials #43)
Cursor Bugbot's 2nd review on commit `31134da` flagged that the new ``auth_post`` / ``auth_get`` helpers silently dropped the ``retry_on_error`` semantic that the pre-PR-Polymarket#42 ``self._post()`` / ``self._get()`` path forwarded from ``ClobClient(retry_on_error=True)``. Result: clients that opted in to a single transient-error retry on ``create_api_key`` lost that behaviour as soon as the auth call moved to the proxy-aware path. Fix --- - ``helpers.py``: extract per-attempt logic to ``_auth_request_attempt``; add ``retry_on_error: bool = False`` parameter to ``auth_request``, ``auth_get``, ``auth_post``. On a transient error (5xx response or ``httpx.ConnectError`` / ``TimeoutException`` / ``NetworkError``), wait 30 ms and try once more — identical contract to ``post()``. 4xx errors (e.g. 401 "Invalid api key") are non-transient and must surface immediately even with ``retry_on_error=True``. - ``client.py``: forward ``self.retry_on_error`` from ``create_api_key`` and ``derive_api_key`` into the auth call. Clients constructed with ``ClobClient(retry_on_error=True)`` get the same retry behaviour they had before PR Polymarket#42. Tests ----- ``TestAuthRetryOnErrorParity`` (4 new tests): - ``test_auth_post_retries_on_500_when_retry_on_error_true`` - ``test_auth_post_does_not_retry_when_retry_on_error_false`` - ``test_auth_post_does_not_retry_on_400`` (401 is non-transient) - ``test_auth_get_forwards_retry_on_error_kwarg`` Test results: 36/36 in ``test_user_agent_header.py`` (was 32), 168 SDK regression tests pass (was 164), zero regressions. 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Author
Bugbot 2nd-review fix (commit
|
| Commit | Findings | Fixed |
|---|---|---|
ba44d13 |
4 (PEP 604 / proxies kwarg / dead-code / Brotli) | 31134da |
31134da |
1 (retry parity) | 7d78df5 |
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Reviewed by Cursor Bugbot for commit 7d78df5. Configure here.
…78df5) Cursor Bugbot's 3rd review on `7d78df5` flagged that the regression test ``test_get_does_not_advertise_brotli_without_dep`` would silently fail to guard against the bug it was written to prevent. Bug --- ``"gzip, deflate, br".split(",")`` produces ``["gzip", " deflate", " br"]`` (leading whitespace). The naïve ``"br" not in split(",")`` membership check passes because Python compares ``"br"`` to ``" br"`` literally — different strings. If a future maintainer re-introduces ``"gzip, deflate, br"``, the test would assert ``not in`` against ``[" br"]`` and PASS, allowing the Brotli-without-dep regression through. Fix --- Strip whitespace from each token AND drop any q-value parameters (``"br;q=0.5"`` is the same regression class). Membership check runs against the cleaned token list. Also keep the original ``deflate`` sanity assertion against the cleaned list so the test fails noisily on any whitespace drift. Tests ----- 36/36 ``test_user_agent_header.py`` pass. 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Author
Bugbot 3rd-review fix (commit
|
| Commit | Findings | Fixed by |
|---|---|---|
ba44d13 |
4 | 31134da |
31134da |
1 (auth retry parity) | 7d78df5 |
7d78df5 |
1 (test regression-strip) | c9f0b4d |
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fix(auth): UA + browser-headers + opt-in residential proxy to bypass Cloudflare 403 (closes #41)
Problem
POST /auth/api-keyreturns HTTP 403 from Cloudflare when using the defaultpython-httpx/X.YUser-Agent string (reported in #38, #41). The previouspartial fix in
_overload_headerssetUser-Agent: py_clob_client_v2— abare, unversioned string that Cloudflare's bot-score heuristic still treats as
suspicious, leaving the 403 unresolved for most users.
Three independent reporters then confirmed that upgrading the UA alone
does NOT bypass the WAF:
copperhuh(Cloudflare blocks API key creation (403) with py_clob_client_v2 #41): "I ran with the UA fix; still 403."Zero-Ace5(Cloudflare blocks API key creation (403) with py_clob_client_v2 #41): "Tried JS variant + same UA; backend still rejects."calrde(this PR review): "Env-var workaround tested — does not unblock."Cloudflare's bot detection scores on multiple signals beyond UA: TLS
fingerprint (JA3/JA4), HTTP/2 frame settings, header order, and IP
reputation. A datacenter IP + a clean UA still scores high enough to
trip the 403; the only confirmed-working bypass in similar deployments
(yfinance, ccxt-pro) is residential rotating proxy + full browser
header bundle (cf. scrapfly.io 2026 Cloudflare bypass guide;
IPRoyal residential pool).
