feat: support for codex as external CLI

fix: improved handling of MCP token limits when handling CLI output

tests/test_clink_codex_agent.py

@@ -0,0 +1,70 @@
+import asyncio
+from pathlib import Path
+
+import pytest
+
+from clink.agents.base import CLIAgentError
+from clink.agents.codex import CodexAgent
+from clink.models import ResolvedCLIClient, ResolvedCLIRole
+
+
+class DummyProcess:
+    def __init__(self, *, stdout: bytes = b"", stderr: bytes = b"", returncode: int = 0):
+        self._stdout = stdout
+        self._stderr = stderr
+        self.returncode = returncode
+
+    async def communicate(self, _input):
+        return self._stdout, self._stderr
+
+
+@pytest.fixture()
+def codex_agent():
+    prompt_path = Path("systemprompts/clink/codex_default.txt").resolve()
+    role = ResolvedCLIRole(name="default", prompt_path=prompt_path, role_args=[])
+    client = ResolvedCLIClient(
+        name="codex",
+        executable=["codex"],
+        internal_args=["exec"],
+        config_args=["--json", "--dangerously-bypass-approvals-and-sandbox"],
+        env={},
+        timeout_seconds=30,
+        parser="codex_jsonl",
+        roles={"default": role},
+        output_to_file=None,
+        working_dir=None,
+    )
+    return CodexAgent(client), role
+
+
+async def _run_agent_with_process(monkeypatch, agent, role, process):
+    async def fake_create_subprocess_exec(*_args, **_kwargs):
+        return process
+
+    monkeypatch.setattr(asyncio, "create_subprocess_exec", fake_create_subprocess_exec)
+    return await agent.run(role=role, prompt="do something", files=[], images=[])
+
+
+@pytest.mark.asyncio
+async def test_codex_agent_recovers_jsonl(monkeypatch, codex_agent):
+    agent, role = codex_agent
+    stdout = b"""
+{"type":"item.completed","item":{"id":"item_0","type":"agent_message","text":"Hello from Codex"}}
+{"type":"turn.completed","usage":{"input_tokens":10,"output_tokens":5}}
+"""
+    process = DummyProcess(stdout=stdout, returncode=124)
+    result = await _run_agent_with_process(monkeypatch, agent, role, process)
+
+    assert result.returncode == 124
+    assert "Hello from Codex" in result.parsed.content
+    assert result.parsed.metadata["usage"]["output_tokens"] == 5
+
+
+@pytest.mark.asyncio
+async def test_codex_agent_propagates_invalid_json(monkeypatch, codex_agent):
+    agent, role = codex_agent
+    stdout = b"not json"
+    process = DummyProcess(stdout=stdout, returncode=1)
+
+    with pytest.raises(CLIAgentError):
+        await _run_agent_with_process(monkeypatch, agent, role, process)