# List a user's ended sessions (admin)

`GET /v1/admin/orgs/{slug}/users/{id}/session-history`

Returns one page of the sessions of the user in the path that ended
within the window, newest end first unless `sort` says otherwise, using
opaque cursor (keyset) pagination. A user's active sessions are
`adminListSessions` with `user_id`.

A session ended on purpose is kept from the moment it ends; one that
timed out is kept as ending when its idle timeout or absolute lifetime
ran out. The user's sessions that have timed out but were not yet swept
are ended before the page is read, so the history holds every one of
them. Ended sessions are kept for the deployment's retention
(`auth.session.history_retention`).

`from` and `to` bound the end time: `from` inclusive, `to` exclusive.
Omitting both means the last 30 days; a window wider than the 90 days
`x-window` allows is refused with a 400, so an older history is read by
moving the window. A cursor is bound to the window it was issued for, so
send it with it.

The address, user agent and device are personal data: a caller without
the `users.pii.read` permission receives none of them. Reading the
history is audited at trace level, since the dashboard polls it.
Requires the `nauthera.sessions:read` scope and the `sessions.read`
permission. The id must belong to `slug`'s organization; one that
belongs to another is answered as 404, exactly like an id that does not
exist.

## Authorization

- [Bearer token](https://www.nauthera.io/docs/v1/api#auth-bearerAuth) (`bearerAuth`) and [OAuth 2.0](https://www.nauthera.io/docs/v1/api#auth-oauth2) (`oauth2`) with scope `nauthera.sessions:read`

Authorization header: The access token, as `Bearer <token>` (RFC 6750 §2.1) or, for a sender-constrained token, `DPoP <token>` (RFC 9449 §7.1). A token minted with a `cnf.jkt` confirmation is only accepted together with a `DPoP` proof signed by that key, whichever of the two schemes carries it.

Requires the permission [`sessions.read`](https://www.nauthera.io/docs/v1/api#permission-sessions.read): Read users' sessions.

This endpoint is rate limited; it answers `429` when a limit is hit.

## Path parameters

- `slug` (string, required): The organization slug. It names the TENANT OF RECORD for the operation: the rows it reads and writes, the policy its secrets are derived under, and the organization its audit record is filed against all come from this organization. A token is admitted only through its own slug, except a main-org token, which may be admitted through any — so cross-tenant administration is performed through the TARGET tenant's slug, never by naming its resources through another. A token reaching for a slug it may not be admitted through is refused identically whether that organization exists or not. Constraints: 1–64 characters.
- `id` (string, required): The user id (UUID). Constraints: 1–64 characters.

## Query parameters

- `limit` (integer, optional): Maximum number of items to return in one page (1–200; default 50). A value outside that range is rejected with a 400. It may be changed freely between pages of the same walk — a cursor marks a position, not a page number. Default: `50`. Constraints: between 1 and 200.
- `sort` (string, optional): Ordering for the listing: a comma-separated list of fields, most significant first, a leading `-` marking a descending term. For example `sort=last_name,-first_name` sorts by last name ascending, then by first name descending. Constraints: at most 256 characters; pattern `^-?[a-z][a-z0-9_]*(,-?[a-z][a-z0-9_]*)*$`. Sortable fields: `ended_at`, `id`. Prefix a field with `-` to sort descending.

  Which fields a given endpoint accepts is listed in its `x-sort-fields`
  extension; naming anything else is a 400. A field may appear only once.

  The server always appends the resource's primary key as a final term, so
  the ordering is TOTAL — rows that tie on every field you named still have
  a defined relative order, without which a page could skip or repeat them.
  The full ordering, including that appended term, is echoed as `page.sort`.

  Send it on the FIRST request of a walk only: every cursor records the
  ordering it was issued under, so it carries forward automatically, and a
  `sort` that contradicts the supplied `cursor` is rejected with a 400
  rather than silently reordering mid-walk.
- `cursor` (string, optional): Opaque keyset cursor identifying where a page begins. Omit it for the first page; afterwards pass the `next_cursor` (or `prev_cursor`) value from the previous response verbatim — the token itself records which direction it steps in, so there is no separate direction parameter. Constraints: at most 1024 characters.

