Switch memory provider to hindsight

pkgs/hindsight/default.nix

@@ -0,0 +1,72 @@
+{ lib
+, callPackage
+, python312
+, stdenv
+, makeWrapper
+
+, hindsight-src
+, uv2nix
+, pyproject-nix
+, pyproject-build-systems
+}:
+
+# Build the hindsight-api-slim venv from upstream's uv workspace. We pick
+# `hindsight-api-slim` (not `hindsight-api`) so we skip the `[all]` extras
+# (local-ml, embedded-db). With openai-codex provider for both LLM and
+# embeddings, and system postgres as the store, those extras are unused weight.
+let
+  workspace = uv2nix.lib.workspace.loadWorkspace {
+    workspaceRoot = hindsight-src;
+  };
+
+  overlay = workspace.mkPyprojectOverlay {
+    sourcePreference = "wheel";
+  };
+
+  pythonSet =
+    (callPackage pyproject-nix.build.packages {
+      python = python312;
+    }).overrideScope
+      (lib.composeManyExtensions [
+        pyproject-build-systems.overlays.default
+        overlay
+      ]);
+
+  venv = pythonSet.mkVirtualEnv "hindsight-api-env" {
+    hindsight-api-slim = [ ];
+  };
+in
+stdenv.mkDerivation {
+  pname = "hindsight-api";
+  version = "0.7.2";
+
+  dontUnpack = true;
+  nativeBuildInputs = [ makeWrapper ];
+
+  installPhase = ''
+    runHook preInstall
+    mkdir -p $out/bin
+    # The venv ships hindsight-api / hindsight-worker / hindsight-admin /
+    # hindsight-local-mcp / alembic in $venv/bin. Link them out so callers
+    # don't have to know about the venv layout.
+    for bin in hindsight-api hindsight-worker hindsight-admin hindsight-local-mcp alembic; do
+      if [ -e ${venv}/bin/$bin ]; then
+        ln -s ${venv}/bin/$bin $out/bin/$bin
+      fi
+    done
+    runHook postInstall
+  '';
+
+  passthru = {
+    inherit venv pythonSet;
+    pythonEnv = venv;
+  };
+
+  meta = with lib; {
+    description = "Hindsight: agent memory with knowledge graph and tiered retrieval";
+    homepage = "https://github.com/vectorize-io/hindsight";
+    license = licenses.mit;
+    mainProgram = "hindsight-api";
+    platforms = platforms.linux;
+  };
+}