init: LightRAG + Graphiti as submodules with Nix flake

Impure devShells using uv + Python 3.12 for each project.
LD_LIBRARY_PATH set for NixOS native wheel compatibility.
Neo4j managed via nix run .#neo4j-start / neo4j-stop.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.env.graphiti

@@ -0,0 +1,14 @@
+# Neo4j (started via: nix run .#neo4j-start)
+NEO4J_URI=bolt://localhost:7687
+NEO4J_USER=neo4j
+NEO4J_PASSWORD=neo4j
+
+# LLM via Ollama (OpenAI-compatible)
+OPENAI_API_KEY=ollama
+OPENAI_BASE_URL=http://localhost:11434/v1
+MODEL_NAME=qwen2.5:7b
+
+# Embeddings via Ollama
+# nomic-embed-text dim=768, mxbai-embed-large dim=1024
+EMBEDDING_MODEL=nomic-embed-text
+EMBEDDING_DIM=768

.env.lightrag

@@ -0,0 +1,18 @@
+# LLM via Ollama
+LLM_BINDING=ollama
+LLM_MODEL=qwen2.5:7b
+LLM_BINDING_HOST=http://localhost:11434
+
+# Embeddings via Ollama
+EMBEDDING_BINDING=ollama
+EMBEDDING_MODEL=nomic-embed-text
+EMBEDDING_BINDING_HOST=http://localhost:11434
+EMBEDDING_DIM=768
+
+# Storage (local files)
+RAG_DIR=./rag_storage
+
+# Server
+HOST=0.0.0.0
+PORT=9621
+WORKERS=1

.gitignore

@@ -0,0 +1,5 @@
+data/
+.venv/
+__pycache__/
+*.pyc
+.env.*.local

.gitmodules

@@ -0,0 +1,6 @@
+[submodule "lightrag"]
+	path = lightrag
+	url = https://github.com/hkuds/lightrag
+[submodule "graphiti"]
+	path = graphiti
+	url = https://github.com/getzep/graphiti

flake.lock

@@ -0,0 +1,27 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1776169885,
+        "narHash": "sha256-l/iNYDZ4bGOAFQY2q8y5OAfBBtrDAaPuRQqWaFHVRXM=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "4bd9165a9165d7b5e33ae57f3eecbcb28fb231c9",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,114 @@
+{
+  description = "LightRAG + Graphiti dev environments";
+
+  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+
+  outputs = { self, nixpkgs }:
+    let
+      system = "x86_64-linux";
+      pkgs = nixpkgs.legacyPackages.${system};
+
+      startNeo4j = pkgs.writeShellScript "start-neo4j" ''
+        set -e
+        : "''${RAGS_ROOT:=$PWD}"
+        NEO4J_DATA="$RAGS_ROOT/data/neo4j"
+        mkdir -p "$NEO4J_DATA"/{data,logs,run,plugins,import,conf}
+
+        cat > "$NEO4J_DATA/conf/neo4j.conf" <<CONF
+        server.directories.data=$NEO4J_DATA/data
+        server.directories.logs=$NEO4J_DATA/logs
+        server.directories.run=$NEO4J_DATA/run
+        server.directories.plugins=$NEO4J_DATA/plugins
+        server.directories.import=$NEO4J_DATA/import
+        server.bolt.listen_address=:7687
+        server.http.listen_address=:7474
+        dbms.security.auth_enabled=false
+        CONF
+
+        export NEO4J_CONF="$NEO4J_DATA/conf"
+        ${pkgs.neo4j}/bin/neo4j start
+        echo ""
+        echo "Neo4j running:"
+        echo "  bolt: bolt://localhost:7687"
+        echo "  http: http://localhost:7474"
+        echo "  stop: RAGS_ROOT=$RAGS_ROOT nix run .#neo4j-stop"
+        echo ""
+      '';
+
+      stopNeo4j = pkgs.writeShellScript "stop-neo4j" ''
+        : "''${RAGS_ROOT:=$PWD}"
+        export NEO4J_CONF="$RAGS_ROOT/data/neo4j/conf"
+        ${pkgs.neo4j}/bin/neo4j stop
+      '';
+
+    in {
+      devShells.${system} = {
+
+        lightrag = pkgs.mkShell {
+          packages = [ pkgs.uv pkgs.python312 pkgs.curl ];
+
+          shellHook = ''
+            RAGS_ROOT="$PWD"
+            export VIRTUAL_ENV="$RAGS_ROOT/lightrag/.venv"
+            export UV_PROJECT_ENVIRONMENT="$VIRTUAL_ENV"
+            export UV_PYTHON="${pkgs.python312}/bin/python3.12"
+            export LD_LIBRARY_PATH="${pkgs.lib.makeLibraryPath [ pkgs.stdenv.cc.cc pkgs.zlib ]}:$LD_LIBRARY_PATH"
+            cd "$RAGS_ROOT/lightrag"
+
+            if [ ! -d .venv ]; then
+              echo "Setting up lightrag venv (first time, ~2min)..."
+              uv sync --extra api --quiet
+            fi
+            source .venv/bin/activate
+
+            if [ -f "$RAGS_ROOT/.env.lightrag" ]; then
+              set -a; source "$RAGS_ROOT/.env.lightrag"; set +a
+            fi
+
+            echo ""
+            echo "LightRAG shell ready."
+            echo "  start:  lightrag-server"
+            echo "  config: $RAGS_ROOT/.env.lightrag"
+            echo "  needs:  ollama with qwen2.5:7b + nomic-embed-text"
+            echo ""
+          '';
+        };
+
+        graphiti = pkgs.mkShell {
+          packages = [ pkgs.uv pkgs.python312 pkgs.neo4j pkgs.curl ];
+
+          shellHook = ''
+            RAGS_ROOT="$PWD"
+            export VIRTUAL_ENV="$RAGS_ROOT/graphiti/.venv"
+            export UV_PROJECT_ENVIRONMENT="$VIRTUAL_ENV"
+            export UV_PYTHON="${pkgs.python312}/bin/python3.12"
+            export LD_LIBRARY_PATH="${pkgs.lib.makeLibraryPath [ pkgs.stdenv.cc.cc pkgs.zlib ]}:$LD_LIBRARY_PATH"
+            cd "$RAGS_ROOT/graphiti"
+
+            if [ ! -d .venv ]; then
+              echo "Setting up graphiti venv (first time, ~1min)..."
+              uv sync --quiet
+            fi
+            source .venv/bin/activate
+
+            if [ -f "$RAGS_ROOT/.env.graphiti" ]; then
+              set -a; source "$RAGS_ROOT/.env.graphiti"; set +a
+            fi
+
+            echo ""
+            echo "Graphiti shell ready."
+            echo "  neo4j:  nix run .#neo4j-start   (in another terminal, run first)"
+            echo "  config: $RAGS_ROOT/.env.graphiti"
+            echo "  needs:  ollama with qwen2.5:7b + nomic-embed-text"
+            echo ""
+          '';
+        };
+
+      };
+
+      apps.${system} = {
+        neo4j-start = { type = "app"; program = "${startNeo4j}"; };
+        neo4j-stop  = { type = "app"; program = "${stopNeo4j}"; };
+      };
+    };
+}