A complaint for divorce is called a petition in Texas, while a summons is called a citation. The state's rules for serving and responding to these papers are similar to those in other jurisdictions.
Service of Petition
After your spouse files her petition for divorce, she must make sure you receive a copy. She can ask the county sheriff or constable to deliver the papers to you, or use a private process server approved by the court. If your divorce is amicable, she can give you the papers herself and you can waive official service. The petition tells you what she's requesting as part of the divorce, while the citation explains when and how you should respond.
Time to Respond
Texas gives you 20 days to respond to your spouse's petition, but you usually have a little more time than this -- up until 10:00 a.m. on the first Monday after the 20th day. If the 20th day is a Tuesday, you actually have six more days, until the following Monday morning, to file. You can submit a simple document called an answer, letting the court know that you want to be involved in the proceedings. You can also file a counter-petition, telling the court what you want the judge to award you. If you do nothing, your spouse can ask for a divorce by default -- and in this case, the court will generally give her everything she requested in her petition.