diff --git a/flake.lock b/flake.lock
index e0456b8..219d87d 100644
--- a/flake.lock
+++ b/flake.lock
@@ -73,11 +73,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1743550720,
-        "narHash": "sha256-hIshGgKZCgWh6AYJpJmRgFdR3WUbkY04o82X05xqQiY=",
+        "lastModified": 1749398372,
+        "narHash": "sha256-tYBdgS56eXYaWVW3fsnPQ/nFlgWi/Z2Ymhyu21zVM98=",
         "owner": "hercules-ci",
         "repo": "flake-parts",
-        "rev": "c621e8422220273271f52058f618c94e405bb0f5",
+        "rev": "9305fe4e5c2a6fcf5ba6a3ff155720fbe4076569",
         "type": "github"
       },
       "original": {
@@ -159,11 +159,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1747978958,
-        "narHash": "sha256-pQQnbxWpY3IiZqgelXHIe/OAE/Yv4NSQq7fch7M6nXQ=",
+        "lastModified": 1749400020,
+        "narHash": "sha256-0nTmHO8AYgRYk5v6zw5oZ3x9nh+feb+Isn7WNe318M0=",
         "owner": "nix-community",
         "repo": "home-manager",
-        "rev": "7419250703fd5eb50e99bdfb07a86671939103ea",
+        "rev": "2835e8ba0ad99ba86d4a5e497a962ec9fa35e48f",
         "type": "github"
       },
       "original": {
@@ -175,11 +175,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1747744144,
-        "narHash": "sha256-W7lqHp0qZiENCDwUZ5EX/lNhxjMdNapFnbErcbnP11Q=",
+        "lastModified": 1749285348,
+        "narHash": "sha256-frdhQvPbmDYaScPFiCnfdh3B/Vh81Uuoo0w5TkWmmjU=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "2795c506fe8fb7b03c36ccb51f75b6df0ab2553f",
+        "rev": "3e3afe5174c561dee0df6f2c2b2236990146329f",
         "type": "github"
       },
       "original": {
diff --git a/modules/home/default.nix b/modules/home/default.nix
index e642e87..4dbd510 100644
--- a/modules/home/default.nix
+++ b/modules/home/default.nix
@@ -24,6 +24,7 @@
     ./gtk
     ./htop
     ./jq
+    ./jujutsu
     ./keyboard
     ./mail
     ./mpv
diff --git a/modules/home/delta/default.nix b/modules/home/delta/default.nix
index 58ee031..b301d2b 100644
--- a/modules/home/delta/default.nix
+++ b/modules/home/delta/default.nix
@@ -11,6 +11,10 @@ in
     git = {
       enable = my.mkDisableOption "git integration";
     };
+
+    jujutsu = {
+      enable = my.mkDisableOption "jujutsu integration";
+    };
   };
 
   config = lib.mkIf cfg.enable {
@@ -30,6 +34,13 @@ in
           enabled.
         '';
       }
+      {
+        assertion = cfg.jujutsu.enable -> cfg.git.enable;
+        message = ''
+          `config.my.home.delta.jujutsu` relies on `config.my.home.delta.git`
+          being enabled.
+        '';
+      }
     ];
 
     home.packages = [ cfg.package ];
@@ -64,5 +75,23 @@ in
         };
       };
     };
+
+    programs.jujutsu = lib.mkIf cfg.jujutsu.enable {
+      settings = {
+        merge-tools = {
+          delta = {
+            # Errors are signaled with exit codes greater or equal to 2
+            diff-expected-exit-codes = [ 0 1 ];
+          };
+        };
+
+        ui = {
+          # Delta expects a `git diff` input
+          diff-formatter = ":git";
+
+          pager = "${lib.getExe cfg.package}";
+        };
+      };
+    };
   };
 }
diff --git a/modules/home/direnv/lib/python.sh b/modules/home/direnv/lib/python.sh
index b4b2bce..b1be8a9 100644
--- a/modules/home/direnv/lib/python.sh
+++ b/modules/home/direnv/lib/python.sh
@@ -46,7 +46,7 @@ layout_uv() {
     fi
 
