Merge pull request #2935 from Molecule-AI/fix/onboarding-friction-2934

fix(onboarding): address Claude Code MCP onboarding friction (#2934)
This commit is contained in:
Hongming Wang
2026-05-05 21:25:57 +00:00
committed by GitHub
4 changed files with 228 additions and 7 deletions
+83 -2
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@@ -290,10 +290,37 @@ directory** by the `publish-runtime` GitHub Actions workflow on every
Operators running an agent outside the platform's container fleet
(any runtime that supports MCP stdio — Claude Code, hermes, codex,
etc.) can install this wheel and run the universal MCP server
locally:
locally.
### Requirements
* **Python ≥3.11.** The wheel sets `requires-python = ">=3.11"`. On
older interpreters `pip install` returns the cryptic
`Could not find a version that satisfies the requirement` — that
message is pip filtering this wheel out, NOT the package missing
from PyPI. Upgrade with `brew install python@3.12` /
`apt install python3.12` / `pyenv install 3.12` first.
* **`pipx` recommended over `pip`.** `pipx install` puts
`molecule-mcp` on PATH automatically and isolates the runtime's
deps from your system Python. Plain `pip install --user` works
but the binary lands in `~/.local/bin` (Linux) or
`~/Library/Python/3.X/bin` (macOS) which is often not on PATH on
a fresh shell — `claude mcp add molecule -- molecule-mcp` then
fails with "command not found" at first use.
### Install
```sh
# Recommended:
pipx install molecule-ai-workspace-runtime
# Alternative (manage PATH yourself):
pip install --user molecule-ai-workspace-runtime
```
### Run
```sh
pip install molecule-ai-workspace-runtime
WORKSPACE_ID=<uuid> \\
PLATFORM_URL=https://<tenant>.staging.moleculesai.app \\
MOLECULE_WORKSPACE_TOKEN=<bearer> \\
@@ -306,10 +333,64 @@ runtimes already get via the workspace's auto-spawned MCP. Register
the binary in your agent's MCP config (e.g. Claude Code's
`claude mcp add molecule -- molecule-mcp` with the env above).
### Keeping the token out of shell history
Inline `MOLECULE_WORKSPACE_TOKEN=<bearer>` ends up in `~/.zsh_history`
and (when registered via `claude mcp add`) plaintext in
`~/.claude.json`. To avoid that, write the token to a 0600 file and
point `MOLECULE_WORKSPACE_TOKEN_FILE` at it:
```sh
umask 077
printf '%s' "<bearer>" > ~/.config/molecule/token
WORKSPACE_ID=<uuid> \\
PLATFORM_URL=https://<tenant>.staging.moleculesai.app \\
MOLECULE_WORKSPACE_TOKEN_FILE=$HOME/.config/molecule/token \\
molecule-mcp
```
Token resolution order: `MOLECULE_WORKSPACE_TOKEN` (inline env) →
`MOLECULE_WORKSPACE_TOKEN_FILE` (path) → `${CONFIGS_DIR}/.auth_token`
(in-container default).
The token comes from the canvas → Tokens tab. Restarting an external
workspace from the canvas no longer revokes the token (PR #2412), so
operator tokens persist across status nudges.
### Push vs poll delivery (Claude Code specifics)
By default the inbox runs in **poll mode** — every turn the agent
calls `wait_for_message`, which blocks up to ~60s on
`/activity?since_id=…`. Real-time push delivery is also supported,
but on Claude Code it requires THREE conditions, ALL of which must
hold:
1. **The MCP server declares `experimental.claude/channel`** — this
wheel does (see `_build_initialize_result`). Nothing for you to
do.
2. **Claude Code installs the server as a marketplace plugin** — a
plain `claude mcp add molecule -- molecule-mcp` produces a
non-plugin-sourced server, which Claude Code rejects with
`channel_enable requires a marketplace plugin`. Until the
official `moleculesai/claude-code-plugin` marketplace lands
(issue #2934 follow-up), operators who want push must scaffold
their own local marketplace under
`~/.claude/marketplaces/molecule-local/` containing a
`marketplace.json` + `plugin.json` that points at this wheel.
3. **Claude Code is launched with the dev-channels flag** — pass
`--dangerously-load-development-channels plugin:molecule@<marketplace>`
on the `claude` invocation. Without this flag the channel
capability is silently ignored.
Symptom of any condition failing: messages arrive but only via the
poll path (every ~160s), not real-time. There's currently no
diagnostic surfaced — `molecule-mcp doctor` (issue #2934 follow-up)
is planned.
If you don't need real-time push, the default poll path works
universally with no extra setup; both modes converge on the same
`inbox_pop` ack so messages never duplicate.
