fix: resolve session dir to an absolute writable path#12
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The session directory was created at a relative `.mm` path, so it landed
in whatever working directory the MCP client launched the server from.
Clients like Claude Desktop launch with a read-only cwd (e.g. `/`), which
crashes startup before the server can connect:
OSError: [Errno 30] Read-only file system: '.mm'
Resolve the session dir to an absolute path instead: honor a new
MONARCH_SESSION_DIR env var, otherwise default to ~/.monarch-mcp (always
writable regardless of launch cwd). Use parents=True on mkdir and update
the docs that referenced the old `.mm/` location.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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THXU |
jamiew
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Jun 30, 2026
- transaction splitting tools (#13) and session-dir fix (#12), both from @caseypugh - dependency refresh and fork-pin bump to 1.4.0
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Problem
The server crashes on startup under MCP clients that launch it with a read-only working directory (e.g. Claude Desktop, which launches from
/):The session directory was
Path(".mm")— a relative path — so it was created in whatever cwd the client used. Withuv runfrom the repo cwd is writable and it works, butuvx monarch-mcp-jamiewlaunched by Claude Desktop runs from a read-only cwd and the process exits before it can connect.Fix
Resolve the session directory to an absolute path:
MONARCH_SESSION_DIRenv var if set~/.monarch-mcp(always writable, independent of launch cwd)mkdir(..., parents=True, exist_ok=True)This makes the published
uvx monarch-mcp-jamiewconfig work out of the box in Claude Desktop and any client with a non-writable cwd. Docs that referenced the old.mm/location are updated.Testing
uv run python scripts/ci.py— ruff, ruff format, mypy, and pytest all pass (197 passed, 5 skipped).🤖 Generated with Claude Code