     # create venv if it doesn't exist
-    uv venv -q
+    uv venv -q --allow-existing
 
     export VIRTUAL_ENV
     export UV_ACTIVE=1
diff --git a/modules/home/jujutsu/default.nix b/modules/home/jujutsu/default.nix
new file mode 100644
index 0000000..2cf6f64
--- /dev/null
+++ b/modules/home/jujutsu/default.nix
@@ -0,0 +1,128 @@
+{ config, pkgs, lib, ... }:
+let
+  cfg = config.my.home.jujutsu;
+
+  inherit (lib.my) mkMailAddress;
+in
+{
+  options.my.home.jujutsu = with lib; {
+    enable = my.mkDisableOption "jujutsu configuration";
+
+    package = mkPackageOption pkgs "jujutsu" { };
+  };
+
+  config = lib.mkIf cfg.enable {
+    assertions = [
+      {
+        # For `jj git` commands
+        assertion = cfg.enable -> config.my.home.git.enable;
+        message = ''
+          `config.my.home.jujutsu` relies on `config.my.home.git` being enabled.
+        '';
+      }
+    ];
+
+    programs.jujutsu = {
+      enable = true;
+
+      inherit (cfg) package;
+
+      settings = {
+        # Who am I?
+        user = {
+          name = "Bruno BELANYI";
+          email = mkMailAddress "bruno" "belanyi.fr";
+        };
+
+        aliases = {
+          jj = [ "util" "exec" "--" "jj" ];
+          # FIXME:
+          # * topo sort by default (I think? test it)
+          # * still not a big fan of the template
+          lol = [ "log" "-r" "..@" "-T" "builtin_log_oneline" ];
+          lola = [ "lol" "-r" "all()" ];
+          # TODO:
+          # * `pick` (https://github.com/jj-vcs/jj/issues/5446): [ "util" "exec" "--" "bash" "-c" "jj log -p -r \"diff_contains($1)\"" ]
+          # * `root`: `jj workspace root` (barely necessary then)
+        };
+
+        # FIXME: git equivalents
+        # blame = {
+        #   coloring = "repeatedLines";
+        #   markIgnoredLines = true;
+        #   markUnblamables = true;
+        # };
+        # FIXME: log colors should probably match git
+        # FIXME: patience diff?
+        # FIXME: fetch prune/pruneTags?
+        # FIXME: pull.rebase=true? Probably true TBH
+        # FIXME: push.default=simple? Probably true TBH
+        # FIXME: conflict style? ui.conflict-marker-style=git is diff3/zdiff3
+
+        # FIXME: from ma_9's config, plus my own stuff
+        # snapshot = {
+        #   auto-track = "none()";
+        # };
+        #
+        # ui = {
+        #   diff-editor = ":builtin"; # To silence hints
+        #   movement = {
+        #     edit = false;
+        #   };
+        # };
+
+        templates = {
+          # Equivalent to `commit.verbose = true` in Git
+          draft_commit_description = "commit_description_verbose(self)";
+        };
+
+        template-aliases = {
+          "commit_description_verbose(commit)" = ''
+            concat(
+              commit_description(commit),
+              "JJ: ignore-rest\n",
+              diff.git(),
+            )
+          '';
+          # FIXME: use `diff.summary()` instead? Supported by syntax highlighting
+          # See https://github.com/jj-vcs/jj/issues/1946#issuecomment-2572986485
+          # FIXME: tree-sitter grammar isn't in `nvim-treesitter` (https://github.com/kareigu/tree-sitter-jjdescription)
+          "commit_description(commit)" = ''
+            concat(
+              commit.description(), "\n",
+              "JJ: This commit contains the following changes:\n",
+              indent("JJ:    ", diff.stat(72)),
+            )
+          '';
+        };
+
+        "--scope" = [
+          # Multiple identities
+          {
+            "--when" = {
+              repositories = [ "~/git/EPITA/" ];
+            };
+            user = {
+              name = "Bruno BELANYI";
+              email = mkMailAddress "bruno.belanyi" "epita.fr";
+            };
+          }
+          {
+            "--when" = {
+              repositories = [ "~/git/work/" ];
+            };
+            user = {
+              name = "Bruno BELANYI";
+              email = mkMailAddress "ambroisie" "google.com";
+            };
+          }
+        ];
+      };
+    };
+
+    # To drop in a `local.toml` configuration, not-versioned
+    xdg.configFile = {
+      "jj/conf.d/.keep".text = "";
+    };
+  };
+}