Fix (three layers)
Layer 1 — Versioned User-Agent (shipped in commit 6fedd7f)
constants.py:__version__resolved at import time viaimportlib.metadata.versionwith a hard-coded fallback ("1.0.1rc1").constants.py:DEFAULT_USER_AGENT = f"polymarket-clob-client-v2/{__version__}"helpers.py:_resolve_user_agent()returnsos.environ.get("POLY_USER_AGENT", DEFAULT_USER_AGENT).Layer 2 — Full browser-header bundle (this commit)
A real browser sends ~10 headers with every navigator-driven fetch.
Sending only
User-Agent+Accept: */*is a strong bot signal evenwith a plausible UA.
_overload_headersnow sets:Accept: application/json, text/plain, */*(Chrome's XHR default)Accept-Language: en-US,en;q=0.9Accept-Encoding: gzip, deflate, br(Chrome's full set; GET only)sec-ch-ua: "Chromium";v="124", "Google Chrome";v="124", "Not-A.Brand";v="99"sec-ch-ua-mobile: ?0sec-ch-ua-platform: "macOS"sec-fetch-dest: emptysec-fetch-mode: corssec-fetch-site: same-siteAll bundle values are set via
dict.setdefault(...)so caller-suppliedheaders still win.
Layer 3 — Opt-in residential proxy for the auth call (this commit)
helpers.py:get_auth_proxy_url()readsPOLY_AUTH_PROXYenv var.helpers.py:build_auth_http_client(timeout_s)returns anhttpx.Clientconfigured withproxies={"https://": url, "http://": url}when the env var is set; otherwise a direct client.
The proxy is wired into the L1
/auth/api-keycall ONLY, NOT theorder or market-data path. Rationale:
the residential-proxy latency cost (typically 100-400 ms) is paid once
per L2 refresh, not per request.
latency-sensitivity; routing it through a residential proxy would add
300+ ms to every taker fill.
Tested provider: IPRoyal residential rotating
pool ($7/GB at the time of writing). BrightData and Smartproxy expose
the same
https://user:pass@host:portURL shape and should workidentically.
Backwards compatibility
POLY_AUTH_PROXYget the existing directpath (UA + browser headers only).
POLY_USER_AGENTget the new versioned UAautomatically on upgrade.
_overload_headersusessetdefault(...)for the bundle, so anycaller-supplied header (e.g. a test that asserts a specific Accept
value) still overrides the default.
Configuration
Testing
tests/test_user_agent_header.pynow covers 23 cases:DEFAULT_USER_AGENTshape_resolve_user_agentenv override_overload_headersUA + Accept-Encoding contractsPOLY_AUTH_PROXYhonoured onbuild_auth_http_client(NEW)All tests pass on Python 3.9–3.14 with only stdlib + httpx installed.
Acknowledgements
Thanks to
copperhuh,Zero-Ace5,lakeswimmer, andcalrdefor thecommunity evidence that UA-only is insufficient — without your repros
this PR would have shipped a partial fix.
Checklist
POLY_AUTH_PROXY(this commit)Note
Medium Risk
Changes the L1 authentication request path (
/auth/api-key) to use a new proxy-capable client and different default headers, which could affect auth reliability and behavior across httpx versions/environments.Overview
Improves Cloudflare WAF avoidance for L1 auth by expanding default outbound headers to a browser-like bundle (via
_overload_headers) and introducing an opt-in residential proxy for auth requests throughPOLY_AUTH_PROXY.Routes
ClobClient.create_api_key/derive_api_keythrough newauth_post/auth_gethelpers that build a per-callhttpx.Client(proxy-aware) and preserveretry_on_errorparity, while keeping all non-auth traffic on the existing shared client.Adds versioned
DEFAULT_USER_AGENT(withPOLY_USER_AGENToverride) and a comprehensive new regression test suite covering UA/header injection, Accept-Encoding behavior, proxy wiring, and Python 3.9 compatibility.Reviewed by Cursor Bugbot for commit c9f0b4d. Bugbot is set up for automated code reviews on this repo. Configure here.