For AI agents: the complete documentation index is available at https://mfeflow.github.io/mfeflow/llms.txt, the full documentation bundle is available at https://mfeflow.github.io/mfeflow/llms-full.txt, and this page is available as Markdown at https://mfeflow.github.io/mfeflow/errors/E121.md.
mfeflow

    MFEFLOW_E121

    A server env key is not listed in turbo.json.

    Turborepo hides variables it was not told about from tasks, and it replays a cached build without running it. A key of the server schema that is not under globalEnv in turbo.json would not reach env.ts in CI, and a missing value would not fail a cached build.

    Fix

    Add the key to globalEnv in turbo.json. mfeflow add env-key does this for you.