diff --git a/ci/test-lib.nix b/ci/test-lib.nix
index 225c9ea1..92731b17 100644
--- a/ci/test-lib.nix
+++ b/ci/test-lib.nix
@@ -10,7 +10,7 @@
 let
   wlib = self.lib;
 
-  errMsg = msg: "(echo ${renderMsg msg} >&2 && return 1)";
+  errMsg = msg: "(echo \"${renderMsg msg}\" >&2 && return 1)";
 
   indentBlock =
     str: num:
@@ -280,10 +280,27 @@ in
     msg = "File ${path} should not exist";
   };
 
+  /**
+    Returns an `Assertion` that checks whether `path` does **not** exist as a directory.
+
+    # Type
+    ```
+    notIsFile :: String -> Assertion
+    ```
+
+    # Arguments
+    path
+    : The filesystem path that should be absent.
+  */
+  notIsDirectory = path: {
+    cond = ''[ ! -d "${path}" ]'';
+    msg = "Directory ${path} should not exist";
+  };
+
   /**
     Returns an `Assertion` that checks whether `file` contains a line matching `pattern`.
 
-    The check is performed with `grep -q`, so `pattern` is treated as a basic regular expression.
+    The check is performed with `grep -Eq`, so `pattern` is treated as an extended regular expression.
 
     # Type
     ```
@@ -295,10 +312,10 @@ in
     : Path to the file to search.
 
     pattern
-    : Basic regular expression to search for.
+    : Extended regular expression to search for.
   */
   fileContains = file: pattern: {
-    cond = ''grep -q '${pattern}' "${file}"'';
+    cond = ''grep -Eq -- '${pattern}' "${file}"'';
     msg = "Pattern '${pattern}' not found in ${file}";
   };
 
diff --git a/wrapperModules/o/oh-my-posh/check.nix b/wrapperModules/o/oh-my-posh/check.nix
new file mode 100644
index 00000000..cbdd1bad
--- /dev/null
+++ b/wrapperModules/o/oh-my-posh/check.nix
@@ -0,0 +1,332 @@
+{
+  pkgs,
+  self,
+  tlib,
+  writeText,
+  ...
+}:
+
+let
+  inherit (tlib)
+    fileContains
+    isFile
+    isDirectory
+    notIsFile
+    notIsDirectory
+    test
+    ;
+  wm = self.wrappers.oh-my-posh;
+in
+test { wrapper = "oh-my-posh"; } {
+
+  "wrapper should output correct version" =
+    let
+      wrapper = wm.wrap {
+        inherit pkgs;
+      };
+    in
+    ''
+      "${wrapper}/bin/oh-my-posh" --version |
+      grep -q "${wrapper.version}"
+    '';
+
+  "If config is provided then config.json is properly set up" =
+    let
+      wrapper = wm.wrap {
+        inherit pkgs;
+        theme = "jandedobbeleer";
+      };
+      configFile = "${wrapper}/config.json";
+    in
+    [
+      (isFile configFile)
+      (fileContains "${wrapper}/bin/oh-my-posh" "--config.*${configFile}")
+    ];
+
+  "If no config is provided then no config.json is set up" =
+    let
+      wrapper = wm.wrap {
+        inherit pkgs;
+      };
+      configFile = "${wrapper}/config.json";
+    in
+    notIsFile configFile;
+
+  "config chains" =
+    let
+      baseWrapper = wm.wrap {
+        inherit pkgs;
+        theme = [
+          "aliens"
+          "agnoster"
+        ];
+        settings.foo = "foo";
+        configFile = writeText "file-config.yaml" "bar: bar";
+      };
+      nixStoreFile = name: "/nix/store/[[:alnum:]]{32}-.*${name}";
+      extendsPattern = path: ''"extends": "${path}"'';
+    in
+    {
+      "theme > file > settings (default order)" =
+        let
+          wrapper = baseWrapper;
+          configChainDir = "${wrapper}/config-chain";
+
+          nixSettingsFile = "${configChainDir}/settings.json";
+          fileSettingsFile = "${configChainDir}/file-config.json";
+          agnosterFile = "${configChainDir}/agnoster.omp.json";
+        in
