fs_append

fs_append(filename, content) appends raw content to a file in the job’s directory. All writes are non-blocking and safe.

Signature

fs_append(filename, content)

async

Note

CWD-jailed: Writes to the job’s directory. Use shared/ prefix to write to the project root’s shared folder (accessible across jobs and server). Absolute paths are not allowed.

Note

Rotation: Files feature automatic 10MB rotation with timestamped filenames (e.g., data.20260514-143005.csv), keeping a history of 5 files.

Parameters

Param	Type	Description
filename	string	File name (relative to job directory)
content	string	Content to append

Returns

None.

Example

function after_extract(items, ctx)
    for _, item in ipairs(items) do
        local row = string.format("%s,%s\n", item.fields.title, item.fields.price)
        fs_append("data.csv", row)
    end
    return items
end

See Also

• fs_overwrite - Replace entire file content
• fs_read - Read file content