diff --git a/.envrc b/.envrc
new file mode 100644
index 0000000..30da14f
--- /dev/null
+++ b/.envrc
@@ -0,0 +1,5 @@
+export DIRENV_WARN_TIMEOUT=20s
+
+eval "$(devenv direnvrc)"
+
+use devenv
diff --git a/.gitignore b/.gitignore
index b7a2128..b64c322 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,12 @@
 result
 .aider*
+
+# Devenv
+.devenv*
+devenv.local.nix
+
+# direnv
+.direnv
+
+# pre-commit
+.pre-commit-config.yaml
diff --git a/devenv.lock b/devenv.lock
new file mode 100644
index 0000000..5bda4b0
--- /dev/null
+++ b/devenv.lock
@@ -0,0 +1,103 @@
+{
+  "nodes": {
+    "devenv": {
+      "locked": {
+        "dir": "src/modules",
+        "lastModified": 1742320965,
+        "owner": "cachix",
+        "repo": "devenv",
+        "rev": "6bde92766ddd3ee1630029a03d36baddd51934e2",
+        "type": "github"
+      },
+      "original": {
+        "dir": "src/modules",
+        "owner": "cachix",
+        "repo": "devenv",
+        "type": "github"
+      }
+    },
+    "flake-compat": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1733328505,
+        "owner": "edolstra",
+        "repo": "flake-compat",
+        "rev": "ff81ac966bb2cae68946d5ed5fc4994f96d0ffec",
+        "type": "github"
+      },
+      "original": {
+        "owner": "edolstra",
+        "repo": "flake-compat",
+        "type": "github"
+      }
+    },
+    "git-hooks": {
+      "inputs": {
+        "flake-compat": "flake-compat",
+        "gitignore": "gitignore",
+        "nixpkgs": [
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1742300892,
+        "owner": "cachix",
+        "repo": "git-hooks.nix",
+        "rev": "ea26a82dda75bee6783baca6894040c8e6599728",
+        "type": "github"
+      },
+      "original": {
+        "owner": "cachix",
+        "repo": "git-hooks.nix",
+        "type": "github"
+      }
+    },
+    "gitignore": {
+      "inputs": {
+        "nixpkgs": [
+          "git-hooks",
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1709087332,
+        "owner": "hercules-ci",
+        "repo": "gitignore.nix",
+        "rev": "637db329424fd7e46cf4185293b9cc8c88c95394",
+        "type": "github"
+      },
+      "original": {
+        "owner": "hercules-ci",
+        "repo": "gitignore.nix",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1733477122,
+        "owner": "cachix",
+        "repo": "devenv-nixpkgs",
+        "rev": "7bd9e84d0452f6d2e63b6e6da29fe73fac951857",
+        "type": "github"
+      },
+      "original": {
+        "owner": "cachix",
+        "ref": "rolling",
+        "repo": "devenv-nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "devenv": "devenv",
+        "git-hooks": "git-hooks",
+        "nixpkgs": "nixpkgs",
+        "pre-commit-hooks": [
+          "git-hooks"
+        ]
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/devenv.nix b/devenv.nix
new file mode 100644
index 0000000..71db03b
--- /dev/null
+++ b/devenv.nix
@@ -0,0 +1,49 @@
+{
+  pkgs,
+  lib,
+  config,
+  inputs,
+  ...
+}: {
+  # https://devenv.sh/basics/
+  # env.GREET = "devenv";
+
+  # https://devenv.sh/packages/
+  packages = with pkgs; [];
+
+  # https://devenv.sh/languages/
+  # languages.rust.enable = true;
+
+  # https://devenv.sh/processes/
+  # processes.cargo-watch.exec = "cargo-watch";
+
+  # https://devenv.sh/services/
+  # services.postgres.enable = true;
+
+  # https://devenv.sh/scripts/
+  # scripts.hello.exec = ''
+  #   echo hello from $GREET
+  # '';
+
+  enterShell = ''
+    jj git fetch
+  '';
+
+  # https://devenv.sh/tasks/
+  # tasks = {
+  #   "myproj:setup".exec = "mytool build";
+  #   "devenv:enterShell".after = [ "myproj:setup" ];
+  # };
+
+  # https://devenv.sh/tests/
+  # enterTest = ''
+  #   echo "Running tests"
+  #   git --version | grep --color=auto "${pkgs.git.version}"
+  # '';
+
+  # https://devenv.sh/git-hooks/
+  # git-hooks.hooks.shellcheck.enable = true;
+
+  # See full reference at https://devenv.sh/reference/options/
+  cachix.enable = false;
+}
diff --git a/devenv.yaml b/devenv.yaml
new file mode 100644
index 0000000..116a2ad
--- /dev/null
+++ b/devenv.yaml
@@ -0,0 +1,15 @@
+# yaml-language-server: $schema=https://devenv.sh/devenv.schema.json
+inputs:
+  nixpkgs:
+    url: github:cachix/devenv-nixpkgs/rolling
+
+# If you're using non-OSS software, you can set allowUnfree to true.
+# allowUnfree: true
+
+# If you're willing to use a package that's vulnerable
+# permittedInsecurePackages:
+#  - "openssl-1.1.1w"
+
+# If you have more than one devenv you can merge them
+#imports:
+# - ./backend