  The token is server-defined and MUST be treated as opaque: it is bound
  to the listing and sort order that issued it, and a cursor that is
  malformed, tampered with, or belongs to a different listing or order is
  rejected with a 400 rather than silently paging through the wrong set.
- `from` (string (date-time), optional): Inclusive start of the end-time window (RFC3339). Defaults to 30 days before `to`. The window from `from` to `to` may span at most 90 days.
- `to` (string (date-time), optional): Exclusive end of the end-time window (RFC3339). Defaults to now. The window from `from` to `to` may span at most 90 days.

## Headers

- `DPoP` (string, optional): DPoP proof JWT (RFC 9449 §4). REQUIRED on a request presenting a DPoP-bound access token, and it must be signed by the key named in the token's `cnf.jkt` and cover this request's method and URI. The proof is read from the request itself rather than from this decoded parameter, so every protected operation is covered whether or not it declares it.

## Responses

### 200 OK

One page of the user's ended sessions.

Content type: `application/json`

Headers:
- `Cache-Control` = `no-store`

One page of a user's ended sessions under cursor (keyset) pagination,
ordered by the request's `sort`. Follow `page.next_cursor` while
`page.has_more` is true.

- `items` (array of objects, required): The ended sessions on this page.

  Each item: A session that has ended, as the session history keeps it: when it began, was last used and ended, why it ended, how its user authenticated and the clients that took part in it. `id` is the session's public id, the `sid` its relying parties received. The address and user agent it was established from, and the `device` read from that user agent, are personal data: a caller without the `users.pii.read` permission receives none of them, and `withheld` names the address and user agent.
  - `id` (string, required): The public session id (`sid`).
  - `created_at` (string (date-time), required): When the user signed in and the session began.
  - `auth_time` (string (date-time), required): When the user last authenticated in this session.
  - `last_seen_at` (string (date-time), required): When the session was last used.
  - `expires_at` (string (date-time), required): The absolute lifetime the session had.
  - `ended_at` (string (date-time), required): When the session ended: when it was ended on purpose, or when its idle timeout or absolute lifetime ran out, whenever that was noticed.
  - `end_reason` (enum, required): Why a session ended: the user signed out (`logout`), an administrator ended it (`admin_revoked`), set the user's password (`password_reset`) or changed the account's status (`account_status`), the user changed their second factor from another session (`second_factor_changed`), the account's address was proven and the identity provider links made before it were removed (`address_proven`), or it went unused for its idle timeout (`expired_idle`) or reached its absolute lifetime (`expired_absolute`). One of: `"logout"`, `"admin_revoked"`, `"password_reset"`, `"account_status"`, `"second_factor_changed"`, `"address_proven"`, `"expired_idle"`, `"expired_absolute"`.
  - `amr` (array of strings, required): The authentication methods the user satisfied (RFC 8176).
  - `client_ids` (array of strings, required): The OAuth client ids of the clients that took part in the session, sorted. Empty when none did.
  - `withheld` (array of enums, required): The personal fields left out because the caller lacks the `users.pii.read` permission; empty when nothing was withheld. One of: `"display_name"`, `"ip"`, `"user_agent"`.

    Each item: A personal field of a session that was left out because the caller lacks the `users.pii.read` permission: the user's display name, the address the session was established from, or its user agent.
  - `acr` (string, optional): The authentication context class satisfied. Absent when none was recorded.
  - `ip` (string, optional): The address the session was established from. Absent when not recorded, or withheld.
  - `ip_country` (string, optional): The ISO 3166-1 alpha-2 code of the country `ip` is in. Present only when the server has an IP geolocation database (`geoip.database`) that knows the address; absent whenever `ip` is. Constraints: pattern `^[A-Z]{2}$`. Example: `"CH"`.
  - `user_agent` (string, optional): The user agent the session was established from. Absent when not recorded, or withheld.
  - `device` (string, optional): The browser and system the user agent names ("Firefox on Linux"). Absent when the user agent names neither, or was withheld. Example: `"Firefox on Linux"`.
- `page` (object, required): Where one page sits in a cursor (keyset) paginated list, returned beside that page's `items`.

  Walk a list by following `next_cursor` for as long as `has_more` is true,
  passing the token back verbatim as the `cursor` query parameter. Keep the
  listing and its filters the same for the whole walk; `limit` MAY change
  between pages (a cursor marks a position, not a page number), and `sort`
  travels in the cursor so it need not be resent. `has_more` is
  authoritative: it is derived from whether a further row actually exists,
  so a page that happens to be full is not mistaken for a page that has a
  successor, and a walk never costs a trailing empty request. `prev_cursor`
  steps back the same way.

