Mistral Security Basics
Overview
Security practices for Mistral AI integrations: API key management, prompt injection defense, output sanitization, content moderation with mistral-moderation-latest, request logging without secrets, and key rotation.
Prerequisites
- Mistral API key provisioned
- Understanding of OWASP LLM Top 10 risks
- Secret management infrastructure
Instructions
Step 1: API Key Management
import os
api_key = os.environ.get("MISTRAL_API_KEY")
if not api_key:
raise RuntimeError("MISTRAL_API_KEY not set")
from google.cloud import secretmanager
def get_api_key() -> str:
client = secretmanager.SecretManagerServiceClient()
response = client.access_secret_version(
name="projects/my-project/secrets/mistral-api-key/versions/latest"
)
return response.payload.data.decode("UTF-8")
Step 2: Prompt Injection Defense
function sanitizeUserInput(input: string): string {
const patterns = [
/ignore (?:previous|all|above) instructions/gi,
/you are now/gi,
/system prompt/gi,
/\boverride\b/gi,
/\bforget\b.*\binstructions\b/gi,
];
let sanitized = input;
for (const pattern of patterns) {
sanitized = sanitized.replace(pattern, '[FILTERED]');
}
return sanitized.slice(0, 4000);
}
function buildSafeMessages(system: string, userInput: string) {
return [
{ role: 'system', content: system },
{
role: 'user',
content: `<user_query>\n${sanitizeUserInput(userInput)}\n</user_query>`,
},
];
}
Step 3: Content Moderation with Mistral API
import { Mistral } from '@mistralai/mistralai';
const client = new Mistral({ apiKey: process.env.MISTRAL_API_KEY });
async function moderateContent(text: string): Promise<{ safe: boolean; flags: string[] }> {
const result = await client.classifiers.moderate({
model: 'mistral-moderation-latest',
inputs: [text],
});
const categories = result.results[0].categories;
const flags = Object.entries(categories)
.filter(([, flagged]) => flagged)
.map(([category]) => category);
return { safe: flags.length === 0, flags };
}
async function safeChatFlow(userInput: string) {
inputCheck = (userInput);
(!inputCheck.) {
();
}
response = client..({
: ,
: [{ : , : userInput }],
: ,
});
output = response.?.[]?.?. ?? ;
outputCheck = (output);
(!outputCheck.) {
;
}
output;
}
Step 4: Output Sanitization
function sanitizeOutput(response: string): string {
let cleaned = response;
cleaned = cleaned.replace(/(?:system prompt|instructions):?\s*.*/gi, '[REDACTED]');
cleaned = cleaned.replace(/<script[^>]*>[\s\S]*?<\/script>/gi, '');
cleaned = cleaned.replace(/\b\d{3}-\d{2}-\d{4}\b/g, '[SSN]');
cleaned = cleaned.replace(/\b[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Z]{2,}\b/gi, '[EMAIL]');
return cleaned;
}
Step 5: Request Logging Without Secrets
function logRequest(model: string, messages: any[], response: any): void {
console.log(JSON.stringify({
timestamp: new Date().toISOString(),
model,
messageCount: messages.length,
inputChars: messages.reduce((sum, m) => sum + (m.content?.length ?? 0), 0),
outputChars: response.choices?.[0]?.message?.content?.length ?? 0,
usage: {
promptTokens: response.usage?.promptTokens,
completionTokens: response.usage?.completionTokens,
},
}));
}
Step 6: API Key Rotation
class KeyRotator {
private keys: string[];
private current = 0;
private lastRotated = Date.now();
private readonly rotationIntervalMs = 3_600_000;
constructor(keys: string[]) {
if (keys.length === 0) throw new Error('At least one API key required');
this.keys = keys;
}
getKey(): string {
if (Date.now() - this.lastRotated > this.rotationIntervalMs) {
this.rotate();
}
return this.keys[this.current];
}
reportAuthFailure(): void {
console.error(`Key ${this.current} failed auth, rotating`);
this.();
}
(): {
. = (. + ) % ..;
. = .();
}
}
Security Audit Checklist
def audit_mistral_security():
checks = {
"api_key_from_env": bool(os.environ.get("MISTRAL_API_KEY")),
"gitignore_has_env": ".env" in open(".gitignore").read() if os.path.exists(".gitignore") else False,
"no_hardcoded_keys": True,
"moderation_enabled": True,
"output_sanitization": True,
"audit_logging": True,
}
passed = all(checks.values())
return {"passed": passed, "checks": checks}
Error Handling
| Issue | Cause | Solution |
|---|
| Key in logs | Logging full request | Log metadata only |
| Prompt injection | Unsanitized user input | Filter + XML-wrap user content |
| PII in responses | Model generating PII | Sanitize output + use moderation |
| Key compromise | Hardcoded or leaked | Use secret manager, rotate immediately |
| XSS via output | Model generating HTML/JS | Strip script tags before rendering |
Resources
Output
- API key management via secret managers
- Prompt injection defense layer
- Content moderation with
mistral-moderation-latest
- Output sanitization pipeline
- Secure audit logging
- Key rotation automation
