| 2001 | UnknownRouteVersion | A route version is missing from the catalog |
| 2002 | DuplicateRoute | Two routes share a method, path, and version |
| 2003 | MissingVersionFile | keja.versioning.ts is missing |
| 2004 | InvalidVersionFile | The version file has no catalog export |
| 2005 | MissingRouteDirectory | The public or service folder is missing |
| 2006 | InvalidRouteFile | A route file exports no defineRoute |
| 2007 | InvalidMiddlewareFile | _middleware.ts has no middleware export |
| 2008 | InvalidVersionId | A version id is not v plus a whole number |
| 2009 | InvalidReleaseDate | A release date cannot be read |
| 2010 | InvalidStatusCode | A response code is outside 100–599 |
| 2011 | InvalidRouteMiddleware | A route middleware was not created with defineMiddleware |
| 2012 | InvalidConfigFile | keja.config.ts is not a defineConfig result |
| 2013 | DatabaseUrl | DATABASE_URL is missing or is not a postgres URL |
| 2014 | MissingMigrations | The migrations folder is missing |
| 2015 | InvalidMigrationFile | A migration file is not 0001_name.sql |
| 2016 | DuplicateMigration | Two files share a migration number |
| 2017 | MigrationChanged | An applied file changed |
| 2018 | MigrationFailed | Postgres rejected a migration |
| 2019 | AccessConfig | Cloudflare Access is missing a team or audience |
| 2020 | ServiceMethod | A service route is not POST |
| 2021 | OwnedObjects | A table does not match the OwnedObjects shape |
| 2022 | DatabaseInit | Postgres could not be reached while the database is enabled |
| 2023 | ArgusInit | The first Argus registration failed |
| 2024 | VaultInit | The Vault token lookup failed |
| 2025 | DependencyNotMet | A feature ran while one it requires is disabled |
| 2026 | InvalidSeeder | A seeder table or row does not match OwnedObjects |
| 2027 | InvalidSeederFile | A seed file exports no defineSeeder |
| 2028 | InvalidRepositorySql | A migration cannot be read as a repository table |
| 2029 | InvalidRepositoryFile | keja.repositories.ts does not export repository flags |
| 2030 | InvalidRoute | A route definition has a method, path, or schema Keja cannot use |