diff --git a/stepup/seed-test-identity.sh b/stepup/seed-test-identity.sh
new file mode 100755
index 0000000..1ddfce9
--- /dev/null
+++ b/stepup/seed-test-identity.sh
@@ -0,0 +1,70 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Seeds a fully vetted Demo GSSP identity directly via Middleware's command API,
+# bypassing registration UI, RA app, e-mail, and any physical/virtual second factor
+# hardware entirely. Mirrors the "has a vetted demo-gssp" step in
+# tests/behat/features/bootstrap/FeatureContext.php (theUserHasAVettedWithIdentifier),
+# adapted from the smoketest DB to this environment's real dev DB/credentials.
+#
+# Usage: ./seed-test-identity.sh <slug> [institution] [gssf-id]
+#
+# After running, log in via the ssp test SP (https://ssp.dev.openconext.local/simplesaml/sp.php)
+# as <slug>/<slug>, request an LoA that Demo GSSP satisfies, and pick "Demo GSSP" as the
+# second factor -- no registration/vetting/hardware step needed.
+
+SLUG="${1:?Usage: $0 <slug> [institution] [gssf-id]}"
+INSTITUTION="${2:-dev.openconext.local}"
+GSSF_ID="${3:-seed-$SLUG}"
+NAME_ID="urn:collab:person:${INSTITUTION}:${SLUG}"
+IDENTITY_ID=$(uuidgen | tr 'A-Z' 'a-z')
+SECOND_FACTOR_ID=$(uuidgen | tr 'A-Z' 'a-z')
+
+# Real SRAA identity in this environment's dev DB (has RA authority everywhere).
+# Look it up fresh rather than hardcoding, in case the admin identity_id ever changes.
+ACTOR_ID=$(docker exec stepup-mariadb-1 mysql -uroot -psecret middleware -N -B \
+  -e "SELECT id FROM identity WHERE name_id='urn:collab:person:dev.openconext.local:admin';")
+
+if [ -z "$ACTOR_ID" ]; then
+  echo "Could not find the admin/SRAA identity in the middleware DB -- is the environment bootstrapped?" >&2
+  exit 1
+fi
+
+MW=https://middleware.dev.openconext.local
+DB="docker exec stepup-mariadb-1 mysql -uroot -psecret -N -B middleware"
+
+post() {
+  local user=$1 pass=$2 body=$3
+  curl -sk -u "$user:$pass" -H 'Content-Type: application/json' -H 'Accept: application/json' -X POST "$MW/command" -d "$body"
+  echo
+}
+
+echo "== Creating identity $NAME_ID ($IDENTITY_ID) =="
+post ss sa_secret "$(printf '{"meta":{"actor_id":null,"actor_institution":null},"command":{"name":"Identity:CreateIdentity","uuid":"%s","payload":{"id":"%s","name_id":"%s","institution":"%s","email":"%s@dev.openconext.local","common_name":"%s","preferred_locale":"en_GB"}}}' \
+  "$(uuidgen)" "$IDENTITY_ID" "$NAME_ID" "$INSTITUTION" "$SLUG" "$SLUG")"
+
+echo "== Proving possession of Demo GSSP token (gssf_id=$GSSF_ID) =="
+post ss sa_secret "$(printf '{"meta":{"actor_id":"%s","actor_institution":"%s"},"command":{"name":"Identity:ProveGssfPossession","uuid":"%s","payload":{"identity_id":"%s","second_factor_id":"%s","stepup_provider":"demo_gssp","gssf_id":"%s"}}}' \
+  "$IDENTITY_ID" "$INSTITUTION" "$(uuidgen)" "$IDENTITY_ID" "$SECOND_FACTOR_ID" "$GSSF_ID")"
+
+# Unlike yubikey/sms, GSSF possession (Identity:ProveGssfPossession) is proven-and-verified
+# in a single event (GssfPossessionProvenAndVerifiedEvent) -- no separate e-mail/nonce step.
