SEND Packages API

Status	Meaning	Recovery
`400`	Malformed request or missing `rate_id`	Check JSON shape, field types, and required ids.
`401`	Missing or invalid API key	Send a valid `X-Api-Key`; verify environment.
`403`	Forbidden (`CANCELLATION_NOT_ALLOWED`)	Cancellation is Send-operated. Contact support.
`404`	Not found (`RECORD_NOT_FOUND`)	Unknown quote, parcel, or customer id.
`409`	Idempotency conflict (`IDEMPOTENCY_CONFLICT`)	The key was reused with different content. Use a fresh key.
`422`	Validation or business rule failure	Read `errors` and `code`:

Code	Cause	Recovery
`VALIDATION_ERROR`	Unsupported lane, mode, commodity, measurements, or forbidden fields	Fix the named fields; see Transport Modes and Cargo.
`EXPORT_NOT_SUPPORTED`	Export direction requested	Only `import` is supported.
`RATE_NOT_CONFIGURED`	Lane/mode has no pricing configured	Pick a supported lane and mode.
`RATE_NOT_FOUND`	`rate_id` not on the quote	`GET` the quote and use a current rate id.
`QUOTE_RATE_OUTDATED`	Rate older than one hour	`GET` the quote to refresh, then retry with the new id.
`INVALID_PARTY`	Sender/recipient missing, unknown, or incomplete	Sender requires a resolving `customer_id`. Recipient needs manual `name`/`phone`/`address`, or `customer_as_recipient: true`.
`INVALID_STATUS`	Quote not pending	Only pending quotes can be booked.
`QUOTE_CANCELLED`	Quote was cancelled	Cancelled quotes never convert; start a new quote.

Error bodies carry an errors array and, where applicable, a stable code.