Add DeepSeek DSML-to-tool_calls conversion at transport and runtime layers.

Promote DSML markup from assistant text into native tool calls during streaming and completion, filter DSML from UI tokens, and document AIA_DSML_TEXT_TOOLS for local vLLM proxies.

Co-authored-by: Cursor <cursoragent@cursor.com>

tests/test_openai_chat_dsml_stream.py

@@ -0,0 +1,122 @@
+"""OpenAI Chat Completions transport: DeepSeek DSML stream filter and recovery."""
+
+from __future__ import annotations
+
+import os
+from types import SimpleNamespace
+
+import pytest
+
+from svc.llm.transports.openai_chat_completions import (
+    OpenAIChatModel,
+    _promote_dsml_in_llm_response,
+    _should_recover_dsml_tool_calls,
+)
+from svc.llm.transports.base import LLMToolCall
+
+
+def test_should_recover_dsml_for_deepseek_url() -> None:
+    assert _should_recover_dsml_tool_calls("deepseek-chat", "https://api.deepseek.com/v1")
+
+
+def test_should_not_recover_for_unrelated_gateway() -> None:
+    assert not _should_recover_dsml_tool_calls("gpt-4o-mini", "https://api.openai.com/v1")
+
+
+def test_should_recover_when_env_forced(monkeypatch: pytest.MonkeyPatch) -> None:
+    monkeypatch.setenv("AIA_DSML_TEXT_TOOLS", "1")
+    assert _should_recover_dsml_tool_calls("local-model", "http://127.0.0.1:8000/v1")
+
+
+def test_promote_dsml_in_llm_response() -> None:
+    dsml = (
+        "prefix\n"
+        "<||DSML||tool_calls>\n"
+        "<||DSML||invoke name=\"run_command\">\n"
+        "<||DSML||parameter name=\"command\" string=\"true\">echo hi</||DSML||parameter>\n"
+        "</||DSML||invoke>\n"
+        "</||DSML||tool_calls>"
+    )
+    content, reasoning, calls = _promote_dsml_in_llm_response(dsml, "", [])
+    assert len(calls) == 1
+    assert calls[0].name == "run_command"
+    assert calls[0].arguments == {"command": "echo hi"}
+    assert "DSML" not in content
+    assert "prefix" in content
+    assert reasoning == ""
+
+
+def test_promote_skips_when_native_tool_calls_present() -> None:
+    dsml = '<||DSML||tool_calls><||DSML||invoke name="x"></||DSML||invoke></||DSML||tool_calls>'
+    native = [LLMToolCall(id="call_1", name="native_tool", arguments={})]
+    content, _, calls = _promote_dsml_in_llm_response(dsml, "", native)
+    assert calls is native
+    assert "DSML" in content
+
+
+def test_chat_stream_filters_dsml_and_promotes_tool_calls(monkeypatch: pytest.MonkeyPatch) -> None:
+    monkeypatch.setenv("OPENAI_API_KEY", "sk-test")
+    model = OpenAIChatModel(
+        model="deepseek-chat",
+        api_key="sk-test",
+        base_url="https://api.deepseek.com/v1",
+    )
+    dsml_text = (
+        "hello "
+        "<||DSML||tool_calls>"
+        "<||DSML||invoke name=\"run_command\">"
+        "<||DSML||parameter name=\"command\" string=\"true\">echo</||DSML||parameter>"
+        "</||DSML||invoke>"
+        "</||DSML||tool_calls>"
+    )
+
+    def fake_stream(_norm_msgs, _tools, *, stream: bool):  # noqa: ANN001, ARG001
+        assert stream is True
+        chunks = []
+        for i in range(0, len(dsml_text), 4):
+            delta = SimpleNamespace(
+                content=dsml_text[i : i + 4],
+                tool_calls=None,
+                reasoning_content="",
+            )
+            chunks.append(SimpleNamespace(choices=[SimpleNamespace(delta=delta)]))
+        return iter(chunks)
+
+    model._create_chat_completion = fake_stream  # type: ignore[method-assign]
+    seen: list[str] = []
+    resp = model.chat([], [], on_token=seen.append)
+    assert "hello" in resp.content
+    assert "DSML" not in resp.content
+    assert len(resp.tool_calls) == 1
+    assert resp.tool_calls[0].name == "run_command"
+    assert resp.tool_calls[0].arguments == {"command": "echo"}
+    joined = "".join(seen)
+    assert "DSML" not in joined
+    assert "hello" in joined
+
+
+def test_llm_response_from_completion_promotes_dsml(monkeypatch: pytest.MonkeyPatch) -> None:
+    monkeypatch.setenv("OPENAI_API_KEY", "sk-test")
+    model = OpenAIChatModel(
+        model="deepseek-chat",
+        api_key="sk-test",
+        base_url="https://api.deepseek.com/v1",
+    )
+    dsml = (
+        "<||DSML||tool_calls>"
+        "<||DSML||invoke name=\"read_file\"></||DSML||invoke>"
+        "</||DSML||tool_calls>"
+    )
+    completion = SimpleNamespace(
+        choices=[
+            SimpleNamespace(
+                message=SimpleNamespace(content=dsml, reasoning_content="", tool_calls=None),
+            )
+        ]
+    )
+    seen: list[str] = []
+    resp = model._llm_response_from_completion(completion, on_token=seen.append)
+    assert len(resp.tool_calls) == 1
+    assert resp.tool_calls[0].name == "read_file"
+    assert "DSML" not in resp.content
+    assert "DSML" not in "".join(seen)