+REG_CODE=$($DB -e "SELECT registration_code FROM verified_second_factor WHERE identity_id='$IDENTITY_ID' ORDER BY registration_requested_at DESC LIMIT 1;")
+if [ -z "$REG_CODE" ]; then
+  echo "No verified_second_factor row found for $IDENTITY_ID -- VerifyEmail likely failed, see output above." >&2
+  exit 1
+fi
+
+echo "== Vetting (registration code $REG_CODE, authority $ACTOR_ID) =="
+post ra ra_secret "$(printf '{"meta":{"actor_id":"%s","actor_institution":"%s"},"command":{"name":"Identity:VetSecondFactor","uuid":"%s","payload":{"authority_id":"%s","identity_id":"%s","second_factor_id":"%s","registration_code":"%s","second_factor_type":"demo_gssp","second_factor_identifier":"%s","document_number":"123456","identity_verified":true}}}' \
+  "$ACTOR_ID" "$INSTITUTION" "$(uuidgen)" "$ACTOR_ID" "$IDENTITY_ID" "$SECOND_FACTOR_ID" "$REG_CODE" "$GSSF_ID")"
+
+VETTED=$($DB -e "SELECT id FROM vetted_second_factor WHERE identity_id='$IDENTITY_ID';")
+echo
+if [ -n "$VETTED" ]; then
+  echo "Done. $SLUG now has a vetted Demo GSSP token (second_factor_id=$VETTED)."
+  echo "Log in at https://ssp.dev.openconext.local/simplesaml/sp.php as ${SLUG}/${SLUG}, pick a Request LOA Demo GSSP satisfies, and select Demo GSSP as the second factor."
+else
+  echo "Vetting did not produce a vetted_second_factor row -- check the command output above for an error." >&2
+  exit 1
+fi
diff --git a/stepup/tests/behat/features/bootstrap/SecondFactorAuthContext.php b/stepup/tests/behat/features/bootstrap/SecondFactorAuthContext.php
index 88ac22e..f574104 100644
--- a/stepup/tests/behat/features/bootstrap/SecondFactorAuthContext.php
+++ b/stepup/tests/behat/features/bootstrap/SecondFactorAuthContext.php
@@ -120,6 +120,24 @@ public function visitServiceProvider()
         }
     }
 
+    /**
+     * @When I visit the service provider with service name :arg1
+     */
+    public function visitServiceProviderWithServiceName(string $serviceName)
+    {
+        $this->minkContext->visit($this->spTestUrl);
+
+        $this->minkContext->fillField('idp', $this->activeIdp);
+        $this->minkContext->fillField('sp', $this->activeSp);
+        $this->minkContext->fillField('loa', $this->requiredLoa);
+        $this->minkContext->fillField('mdui_displayname', $serviceName);
+
+        if ($this->activeIdp === self::SFO_IDP) {
+            $this->minkContext->fillField('subject', self::TEST_NAMEID);
+        }
+        $this->minkContext->pressButton('Login');
+    }
+
     /**
      * @When I start an SFO authentication for :arg1 with GSSP extension subject :arg2 and institution :arg3
      */
@@ -137,6 +155,38 @@ public function startASfoAuthenticationWithGsspExtension(string $userIdentifier,
         $this->minkContext->pressButton('Login');
     }
 
+    /**
+     * @When I start an SFO authentication for :arg1 with service name :arg2
+     */
+    public function startASfoAuthenticationWithServiceName(string $userIdentifier, string $serviceName)
+    {
+        $this->minkContext->visit($this->spTestUrl);
+        $this->minkContext->fillField('idp', $this->activeIdp);
+        $this->minkContext->fillField('sp', $this->activeSp);
+        $this->minkContext->fillField('loa', $this->requiredLoa);
+        $this->minkContext->fillField('subject', $userIdentifier);
+        $this->minkContext->fillField('mdui_displayname', $serviceName);
+        $this->minkContext->pressButton('Login');
+    }
+
+    /**
+     * @Then I see service name :arg1 on the GSSP authentication page
+     */
+    public function iSeeServiceNameOnTheGsspAuthenticationPage(string $serviceName)
+    {
+        $this->minkContext->assertPageAddress('https://demogssp.dev.openconext.local/authentication');
+        $this->minkContext->assertPageContainsText($serviceName);
+    }
+
+    /**
+     * @Then I see service name :arg1 on the GSSP registration page
+     */