  A cursor is opaque — server-defined, bound to this listing and sort
  order, and not parseable by clients. It stays valid across page-size
  changes but not across a change of sort order or filters; a cursor that
  does not belong to the request is rejected with a 400 rather than
  silently paging through the wrong set.

  Keyset paging is stable under concurrent writes, with one qualification.
  A row whose SORT KEY does not change is returned exactly once for the
  whole walk. Rows created or deleted mid-walk may or may not appear,
  depending on which side of the cursor they fall — and so may a row whose
  sort key is UPDATED mid-walk, since that moves it across the boundary: it
  can be seen twice or missed. Sorting by a field that does not change (the
  default id ordering, or `created_at`) avoids this entirely.
  - `limit` (integer, required): The page size in effect: the `limit` that was sent, or the server's default when it was omitted. Echoed so a client resuming from a stored cursor knows the page size without having to remember it. Example: `50`.
  - `sort` (string, required): The ordering this walk is pinned to, in the `sort` parameter's syntax and INCLUDING the primary-key term the server appends to make it total. Cursors carry it, so it need only be sent on the first request. Example: `"last_name,-first_name,id"`.
  - `has_more` (boolean, required): Whether a page follows this one and `next_cursor` can reach it. When false this is the last page and `next_cursor` is absent.
  - `has_prev` (boolean, required): Whether a page precedes this one and `prev_cursor` can reach it. False on the first page of a walk.

    Both flags report REACHABILITY, not bare existence. A cursor that overshoots the set — a stale bookmark, or rows deleted mid-walk — returns an empty page with both flags false even though rows precede it, because an empty page has no row to anchor a cursor on. Restart the walk if you land there; a client following `has_more` never does.
  - `next_cursor` (string, optional): Opaque cursor for the next page. Present exactly when `has_more` is true, and ABSENT (the field is omitted, not null) otherwise. Pass it back verbatim as the `cursor` query parameter; never parse it. Constraints: at most 512 characters.
  - `prev_cursor` (string, optional): Opaque cursor for the previous page. Present exactly when `has_prev` is true, and absent otherwise. Passed back as `cursor`, exactly like `next_cursor` — the token itself records which way it steps. Constraints: at most 512 characters.

### 400 Bad Request

The window or the pagination parameters were invalid: a window that ends at or before it starts or is wider than `x-window` allows, a malformed instant, or a cursor that is malformed, foreign or contradicts `sort`.

Content type: `application/problem+json`

RFC 9457 (formerly RFC 7807) problem details (application/problem+json). `code` is a stable machine-readable slug for the problem kind (it mirrors the last path segment of `type`), so consumers can branch on it without parsing prose. `type` is `https://nauthera.io/problems/<code>`, which resolves to the code's runbook: why it happened, who is affected and what to do (RFC 9457 §3.1.1). A problem without a code has `about:blank`. `errors` is present on validation failures and lists every offending field.

- `title` (string, required): Example: `"Request validation failed"`.
- `status` (integer, required): Example: `400`.
- `type` (string (uri), optional): Example: `"https://nauthera.io/problems/validation_error"`.
- `detail` (string, optional): Example: `"One or more fields did not satisfy the API schema."`.
- `code` (enum, optional): The kind of problem, as a stable machine-readable slug a client branches on and translates rather than parsing `title` or `detail`, which are English prose for logs. A problem whose status says everything the server knows carries no `code`. One of: `"invalid_request"`, `"invalid_credentials"`, `"forbidden"`, `"unauthorized"`, `"insufficient_user_authentication"`, `"protected_account"`, `"password_held_by_directory"`, `"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"`, `"password_reused"`, `"password_too_short"`, `"password_too_long"`, `"password_compromised"`, `"invalid_verification_link"`, `"invalid_invitation_link"`, `"mail_relay_missing"`, `"email_unverified"`, `"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"`.

  `validation_error` is the one code whose message is not a sentence about
  the code itself: the request failed the schema, and the specifics are
  the `errors` list — one entry per offending field — which a form renders
  on those fields. `required` and `malformed` are 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.
- `instance` (string, optional): Example: `"/introspect"`.
- `request_id` (string, optional): Example: `"8d94ed49-1caf-4ab3-9594-557142f2d023"`.
- `trace_id` (string, optional): 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"`.
- `errors` (array of objects, optional): Field-level violations (present for validation errors).