+        [
+          "[[ -h ${wrapper}/config.json ]]"
+          "[[ $(readlink -f ${wrapper}/config.json) == ${nixSettingsFile} ]]"
+          (fileContains nixSettingsFile (extendsPattern fileSettingsFile))
+          (fileContains fileSettingsFile (extendsPattern agnosterFile))
+          (fileContains agnosterFile (extendsPattern (nixStoreFile "aliens.omp.json")))
+        ];
+
+      "file > theme > settings" =
+        let
+          wrapper = baseWrapper.wrap {
+            order = [
+              "file"
+              "theme"
+              "settings"
+            ];
+          };
+          configChainDir = "${wrapper}/config-chain";
+
+          nixSettingsFile = "${configChainDir}/settings.json";
+          agnosterFile = "${configChainDir}/agnoster.omp.json";
+          aliensFile = "${configChainDir}/aliens.omp.json";
+        in
+        [
+          "[[ -h ${wrapper}/config.json ]]"
+          "[[ $(readlink -f ${wrapper}/config.json) == ${nixSettingsFile} ]]"
+          (fileContains nixSettingsFile (extendsPattern agnosterFile))
+          (fileContains agnosterFile (extendsPattern aliensFile))
+          (fileContains aliensFile (extendsPattern (nixStoreFile "file-config.json")))
+        ];
+
+      "file > settings > theme" =
+        let
+          wrapper = baseWrapper.wrap {
+            order = [
+              "file"
+              "settings"
+              "theme"
+            ];
+          };
+          configChainDir = "${wrapper}/config-chain";
+
+          agnosterFile = "${configChainDir}/agnoster.omp.json";
+          aliensFile = "${configChainDir}/aliens.omp.json";
+          nixSettingsFile = "${configChainDir}/settings.json";
+        in
+        [
+          "[[ -h ${wrapper}/config.json ]]"
+          "[[ $(readlink -f ${wrapper}/config.json) == ${agnosterFile} ]]"
+          (fileContains agnosterFile (extendsPattern aliensFile))
+          (fileContains aliensFile (extendsPattern nixSettingsFile))
+          (fileContains nixSettingsFile (extendsPattern (nixStoreFile "file-config.json")))
+        ];
+
+      "settings > theme > file" =
+        let
+          wrapper = baseWrapper.wrap {
+            order = [
+              "settings"
+              "theme"
+              "file"
+            ];
+          };
+          configChainDir = "${wrapper}/config-chain";
+
+          fileSettingsFile = "${configChainDir}/file-config.json";
+          agnosterFile = "${configChainDir}/agnoster.omp.json";
+          aliensFile = "${configChainDir}/aliens.omp.json";
+        in
+        [
+          "[[ -h ${wrapper}/config.json ]]"
+          "[[ $(readlink -f ${wrapper}/config.json) == ${fileSettingsFile} ]]"
+          (fileContains fileSettingsFile (extendsPattern agnosterFile))
+          (fileContains agnosterFile (extendsPattern aliensFile))
+          (fileContains aliensFile (extendsPattern (nixStoreFile "settings.json")))
+        ];
+
+      "theme > settings > file" =
+        let
+          wrapper = baseWrapper.wrap {
+            order = [
+              "theme"
+              "settings"
+              "file"
+            ];
+          };
+          configChainDir = "${wrapper}/config-chain";
+
+          fileSettingsFile = "${configChainDir}/file-config.json";
+          nixSettingsFile = "${configChainDir}/settings.json";
+          agnosterFile = "${configChainDir}/agnoster.omp.json";
+        in
+        [
+          "[[ -h ${wrapper}/config.json ]]"
