Ship the baseline universal MCP path that any external runtime (Claude
Code, hermes, codex, anything that speaks MCP stdio) can use, before
optimizing per-runtime channels. Today the workspace MCP server only
spins up inside the container; external operators have no way to call
the 8 platform tools (delegate_task, list_peers, send_message_to_user,
commit_memory, etc.) from outside.
Three additive changes:
1. **`platform_auth.get_token()` env-var fallback** — adds
`MOLECULE_WORKSPACE_TOKEN` as a fallback when no
`${CONFIGS_DIR}/.auth_token` file exists. File-first preserves
in-container behavior unchanged. External operators (no /configs
volume) now have a way to supply the token without faking the
filesystem layout.
2. **`molecule-mcp` console script** — adds a new entry point in the
published `molecule-ai-workspace-runtime` PyPI wheel. Operators run
`pip install molecule-ai-workspace-runtime`, set 3 env vars
(WORKSPACE_ID, PLATFORM_URL, MOLECULE_WORKSPACE_TOKEN), and register
the binary in their agent's MCP config. `mcp_cli.main` is a thin
validator wrapper — it checks env BEFORE importing the heavy
`a2a_mcp_server` module so a misconfigured first-run gets a friendly
3-line error instead of a 20-line module-level RuntimeError
traceback.
3. **Wheel smoke gate** — extends `scripts/wheel_smoke.py` to assert
`cli_main` and `mcp_cli.main` are importable. Same regression class
as the 0.1.16 main_sync incident: a silent rename or unrewritten
import here would break every external operator on the next wheel
publish (memory: feedback_runtime_publish_pipeline_gates.md).
Test coverage:
- `tests/test_platform_auth.py` — 8 new tests for the env-var fallback:
file-priority, env-fallback, whitespace handling, cache, header
construction, empty-env-as-unset.
- `tests/test_mcp_cli.py` — 8 new tests for the validator: each
required var separately, file-or-env satisfies token requirement,
whitespace-only env treated as missing, help mentions canvas Tokens
tab.
- Full `workspace/tests/` suite green: 1346 passed, 1 skipped.
- Local end-to-end: built wheel, installed in venv, ran `molecule-mcp`
with no env → friendly error; with env → MCP server starts.
Why now / why this shape: user redirect was "support the baseline
first so all runtimes can use, then optimize". A claude-only MCP
channel leaves hermes/codex/third-party operators broken on
runtime=external. This PR ships the runtime-agnostic baseline; per-
runtime polish (claude-channel push delivery, hermes-native
bindings) is a follow-up PR. PR #2412 fixed the partner bug where
canvas Restart silently revoked the operator's token — the two
together unblock the external-runtime story end-to-end.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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