MS Agent Character file
application/octet-stream
Magic Bytes
Offset: 0
C5 D0 D3 C6
Microsoft Agent Character (ACS) is a proprietary file format developed by Microsoft for the Microsoft Agent software framework. These files store the animations, graphics, and voice data necessary to render interactive desktop assistants that facilitate text-to-speech synthesis and user interaction within Windows-based applications. While the format is generally safe, the underlying technology was officially deprecated with the release of Windows 7 and is considered obsolete on contemporary operating systems.
Validation Code
How to validate .acs files in Python
Python
def is_acs(file_path: str) -> bool:
"""Check if file is a valid ACS by magic bytes."""
signature = bytes([0xC5, 0xD0, 0xD3, 0xC6])
with open(file_path, "rb") as f:
return f.read(4) == signatureHow to validate .acs files in Node.js
Node.js
function isACS(buffer: Buffer): boolean {
const signature = Buffer.from([0xC5, 0xD0, 0xD3, 0xC6]);
return buffer.subarray(0, 4).equals(signature);
}
Go
func IsACS(data []byte) bool {
signature := []byte{0xC5, 0xD0, 0xD3, 0xC6}
if len(data) < 4 {
return false
}
return bytes.Equal(data[:4], signature)
}API Endpoint
GET
/api/v1/acs
curl https://filesignature.org/api/v1/acs