+    public function iSeeServiceNameOnTheGsspRegistrationPage(string $serviceName)
+    {
+        $this->minkContext->assertPageAddress('https://demogssp.dev.openconext.local/registration');
+        $this->minkContext->assertPageContainsText($serviceName);
+    }
+
     /**
      * @When I start an SFO authentication for :arg1
      */
@@ -342,13 +392,13 @@ public function authenticateUserYubikeyInGateway()
             $this->minkContext->assertPageAddress('https://gateway.dev.openconext.local/verify-second-factor/sfo/yubikey');
         }
         // Give an OTP
-        $this->minkContext->fillField('gateway_verify_yubikey_otp_otp', 'ccccccdhgrbtucnfhrhltvfkchlnnrndcbnfnnljjdgf');
+        $this->minkContext->fillField('gateway_verify_yubikey_yubikeyInput', 'ccccccdhgrbtucnfhrhltvfkchlnnrndcbnfnnljjdgf');
         // Simulate the enter press the yubikey otp generator
-        $form = $this->minkContext->getSession()->getPage()->find('css', '[id="gateway_verify_yubikey_otp_otp"]');
+        $form = $this->minkContext->getSession()->getPage()->find('css', '[id="gateway_verify_yubikey_yubikeyInput"]');
         if (!$form) {
             throw new ElementNotFoundException('Yubikey OTP Submit form could not be found on the page');
         }
-        $this->minkContext->pressButton('gateway_verify_yubikey_otp_submit');
+        $this->minkContext->pressButton('gateway_verify_yubikey_submit');
         // Pass through the 'return to sp' redirection page.
         $this->minkContext->pressButton('Submit');
     }
@@ -489,8 +539,20 @@ public function authenticateWithIdentityProviderFor($userName)
         $this->minkContext->fillField('password', $userName);
 
         $this->minkContext->pressButton('Login');
-        $this->minkContext->pressButton('Yes, continue');
+        $this->pressConsentIfShown();
+    }
 
+    /**
+     * SimpleSAMLphp's consent module remembers a given SP+attribute-set combination for the
+     * browser session, so a consent screen may or may not appear depending on what earlier
+     * scenarios in the same feature already consented to.
+     */
+    private function pressConsentIfShown(): void
+    {
+        try {
+            $this->minkContext->pressButton('Yes, continue');
+        } catch (ElementNotFoundException $e) {
+        }
     }
 
     public function authenticateWithIdentityProviderForWithStepup($userName)
diff --git a/stepup/tests/behat/features/bootstrap/SelfServiceContext.php b/stepup/tests/behat/features/bootstrap/SelfServiceContext.php
index 12cc2d1..c912cf9 100644
--- a/stepup/tests/behat/features/bootstrap/SelfServiceContext.php
+++ b/stepup/tests/behat/features/bootstrap/SelfServiceContext.php
@@ -491,9 +491,9 @@ public function removeRecoveryToken(string $recoveryTokenType)
 
     private function performYubikeyAuthentication()
     {
-        $this->minkContext->fillField('gateway_verify_yubikey_otp_otp', 'ccccccdhgrbtfddefpkffhkkukbgfcdilhiltrrncmig');
+        $this->minkContext->fillField('gateway_verify_yubikey_yubikeyInput', 'ccccccdhgrbtfddefpkffhkkukbgfcdilhiltrrncmig');
         $page = $this->minkContext->getSession()->getPage();
-        $form = $page->find('css', 'form[name="gateway_verify_yubikey_otp"]');
+        $form = $page->find('css', 'form[name="gateway_verify_yubikey"]');
         $form->submit();
         $this->minkContext->pressButton('Submit');
     }
diff --git a/stepup/tests/behat/features/gssp_service_name.feature b/stepup/tests/behat/features/gssp_service_name.feature
new file mode 100644
index 0000000..0d6c00a
--- /dev/null
+++ b/stepup/tests/behat/features/gssp_service_name.feature
@@ -0,0 +1,49 @@
+# Tagged SKIP until Stepup-Gateway PR #624 (append_service_name_to_authnrequest) is merged
+# and released in the test image. (OpenConext-devssp's mdui_displayname field already merged
+# and is in the stock devssp image, so no local sp.php override is needed anymore.)
