TypeScript Coding Standards
Apply these conventions when writing, reviewing, or refactoring TypeScript in frontend apps, backend services, workers, and shared libraries.
Read the target repository's AGENTS.md, package scripts, and lint/test
configuration first. Explicit local requirements take precedence over these
shared defaults. Keep changes within the requested scope; existing violations
do not justify an unrelated repository-wide migration.
Guides
Read the guides relevant to the change before editing.
| Guide | Read when |
|---|---|
| TypeScript contracts | Writing or reviewing functions, arguments, types, or constants. |
| File naming and size | Creating, renaming, or splitting files. |
| Comments and JSDoc | Documenting functions, types, or non-obvious logic. |
| Modules and organization | Choosing exports, import boundaries, or where code belongs. |
| Dependencies and catalogs | Adding or updating dependencies, package manifests, catalogs, or lockfiles. |
| Runtime behavior | Handling errors, external data, service dependencies, or backend import boundaries. |
| React and Next.js | Changing components, callbacks, or hooks; read the Next.js section only in Next.js apps. |
| Testing | Deciding whether a test is useful, adding coverage, or reviewing assertions. |
| Tooling and verification | Selecting tools or validating a code change. |
For backend-only work, skip the React guide. Use the consumer's existing tooling and runtime conventions; the skill does not require adopting another repo's framework, formatter, or dependencies.