fix: serialize filesystem paths with POSIX separators for provider APIs and add Windows CI

.github/workflows/ci.yml

@@ -10,9 +10,11 @@ permissions:
 
 jobs:
   test:
-    runs-on: ubuntu-latest
+    runs-on: ${{ matrix.os }}
     strategy:
+      fail-fast: false
       matrix:
+        os: [ubuntu-latest, windows-latest]
         python-version: ["3.11", "3.12", "3.13"]
     steps:
       - uses: actions/checkout@v4

src/yoke/models.py

@@ -893,7 +893,7 @@ def native_input(self) -> dict[str, Any]:
         if self.native_name is not None:
             data["name"] = self.native_name
         if self.script_path is not None:
-            data["scriptPath"] = str(self.script_path)
+            data["scriptPath"] = self.script_path.as_posix()
         if self.args is not None:
             data["args"] = self.args
         if self.resume_from_run_id is not None:

src/yoke/providers/claude.py

@@ -354,7 +354,7 @@ async def read_session(
             from claude_agent_sdk import get_session_info, get_session_messages
         except ImportError as exc:
             raise YokeError(f"Claude support requires `{CLAUDE_INSTALL}`.") from exc
-        directory = str(harness.cwd) if harness.cwd else None
+        directory = harness.cwd.as_posix() if harness.cwd else None
         info = await asyncio.to_thread(
             get_session_info,
             session_id,
@@ -396,7 +396,7 @@ async def rename(self, session: Session, title: str) -> SessionSummary:
         except ImportError as exc:
             raise YokeError(f"Claude support requires `{CLAUDE_INSTALL}`.") from exc
         session_id = session.provider_session_id or session.id
-        directory = str(session.cwd) if session.cwd else None
+        directory = session.cwd.as_posix() if session.cwd else None
         await asyncio.to_thread(
             rename_session,
             session_id,
@@ -409,7 +409,7 @@ async def rename(self, session: Session, title: str) -> SessionSummary:
             id=session_id,
             provider_session_id=session_id,
             title=title,
-            cwd=str(session.cwd) if session.cwd else None,
+            cwd=session.cwd.as_posix() if session.cwd else None,
         )
 
     async def tag(self, session: Session, tag: str | None) -> SessionSummary:
@@ -418,7 +418,7 @@ async def tag(self, session: Session, tag: str | None) -> SessionSummary:
         except ImportError as exc:
             raise YokeError(f"Claude support requires `{CLAUDE_INSTALL}`.") from exc
         session_id = session.provider_session_id or session.id
-        directory = str(session.cwd) if session.cwd else None
+        directory = session.cwd.as_posix() if session.cwd else None
         await asyncio.to_thread(
             tag_session,
             session_id,
@@ -431,7 +431,7 @@ async def tag(self, session: Session, tag: str | None) -> SessionSummary:
             id=session_id,
             provider_session_id=session_id,
             tag=tag,
-            cwd=str(session.cwd) if session.cwd else None,
+            cwd=session.cwd.as_posix() if session.cwd else None,
         )
 
     async def start(self, harness: Harness, options: SessionOptions) -> Session:
@@ -716,7 +716,7 @@ def claude_options(
             goal,
             compile_inline=deployment is None,
         ),
-        "cwd": str(harness.cwd),
+        "cwd": harness.cwd.as_posix() if harness.cwd else None,
         "model": options.model or agent.model,
         "effort": options.effort or agent.effort,
         "max_turns": options.max_turns,

src/yoke/providers/codex_agents.py

@@ -161,7 +161,7 @@ def codex_agent_toml(
             continue
         lines.append("")
         lines.append("[[skills.config]]")
-        lines.append(f"path = {toml_string(str(path))}")
+        lines.append(f"path = {toml_string(path_string(path))}")
         lines.append(f"enabled = {'true' if enabled else 'false'}")
 
     return "\n".join(lines) + "\n"
@@ -225,6 +225,11 @@ def slug(value: str) -> str:
     return normalized or "agent"
 