See [`docs/workspace-runtime-package.md`](https://github.com/Molecule-AI/molecule-core/blob/main/docs/workspace-runtime-package.md)
for the publish flow and architecture.
"""
+10 -1
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@@ -425,7 +425,16 @@ def _build_initialize_result() -> dict:
"tools": {"listChanged": False},
"experimental": {"claude/channel": {}},
},
"serverInfo": {"name": "a2a-delegation", "version": "1.0.0"},
# Identifier convention: this server is what users register with
# `claude mcp add molecule -- molecule-mcp` (and similar across
# other MCP hosts), so the canonical name is "molecule". Earlier
# versions reported "a2a-delegation" — accurate to the original
# purpose but a mismatch with how operators actually name it.
# Mismatch is harmless on tool routing (all MCP hosts dispatch
# by the user-supplied registration name, NOT serverInfo.name)
# but matters for any future Claude Code allowlist that gates
# channel push by hardcoded server name (issue #2934).
"serverInfo": {"name": "molecule", "version": "1.0.0"},
# Built per-call (not the module-level constant) so an operator
# who sets MOLECULE_MCP_POLL_TIMEOUT_SECS after import — e.g.
# via a wrapper script that exports then re-imports — sees
+51 -4
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@@ -35,9 +35,15 @@ def resolve_workspaces() -> tuple[list[tuple[str, str]], list[str]]:
N workspaces). When set, ``WORKSPACE_ID`` / ``MOLECULE_WORKSPACE_TOKEN``
are IGNORED — the JSON is the source of truth.
2. Single-workspace fallback — ``WORKSPACE_ID`` env var + token from
``MOLECULE_WORKSPACE_TOKEN`` or ``${CONFIGS_DIR}/.auth_token``.
This is the pre-existing path; back-compat exact.
2. Single-workspace fallback — ``WORKSPACE_ID`` env var + token
resolved in this order:
a. ``MOLECULE_WORKSPACE_TOKEN`` (inline env — convenient but
leaks into shell history + plaintext MCP-host config).
b. ``MOLECULE_WORKSPACE_TOKEN_FILE`` (path to a file holding
the token — operator can keep it 0600 in their home dir;
survives shell-history scrubs).
c. ``${CONFIGS_DIR}/.auth_token`` (in-container runtimes —
the platform writes this on provision).
Returns ``(workspaces, errors)``:
* ``workspaces``: list of ``(workspace_id, token)`` — non-empty
@@ -98,16 +104,47 @@ def resolve_workspaces() -> tuple[list[tuple[str, str]], list[str]]:
wsid = os.environ.get("WORKSPACE_ID", "").strip()
if not wsid:
return [], ["WORKSPACE_ID (or MOLECULE_WORKSPACES) is required"]
# Token resolution order (#2934): inline env → file path → CONFIGS_DIR
# default. The file-path option exists so operators can keep the
# bearer out of shell history and out of MCP-host config plaintext
# (e.g. ~/.claude.json) — set MOLECULE_WORKSPACE_TOKEN_FILE to a
# 0600 file containing the token. The CONFIGS_DIR/.auth_token
# fallback predates this and stays for in-container runtimes.
tok = os.environ.get("MOLECULE_WORKSPACE_TOKEN", "").strip()
if not tok:
tok = _read_token_from_file_env()
if not tok:
tok = read_token_file()
if not tok:
return [], [
"MOLECULE_WORKSPACE_TOKEN (or CONFIGS_DIR/.auth_token) is required"
"MOLECULE_WORKSPACE_TOKEN, MOLECULE_WORKSPACE_TOKEN_FILE, or "
"CONFIGS_DIR/.auth_token is required"
]
return [(wsid, tok)], []
def _read_token_from_file_env() -> str:
"""Read the token from the file path in MOLECULE_WORKSPACE_TOKEN_FILE.
Returns "" on:
- env var unset / blank
- file not found, unreadable, or empty
- any OSError on read
Empty-on-failure (rather than raising) lets the resolver fall through
to the CONFIGS_DIR fallback. The caller surfaces the combined "no
token" error if every source is empty.
