"""Regression guard: Codex Cloudflare 403 mitigation headers. The ``chatgpt.com/backend-api/codex`` endpoint sits behind a Cloudflare layer that whitelists a small set of first-party originators (``codex_cli_rs``, ``codex_vscode``, ``codex_sdk_ts``, ``Codex*``). Requests from non-residential IPs (VPS, always-on servers, some corporate egress) that don't advertise an allowed originator are served 403 with ``cf-mitigated: challenge`` regardless of auth correctness. ``_codex_cloudflare_headers`` in ``agent.auxiliary_client`` centralizes the header set so the primary chat client (``run_agent.AIAgent.__init__`` + ``_apply_client_headers_for_base_url``) and the auxiliary client paths (``_build_codex_client`` and the ``raw_codex`` branch of ``resolve_provider_client``) all emit the same headers. These tests pin: - the originator value (must be ``codex_cli_rs`` — the whitelisted one) - the User-Agent shape (codex_cli_rs-prefixed) - ``ChatGPT-Account-ID`` extraction from the OAuth JWT (canonical casing, from codex-rs ``auth.rs``) - graceful handling of malformed tokens (drop the account-ID header, don't raise) - primary-client wiring at both entry points in ``run_agent.py`` - aux-client wiring at both entry points in ``agent/auxiliary_client.py`` """ from __future__ import annotations import base64 import json from unittest.mock import MagicMock, patch import pytest # --------------------------------------------------------------------------- # Fixtures # --------------------------------------------------------------------------- def _make_codex_jwt(account_id: str = "acct-test-123") -> str: """Build a syntactically valid Codex-style JWT with the account_id claim.""" def b64url(data: bytes) -> str: return base64.urlsafe_b64encode(data).rstrip(b"=").decode() header = b64url(b'{"alg":"RS256","typ":"JWT"}') claims = { "sub": "user-xyz", "exp": 9999999999, "https://api.openai.com/auth": { "chatgpt_account_id": account_id, "chatgpt_plan_type": "plus", }, } payload = b64url(json.dumps(claims).encode()) sig = b64url(b"fake-sig") return f"{header}.{payload}.{sig}" # --------------------------------------------------------------------------- # _codex_cloudflare_headers — the shared helper # --------------------------------------------------------------------------- class TestCodexCloudflareHeaders: def test_originator_is_codex_cli_rs(self): """Cloudflare whitelists codex_cli_rs — any other value is 403'd.""" from agent.auxiliary_client import _codex_cloudflare_headers headers = _codex_cloudflare_headers(_make_codex_jwt()) assert headers["originator"] == "codex_cli_rs" def test_user_agent_advertises_codex_cli_rs(self): from agent.auxiliary_client import _codex_cloudflare_headers headers = _codex_cloudflare_headers(_make_codex_jwt()) assert headers["User-Agent"].startswith("codex_cli_rs/") def test_account_id_extracted_from_jwt(self): from agent.auxiliary_client import _codex_cloudflare_headers headers = _codex_cloudflare_headers(_make_codex_jwt("acct-abc-999")) # Canonical casing — matches codex-rs auth.rs assert headers["ChatGPT-Account-ID"] == "acct-abc-999" def test_canonical_header_casing(self): """Upstream codex-rs uses PascalCase with trailing -ID. Match exactly.""" from agent.auxiliary_client import _codex_cloudflare_headers headers = _codex_cloudflare_headers(_make_codex_jwt()) assert "ChatGPT-Account-ID" in headers # The lowercase/titlecase variants MUST NOT be used — pin to be explicit assert "chatgpt-account-id" not in headers assert "ChatGPT-Account-Id" not in headers def test_malformed_token_drops_account_id_without_raising(self): from agent.auxiliary_client import _codex_cloudflare_headers for bad in ["not-a-jwt", "", "only.one", " ", "...."]: headers = _codex_cloudflare_headers(bad) # Still returns base headers — never raises assert headers["originator"] == "codex_cli_rs" assert "ChatGPT-Account-ID" not in headers def test_non_string_token_handled(self): from agent.auxiliary_client import _codex_cloudflare_headers headers = _codex_cloudflare_headers(None) # type: ignore[arg-type] assert headers["originator"] == "codex_cli_rs" assert "ChatGPT-Account-ID" not in headers def test_jwt_without_chatgpt_account_id_claim(self): """A valid JWT that lacks the account_id claim should still return headers.""" from agent.auxiliary_client import _codex_cloudflare_headers import base64 as _b64, json as _json def b64url(data: bytes) -> str: return _b64.urlsafe_b64encode(data).rstrip(b"=").decode() payload = b64url(_json.dumps({"sub": "user-xyz", "exp": 9999999999}).encode()) token = f"{b64url(b'{}')}.{payload}.