v0.7.12 — mcptoon demo-server: a built-in MCP server that runs where Node does not

[0.7.12] — 2026-09-14

Added

• mcptoon demo-server — a built-in MCP server that needs nothing but Python.
  Eleven tools, standard library only, speaking MCP over stdio: echo, TOON
  encode/decode, format comparison, token estimation, tool-schema slimming, manifest
  indexing, benchmark rows, agent config targets, config validation, runtime
  description. Add it with
  mcptoon add demo --stdio python -m mcptoon demo-server.

  Why it is in the package at all: hosted quality scores are computed by a sandbox
  that starts your server and calls tools/list. Ours was seeded with
  npx -y @modelcontextprotocol/server-everything, and the Python-only image has no
  Node in it — the seed resolved to zero tools, so the exam was handed a blank
  sheet (measured 2026-09-14). The same sandbox, same PATH, same empty home directory:
  the old seed lists 0 tools, demo-server lists 11.

  It changes nothing about the architecture. It registers no server, writes no
  config, opens no file, spawns no process, and touches no network; mcptoon serve
  with an empty config still lists zero tools, because the bridge is still a proxy and
  not a runtime. Both properties are pinned by tests, not by promises. The tool
  descriptions were written against the published TDQS rubric (verb first, a named
  sibling as the boundary, parameters described, limits disclosed) and the mechanical
  part of that rubric is now asserted in CI.

Changed

• Footprint claims refreshed to measured values: 146KB wheel (was 128KB), 22 modules
  (was 21), 12,634 physical lines (was 11,750). Both READMEs, DEVELOPERS.md,
  docs/, the skill files and tests/test_footprint_claims.py move together.
• Both READMEs state the one exception to "mcptoon bundles nothing": the package ships
  a self-demo, and it reaches your context only if you add it deliberately.

Testing

• tests/test_demo_server.py — 43 cases, 104 subtests: handshake, protocol fallback,
  notifications, stateless tools/list, every tool called in-process, the error paths,
  a real subprocess over stdio (including non-ASCII under a cp1252 console), the TDQS
  hard gates with a negative control proving the guard fires, the inlined benchmark
  rows compared against assets/benchmark_tiktoken.json, and a source-level check that
  the module imports no I/O, process or config machinery.

Install: pip install mcptoon==0.7.12 (PyPI propagation lags the JSON API by a few minutes; the aliyun mirror this box defaults to lags much longer, so add --index-url https://pypi.org/simple/ when verifying).

Zero dependencies, 146KB wheel, 22 modules, 12,634 physical lines. Full suite: 868 passed, 1 skipped.