CircleCI will end support for configuration version: 2.0 on June 27, 2026. After this date, all pipelines must use version: 2.1.
CircleCI has supported two config versions for several years: v2 (legacy) and v2.1 (current). Version 2.1 introduced orbs, pipeline parameters, reusable commands, reusable executors, and a well-defined schema with strict validation. As we build next-generation config tooling, we are consolidating onto v2.1 as the single supported configuration format.
For a step-by-step migration guide and common issues, see the detailed guide on CircleCI Discuss.