+          "[[ $(readlink -f ${wrapper}/config.json) == ${fileSettingsFile} ]]"
+          (fileContains fileSettingsFile (extendsPattern nixSettingsFile))
+          (fileContains nixSettingsFile (extendsPattern agnosterFile))
+          (fileContains agnosterFile (extendsPattern (nixStoreFile "aliens.omp.json")))
+        ];
+
+      "settings > file > theme" =
+        let
+          wrapper = baseWrapper.wrap {
+            order = [
+              "settings"
+              "file"
+              "theme"
+            ];
+          };
+          configChainDir = "${wrapper}/config-chain";
+
+          agnosterFile = "${configChainDir}/agnoster.omp.json";
+          aliensFile = "${configChainDir}/aliens.omp.json";
+          fileSettingsFile = "${configChainDir}/file-config.json";
+        in
+        [
+          "[[ -h ${wrapper}/config.json ]]"
+          "[[ $(readlink -f ${wrapper}/config.json) == ${agnosterFile} ]]"
+          (fileContains agnosterFile (extendsPattern aliensFile))
+          (fileContains aliensFile (extendsPattern fileSettingsFile))
+          (fileContains fileSettingsFile (extendsPattern (nixStoreFile "settings.json")))
+        ];
+    };
+
+  "config file formats" =
+    let
+      key = "dummy_key";
+      value = "dummy_value";
+    in
+    {
+      "json configFile is loaded" =
+        let
+          wrapper = wm.wrap {
+            inherit pkgs;
+            configFile = writeText "config.json" ''{"${key}": "${value}"}'';
+          };
+          generatedConfig = "${wrapper}/config.json";
+        in
+        [
+          (isFile generatedConfig)
+          (fileContains generatedConfig key)
+          (fileContains generatedConfig value)
+        ];
+
+      "yaml configFile is loaded" =
+        let
+          wrapper = wm.wrap {
+            inherit pkgs;
+            configFile = writeText "config.yaml" "${key}: ${value}";
+          };
+          generatedConfig = "${wrapper}/config.json";
+        in
+        [
+          (isFile generatedConfig)
+          (fileContains generatedConfig key)
+          (fileContains generatedConfig value)
+        ];
+
+      "toml configFile is loaded" =
+        let
+          wrapper = wm.wrap {
+            inherit pkgs;
+            configFile = writeText "config.toml" ''${key} = "${value}"'';
+          };
+          generatedConfig = "${wrapper}/config.json";
+        in
+        [
+          (isFile generatedConfig)
+          (fileContains generatedConfig key)
+          (fileContains generatedConfig value)
+        ];
+    };
+
+  "explicit `extends` in settings breaks the config chain" =
+    let
+      wrapper = wm.wrap {
+        inherit pkgs;
+        theme = [
+          "aliens"
+          "agnoster"
+        ];
+        settings.extends = "foo";
+      };
+      configChainDir = "${wrapper}/config-chain";
+    in
+    [
+      (isFile "${configChainDir}/settings.json")
+      (notIsFile "${configChainDir}/agnoster.omp.json")
+      (notIsFile "${configChainDir}/aliens.omp.json")
+    ];
+
+  "If a single config is provided then no config-chain dir is created" =
+    let
+      wrapper = wm.wrap {
+        inherit pkgs;
+        settings.extends = "foo";
+      };
+    in
+    [
+      (isFile "${wrapper}/config.json")
+      (notIsDirectory "${wrapper}/config-chain")
+    ];
+
+  "extending segments works as expected" =
+    let
+      wrapper = wm.wrap {
+        inherit pkgs;
+        configFile = writeText "config.yaml" ''
+          blocks:
+            - type: prompt
+              alignment: left
+              segments:
+                - type: text
+                  style: plain
+                  template: "[b1s1]"
+                - type: text
+                  style: plain
+                  template: "[b1s2]"
+            - type: prompt
+              alignment: right
+              segments:
+                - type: text
+                  style: plain
+                  template: "[b2s1]"
+                - type: text
+                  style: plain
+                  template: "[b2s2]"
+                  alias: foo
+        '';
+        settings.blocks = [
+          {
+            type = "prompt";
+            alignment = "right";
+            segments = [
+              {
+                type = "text";
+                style = "plain";
+                alias = "foo";
+                template = "foo";
+              }
+            ];
+          }
+        ];
+      };
+    in
+    # '[b2s2]' should be overridden with 'foo'
+    [
+      "${wrapper}/bin/oh-my-posh print primary | grep -Fq  '[b1s1]'"
+      "${wrapper}/bin/oh-my-posh print primary | grep -Fq  '[b1s2]'"
+      "${wrapper}/bin/oh-my-posh print primary | grep -Fq  '[b2s1]'"
+      "${wrapper}/bin/oh-my-posh print primary | grep -Fqv '[b2s2]'"
+      "${wrapper}/bin/oh-my-posh print primary | grep -Fq  'foo'"
+    ];
+}
diff --git a/wrapperModules/o/oh-my-posh/module.nix b/wrapperModules/o/oh-my-posh/module.nix
new file mode 100644
index 00000000..65688845
--- /dev/null
+++ b/wrapperModules/o/oh-my-posh/module.nix
@@ -0,0 +1,296 @@
+{
+  wlib,
+  lib,
+  config,
+  pkgs,
+  ...
+}:
+let
+  jsonFmt = pkgs.formats.json { };
+
+  themeKey = "theme";
+  fileKey = "file";
+  settingsKey = "settings";
+
+  defaultOrder = [
+    themeKey
+    fileKey
+    settingsKey
+  ];
+in
+{
+  imports = [ wlib.modules.default ];
+
+  options = {
+    settings = lib.mkOption {
+      inherit (jsonFmt) type;
+      default = { };
+      description = ''
+        Pure nix configuration oh-my-posh.
+        See <https://ohmyposh.dev/docs/configuration/general>
+      '';
+      example = {
+        console_title_template = "{{ .Folder }}";
+      };
+    };
+    configFile = lib.mkOption {
+      type = with lib.types; nullOr (either path package);
+      default = null;
+      description = ''
+        Path to an oh-my-posh configuration file.
+        Supported formats are JSON (`.json`), TOML (`.toml`), and YAML (`.yaml`, `.yml`).
+        See <https://ohmyposh.dev/docs/configuration/general>
+      '';
+      example = lib.literalExpression "./config.yaml";
+    };
+    theme = lib.mkOption {
+      type = with lib.types; either str (listOf str);
+      default = [ ];
+      apply = lib.toList;
+      description = ''
+        One or more built-in oh-my-posh themes to use as configuration.
+        When a list is provided, they will be merged by chaining them with 
+        [`.extends`](https://ohmyposh.dev/docs/configuration/general#extends).
+        Themes later in the list take precedence.
+
+        See <https://ohmyposh.dev/docs/themes/>.
+      '';
+      example = [
+        "1_shell"
+        "agnoster"
+      ];
+    };
+    order = lib.mkOption {
+      type = with lib.types; wlib.types.fixedList 3 (enum defaultOrder);
+      default = defaultOrder;
+      description = ''
+        The order in which the specified settings are merged.
+        Values later in the list will take precedence.