{b64url(b'sig')}" headers = _codex_cloudflare_headers(token) assert headers["originator"] == "codex_cli_rs" assert "ChatGPT-Account-ID" not in headers # --------------------------------------------------------------------------- # Primary chat client wiring (run_agent.AIAgent) # --------------------------------------------------------------------------- class TestPrimaryClientWiring: def test_init_wires_codex_headers_for_chatgpt_base_url(self): from run_agent import AIAgent token = _make_codex_jwt("acct-primary-init") with patch("run_agent.OpenAI") as mock_openai: mock_openai.return_value = MagicMock() AIAgent( api_key=token, base_url="https://chatgpt.com/backend-api/codex", provider="openai-codex", model="gpt-5.4", quiet_mode=True, skip_context_files=True, skip_memory=True, ) headers = mock_openai.call_args.kwargs.get("default_headers") or {} assert headers.get("originator") == "codex_cli_rs" assert headers.get("ChatGPT-Account-ID") == "acct-primary-init" assert headers.get("User-Agent", "").startswith("codex_cli_rs/") def test_apply_client_headers_on_base_url_change(self): """Credential-rotation / base-url change path must also emit codex headers.""" from run_agent import AIAgent token = _make_codex_jwt("acct-rotation") with patch("run_agent.OpenAI") as mock_openai: mock_openai.return_value = MagicMock() agent = AIAgent( api_key="placeholder-openrouter-key", base_url="https://openrouter.ai/api/v1", provider="openrouter", model="anthropic/claude-sonnet-4.6", quiet_mode=True, skip_context_files=True, skip_memory=True, ) # Simulate rotation into a Codex credential agent._client_kwargs["api_key"] = token agent._apply_client_headers_for_base_url( "https://chatgpt.com/backend-api/codex" ) headers = agent._client_kwargs.get("default_headers") or {} assert headers.get("originator") == "codex_cli_rs" assert headers.get("ChatGPT-Account-ID") == "acct-rotation" assert headers.get("User-Agent", "").startswith("codex_cli_rs/") def test_apply_client_headers_clears_codex_headers_off_chatgpt(self): """Switching AWAY from chatgpt.com must drop the codex headers.""" from run_agent import AIAgent token = _make_codex_jwt() with patch("run_agent.OpenAI") as mock_openai: mock_openai.return_value = MagicMock() agent = AIAgent( api_key=token, base_url="https://chatgpt.com/backend-api/codex", provider="openai-codex", model="gpt-5.4", quiet_mode=True, skip_context_files=True, skip_memory=True, ) # Sanity: headers are set initially assert "originator" in (agent._client_kwargs.get("default_headers") or {}) agent._apply_client_headers_for_base_url( "https://api.anthropic.com" ) # default_headers should be popped for anthropic base assert "default_headers" not in agent._client_kwargs def test_openrouter_base_url_does_not_get_codex_headers(self): from run_agent import AIAgent with patch("run_agent.OpenAI") as mock_openai: mock_openai.return_value = MagicMock() AIAgent( api_key="sk-or-test", base_url="https://openrouter.ai/api/v1", provider="openrouter", model="anthropic/claude-sonnet-4.6", quiet_mode=True, skip_context_files=True, skip_memory=True, ) headers = mock_openai.call_args.kwargs.get("default_headers") or {} assert headers.get("originator") != "codex_cli_rs" # --------------------------------------------------------------------------- # Auxiliary client wiring (agent.auxiliary_client) # --------------------------------------------------------------------------- class TestAuxiliaryClientWiring: def test_build_codex_client_passes_codex_headers(self, monkeypatch): """_build_codex_client builds the OpenAI client used for compression / vision / title generation when routed through Codex. Must emit codex headers.""" from agent import auxiliary_client token = _make_codex_jwt("acct-aux-try-codex") # Force _select_pool_entry to return "no pool" so we fall through to # _read_codex_access_token. monkeypatch.setattr( auxiliary_client, "_select_pool_entry", lambda provider: (False, None), ) monkeypatch.setattr( auxiliary_client, "_read_codex_access_token", lambda: token, ) with patch("agent.auxiliary_client.OpenAI") as mock_openai: mock_openai.return_value = MagicMock() client, model = auxiliary_client._build_codex_client("gpt-5.4") assert client is not None headers = mock_openai.call_args.kwargs.get("default_headers") or {} assert headers.get("originator") == "codex_cli_rs" assert headers.get("ChatGPT-Account-ID") == "acct-aux-try-codex" assert headers.get("User-Agent", "").startswith("codex_cli_rs/") def test_resolve_provider_client_raw_codex_passes_codex_headers(self, monkeypatch): """The ``raw_codex=True`` branch (used by the main agent loop for direct responses.stream() access) must also emit codex headers.""" from agent import auxiliary_client token = _make_codex_jwt("acct-aux-raw-codex") monkeypatch.setattr( auxiliary_client, "_read_codex_access_token", lambda: token, ) with patch("agent.auxiliary_client.OpenAI") as mock_openai: mock_openai.return_value = MagicMock() client, model = auxiliary_client.resolve_provider_client( "openai-codex", model="gpt-5.4", raw_codex=True, ) assert client is not None headers = mock_openai.call_args.kwargs.get("default_headers") or {} assert headers.get("originator") == "codex_cli_rs" assert headers.get("ChatGPT-Account-ID") == "acct-aux-raw-codex" assert headers.get("User-Agent", "").startswith("codex_cli_rs/")