---
set: 4
code: 417
title: Expectation Failed
references:
    "Rails HTTP Status Symbol": ":expectation_failed"
    "Go HTTP Status Constant": "http.StatusExpectationFailed"
    "Symfony HTTP Status Constant": "Response::HTTP_EXPECTATION_FAILED"
    "Python2 HTTP Status Constant": "httplib.EXPECTATION_FAILED"
    "Python3+ HTTP Status Constant": "http.client.EXPECTATION_FAILED"
    "Python3.5+ HTTP Status Constant": "http.HTTPStatus.EXPECTATION_FAILED"
---

The expectation given in the request's Expect header field<sup>[1](#ref-1)</sup> could not be met by at least one of the inbound servers.

---

* <span id="ref-1"><sup>1</sup> Expect [RFC7231 Section 5.1.1][2]</span>
* Source: [RFC7231 Section 6.5.14][1]

[1]: <http://tools.ietf.org/html/rfc7231#section-6.5.14>
[2]: <http://tools.ietf.org/html/rfc7231#section-5.1.1>