  Each item: A single field-level validation violation.
  - `field` (string, required): Offending field, dotted for nested bodies (e.g. child.id). Example: `"token_type_hint"`.
  - `code` (string, required): 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"`.
  - `message` (string, required): Example: `"field token_type_hint must be one of [access_token, refresh_token]"`.

### 401 Unauthorized

Problem details (RFC 9457) with an RFC 6750 / RFC 9449 challenge.

Content type: `application/problem+json`

Headers:
- `Cache-Control` = `no-store`
- `WWW-Authenticate` (string)
- `DPoP-Nonce` (string)

RFC 9457 (formerly RFC 7807) problem details (application/problem+json). `code` is a stable machine-readable slug for the problem kind (it mirrors the last path segment of `type`), so consumers can branch on it without parsing prose. `type` is `https://nauthera.io/problems/<code>`, which resolves to the code's runbook: why it happened, who is affected and what to do (RFC 9457 §3.1.1). A problem without a code has `about:blank`. `errors` is present on validation failures and lists every offending field.

- `title` (string, required): Example: `"Request validation failed"`.
- `status` (integer, required): Example: `400`.
- `type` (string (uri), optional): Example: `"https://nauthera.io/problems/validation_error"`.
- `detail` (string, optional): Example: `"One or more fields did not satisfy the API schema."`.
- `code` (enum, optional): The kind of problem, as a stable machine-readable slug a client branches on and translates rather than parsing `title` or `detail`, which are English prose for logs. A problem whose status says everything the server knows carries no `code`. One of: `"invalid_request"`, `"invalid_credentials"`, `"forbidden"`, `"unauthorized"`, `"insufficient_user_authentication"`, `"protected_account"`, `"password_held_by_directory"`, `"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"`, `"password_reused"`, `"password_too_short"`, `"password_too_long"`, `"password_compromised"`, `"invalid_verification_link"`, `"invalid_invitation_link"`, `"mail_relay_missing"`, `"email_unverified"`, `"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"`.

  `validation_error` is the one code whose message is not a sentence about
  the code itself: the request failed the schema, and the specifics are
  the `errors` list — one entry per offending field — which a form renders
  on those fields. `required` and `malformed` are 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.
- `instance` (string, optional): Example: `"/introspect"`.
- `request_id` (string, optional): Example: `"8d94ed49-1caf-4ab3-9594-557142f2d023"`.
- `trace_id` (string, optional): 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"`.
- `errors` (array of objects, optional): Field-level violations (present for validation errors).

  Each item: A single field-level validation violation.
  - `field` (string, required): Offending field, dotted for nested bodies (e.g. child.id). Example: `"token_type_hint"`.
  - `code` (string, required): 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"`.
  - `message` (string, required): Example: `"field token_type_hint must be one of [access_token, refresh_token]"`.

### 403 Forbidden

Problem details (RFC 9457) with an RFC 6750 / RFC 9449 challenge.

Content type: `application/problem+json`

Headers:
- `Cache-Control` = `no-store`
- `WWW-Authenticate` (string)
- `DPoP-Nonce` (string)

RFC 9457 (formerly RFC 7807) problem details (application/problem+json). `code` is a stable machine-readable slug for the problem kind (it mirrors the last path segment of `type`), so consumers can branch on it without parsing prose. `type` is `https://nauthera.io/problems/<code>`, which resolves to the code's runbook: why it happened, who is affected and what to do (RFC 9457 §3.1.1). A problem without a code has `about:blank`. `errors` is present on validation failures and lists every offending field.

- `title` (string, required): Example: `"Request validation failed"`.
- `status` (integer, required): Example: `400`.
- `type` (string (uri), optional): Example: `"https://nauthera.io/problems/validation_error"`.
- `detail` (string, optional): Example: `"One or more fields did not satisfy the API schema."`.
- `code` (enum, optional): The kind of problem, as a stable machine-readable slug a client branches on and translates rather than parsing `title` or `detail`, which are English prose for logs. A problem whose status says everything the server knows carries no `code`. One of: `"invalid_request"`, `"invalid_credentials"`, `"forbidden"`, `"unauthorized"`, `"insufficient_user_authentication"`, `"protected_account"`, `"password_held_by_directory"`, `"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"`, `"password_reused"`, `"password_too_short"`, `"password_too_long"`, `"password_compromised"`, `"invalid_verification_link"`, `"invalid_invitation_link"`, `"mail_relay_missing"`, `"email_unverified"`, `"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"`.

