Merge pull request 'mars: provision the Mnemosyne memory provider for Hermes' (#6) from feat/mars-hermes-mnemosyne into master

Reviewed-on: #6

hosts/mars/hermes-agent.nix

@@ -74,11 +74,7 @@ let
     builtins.readFile ./gitea-pr-review-prompt.md
   );
 
-  # Mnemosyne memory provider (local SQLite, third-party plugin — not bundled
-  # with the official image). Fully built as a Nix derivation — see
-  # pkgs/mnemosyne-env.nix — and mounted READ-ONLY into the container at a
-  # fixed path. The oneshot near the bottom of this file only writes the
-  # plugin symlink Docker needs at $HERMES_HOME/plugins/mnemosyne.
+  # Mnemosyne memory provider: third-party plugin, not in the image.
   mnemosyneEnv = pkgs.callPackage ../../pkgs/mnemosyne-env.nix { };
 
   # Wire event names (X-GitHub-Event) each route accepts — NOT the
@@ -235,15 +231,6 @@ in
       "${hermesHome}:/opt/data"
       "${dropboxDir}:/opt/data/dropbox"
 
-      # Mnemosyne memory provider — a Nix-built python env, mounted :ro.
-      # Nothing fetched at boot, nothing writable from inside the container.
-      # The plugin symlink the oneshot at the bottom of this file writes
-      # points at the canonical store path (site-packages passthru), which
-      # is visible inside thanks to the existing /nix/store ro mount, so
-      # this /opt/data restatement is a readability alias, not a load
-      # bearing path.
-      "${mnemosyneEnv}:/opt/data/mnemosyne-env:ro"
-
       # luna's Obsidian vault, synced with CouchDB on jupiter by
       # livesync-bridge.nix. Under /opt/data so she can write notes, not just
       # read them; the bridge runs as this same uid/gid so no chown is needed.
@@ -435,26 +422,9 @@ in
     '';
   };
 
-  # ---- Mnemosyne memory provider ----------------------------------------
-  # The provider's Python closure (mnemosyneEnv, callPackage'd
-  # pkgs/mnemosyne-env.nix above) is a READ-ONLY nix store path mounted into
-  # the container — nothing fetched at boot, nothing inside the container can
-  # write to it, and the mono-repo reproducibility story applies. Hermes only
-  # needs one mutable pickup point: $HERMES_HOME/plugins/mnemosyne, the
-  # symlink its discovery scan looks for. Both the plugin wrapper and its
-  # sibling `mnemosyne` core package live in that env's single site-packages,
-  # so one link covers them.
-  #
-  # Path handling: the symlink target is spelled in the CONTAINER's path
-  # space (/opt/data/...), because Hermes resolves the plugin from inside the
-  # container — the same host/container mismatch the webhook prompts already
-  # navigate via containerHome. Host-side the identical literal resolves
-  # onto the same store path through hermesHome's bind mount.
-  #
-  # Failure posture: after=, not requires= — a failed link write leaves the
-  # container running with whatever memory.provider falls back to Hermes's
-  # built-in memory, not a dead bot. The ro mount itself is evaluated at
-  # build time, so there is nothing provisionable to drift at runtime.
+  # Hermes discovers memory providers under $HERMES_HOME/plugins; the target
+  # is a store path, readable in the container via the /nix/store ro mount.
+  # wantedBy, not requiredBy: a failure leaves Hermes on built-in memory.
   systemd.services.hermes-agent-mnemosyne-plugin = {
     description = "Link Mnemosyne provider into the Hermes plugin dir";
     before = [ "podman-hermes-agent.service" ];
@@ -468,27 +438,13 @@ in
     };
     script = ''
       set -euo pipefail
-
       pluginsDir=${hermesHome}/plugins
       pluginDir=$pluginsDir/mnemosyne
-      # Target is the STORE path itself, not a /opt/data restatement: the
-      # container already ro-mounts /nix/store for git/tea (see the volumes
-      # list), so the identical literal resolves on both sides of the bind
-      # mount. Using the canonical store path directly — not the
-      # /opt/data/mnemosyne-env mount — keeps one truth and still works
-      # whether Hermes resolves the link inside the container or host-side
-      # during debugging.
-      target="${mnemosyneEnv.sitePackages}/hermes_memory_provider"
-
-      if [ ! -d "$target" ]; then
-        echo "hermes_memory_provider not found in the mnemosyne env — unit bug, not transient" >&2
-        exit 1
-      fi
+      target=${mnemosyneEnv}/${mnemosyneEnv.sitePackages}/hermes_memory_provider
+      [ -d "$target" ] || { echo "$target missing" >&2; exit 1; }
 
