Track + metadata + state + tracks.md registration for the 2,205-line
mcp_client.py split into a slim controller + 6 native sub-MCPs + 1
external sub-MCP.
Key design decisions (per user feedback):
- Naming convention: mcp_<type>.py for native MCPs (mcp_file_io.py,
mcp_python.py, mcp_c.py, mcp_cpp.py, mcp_web.py, mcp_analysis.py).
- ExternalMCPManager class name preserved (moves to mcp_external.py).
- Sub-MCP shape: class with name / description / tools / invoke().
- MCPController: holds ALL_SUB_MCPS list, inverted-dict tool lookup,
3-layer security (extracted to mcp_client_security.py), schema
aggregation.
- Each invoke() returns Result[str, ErrorInfo] (from
data_oriented_error_handling_20260606).
- Backward compat: mcp_client_legacy.py re-exports all 45+ old
symbols; the 4 existing test files + src/app_controller.py:61
direct call continue to work.
DSL future (per user notes on APL/K/Cosy): NOT in this track.
Documented in spec §12.1 as the mcp_dsl_20260606 follow-up.
Sub-MCP architecture is the natural unit to pair with a DSL emitter.
7 phases. ~22 task slots. New tests: 9 (one per sub-MCP + controller +
security + legacy). Modified tests: 4 (existing mcp_* tests must
pass unchanged).
Blocked by: data_oriented_error_handling_20260606, data_structure_strengthening_20260606.
Blocks: mcp_dsl_20260606 (future DSL track).
