Skip to main content

​
FileWriterTool

​
Description

FileWriterTool writes text content to a file. Missing directories are created automatically. The default text encoding is UTF-8. Writes are confined to a sandbox directory. By default that directory is the current working directory. Pass base_dir to change it.

​
Installation

​
Example

Code

​
Arguments

The agent supplies these at runtime:
  • filename: Name of the file to write, relative to directory. May include subdirectories. Those subdirectories are created if they do not exist.
  • content: Text content to write.
  • directory (optional): Directory to write into. A relative path resolves inside the tool’s allowed directory (base_dir when set, otherwise the current working directory) and defaults to that directory’s root (./). Created if it does not exist.
  • overwrite (optional): Whether to replace an existing file. Accepts a boolean or the strings y/yes/t/true/on/1 and n/no/f/false/off/0. Defaults to false. When false and the file already exists, the tool returns an error and does not modify the file.
You set these when constructing the tool:
  • base_dir (optional): Directory that writes must stay inside. Defaults to the current working directory. A relative path is resolved when the tool is constructed, so a later change of working directory does not move the sandbox.
  • encoding (optional): Text encoding used to write the file. Defaults to utf-8.

​
Allowed paths

Runtime directory and filename values are usually chosen by an LLM. The tool rejects paths that escape the sandbox:
  • The resolved directory must be inside base_dir (the current working directory by default).
  • The resolved file path must be inside that directory.
  • .. segments, absolute paths, and symlinks are resolved before both checks.
To allow writes under a different tree, set base_dir:
Code
Previously, an absolute directory could write anywhere the process had permission. If you relied on that, set base_dir to the tree you want to allow. Setting CREWAI_TOOLS_ALLOW_UNSAFE_PATHS=true restores the old behavior, but it disables path and URL checks process-wide for every crewai-tools tool. Prefer base_dir.