       mkdir -p "$pluginsDir"
       chown ${hermesUid}:${hermesGid} "$pluginsDir"
-      # Atomic swap: write to a temp name, rename over the old link. `-T`
-      # errors loudly if the target turned into a directory for any reason.
       ln -sfn "$target" "$pluginDir.new"
       mv -Tf "$pluginDir.new" "$pluginDir"
       chown -h ${hermesUid}:${hermesGid} "$pluginDir"

hosts/mars/mnemosyne/requirements.txt

@@ -1,46 +0,0 @@
-# Pinned requirements for a Mnemosyne side-venv on mars.
-#
-# Hermes vendors its own Python (the official image's venv) and deliberately
-# stays minimal: no pip module inside it, PEP 668 external-management on top.
-# Installing provider packages straight into that interpreter would fight the
-# image on every rebuild, so Mnemosyne (and its plugin wrapper) live in their
-# own venv instead — see the provisioning unit in hosts/mars/hermes-agent.nix.
-#
-# Freeze captured 2026-09-19 from a verified container-side install of
-# `mnemosyne-memory[embeddings]` + `mnemosyne-hermes` — side venv at
-# $HERMES_HOME/mnemosyne-venv, activated via $HERMES_HOME/plugins/mnemosyne.
-# Versions pinned exactly; transitive deps frozen for reproducibility
-# (onnxruntime/numpy drift under a long-lived SQLite state dir is what a
-# freeze is here to prevent).
-#
-anyio==4.15.0
-certifi==2026.7.22
-charset-normalizer==3.5.1
-click==8.5.0
-fastembed==0.8.0
-filelock==3.32.5
-flatbuffers==25.12.19
-fsspec==2026.7.0
-h11==0.16.0
-hf-xet==1.6.0
-httpcore==1.0.9
-httpx==0.28.1
-huggingface-hub==1.32.0
-idna==3.19
-loguru==0.7.3
-mmh3==5.3.0
-mnemosyne-hermes==0.5.0
-mnemosyne-memory==3.15.1
-numpy==2.5.3
-onnxruntime==1.30.0
-packaging==26.3
-pillow==12.3.0
-protobuf==7.36.1
-py-rust-stemmers==0.1.8
-pyyaml==6.0.3
-requests==2.34.2
-sqlite-vec==0.1.9
-tokenizers==0.23.2
-tqdm==4.70.0
-typing-extensions==4.16.0
-urllib3==2.7.0

pkgs/mnemosyne-env.nix

@@ -1,86 +1,56 @@
-# Mnemosyne memory provider for Hermes on mars — packaged for real (Nix).
+# Mnemosyne memory provider for Hermes. Built here rather than pip-installed:
+# the image's Python has no pip and is PEP 668 managed.
 #
-# Why derivations instead of a runtime side-venv: the official Hermes image
-# vendors its own Python and stays off-limits to pip (no pip module, PEP 668),
-# and a runtime venv built host-side breaks twice over inside the container:
-# the venv's pyvenv.cfg records a /nix/store python home the container never
-# mounts, and a plugins symlink with an absolute host path points nowhere
-# from /opt/data. Building here means nothing is fetched at boot, nothing
-# under the provider's control is writable from inside the container, and
-# the closure is as reproducible as the rest of the host.
-#
-# Package set (one shared site-packages — the plugin wrapper imports its
-# sibling `mnemosyne` core package, so withPackages, not separate envs):
-#
-#   mnemosyne-memory  core engine: SQLite/FTS5 storage, recall, tools.
-#                     Base deps only (PyYAML); the optional extras (llm,
-#                     embeddings via fastembed/onnxruntime, mcp, sync) are
-#                     deliberately NOT pulled — recall uses the bundled FTS5
-#                     lexical path, and the heavyweight ML stack (~hundreds of
-#                     MB, live network on first vector use) buys nothing for
-#                     a first deployment. Adding the embeddings extra later
-#                     is pinning fastembed + sqlite-vec here.
-#   mnemosyne-hermes  the wrapper Hermes discovers under $HERMES_HOME/plugins
-#                     (installs itself as package `hermes_memory_provider`).
-#                     Hard dependency: mnemosyne-memory, PyYAML.
-#
-# Platform note: both sdists are pure Python (build no C extensions), so
-# nothing here constrains the host arch beyond the interpreter itself.
+# Core deps only: the embeddings extra (fastembed/onnxruntime) is optional at
+# runtime, and recall falls back to FTS5.
 {
   python3,
   fetchPypi,
 }:
 
