Error Structure

Status Codes

Status	Meaning	Returned by
`400`	Invalid body, occupancy, components, inventory or currency.	Book
`401`	Missing or invalid API key.	All APIs
`404`	Listing not found, or not bookable for your organisation.	Package Details, Day-wise Itinerary, Book
`409`	Prices have changed: `total_amount` does not match the current price.	Book
`500`	Unexpected error.	All APIs

Error Response Formats

401 Unauthorized

{
  "success": false,
  "code": 401,
  "message": "Unauthorized"
}

Key	Type	Description
`success`	Boolean	Always `false` for errors.
`code`	Integer	HTTP status code.
`message`	String	Error message.

400 and 404

{
  "status": 404,
  "message": "Listing not found"
}

Key	Type	Description
`status`	Integer	HTTP status code.
`message`	String	What went wrong.

409 Prices Have Changed

{
  "status": 409,
  "message": "Prices have changed",
  "data": {
    "requested_amount": 80000.0,
    "expected_amount": 85000.0,
    "difference": 5000.0,
    "currency": "INR"
  }
}

Key	Type	Description
`status`	Integer	`409`.
`message`	String	Always `Prices have changed`.
`data.requested_amount`	Number	The `total_amount` you sent.
`data.expected_amount`	Number	The current price for these travellers and selections.
`data.difference`	Number	`expected_amount` minus `requested_amount`.
`data.currency`	String	Currency of the amounts.

How to Handle Errors

Status	What to do
`400`	Check the request: every room fits the room rules, the codes come from the Package Details response, and every field is sent (`[]` when nothing was chosen). See Pricing and Occupancy Rules.
`401`	Check that the `x-api-key` header is sent as `Bearer <API_KEY>`, and that the key matches the environment (sandbox or production).
`404`	Check the package `code`. The package may no longer be available; refresh your listings.
`409`	Read the package again with the Package Details API, recalculate the total, show the new price to the traveller and call Book again.
`500`	Retry after a short wait. If it continues, contact Volt API support.