+# Until then, run locally with:
+#   ./start-dev-env.sh gateway:<Stepup-Gateway checkout> demogssp:<Stepup-gssp-example checkout>
+#   docker compose exec behat ./vendor/bin/behat --config config/behat.yml --tags='~@wip' features/gssp_service_name.feature
+@SKIP
+Feature: The GSSP shows the name of the service the user is authenticating for
+  In order to know which service I am authenticating for
+  As a user
+  I want the GSSP authentication page to show the service name from the AuthnRequest
+
+  # Covers the cross-repo flow of the mdui:UIInfo service name:
+  # the SP sends an AuthnRequest with an mdui:UIInfo/mdui:DisplayName extension,
+  # the Stepup-Gateway (feature flag append_service_name_to_authnrequest)
+  # reads it and forwards it in the proxy AuthnRequest to the GSSP, where the
+  # GSSP (Stepup-gssp-example via Stepup-gssp-bundle and Stepup-saml-bundle)
+  # displays it on the authentication page.
+  Scenario: Service name from the AuthnRequest mdui:UIInfo is shown on the GSSP authentication page
+    Given a service provider configured for second-factor-only
+    And a user "jane-a-ra" identified by "urn:collab:person:institution-a.example.com:jane-a-ra" from institution "institution-a.example.com" with UUID "00000000-0000-4000-8000-000000000001"
+    And the user "urn:collab:person:institution-a.example.com:jane-a-ra" has a vetted "demo-gssp" with identifier "gssp-identifier123"
+    When I start an SFO authentication for "urn:collab:person:institution-a.example.com:jane-a-ra" with service name "Behat Test Service"
+    Then I see service name "Behat Test Service" on the GSSP authentication page
+    When I verify the "demo-gssp" second factor
+    Then I am logged on the service provider
+
+  # Reuses the identity vetted in the previous scenario, like sfo.feature does.
+  Scenario: No service name is shown when the AuthnRequest carries no mdui:UIInfo
+    Given a service provider configured for second-factor-only
+    When I start an SFO authentication for "urn:collab:person:institution-a.example.com:jane-a-ra"
+    Then I should not see "Behat Test Service"
+    When I verify the "demo-gssp" second factor
+    Then I am logged on the service provider
+
+  # Gateway has three independent LoginService::singleSignOn implementations that each
+  # read the mdui:UIInfo extension behind the same feature flag: GatewayBundle (plain
+  # SSO, exercised here), SecondFactorOnlyBundle, and SamlStepupProviderBundle (both
+  # exercised by the SFO scenarios above). Without this scenario, a regression in the
+  # SSO copy specifically would go undetected even with the SFO scenarios passing.
+  Scenario: Service name from the AuthnRequest mdui:UIInfo is shown on the GSSP authentication page via the plain SSO flow
+    Given a service provider configured for single-signon
+    And a user "Jane Toppan" identified by "urn:collab:person:institution-a.example.com:jane-a2" from institution "institution-a.example.com"
+    And the user "urn:collab:person:institution-a.example.com:jane-a2" has a vetted "demo-gssp" with identifier "gssp-identifier-sso1"
+    When I visit the service provider with service name "SSO Flow Service Name"
+    And I authenticate as "jane-a2" with the identity provider
+    Then I see service name "SSO Flow Service Name" on the GSSP authentication page
+    When I verify the "demo-gssp" second factor
+    Then I am logged on the service provider