Errors

The API uses conventional HTTP status codes. Any error response carries a JSON body with a stable, machine-readable code and a human-readable message:

{
  "error": {
    "code": "not_found",
    "message": "Booking not found"
  }
}

Branch on error.code in your integration; surface or log message for people.

Exception — unauthenticated reporting requests. The reporting endpoints (/reports, /reports/runs, /reports/files) answer a request with no credentials with 401 and a WWW-Authenticate: Basic challenge rather than the JSON envelope above. The body is plain text (HTTP Basic: Access denied.) and Content-Type is text/html. Do not parse that 401 as JSON. See Authentication.

Status	`error.code`	When it happens
`400`	`bad_request`	Malformed JSON or a missing required parameter.
`400`	`idempotency_key_in_use`	Same idempotency key reused with a different request body — see Idempotency.
`401`	`unauthorized`	Missing or invalid API key — see Authentication. On reporting endpoints, an unauthenticated request returns a Basic challenge instead of this envelope.
`404`	`not_found`	The resource doesn't exist, or isn't visible to your key.
`409`	`idempotency_key_in_progress`	A request with the same idempotency key is still being processed — see Idempotency.
`422`	`unprocessable_entity`	The request was well-formed but failed validation or a business rule.
`422`	`unsupported_api_version`	Unknown or unsupported `Easol-API-Version` — see Versioning.
`422`	`idempotency_key_required`	Required `Idempotency-Key` header missing on endpoints that mandate it — see Idempotency.
`422`	`idempotency_key_too_long`	`Idempotency-Key` exceeds 255 characters — see Idempotency.
`500`	`internal_server_error`	An unexpected error on our side. Safe to retry.
`503`	`idempotency_store_unavailable`	The idempotency store is temporarily unavailable — see Idempotency. Safe to retry.
`503`	`payment_provider_unavailable`	A payment provider is temporarily unreachable. Safe to retry.