I think the preferred way is to first try mempalace binary if it can be found

Thanks for tackling this — the underlying need is real (we use uv in some setups and don't always have python on PATH, so MEMPALACE_PYTHON as an escape hatch is exactly right).

Blocker before we merge: the two Windows checkboxes in the test plan are unchecked, and Windows is the primary platform this fix targets. Specifically the scenarios that would confirm the fix works:

1. Git Bash on Windows 11 with no python3 on PATH but python present — confirm find_python falls back to python and the save hook's inline python -c JSON parsing actually runs.
2. MEMPALACE_PYTHON override — set it to an absolute path like C:\Users\you\.local\pipx\venvs\mempalace\Scripts\python.exe and verify the background mempalace mine call picks it up.
3. Python 3.14 guard — launch the MCP server under 3.14 and confirm the JSON-RPC error lands on stdout without the pydantic ConfigError.

Without those, we'd be merging a Windows fix on faith. Can you run through those three and report back what you saw?

Two secondary points to consider while you're in there:

• Python 3.14 guard is future-fragile. sys.version_info >= (3, 14) becomes wrong the moment chromadb supports 3.14 — the guard will tell users to downgrade when they no longer need to. Two alternatives that age better: (a) catch the pydantic ConfigError around the chromadb import and re-raise with a better message, or (b) gate the guard on a chromadb version range (if chromadb.__version__ < "1.0" and sys.version_info >= (3, 14)). Either way the message stays useful; neither locks us out later.
• else echo "python3" in find_python silently keeps the broken default when both python3 and python are missing. It'd be friendlier to echo "" && return 1 and have the caller exit with a clear "no Python found — set MEMPALACE_PYTHON" message, since downstream $PYTHON -c calls will fail opaquely otherwise.

Context on prior art: #740 by @milla-jovovich touched the same files and was closed yesterday. The closure reasoning was narrower than your PR's scope (nohup PATH stripping in a private variant, not addressed by the public python3 -m mempalace entry point). Your PR legitimately covers a different angle — the inline python3 -c / python3 - <<PYEOF calls in the save hook bypass the module entry point and hit the python3-doesn't-exist path on Windows directly. Worth naming that distinction in the PR body so reviewers don't bounce it as a duplicate.

cc @milla-jovovich — you closed #740 with a clear model of the hook failure modes; wanted to make sure your perspective is folded in before this lands.

Thanks for tackling this — the underlying need is real (we use uv in some setups and don't always have python on PATH, so MEMPALACE_PYTHON as an escape hatch is exactly right).

Blocker before we merge: the two Windows checkboxes in the test plan are unchecked, and Windows is the primary platform this fix targets. Specifically the scenarios that would confirm the fix works:

1. Git Bash on Windows 11 with no python3 on PATH but python present — confirm find_python falls back to python and the save hook's inline python -c JSON parsing actually runs.
2. MEMPALACE_PYTHON override — set it to an absolute path like C:\Users\you\.local\pipx\venvs\mempalace\Scripts\python.exe and verify the background mempalace mine call picks it up.
3. Python 3.14 guard — launch the MCP server under 3.14 and confirm the JSON-RPC error lands on stdout without the pydantic ConfigError.

Without those, we'd be merging a Windows fix on faith. Can you run through those three and report back what you saw?

Two secondary points to consider while you're in there:

• Python 3.14 guard is future-fragile. sys.version_info >= (3, 14) becomes wrong the moment chromadb supports 3.14 — the guard will tell users to downgrade when they no longer need to. Two alternatives that age better: (a) catch the pydantic ConfigError around the chromadb import and re-raise with a better message, or (b) gate the guard on a chromadb version range (if chromadb.__version__ < "1.0" and sys.version_info >= (3, 14)). Either way the message stays useful; neither locks us out later.
• else echo "python3" in find_python silently keeps the broken default when both python3 and python are missing. It'd be friendlier to echo "" && return 1 and have the caller exit with a clear "no Python found — set MEMPALACE_PYTHON" message, since downstream $PYTHON -c calls will fail opaquely otherwise.

Context on prior art: #740 by @milla-jovovich touched the same files and was closed yesterday. The closure reasoning was narrower than your PR's scope (nohup PATH stripping in a private variant, not addressed by the public python3 -m mempalace entry point). Your PR legitimately covers a different angle — the inline python3 -c / python3 - <<PYEOF calls in the save hook bypass the module entry point and hit the python3-doesn't-exist path on Windows directly. Worth naming that distinction in the PR body so reviewers don't bounce it as a duplicate.

cc @milla-jovovich — you closed #740 with a clear model of the hook failure modes; wanted to make sure your perspective is folded in before this lands.

thanks for the review.
For Windows machine, I'm afraid to let you know that I don't have any windows machine to test but anyone with Window machine is welcome and would be glad to continue if there's anything broke.

Hi, thanks for the contribution.

This PR has merge conflicts with develop, and the branch has not been updated in over 7 days, which puts it before our most recent release. The conflicts are likely against work that landed in that release.

Could you rebase onto develop so we can take another look?

If this change is no longer relevant, feel free to close the PR.

(This message is part of a periodic backlog pass, sent to all open PRs that match this state.)