  `validation_error` is the one code whose message is not a sentence about
  the code itself: the request failed the schema, and the specifics are
  the `errors` list — one entry per offending field — which a form renders
  on those fields. `required` and `malformed` are 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.
- `instance` (string, optional): Example: `"/introspect"`.
- `request_id` (string, optional): Example: `"8d94ed49-1caf-4ab3-9594-557142f2d023"`.
- `trace_id` (string, optional): 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"`.
- `errors` (array of objects, optional): Field-level violations (present for validation errors).

  Each item: A single field-level validation violation.
  - `field` (string, required): Offending field, dotted for nested bodies (e.g. child.id). Example: `"token_type_hint"`.
  - `code` (string, required): 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"`.
  - `message` (string, required): Example: `"field token_type_hint must be one of [access_token, refresh_token]"`.

### 404 Not Found

Problem details (RFC 9457).

Content type: `application/problem+json`

RFC 9457 (formerly RFC 7807) problem details (application/problem+json). `code` is a stable machine-readable slug for the problem kind (it mirrors the last path segment of `type`), so consumers can branch on it without parsing prose. `type` is `https://nauthera.io/problems/<code>`, which resolves to the code's runbook: why it happened, who is affected and what to do (RFC 9457 §3.1.1). A problem without a code has `about:blank`. `errors` is present on validation failures and lists every offending field.

- `title` (string, required): Example: `"Request validation failed"`.
- `status` (integer, required): Example: `400`.
- `type` (string (uri), optional): Example: `"https://nauthera.io/problems/validation_error"`.
- `detail` (string, optional): Example: `"One or more fields did not satisfy the API schema."`.
- `code` (enum, optional): The kind of problem, as a stable machine-readable slug a client branches on and translates rather than parsing `title` or `detail`, which are English prose for logs. A problem whose status says everything the server knows carries no `code`. One of: `"invalid_request"`, `"invalid_credentials"`, `"forbidden"`, `"unauthorized"`, `"insufficient_user_authentication"`, `"protected_account"`, `"password_held_by_directory"`, `"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"`, `"password_reused"`, `"password_too_short"`, `"password_too_long"`, `"password_compromised"`, `"invalid_verification_link"`, `"invalid_invitation_link"`, `"mail_relay_missing"`, `"email_unverified"`, `"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"`.

  `validation_error` is the one code whose message is not a sentence about
  the code itself: the request failed the schema, and the specifics are
  the `errors` list — one entry per offending field — which a form renders
  on those fields. `required` and `malformed` are 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.
- `instance` (string, optional): Example: `"/introspect"`.
- `request_id` (string, optional): Example: `"8d94ed49-1caf-4ab3-9594-557142f2d023"`.
- `trace_id` (string, optional): 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"`.
- `errors` (array of objects, optional): Field-level violations (present for validation errors).

  Each item: A single field-level validation violation.
  - `field` (string, required): Offending field, dotted for nested bodies (e.g. child.id). Example: `"token_type_hint"`.
  - `code` (string, required): 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"`.
  - `message` (string, required): Example: `"field token_type_hint must be one of [access_token, refresh_token]"`.

### 429 Too Many Requests

Too many requests.

Content type: `application/problem+json`

RFC 9457 (formerly RFC 7807) problem details (application/problem+json). `code` is a stable machine-readable slug for the problem kind (it mirrors the last path segment of `type`), so consumers can branch on it without parsing prose. `type` is `https://nauthera.io/problems/<code>`, which resolves to the code's runbook: why it happened, who is affected and what to do (RFC 9457 §3.1.1). A problem without a code has `about:blank`. `errors` is present on validation failures and lists every offending field.

- `title` (string, required): Example: `"Request validation failed"`.
- `status` (integer, required): Example: `400`.
- `type` (string (uri), optional): Example: `"https://nauthera.io/problems/validation_error"`.
- `detail` (string, optional): Example: `"One or more fields did not satisfy the API schema."`.
- `code` (enum, optional): The kind of problem, as a stable machine-readable slug a client branches on and translates rather than parsing `title` or `detail`, which are English prose for logs. A problem whose status says everything the server knows carries no `code`. One of: `"invalid_request"`, `"invalid_credentials"`, `"forbidden"`, `"unauthorized"`, `"insufficient_user_authentication"`, `"protected_account"`, `"password_held_by_directory"`, `"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"`, `"password_reused"`, `"password_too_short"`, `"password_too_long"`, `"password_compromised"`, `"invalid_verification_link"`, `"invalid_invitation_link"`, `"mail_relay_missing"`, `"email_unverified"`, `"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"`.

