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API documentation

This API is for GOV.UK Publishing microservices (the things which make up www.gov.uk) to implement personalisation and user session management. This API is not for other government services.

Nomenclature

Identity provider

The service which authenticates a user. Currently we use the Digital Identity authentication service.

Session identifier

An opaque token which identifies a user and provides access to their attributes.

Using this API

You should use this API in combination with the govuk_personalisation gem, like so:

class YourRailsController < ApplicationController
  # include the concern in your controller
  include GovukPersonalisation::AccountConcern

  def show
    # call the API with gds-api-adapters, the @govuk_account_session is provided by the concern
    result = GdsApi.account_api.get_attributes(
      attributes: %w[some user attributes],
      govuk_account_session: @govuk_account_session,
    )

    # set up the response header and update @govuk_account_session
    set_account_session_header(result["govuk_account_session"])

    # do something in your view with the result
    @attributes = result["values"]
  rescue GdsApi::HTTPUnauthorized
    # the user's session is invalid
    logout!
  rescue GdsApi::HTTPForbidden
    # the user needs to reauthenticate with MFA
  end
end

The govuk_personalisation gem handles setting the GOVUK-Account-Session and Vary response headers for your app, ensuring that responses are not cached. In local development there is a cookie instead of a custom header, which the gem also handles for you.

API endpoints

GET /api/oauth2/sign-in

Generates an OAuth sign in URL.

This URL should be served to the user with a 302 response to authenticate the user against the identity provider.

Query parameters

  • mfa (optional)
    • either true (require MFA) or false (do not require MFA, the default)
  • redirect_path (optional)
    • a path on GOV.UK to send the user to after authenticating

JSON response fields

  • auth_uri
    • an absolute URL, pointing to the identity provider, which the user should be redirected to so they can authenticate
  • state
    • a random string, used for CSRF protection, which should be stored in a cookie and compared with the state returned by the identity provider after the user authenticated

Response codes

  • 200

Example request / response

Request (with gds-api-adapters):

GdsApi.account_api.get_sign_in_url(
    redirect_path: "/guidance/keeping-a-pet-pig-or-micropig",
)

Response:

{
    "auth_uri": "https://www.account.publishing.service.gov.uk/oauth/authorize?client_id=clientid&nonce=nonce&redirect_uri=https%3A%2F%2Fwww.gov.uk%2Fsign-in%2Fcallback&response_type=code&scope=openid&state=12345%3Aabcd",
    "state": "12345:abcdef"
}

POST /api/oauth2/callback

Validates an OAuth response from the identity provider.

This is only used by the SessionsController in frontend, as the identity provider redirects the user after signing in to https://www.gov.uk/sign-in/callback.

Request parameters

  • code
    • the value of the code parameter returned from the identity provider
  • state
    • the value of the state parameter returned from the identity provider

JSON response fields

  • govuk_account_session
    • a session identifier
  • redirect_path (optional)
    • the redirect_path which was previously passed to GET /api/oauth2/sign-in, if given

Response codes

  • 401 if authentication is unsuccessful
  • 200 otherwise

Example request / response

Request (with gds-api-adapters):

GdsApi.account_api.validate_auth_response(
    code: "12345",
    state: "67890",
)

Response:

{
    "govuk_account_session": "YWNjZXNzLXRva2Vu.cmVmcmVzaC10b2tlbg==",
    "redirect_path": "/guidance/keeping-a-pet-pig-or-micropig",
    "cookie_consent": false,
}

GET /api/oauth2/end-session

Generates a sign out URL.

This URL should be served to the user with a 302 response to terminate their session with the identity provider and connected services. If the session identifier is given, it may be passed to the identity provider to validate the user's session.

This does not invalidate the user's session on www.gov.uk. You must also use the logout! method in govuk_personalisation to do that.