+
+        The allowed keys are:
+
+        - "${themeKey}": Settings from the the specified theme (`config.theme`)
+        - "${fileKey}": Settings from the specified config file (`config.configFile`)
+        - "${settingsKey}": Settings specified as a nix attrs (`config.settings`)
+      '';
+    };
+  };
+
+  config =
+    let
+      nixSettingsFile = pkgs.writeText "settings.json" (builtins.toJSON config.settings);
+
+      stripStoreHash =
+        name:
+        let
+          m = builtins.match "[a-z0-9]{32}-(.*)" name;
+        in
+        if m != null then builtins.head m else name;
+
+      normalizedConfigFile =
+        if config.configFile == null then
+          null
+        else
+          let
+            path = toString config.configFile;
+            baseName = stripStoreHash (baseNameOf path);
+            isJson = lib.hasSuffix ".json" baseName;
+            isToml = lib.hasSuffix ".toml" baseName;
+            isYaml = lib.hasSuffix ".yaml" baseName || lib.hasSuffix ".yml" baseName;
+            configFileName =
+              lib.pipe baseName [
+                (lib.removeSuffix ".toml")
+                (lib.removeSuffix ".yaml")
+                (lib.removeSuffix ".yml")
+              ]
+              + ".json";
+          in
+          if isJson then
+            config.configFile
+          else if isToml || isYaml then
+            pkgs.runCommand configFileName { } ''
+              ${pkgs.yq-go}/bin/yq -o=json '.' ${lib.escapeShellArg "${config.configFile}"} > $out
+            ''
+          else
+            throw "oh-my-posh: configFile must have a .json, .toml, .yaml, or .yml extension, got: ${path}";
+
+      # List of { srcPath, name } in precedence order (lowest to highest)
+      orderedConfigs = lib.concatMap (
+        key:
+        {
+          ${themeKey} = map (p: {
+            srcPath = "${config.package}/share/oh-my-posh/themes/${p}.omp.json";
+            name = "${p}.omp.json";
+          }) config.theme;
+          ${fileKey} = lib.optional (config.configFile != null) {
+            srcPath = "${normalizedConfigFile}";
+            name = stripStoreHash (baseNameOf (toString normalizedConfigFile));
+          };
+          ${settingsKey} = lib.optional (config.settings != { }) {
+            srcPath = "${nixSettingsFile}";
+            name = "settings.json";
+          };
+        }
+        .${key}
+      ) config.order;
+
+      jq = "${pkgs.jq}/bin/jq";
+
+      # Build constructFile entries for the config chain.
+      #
+      # `curr`: the current (higher-precedence) config being processed.
+      # `configs`: remaining configs in descending precedence order.
+      #
+      # The builder for `curr` will add an ".extends" key to the json which will
+      # point to the next (lower-precedence) entry in the `configs` list
+      generateConstructFileEntries =
+        curr: configs:
+        let
+          relPath = "config-chain/${curr.name}";
+          prev = builtins.head configs;
+
+          # If currPath already has an "extends" key, symlink it as-is.
+          # Otherwise, add prevPath as the "extends" value.
+          generateBuilderScript = currPath: prevPath: ''
+            mkdir -p "$(dirname "$2")"
+            if [ "$(${jq} 'has("extends")' ${lib.escapeShellArg currPath})" = "true" ]; then
+              ln -s ${lib.escapeShellArg currPath} "$2"
+            else
+              ${jq} --arg ext ${lib.escapeShellArg prevPath} '. + {extends: $ext}' ${lib.escapeShellArg currPath} > "$2"
+            fi
+          '';
+
+        in
+        if builtins.length configs == 1 then
+          # Base: prev is the lowest-precedence config — point directly to its source
+          {
+            ${relPath} = {
+              inherit relPath;
+              builder = generateBuilderScript curr.srcPath prev.srcPath;
+            };
+          }
+        else
+          # Recursive: prev will itself be a generated file in config-chain
+          {
+            ${relPath} = {
+              inherit relPath;
+              builder = generateBuilderScript curr.srcPath "${placeholder "out"}/config-chain/${prev.name}";
+            };
+          }
+          // generateConstructFileEntries prev (builtins.tail configs);
+
+      n = builtins.length orderedConfigs;
+
+      constructFiles =
+        if n == 0 then
+          { }
+        else if n == 1 then
+          let