 
+def path_string(path: Path | str) -> str:
+    """Serialize filesystem paths with forward slashes for Codex agent TOML."""
+    return Path(path).as_posix()
+
+
 def toml_string(value: str) -> str:
     return json.dumps(value)
 

src/yoke/providers/codex_app_server.py

@@ -1001,7 +1001,7 @@ def codex_runtime_config(deployment: RuntimeDeployment) -> dict[str, Any]:
     if deployment.codex_parent_skill_settings:
         config["skills"] = {
             "config": [
-                {"path": str(path), "enabled": enabled}
+                {"path": Path(path).as_posix(), "enabled": enabled}
                 for path, enabled in deployment.codex_parent_skill_settings
             ]
         }
@@ -1105,7 +1105,7 @@ def thread_params(
 ) -> dict[str, Any]:
     permission_profile = codex_app_server_option(provider_options, "permissions")
     params: dict[str, Any] = {
-        "cwd": str(harness.cwd),
+        "cwd": harness.cwd.as_posix() if harness.cwd else None,
         "model": model or harness.agent.model,
         "approvalPolicy": approval_policy(permissions, provider_options),
         "developerInstructions": developer_instructions(
@@ -1164,7 +1164,7 @@ def turn_params(
     permission_profile = codex_app_server_option(effective_options, "permissions")
     params: dict[str, Any] = {
         "threadId": thread.thread_id,
-        "cwd": str(thread.cwd),
+        "cwd": thread.cwd.as_posix() if thread.cwd else None,
         "input": [
             {
                 "type": "text",

src/yoke/providers/codex_sdk.py

@@ -353,7 +353,7 @@ async def stream(self, session: Session, turn: Turn, options: RunOptions):
         permissions = options.permissions or session.permissions
         handle = await sdk_session.thread.turn(
             prompt_with_goal(turn.prompt, options.resolve_goal(session.goal)),
-            cwd=str(session.cwd) if session.cwd else None,
+            cwd=session.cwd.as_posix() if session.cwd else None,
             effort=str(options.effort or session.agent.effort)
             if options.effort or session.agent.effort
             else None,
@@ -398,7 +398,7 @@ async def fork(self, session: Session, options: ForkOptions) -> Session:
         thread = await sdk_session.process.client.thread_fork(
             session.id,
             approval_mode=approval_mode(sdk, permissions),
-            cwd=str(session.cwd) if session.cwd else None,
+            cwd=session.cwd.as_posix() if session.cwd else None,
             developer_instructions=developer_instructions(session.agent),
             ephemeral=options.ephemeral,
             model=sdk_session.model,
@@ -437,7 +437,7 @@ async def _thread(
         kwargs = {
             "approval_mode": approval_mode(sdk, permissions),
             "config": codex_config(options),
-            "cwd": str(harness.cwd),
+            "cwd": harness.cwd.as_posix() if harness.cwd else None,
             "developer_instructions": developer_instructions(harness.agent),
             "model": options.model or harness.agent.model,
             "sandbox": sandbox(sdk, permissions),
@@ -466,7 +466,7 @@ async def _send(
         try:
             result = await sdk_session.thread.run(
                 prompt_with_goal(turn.prompt, run_options.resolve_goal(session.goal)),
-                cwd=str(session.cwd) if session.cwd else None,
+                cwd=session.cwd.as_posix() if session.cwd else None,
                 effort=str(run_options.effort or session.agent.effort)
                 if run_options.effort or session.agent.effort
                 else None,

tests/test_claude_options.py

@@ -85,7 +85,7 @@ def test_claude_provider_options_reach_sdk_options(
     assert options.kwargs["include_partial_messages"] is True
     assert options.kwargs["include_hook_events"] is True
     assert options.kwargs["max_budget_usd"] == 1.5
-    assert options.kwargs["cwd"] == str(Path.cwd())
+    assert options.kwargs["cwd"] == Path.cwd().as_posix()
     assert options.kwargs["append_system_prompt"] == "extra"
     assert options.kwargs["model"] == "sonnet"