diff --git a/.gitignore b/.gitignore
index fc7af979..d8aebf8d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -157,3 +157,5 @@ cython_debug/
 
 # ruff code style
 .ruff_cache/
+
+playground/*
\ No newline at end of file
diff --git a/src/datatrove/executor/slurm.py b/src/datatrove/executor/slurm.py
index 0443cec3..e4b48977 100644
--- a/src/datatrove/executor/slurm.py
+++ b/src/datatrove/executor/slurm.py
@@ -27,6 +27,7 @@ def __init__(
         mem_per_cpu_gb: int = 2,
         workers: int = -1,
         job_name: str = "data_processing",
+        env_command: str = None,
         condaenv: str = None,
         venv_path: str = None,
         sbatch_args: dict | None = None,
@@ -54,6 +55,7 @@ def __init__(
         self.logging_dir = logging_dir
         self.time = time
         self.job_name = job_name
+        self.env_command = env_command
         self.condaenv = condaenv
         self.venv_path = venv_path
         self.depends = depends
@@ -158,9 +160,10 @@ def launch_file(self):
     def get_launch_file(self, sbatch_args: dict, run_script: str):
         args = "\n".join([f"#SBATCH --{k}={v}" for k, v in sbatch_args.items()])
 
-        env_command = (
+        env_command = self.env_command if self.env_command else (
             f"""conda init bash
-        conda activate {self.condaenv}"""
+        conda activate {self.condaenv}
+        source ~/.bashrc"""
             if self.condaenv
             else (f"source {self.venv_path}" if self.venv_path else "")
         )
@@ -172,7 +175,6 @@ def get_launch_file(self, sbatch_args: dict, run_script: str):
                 f"""
         echo "Starting data processing job {self.job_name}"
         {env_command}
-        source ~/.bashrc
         set -xe
         {run_script}
         """
diff --git a/src/datatrove/io/base.py b/src/datatrove/io/base.py
index da00fae4..608e371a 100644
--- a/src/datatrove/io/base.py
+++ b/src/datatrove/io/base.py
@@ -66,6 +66,15 @@ def open(self, binary=False, compression: Literal["gzip", "zst"] | None = None):
 
 @dataclass
 class BaseInputDataFolder(ABC):
+    """An input data folder
+
+    Args:
+        path (str): path to the folder
+        extension (str | list[str], optional): file extensions to filter. Defaults to None.
+        recursive (bool, optional): whether to search recursively. Defaults to True.
+        match_pattern (str, optional): pattern to match file names. Defaults to None.
+    """
+
     path: str
     extension: str | list[str] = None
     recursive: bool = True
diff --git a/src/datatrove/io/fsspec.py b/src/datatrove/io/fsspec.py
index f7af5a39..7160da6d 100644
--- a/src/datatrove/io/fsspec.py
+++ b/src/datatrove/io/fsspec.py
@@ -50,7 +50,10 @@ class FSSpecInputDataFolder(BaseInputDataFolder):
 
     def __post_init__(self):
         super().__post_init__()
-        protocol, self.path = self.path.split("://")
+        if "://" in self.path:
+            protocol, self.path = self.path.split("://")
+        else:
+            protocol = "file"
         self._fs = fsspec.filesystem(protocol, **(self.storage_options if self.storage_options else {}))
 
     def list_files(self, extension: str | list[str] = None, suffix: str = "") -> list[InputDataFile]:
diff --git a/src/datatrove/pipeline/readers/jsonl.py b/src/datatrove/pipeline/readers/jsonl.py
index b66801ea..17bca9f2 100644
--- a/src/datatrove/pipeline/readers/jsonl.py
+++ b/src/datatrove/pipeline/readers/jsonl.py
@@ -17,10 +17,12 @@ def __init__(
         data_folder: BaseInputDataFolder,
         compression: Literal["gzip", "zst"] | None = None,
         adapter: Callable = None,
+        content_key: str = "content",
         **kwargs,
     ):
         super().__init__(data_folder, **kwargs)
         self.compression = compression
+        self.content_key = content_key
         self.adapter = adapter if adapter else lambda d, path, li: d
         self.empty_warning = False
 
@@ -30,7 +32,7 @@ def read_file(self, datafile: InputDataFile):
                 with self.stats.time_manager:
                     try:
                         d = json.loads(line)
-                        if not d.get("content", None):
+                        if not d.get(self.content_key, None):
                             if not self.empty_warning:
                                 self.empty_warning = True
                                 logger.warning("Found document without content, skipping.")