feat: add Claude Code OAuth and Codex CLI as LLM providers (#1166)

* feat: add Claude Code OAuth and Codex CLI providers

Port of bytedance/deer-flow#1136 from @solanian's feat/cli-oauth-providers branch.\n\nCarries the feature forward on top of current main without the original CLA-blocked commit metadata, while preserving attribution in the commit message for review.

* fix: harden CLI credential loading

Align Codex auth loading with the current ~/.codex/auth.json shape, make Docker credential mounts directory-based to avoid broken file binds on hosts without exported credential files, and add focused loader tests.

* refactor: tighten codex auth typing

Replace the temporary Any return type in CodexChatModel._load_codex_auth with the concrete CodexCliCredential type after the credential loader was stabilized.

* fix: load Claude Code OAuth from Keychain

Match Claude Code's macOS storage strategy more closely by checking the Keychain-backed credentials store before falling back to ~/.claude/.credentials.json. Keep explicit file overrides and add focused tests for the Keychain path.

* fix: require explicit Claude OAuth handoff

* style: format thread hooks reasoning request

* docs: document CLI-backed auth providers

* fix: address provider review feedback

* fix: harden provider edge cases

* Fix deferred tools, Codex message normalization, and local sandbox paths

* chore: narrow PR scope to OAuth providers

* chore: remove unrelated frontend changes

* chore: reapply OAuth branch frontend scope cleanup

* fix: preserve upload guards with reasoning effort wiring

---------

Co-authored-by: Willem Jiang <willem.jiang@gmail.com>

backend/tests/test_credential_loader.py

@@ -0,0 +1,156 @@
+import json
+import os
+
+from deerflow.models.credential_loader import (
+    load_claude_code_credential,
+    load_codex_cli_credential,
+)
+
+
+def _clear_claude_code_env(monkeypatch) -> None:
+    for env_var in (
+        "CLAUDE_CODE_OAUTH_TOKEN",
+        "ANTHROPIC_AUTH_TOKEN",
+        "CLAUDE_CODE_OAUTH_TOKEN_FILE_DESCRIPTOR",
+        "CLAUDE_CODE_CREDENTIALS_PATH",
+    ):
+        monkeypatch.delenv(env_var, raising=False)
+
+
+def test_load_claude_code_credential_from_direct_env(monkeypatch):
+    _clear_claude_code_env(monkeypatch)
+    monkeypatch.setenv("CLAUDE_CODE_OAUTH_TOKEN", "  sk-ant-oat01-env  ")
+
+    cred = load_claude_code_credential()
+
+    assert cred is not None
+    assert cred.access_token == "sk-ant-oat01-env"
+    assert cred.refresh_token == ""
+    assert cred.source == "claude-cli-env"
+
+
+def test_load_claude_code_credential_from_anthropic_auth_env(monkeypatch):
+    _clear_claude_code_env(monkeypatch)
+    monkeypatch.setenv("ANTHROPIC_AUTH_TOKEN", "sk-ant-oat01-anthropic-auth")
+
+    cred = load_claude_code_credential()
+
+    assert cred is not None
+    assert cred.access_token == "sk-ant-oat01-anthropic-auth"
+    assert cred.source == "claude-cli-env"
+
+
+def test_load_claude_code_credential_from_file_descriptor(monkeypatch):
+    _clear_claude_code_env(monkeypatch)
+
+    read_fd, write_fd = os.pipe()
+    try:
+        os.write(write_fd, b"sk-ant-oat01-fd")
+        os.close(write_fd)
+        monkeypatch.setenv("CLAUDE_CODE_OAUTH_TOKEN_FILE_DESCRIPTOR", str(read_fd))
+
+        cred = load_claude_code_credential()
+    finally:
+        os.close(read_fd)
+
+    assert cred is not None
+    assert cred.access_token == "sk-ant-oat01-fd"
+    assert cred.refresh_token == ""
+    assert cred.source == "claude-cli-fd"
+
+
+def test_load_claude_code_credential_from_override_path(tmp_path, monkeypatch):
+    _clear_claude_code_env(monkeypatch)
+    cred_path = tmp_path / "claude-credentials.json"
+    cred_path.write_text(
+        json.dumps(
+            {
+                "claudeAiOauth": {
+                    "accessToken": "sk-ant-oat01-test",
+                    "refreshToken": "sk-ant-ort01-test",
+                    "expiresAt": 4_102_444_800_000,
+                }
+            }
+        )
+    )
+    monkeypatch.setenv("CLAUDE_CODE_CREDENTIALS_PATH", str(cred_path))
+
+    cred = load_claude_code_credential()
+
+    assert cred is not None
+    assert cred.access_token == "sk-ant-oat01-test"
+    assert cred.refresh_token == "sk-ant-ort01-test"
+    assert cred.source == "claude-cli-file"
+
+
+def test_load_claude_code_credential_ignores_directory_path(tmp_path, monkeypatch):
+    _clear_claude_code_env(monkeypatch)
+    cred_dir = tmp_path / "claude-creds-dir"
+    cred_dir.mkdir()
+    monkeypatch.setenv("CLAUDE_CODE_CREDENTIALS_PATH", str(cred_dir))
+
+    assert load_claude_code_credential() is None
+
+
+def test_load_claude_code_credential_falls_back_to_default_file_when_override_is_invalid(tmp_path, monkeypatch):
+    _clear_claude_code_env(monkeypatch)
+    monkeypatch.setenv("HOME", str(tmp_path))
+
+    cred_dir = tmp_path / "claude-creds-dir"
+    cred_dir.mkdir()
+    monkeypatch.setenv("CLAUDE_CODE_CREDENTIALS_PATH", str(cred_dir))
+
+    default_path = tmp_path / ".claude" / ".credentials.json"
+    default_path.parent.mkdir()
+    default_path.write_text(
+        json.dumps(
+            {
+                "claudeAiOauth": {
+                    "accessToken": "sk-ant-oat01-default",
+                    "refreshToken": "sk-ant-ort01-default",
+                    "expiresAt": 4_102_444_800_000,
+                }
+            }
+        )
+    )
+
+    cred = load_claude_code_credential()
+
+    assert cred is not None
+    assert cred.access_token == "sk-ant-oat01-default"
+    assert cred.refresh_token == "sk-ant-ort01-default"
+    assert cred.source == "claude-cli-file"
+
+
+def test_load_codex_cli_credential_supports_nested_tokens_shape(tmp_path, monkeypatch):
+    auth_path = tmp_path / "auth.json"
+    auth_path.write_text(
+        json.dumps(
+            {
+                "tokens": {
+                    "access_token": "codex-access-token",
+                    "account_id": "acct_123",
+                }
+            }
+        )
+    )
+    monkeypatch.setenv("CODEX_AUTH_PATH", str(auth_path))
+
+    cred = load_codex_cli_credential()
+
+    assert cred is not None
+    assert cred.access_token == "codex-access-token"
+    assert cred.account_id == "acct_123"
+    assert cred.source == "codex-cli"
+
+
+def test_load_codex_cli_credential_supports_legacy_top_level_shape(tmp_path, monkeypatch):
+    auth_path = tmp_path / "auth.json"
+    auth_path.write_text(json.dumps({"access_token": "legacy-access-token"}))
+    monkeypatch.setenv("CODEX_AUTH_PATH", str(auth_path))
+
+    cred = load_codex_cli_credential()
+
+    assert cred is not None
+    assert cred.access_token == "legacy-access-token"
+    assert cred.account_id == ""