 let
-  python = python3;
-
-  mnemosyneMemory = python.pkgs.buildPythonPackage rec {
+  mnemosyneMemory = python3.pkgs.buildPythonPackage rec {
     pname = "mnemosyne-memory";
     version = "3.15.1";
     pyproject = true;
 
     src = fetchPypi {
-      inherit pname version;
-      sha256 = "sha256-lspUMxc0pUSkhSUrNdiiO5OJ1NMC/S853EYSanXtXKM=";
+      pname = "mnemosyne_memory";
+      inherit version;
+      hash = "sha256-lspUMxc0pUSkhSUrNdiiO5OJ1NMC/S853EYSanXtXKM=";
     };
 
-    build-system = with python.pkgs; [ setuptools ];
+    build-system = with python3.pkgs; [ setuptools ];
+    dependencies = with python3.pkgs; [ pyyaml ];
 
-    # Base dependency set — everything else in the upstream metadata is an
-    # optional extra (llm / embeddings / mcp / sync / test / dev) and is not
-    # installed; see the file-level comment.
-    dependencies = with python.pkgs; [ pyyaml ];
-
-    doCheck = false; # upstream tests want a live Hermes + LLM key present
-    pythonImportsCheck = [ "mnemosyne" ];
+    doCheck = false; # tests want a live Hermes + LLM key
+    # Ships the Hermes plugin package too, not just the core.
+    pythonImportsCheck = [
+      "mnemosyne"
+      "hermes_memory_provider"
+    ];
   };
 
-  mnemosyneHermes = python.pkgs.buildPythonPackage rec {
+  mnemosyneHermes = python3.pkgs.buildPythonPackage rec {
     pname = "mnemosyne-hermes";
     version = "0.5.0";
     pyproject = true;
 
     src = fetchPypi {
-      inherit pname version;
-      sha256 = "sha256-CzEvnUw5oPFtT5bHQQ/GBdy2C/E7qShQn32irIRYKqw=";
+      pname = "mnemosyne_hermes";
+      inherit version;
+      hash = "sha256-CzEvnUw5oPFtT5bHQQ/GBdy2C/E7qShQn32irIRYKqw=";
     };
 
-    build-system = with python.pkgs; [ setuptools ];
-
-    # The wrapper declares `mnemosyne-memory[embeddings]>=3.11.1` on PyPI, but
-    # the embeddings extra is only consulted when vector recall is enabled
-    # (see above) — pass the core dependency explicitly rather than dragging
-    # in onnxruntime for nothing.
-    dependencies = [ mnemosyneMemory ] ++ (with python.pkgs; [ pyyaml ]);
+    build-system = with python3.pkgs; [ setuptools ];
+    # Upstream asks for mnemosyne-memory[embeddings]; see the header.
+    dependencies = [ mnemosyneMemory ] ++ (with python3.pkgs; [ pyyaml ]);
 
     doCheck = false;
-    pythonImportsCheck = [ "hermes_memory_provider" ];
+    pythonImportsCheck = [ "mnemosyne_hermes" ];
   };
-
-  # The exposed value is the python env itself (a store path mounted :ro).
-  # Hermes only needs the site-packages dir inside it; `sitePackages` is a
-  # passthru the python interpreter derivation (and hence withPackages envs)
-  # exposes, so the caller uses `${env.sitePackages}` instead of guessing
-  # the python version in a path literal.
 in
-python.withPackages (_: [ mnemosyneMemory mnemosyneHermes ])
+python3.withPackages (_: [
+  mnemosyneMemory
+  mnemosyneHermes
+])