# System Fingerprint
The `system_fingerprint` is a unique identifier included in every API response that serves as a version identifier for the backend system's configuration.
## Overview
Every API response includes a `system_fingerprint` field:
```json
{
"id": "chatcmpl-abc123",
"object": "chat.completion",
"created": 1699000000,
"model": "grok-4",
"system_fingerprint": "fp_6ca29cf396",
"choices": [...]
}
```
## Purpose
The system fingerprint changes whenever any part of the backend system changes:
- Model parameters
- Server settings
- Infrastructure configuration
- System updates
## Use Cases
### 1. Monitoring Backend Modifications
Track when the backend system has been updated:
```python
response = client.chat.completions.create(
model="grok-4",
messages=[{"role": "user", "content": "Hello"}]
)
fingerprint = response.system_fingerprint
print(f"Current system fingerprint: {fingerprint}")
# Store and compare fingerprints over time
if fingerprint != previous_fingerprint:
print("Backend system has been updated")
```
### 2. Debugging and Performance Optimization
Use fingerprints to correlate responses with specific system configurations:
```python
# Log fingerprint with each request for debugging
import logging
response = client.chat.completions.create(
model="grok-4",
messages=[{"role": "user", "content": query}]
)
logging.info(f"Query: {query}")
logging.info(f"Fingerprint: {response.system_fingerprint}")
logging.info(f"Latency: {response.usage.total_tokens}")
```
### 3. Response Integrity Verification
For security-sensitive applications, verify response integrity:
```python
def verify_response_source(response, expected_fingerprints):
"""Verify response came from expected system configuration."""
if response.system_fingerprint not in expected_fingerprints:
raise SecurityError("Response from unexpected system configuration")
return True
```
### 4. Audit Trails for Compliance
Create audit trails tracking which system version produced each response:
```python
audit_record = {
"timestamp": response.created,
"request_id": response.id,
"model": response.model,
"system_fingerprint": response.system_fingerprint,
"user_id": current_user_id
}
audit_log.append(audit_record)
```
## Important Notes
- **Variations are normal**: The fingerprint is expected to change over time as the system evolves
- **Not a security token**: Don't use fingerprints for authentication
- **Informational only**: Changes don't indicate breaking changes to the API
- **Consistent within session**: Typically stable within a single session but may change between sessions
## Best Practices
1. **Log fingerprints**: Include in your logging for debugging
2. **Don't hardcode**: Don't build logic that depends on specific fingerprint values
3. **Monitor changes**: Track fingerprint changes for observability
4. **Document for compliance**: Store with responses for audit purposes
