Generated endpoints are usually 80% there and missing exactly the 20% that matters in production. This constraint block closes the gap:

"Write an Express + TypeScript endpoint.

Endpoint: [method] [path]
Purpose: [one sentence]

Non-negotiables:

• Validate the body with express-validator; return 422 with field-level errors

• Auth via the existing authMiddleware; 401 if absent, 403 if the role is wrong

• Wrap DB work in a transaction and roll back on any throw

• No secrets or IDs in log lines

• Return the shared ResponseHelper envelope, never res.json directly

• Paginate any list response, default 20, max 100

• Handle the unique-constraint violation explicitly, not as a 500"

The last two are the ones I used to fix by hand on every single generated endpoint. Putting them in the prompt cut my review time roughly in half.

Generated Outputs (1)

1 weeks ago

Claude

claude-sonnet-4

1 weeks ago

Generated Output

router.post("/orders", authMiddleware, validate(createOrderRules), async (req, res) => {
const t = await sequelize.transaction()
try {
const order = await Order.create({ ...req.body, user_id: req.user.id }, { transaction: t })
await t.commit()
return ResponseHelper.success(res, "Order created", order)
} catch (err) {
await t.rollback()
if (err instanceof UniqueConstraintError) {
return ResponseHelper.validationError(res, "Order reference already exists")
}
throw err
}
})

A Prompt That Writes Express Endpoints I Actually Ship

Generated Outputs (1)