SendGrid API Key Regex for Python

What this pattern does

This page provides a lightweight, single-purpose regular expression for matching sendgrid api key, ported and verified for Python. In security-sensitive code, using an unverified regex can open the door to both false positives and denial-of-service attacks. The snippet below is ready to drop into your Python project — whether you're validating in a Django view, a FastAPI endpoint, or a standalone data processing script.

Python Implementation

# SendGrid API Key
# ReDoS-safe | RegexVault — Security > API Keys & Tokens

import re

sendgrid_api_key_pattern = re.compile(r'^SG\.[A-Za-z0-9_\-.]{30,100}$')

def validate_sendgrid_api_key(value: str) -> bool:
    return bool(sendgrid_api_key_pattern.fullmatch(value))

# Example
print(validate_sendgrid_api_key("SG.aBcDeFgHiJkLmNoPqRsTuVw.aBcDeFgHiJkLmNoPqRsTuVwXyZ0123456789aBcDeFg"))  # True

Test Cases

When to use this pattern

This pattern is drawn from the Security > API Keys & Tokens category and carries a ReDoS-safe certification. That matters for Python developers because particularly important in Python web servers where CPU-bound regex operations can stall concurrent request handling. RegexVault audits patterns against known backtracking attack vectors, ensuring you have the necessary context before using this regex in a high-stakes production environment.

Common Pitfalls

Technical Notes

SendGrid API keys: SG. + 22-char API key ID + . + 43-char token. Three-part structure, always 69 characters after the SG. prefix. Can be scoped to specific mail operations (send, read stats, manage contacts).