If you’re not familiar with this sauce, and you like things spicy, do yourself a favor and find a bottle. Sriracha is a hot sauce made from chili peppers, garlic, vinegar, sugar, and salt. Those ingredients come together to make an amazing spicy, sweet, garlicky combo that works well on its own drizzled over stir-fried noodles or when mixed with other ingredients. I love to mix a few drops into some veganaise for dipping my fries into. It also gives a great kick to sauces mixed with tahini or peanut butter.
Most brands should be vegan, considering the traditional ingredients used. The brand I’m most familiar with is Huy Fong, which I know for sure is vegan and is readily available at most Asian markets. Many supermarkets also seem to sell the Flying Goose brand (in small, squat bottles) which is also vegan, although gram for gram a lot more expensive. If you stumble on other brands, I’d definitely advise checking the ingredient list just to be sure.