PER CURIAM:

Lee Cantwell is a Texas prisoner who claims in this case that prison officials were deliberately indifferent to his serious medical needs, causing him injury and violating his constitutional rights. The defendants moved for summary judgment, contending that Cantwell failed to satisfy the statutory prerequisite under the Prison Litigation Reform Act of exhausting available administrative remedies prior to filing suit. See 42 U.S.C. § 1997e(a) ("No action shall be brought with respect to prison conditions under section 1983 of this title, or any other Federal law, by a prisoner confined in any jail, prison, or other correctional facility until such administrative remedies as are available are exhausted."). The district court granted the motion, and Cantwell appealed.

For the following reasons, Cantwell's appeal is not frivolous, and his motion to proceed in forma pauperis is therefore GRANTED. See Howard v. King, 707 F.2d 215, 220 (5th Cir.1983). We conclude that further briefing is unnecessary and now turn to the merits. See Fussell v. Vannoy, 584 Fed.Appx. 270, 271 (5th Cir.2014) (unpublished); Perkins v. Collins, 482 Fed. Appx. 959, 960 (5th Cir.2012) (unpublished).

Exhaustion is an affirmative defense; the defendants have the burden of proving that the plaintiff failed to exhaust available administrative remedies. Jones v. Bock, 549 U.S. 199, 216, 127 S.Ct. 910, 166 L.Ed.2d 798 (2007); Dillon v. Rogers, 596 F.3d 260, 266 (5th Cir.2010). Here, it is undisputed that Texas prisons have a two-step grievance process. Cantwell says that he filed a step-one grievance with prison authorities but never received a response. Because there was no response, he says, he did not proceed to the second step.1 The question for us is whether these circumstances suffice for exhaustion. But we cannot decide that issue on the present record.

Exhaustion is defined by the prison's grievance procedures, and courts neither may add to nor subtract from them. Jones, 549 U.S. at 218, 127 S.Ct. 910 ("[I]t is the prison's requirements, and not the PLRA, that define the boundaries of proper exhaustion."); Wright v. Hollingsworth, 260 F.3d 357, 358 (5th Cir.2001) ("Nothing in the Prison Litigation Reform Act, however, prescribes appropriate grievance procedures or enables judges, by creative interpretation of the exhaustion doctrine, to prescribe or oversee prison grievance systems."); Little v. Jones, 607 F.3d 1245, 1249 (10th Cir.2010) ("[T]he prison's procedural requirements define the steps necessary for exhaustion."). Here, however, we do not know what the applicable grievance procedures — those used in Cantwell's facility during the time period involved in this case — were. They are nowhere in the record because the defendants never introduced them as evidence. Texas does put its grievance procedures on its website, though, Tex. Dep't of Criminal Justice, Offender Orientation Handbook, available at http://www.tdcj.state.tx.us/documents/ Offender_Orientation_Handbook_English. pdf (last visited June 10, 2015), and we may take judicial notice of the state's website. See Coleman v. Dretke, 409 F.3d 665, 667 (5th Cir.2005). The procedures on the website, however, are dated January 2015, and the events involved in this case took place years prior. We have no evidence of whether the procedures were the same during the relevant time, so the state's website is of no help here. In short, the defendants have not put before the district court or this court the applicable grievance procedures (and we stress applicable — the ones in force at the relevant time, in the relevant place).

Without knowing what the applicable grievance procedures say, it's impossible to determine whether Cantwell exhausted them. See Scott v. Poret, 548 Fed.Appx. 160, 160 (5th Cir.2013) (unpublished); Torns v. Miss. Dep't of Corr., 301 Fed. Appx. 386, 389 n. 3 (5th Cir.2008) (unpublished). The defendants had the burden to establish that there were available procedures that Cantwell did not exhaust, and the district court erred in not holding them to it.2

The district court's summary judgment is REVERSED. The case is REMANDED for further proceedings.