Summary

DeepSeek Web emits native function calls as XML:

<tool_call name="todo_write">
[{"id":"1","content":"...","status":"in_progress"}]
</tool_call>

The current parseToolCall() expected a JSON body inside the tag and silently dropped these as plain text. This PR vendors a deterministic normalizer (toolcall_normalizer.js) that runs as a FAST-PATH inside parseToolCall() and converts the native shape (plus strict-JSON / fenced-JSON / legacy TOOL_CALL: variants) into a clean OpenAI tool_calls payload.

• Zero new npm dependencies (Node 18+, same as the project).
• The normalizer is a drop-in companion of RC-ia/deepseek-toolcall-normalizer.
• Behavior for all existing formats is preserved; the fast-path only short-circuits when the normalizer actually recognizes a tool call.

Changes

• toolcall_normalizer.js — new, deterministic multi-shape parser.
• server.js — require the normalizer (guarded try/catch) + pre-pass in parseToolCall(); export parseToolCall for tests.
• tests/unit.test.js — +3 tests (native XML, plain-text returns null, multi-parameter mixed types).
• README.md — adds a short Tool-call normalization patch section crediting the upstream project.

Test plan

npm test
All 12 unit tests pass (9 original + 3 new). Sample log line on a native call:
[parseToolCall] SUCCESS normalized (native/companion): todo_write

Notes

• Credits to ForgetMeAI (t.me/forgetmeai) for the upstream proxy — MIT.
• Happy to adjust (inline vs separate file, code style) if you prefer.

Generated with Hermes Agent (https://hermes-agent.nousresearch.com)