Request headers

  • GOVUK-Account-Session (optional)
    • the user's session identifier

JSON response fields

  • end_session_uri
    • an absolute URL, pointing to the identity provider, which the user should be redirected to to end their session

Response codes

  • 200

Example request / response

Request (with gds-api-adapters):

GdsApi.account_api.get_end_session_url(
    govuk_account_session: "session-identifier",
)

Response:

{
    "end_session_uri": "https://www.account.publishing.service.gov.uk/sign-out?continue=1"
}

GET /api/user

Retrieves the information needed to render the /account/home page.

Request headers

  • GOVUK-Account-Session
    • the user's session identifier

JSON response fields

  • id
    • the user identifier
  • mfa
    • true if the user has authenticated with MFA, false otherwise
  • email
    • the user's current email address
  • email_verified
    • whether the user has confirmed their email address or not
  • services
    • object of known services, keys are service names and values are one of:
      • yes: the user has used the service and can use it now
      • yes_but_must_reauthenticate: the user has used the service but must reauthenticate with MFA
      • no: the user has not used the service
      • unknown: the user must reauthenticate with MFA to check whether they have used the service or not

Response codes

  • 401 if the session identifier is invalid
  • 200 otherwise

Example request / response

Request (with gds-api-adapters):

GdsApi.account_api.get_user(
    govuk_account_session: "session-identifier",
)

Response:

{
    "id": "some-user-identifier",
    "mfa": false,
    "email": "email@example.com",
    "email_verified": false,
    "services": {}
}

GET /user/match-by-email

Checks if a user with the given email address exists and if it is the logged-in user (if a session is given).

This is only used by email-alert-frontend, so it can check if an address corresponds to an account and either log the user in or show an appropriate message with a single API call.

Request headers

  • GOVUK-Account-Session (optional)
    • the user's session identifier, if not given "match": true is not a possible response

Query parameters

  • email
    • the email address to search for

JSON response fields

  • match
    • true if the session has the given email address, or false if a different user has that email address

Response codes

  • 404 if there is no user with that email address
  • 200 otherwise

Example request / response

Request (with gds-api-adapters):

GdsApi.account_api.match_user_by_email(
    email: "email@example.com",
)

Response:

{
    "match": false
}

Request with a session (with gds-api-adapters):

GdsApi.account_api.match_user_by_email(
    email: "email@example.com",
    govuk_account_session: "session-identifier",
)

Response:

{
    "match": true
}

GET /api/attributes

Retrieves attribute values for the current user.

Request headers

  • GOVUK-Account-Session
    • the user's session identifier

Query parameters

  • attributes[] (one for each attribute)
    • a list of attribute names, specified once for each name

JSON response fields

  • govuk_account_session (optional)
    • a new session identifier
  • values
    • a JSON object of attribute values, where keys are attribute names and values are attribute values

Response codes

Example request / response

Request (with gds-api-adapters):

GdsApi.account_api.get_attributes(
    attributes: %w[name1 name2],
    govuk_account_session: "session-identifier",
)

Response:

{
    "govuk_account_session": "YWNjZXNzLXRva2Vu.cmVmcmVzaC10b2tlbg==",
    "values": {
        "name1": "value1",
        "name2": "value2"
    }
}

PATCH /api/attributes

Updates the attributes of the current user.

Request headers

  • GOVUK-Account-Session
    • the user's session identifier

JSON request parameters

  • attributes
    • a JSON object where keys are attribute names and values are attribute values

JSON response fields

  • govuk_account_session (optional)
    • a new session identifier

Response codes

Example request / response

Request (with gds-api-adapters):

GdsApi.account_api.set_attributes(
    attributes: { name1: "value1", name2: "value2" },
    govuk_account_session: "session-identifier",
)

Response:

{
    "govuk_account_session": "YWNjZXNzLXRva2Vu.cmVmcmVzaC10b2tlbg=="
}

PUT /api/oidc-users/:subject_identifier

Update an account and its email subscriptions by subject identifier. This endpoint requires the update_protected_attributes scope.