"""
path = os.environ.get("MOLECULE_WORKSPACE_TOKEN_FILE", "").strip()
if not path:
return ""
try:
with open(path, encoding="utf-8") as fh:
return fh.read().strip()
except OSError:
return ""
def print_missing_env_help(missing: list[str], have_token_file: bool) -> None:
print("molecule-mcp: missing required environment.\n", file=sys.stderr)
print("Set the following before running molecule-mcp:", file=sys.stderr)
@@ -123,6 +160,16 @@ def print_missing_env_help(missing: list[str], have_token_file: bool) -> None:
"(canvas → Tokens tab)",
file=sys.stderr,
)
print(
" OR set MOLECULE_WORKSPACE_TOKEN_FILE"
" to a path that holds the token",
file=sys.stderr,
)
print(
" (keeps the secret out of shell"
" history and MCP-host config plaintext)",
file=sys.stderr,
)
print("", file=sys.stderr)
print(f"Currently missing: {', '.join(missing)}", file=sys.stderr)
+84
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@@ -229,3 +229,87 @@ class TestResolveWorkspacesDirect:
out, errors = mcp_workspace_resolver.resolve_workspaces()
assert out == [("ws-a", "a"), ("ws-b", "b")]
assert errors == []
# ============== Token-from-file env var (issue #2934) ==============
class TestTokenFileEnv:
"""``MOLECULE_WORKSPACE_TOKEN_FILE`` lets operators keep the bearer
out of shell history and out of MCP-host config plaintext (e.g.
~/.claude.json). Resolution order: inline TOKEN env > TOKEN_FILE
env > ${CONFIGS_DIR}/.auth_token.
"""
@pytest.fixture(autouse=True)
def _isolate(self, monkeypatch, tmp_path):
for v in (
"WORKSPACE_ID",
"MOLECULE_WORKSPACE_TOKEN",
"MOLECULE_WORKSPACE_TOKEN_FILE",
"MOLECULE_WORKSPACES",
):
monkeypatch.delenv(v, raising=False)
# Point CONFIGS_DIR at an empty tmp_path so the .auth_token
# fallback returns "" — keeps the test cases unambiguous.
monkeypatch.setenv("CONFIGS_DIR", str(tmp_path))
yield tmp_path
def test_token_file_env_resolves(self, monkeypatch, tmp_path):
token_path = tmp_path / "token.txt"
token_path.write_text("file-tok-123\n") # trailing newline must strip
monkeypatch.setenv("WORKSPACE_ID", "ws-1")
monkeypatch.setenv("MOLECULE_WORKSPACE_TOKEN_FILE", str(token_path))
out, errors = mcp_workspace_resolver.resolve_workspaces()
assert out == [("ws-1", "file-tok-123")]
assert errors == []
def test_inline_token_takes_precedence_over_file(self, monkeypatch, tmp_path):
# If both env vars are set, inline wins — matches the docstring's
# documented order. (Operators sometimes set both during a
# rotation; we want predictable behavior.)
token_path = tmp_path / "token.txt"
token_path.write_text("file-tok")
monkeypatch.setenv("WORKSPACE_ID", "ws-1")
monkeypatch.setenv("MOLECULE_WORKSPACE_TOKEN", "inline-tok")
monkeypatch.setenv("MOLECULE_WORKSPACE_TOKEN_FILE", str(token_path))
out, _ = mcp_workspace_resolver.resolve_workspaces()
assert out == [("ws-1", "inline-tok")]
def test_missing_file_falls_through_to_error(self, monkeypatch, tmp_path):
# Pointed at a non-existent path — resolver should return the
# combined "no token" error, NOT crash.
monkeypatch.setenv("WORKSPACE_ID", "ws-1")
monkeypatch.setenv(
"MOLECULE_WORKSPACE_TOKEN_FILE", str(tmp_path / "does-not-exist")
)
out, errors = mcp_workspace_resolver.resolve_workspaces()
assert out == []
assert any("MOLECULE_WORKSPACE_TOKEN_FILE" in e for e in errors)
def test_empty_file_falls_through_to_error(self, monkeypatch, tmp_path):
# File exists but is blank — same shape as no token at all.
token_path = tmp_path / "empty.txt"
token_path.write_text("")
monkeypatch.setenv("WORKSPACE_ID", "ws-1")
monkeypatch.setenv("MOLECULE_WORKSPACE_TOKEN_FILE", str(token_path))
out, errors = mcp_workspace_resolver.resolve_workspaces()
assert out == []
assert errors # at least one combined error message
def test_blank_env_var_treated_as_unset(self, monkeypatch):
# Empty string is treated as "not set" — common pitfall when
# users export an unset shell var.
monkeypatch.setenv("WORKSPACE_ID", "ws-1")
monkeypatch.setenv("MOLECULE_WORKSPACE_TOKEN_FILE", "")
out, errors = mcp_workspace_resolver.resolve_workspaces()
assert out == []
assert errors
def test_help_message_advertises_token_file(self, capsys):
# Help text must mention TOKEN_FILE so a first-run operator
# learns about the safer option without grepping the source.
mcp_workspace_resolver.print_missing_env_help(
["WORKSPACE_ID", "MOLECULE_WORKSPACE_TOKEN"], have_token_file=False
)
err = capsys.readouterr().err
assert "MOLECULE_WORKSPACE_TOKEN_FILE" in err