OP session-management iframe (OIDC Session Management 1.0 §3.2)
/check_session_iframeServes the OP iframe an RP embeds to poll the end user's login status at
the provider without network traffic. It accepts postMessage payloads of
the form <client_id> <session_state> from the RP iframe and posts back
unchanged, changed, or error.
Relying parties must append ?client_id=<their client id>. §3.2
requires the OP iframe to "enforce that the caller is from an expected
origin" and to "reject postMessage requests from any other source origin",
and the only way this page can know which origins are expected is to be
told which client is asking: the parameter selects that client's registered
redirect-URI origins as the page's allowlist.
A page loaded from the bare URL — which is what the check_session_iframe
metadata value is, since one fixed URL cannot name a client — therefore has
an empty allowlist and answers nobody. Not knowing which origins are
expected is not a license to accept every origin.
A rejected caller receives no reply at all. §3.1 assigns a meaning to each of the three replies and none of them means "you should not be talking to me", and answering would confirm to an unexpected origin that it has found the OP iframe.
- client_idstring
The RP whose registered redirect-URI origins become the page's postMessage allowlist, and the only client the page will answer about. Nominally optional, because the metadata value cannot carry one; a page loaded without it answers no origin at all. An unknown client_id is treated the same as none, so this cannot be used to enumerate clients.
at most 256 characters
- Cookiestring
The request Cookie header; the interactive login / pending-auth session cookie, and the browser marker a sign-in is recognized by, are read from it.
200 OKtext/htmlThe OP session-management iframe document.
The OP session-management iframe document.
Headers
Content-Security-PolicystringPer-response policy carrying the script nonce and a framable frame-ancestors.Cache-Controlno-storePragmano-cache
429 Too Many Requestsapplication/problem+jsonToo many requests.
Too many requests.
Body
RFC 9457 (formerly RFC 7807) problem details (application/problem+json).
codeis a stable machine-readable slug for the problem kind (it mirrors the suffix oftype), so consumers can branch on it without parsing prose.errorsis present on validation failures and lists every offending field.- Example
"Request validation failed" - Example
400 - typestring · uriExample
"urn:problem-type:validation_error" - detailstringExample
"One or more fields did not satisfy the API schema." - codeenum
The kind of problem, as a stable machine-readable slug a client branches on and translates rather than parsing
titleordetail, which are English prose for logs. A problem whose status says everything the server knows carries nocode.Show moreShow less
validation_erroris the one code whose message is not a sentence about the code itself: the request failed the schema, and the specifics are theerrorslist — one entry per offending field — which a form renders on those fields.requiredandmalformedare spelled like two of the per-field violation codes (FieldError.code) but mean something else; the two vocabularies are told apart by position, never by spelling.Compatibility: this is a CLOSED enum, with the same cost as
AuditAction: a client generated against an older version of this document rejects a problem carrying a code added after it was built. Regenerate on upgrade, or decode the field as a plain string. It is enumerated anyway so that what a client must translate is knowable from the contract alone.Possible values"invalid_request""invalid_credentials""forbidden""unauthorized""insufficient_user_authentication""protected_account""last_role_administrator""invalid_code""too_many_requests""too_many_attempts""account_locked""account_unavailable""already_enrolled""registration_disabled""registration_conflict""captcha_failed""invalid_reset_link""invalid_verification_link""invalid_invitation_link""mail_relay_missing""not_found""conflict""unavailable""busy""window_too_large""too_many_series""internal_error""rate_limited""malformed""body_too_large""required""validation_error""unknown_org""invalid_token""invalid_dpop_proof""use_dpop_nonce""server_error" - instancestringExample
"/introspect" - request_idstringExample
"8d94ed49-1caf-4ab3-9594-557142f2d023" - trace_idstring
Distributed-trace id (hex) for correlating this response with traces and logs. Present only when tracing is enabled and the request was recorded. Opaque and safe to log/share.
Example"4bf92f3577b34da6a3ce929d0e0e4736" - errorsarray of objects
Field-level violations (present for validation errors).
Each item:A single field-level validation violation.
Show item attributesHide item attributes
Offending field, dotted for nested bodies (e.g. child.id).
Example"token_type_hint"Machine-readable violation code: required, too_short, too_long, pattern, invalid_format, not_allowed, minimum, maximum, multiple_of, too_few, too_many, not_unique, malformed.
Example"not_allowed"- Example
"field token_type_hint must be one of [access_token, refresh_token]"
Errorapplication/jsonOAuth2 error response (RFC 6749 §5.2).
OAuth2 error response (RFC 6749 §5.2).
Headers
Cache-Controlno-storeWWW-AuthenticatestringDPoP-Noncestring
Body
An OAuth2 error response (RFC 6749 §5.2).
iss(RFC 9207) is present on authorization-endpoint error responses so clients can detect mix-up.A single ASCII error code.
Example"invalid_request"- error_descriptionstringExample
"client_id, redirect_uri and response_type are required" - error_uristring · uri
- statestring
Echoed authorization-request state (RFC 6749 §4.1.2.1).
- issstring · uri
Issuer identifier on authorization error responses (RFC 9207).