Request parameters

  • subject_identifier
    • the subject identifier of the user to update

JSON request parameters

  • legacy_sub (optional)
    • if this is a user created pre-migration, their original subject identifier (a string)
  • email (optional)
    • the new email address (a string)
  • email_verified (optional)
    • whether the new email address is verified (a boolean)

JSON response fields

  • sub
    • the subject identifier
  • email
  • email_verified

Response codes

  • 200

Example request / response

Request (with gds-api-adapters):

GdsApi.account_api.update_user_by_subject_identifier(
    subject_identifier: "subject-identifier",
    email: "user@example.com",
    email_verified: true,
)

Response:

{
    "sub": "subject-identifier",
    "email": "user@example.com",
    "email_verified": true,
}

DELETE /api/oidc-users/:subject_identifier

Delete an account by subject identifier. This endpoint requires the update_protected_attributes scope.

Request parameters

  • subject_identifier
    • the subject identifier of the user to delete

Query parameters

  • legacy_sub (optional)
    • if this is a user created pre-migration, their original subject identifier (a string)

Response codes

  • 404 if the user cannot be found
  • 204 otherwise

Example request / response

Request (with gds-api-adapters):

GdsApi.account_api.delete_user_by_subject_identifier(
    subject_identifier: "subject-identifier",
)

Response is status code only.

GET /api/personalisation/check-email-subscription

Personalisation endpoint for checking if an email subscription is active.

See Progressive enhancement ADR for more details

Request parameters

  • subject_identifier
    • the subject identifier from a user session

Query parameters

  • base_path (optional)
    • the base path of the page (to match against the "url" of an email-alert-api subscriber list)
  • topic_slug (optional)
    • the email-alert-api topic slug

Exactly one of base_path and topic_slug must be specified.

JSON response fields

  • base_path
    • the base_path parameter, if there is one (a string)
  • topic_slug
    • the topic_slug parameter, if there is one (a string)
  • active
    • whether the subscription is active (a boolean)

Response codes

  • 401 if the session identifier is invalid
  • 422 if neither base_path nor topic_slug are passed; or if both are
  • 200 otherwise

Example request / response

Note: This endpoint is not included in the GDS API Adaptors wrappers. As a personalisation endpoint, it allows us to progressively enhance pages from client side requests.

To test the endpoint with curl:

curl -H "GOVUK-Account-Session={{account_session_header}}" \
  "{{GOV.UK environment}}/api/personalisation/check-email-subscription?base_path=/guidance/keeping-a-pet-pig-or-micropig"

{
    "base_path": "/guidance/keeping-a-pet-pig-or-micropig",
    "active": true,
    "button_html": "<form>...</form>"
}

POST /api/oidc_events/backchannel_logout

A public API endpoint that Implements OpenID Connect Back-Channel Logout 1.0 - draft 07.

Query parameters

  • logout_token
    • A signed JWT

Response codes

  • 400 if the Logout Token JWT is invalid or signature cannot be verified
  • 200 otherwise

Note

This endpoint will only ever receive calls from the Oidc OP (Digital Identity), as an OIDC event. Because of that, there is not an GDS API Adaptor for this endpoint, as it will not be called from another Ruby application.

API errors

API errors are returned as an RFC 7807 "Problem Detail" object, in the following format:

{
  "type": "URI which identifies the problem type and points to further information",
  "title": "Short human-readable summary of the problem type",
  "detail": "Human-readable explanation of this specific instance of the problem."
}

Each error type may define additional response fields.

MFA required

You have tried to access something requires MFA, but the current user has not authenticated with MFA.

Debugging steps

This is not an error, the user must be reauthenticated with MFA.

Unknown attribute names

One or more of the attribute names you have specified are not known. The attributes response field lists these.

Unwritable attributes

One or more of the attributes you have specified cannot be updated through account-api. The attributes response field lists these.

Do not just reauthenticate the user and try again.

Debugging steps

  • check the errors returned as an extra detail in the response for specific error messages