  `validation_error` is the one code whose message is not a sentence about
  the code itself: the request failed the schema, and the specifics are
  the `errors` list — one entry per offending field — which a form renders
  on those fields. `required` and `malformed` are 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.
- `instance` (string, optional): Example: `"/introspect"`.
- `request_id` (string, optional): Example: `"8d94ed49-1caf-4ab3-9594-557142f2d023"`.
- `trace_id` (string, optional): 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"`.
- `errors` (array of objects, optional): Field-level violations (present for validation errors).

  Each item: A single field-level validation violation.
  - `field` (string, required): Offending field, dotted for nested bodies (e.g. child.id). Example: `"token_type_hint"`.
  - `code` (string, required): 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"`.
  - `message` (string, required): Example: `"field token_type_hint must be one of [access_token, refresh_token]"`.

### Error

Problem details (RFC 9457) with an RFC 6750 / RFC 9449 challenge.

Content type: `application/problem+json`

Headers:
- `Cache-Control` = `no-store`
- `WWW-Authenticate` (string)
- `DPoP-Nonce` (string)

RFC 9457 (formerly RFC 7807) problem details (application/problem+json). `code` is a stable machine-readable slug for the problem kind (it mirrors the last path segment of `type`), so consumers can branch on it without parsing prose. `type` is `https://nauthera.io/problems/<code>`, which resolves to the code's runbook: why it happened, who is affected and what to do (RFC 9457 §3.1.1). A problem without a code has `about:blank`. `errors` is present on validation failures and lists every offending field.

- `title` (string, required): Example: `"Request validation failed"`.
- `status` (integer, required): Example: `400`.
- `type` (string (uri), optional): Example: `"https://nauthera.io/problems/validation_error"`.
- `detail` (string, optional): Example: `"One or more fields did not satisfy the API schema."`.
- `code` (enum, optional): The kind of problem, as a stable machine-readable slug a client branches on and translates rather than parsing `title` or `detail`, which are English prose for logs. A problem whose status says everything the server knows carries no `code`. One of: `"invalid_request"`, `"invalid_credentials"`, `"forbidden"`, `"unauthorized"`, `"insufficient_user_authentication"`, `"protected_account"`, `"password_held_by_directory"`, `"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"`, `"password_reused"`, `"password_too_short"`, `"password_too_long"`, `"password_compromised"`, `"invalid_verification_link"`, `"invalid_invitation_link"`, `"mail_relay_missing"`, `"email_unverified"`, `"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"`.

  `validation_error` is the one code whose message is not a sentence about
  the code itself: the request failed the schema, and the specifics are
  the `errors` list — one entry per offending field — which a form renders
  on those fields. `required` and `malformed` are 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.
- `instance` (string, optional): Example: `"/introspect"`.
- `request_id` (string, optional): Example: `"8d94ed49-1caf-4ab3-9594-557142f2d023"`.
- `trace_id` (string, optional): 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"`.
- `errors` (array of objects, optional): Field-level violations (present for validation errors).

  Each item: A single field-level validation violation.
  - `field` (string, required): Offending field, dotted for nested bodies (e.g. child.id). Example: `"token_type_hint"`.
  - `code` (string, required): 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"`.
  - `message` (string, required): Example: `"field token_type_hint must be one of [access_token, refresh_token]"`.

## Example request

```bash
curl -g 'https://auth.example.com/v1/admin/orgs/{slug}/users/{id}/session-history' \
  -H "Authorization: Bearer $ACCESS_TOKEN"
```

## Example response (200)

```json
{
  "items": [
    {
      "id": "string",
      "created_at": "2026-01-15T09:30:00Z",
      "auth_time": "2026-01-15T09:30:00Z",
      "last_seen_at": "2026-01-15T09:30:00Z",
      "expires_at": "2026-01-15T09:30:00Z",
      "ended_at": "2026-01-15T09:30:00Z",
      "end_reason": "logout",
      "amr": [
        "string"
      ],
      "client_ids": [
        "string"
      ],
      "ip_country": "CH",
      "device": "Firefox on Linux",
      "withheld": [
        "display_name"
      ]
    }
  ],
  "page": {
    "limit": 50,
    "sort": "last_name,-first_name,id",
    "has_more": false,
    "has_prev": false
  }
}
```