+            cfg = builtins.head orderedConfigs;
+          in
+          {
+            "config.json" = {
+              relPath = "config.json";
+              builder = ''
+                mkdir -p "$(dirname "$2")"
+                ln -s ${lib.escapeShellArg cfg.srcPath} "$2"
+              '';
+            };
+          }
+        else
+          let
+            reversed = lib.reverseList orderedConfigs;
+            lastConfig = lib.last orderedConfigs;
+          in
+          generateConstructFileEntries (builtins.head reversed) (builtins.tail reversed)
+          // {
+            "config.json" = {
+              relPath = "config.json";
+              builder =
+                let
+                  chainDir = "${placeholder "out"}/config-chain";
+                  lastConfigPath = "${chainDir}/${lastConfig.name}";
+                in
+                ''
+                  # Follow the extends chain and remove files in config-chain that are
+                  # no longer reachable (cut off by a config that already had "extends")
+                  declare -A reachable
+                  current=${lib.escapeShellArg lastConfigPath}
+                  while [ -f "$current" ]; do
+                    reachable["$current"]=1
+                    ext=$(${jq} -r '.extends // empty' "$current")
+                    [[ "$ext" == ${lib.escapeShellArg chainDir}/* ]] || break
+                    current="$ext"
+                  done
+                  for f in ${lib.escapeShellArg chainDir}/*; do
+                    [ -v 'reachable[$f]' ] || rm "$f"
+                  done
+                  rmdir ${lib.escapeShellArg chainDir} 2>/dev/null || true
+
+                  mkdir -p "$(dirname "$2")"
+                  ln -s ${lib.escapeShellArg lastConfigPath} "$2"
+                '';
+            };
+          };
+    in
+    {
+      inherit constructFiles;
+      package = lib.mkDefault pkgs.oh-my-posh;
+      flags."--config" = lib.mkIf (n > 0) config.constructFiles."config.json".path;
+      meta = {
+        maintainers = with wlib.maintainers; [
+          zenoli
+        ];
+        description = ''
+          Wrapper Module for the [Oh-My-Posh Prompt](https://ohmyposh.dev/).
+
+          Oh-My-Posh is configured via a [JSON/YAML/TOML file](https://ohmyposh.dev/docs/configuration/general).
+          This module provides three ways to do this:
+
+          - By specifying one (or many) of the [built-in themes](https://ohmyposh.dev/docs/themes/).
+          - By pointing to a JSON, TOML, or YAML configuration file.
+          - By using pure Nix to write an attribute set that gets converted to JSON.
+
+          These options are not mutually exclusive. If multiple are defined,
+          they will be merged according to the order specified in `config.order`.
+
+          Merging is done using Oh-My-Posh's native
+          [extends](https://ohmyposh.dev/docs/configuration/general#extends) mechanic,
+          which allows a configuration file to inherit from another and override individual values.
+
+          Configs will be modified during build-time to add an `.extends` key
+          pointing to the next config in the list. If a config already has an `.extends` key present,
+          it is used as-is and the remaining lower-precedence configs are ignored.
+
+          **Example**
+
+          ```nix
+          theme = "jandedobbeleer";
+          configFile = ./my-config.yaml;
+          settings.console_title_template = "{{ .Folder }}";
+          ```
+
+          With the default order (`theme < file < settings`), this produces the chain:
+
+          ```
+          settings.json  →  my-config.json  →  jandedobbeleer.omp.json
+          (highest precedence)                  (lowest precedence)
+          ```
+
+          `settings.json` has an `extends` key pointing to `my-config.json`,
+          which in turn extends `jandedobbeleer.omp.json`.
+
+          If `my-config.yaml` already contains an `extends` key (e.g. pointing to another theme),
+          it is left unchanged and the chain stops there:
+
+          ```
+          settings.json  →  my-config.json  -x-  jandedobbeleer.omp.json
+          (highest precedence)    ↓
+                           (its own extends)
+          ```
+
+          `jandedobbeleer.omp.json` is dropped entirely — `my-config.yaml`'s own `extends` takes over as the base.
+        '';
+      };
+    };
+}