index.md

---

title: AuthenticatorAssertionResponse
slug: Web/API/AuthenticatorAssertionResponse
page-type: web-api-interface
browser-compat: api.AuthenticatorAssertionResponse

---

{{APIRef("Web Authentication API")}}{{securecontext_header}}

The AuthenticatorAssertionResponse interface of the Web Authentication API is returned by {{domxref('CredentialsContainer.get()')}} when a {{domxref('PublicKeyCredential')}} is passed, and provides proof to a service that it has a key pair and that the authentication request is valid and approved.

This interface inherits from {{domxref("AuthenticatorResponse")}}.

{{InheritanceDiagram}}

Note: This interface is restricted to top-level contexts. Use from within an {{HTMLElement("iframe")}} element will not have any effect.

Instance properties

Also inherits properties from its parent, {{domxref("AuthenticatorResponse")}}.

• {{domxref("AuthenticatorAssertionResponse.authenticatorData")}} {{securecontext_inline}} {{ReadOnlyInline}}

  • : An {{jsxref("ArrayBuffer")}} containing information from the authenticator such as the Relying Party ID Hash (rpIdHash), a signature counter, test of user presence and user verification flags, and any extensions processed by the authenticator.

• {{domxref("AuthenticatorAssertionResponse.signature")}} {{securecontext_inline}} {{ReadOnlyInline}}

  • : An assertion signature over {{domxref("AuthenticatorAssertionResponse.authenticatorData")}} and {{domxref("AuthenticatorResponse.clientDataJSON")}}. The assertion signature is created with the private key of keypair that was created during the {{domxref("CredentialsContainer.create()","navigator.credentials.create()")}} call and verified using the public key of that same keypair.

• {{domxref("AuthenticatorAssertionResponse.userHandle")}} {{securecontext_inline}} {{ReadOnlyInline}}

  • : An {{jsxref("ArrayBuffer")}} containing an opaque user identifier.

Instance methods

None.

Examples

const options = {
  challenge: new Uint8Array([
    /* bytes sent from the server */
  ]),
};

navigator.credentials
  .get({ publicKey: options })
  .then((credentialInfoAssertion) => {
    const assertionResponse = credentialInfoAssertion.response;
    // Do something specific with the response

    // send assertion response back to the server
    // to proceed with the control of the credential
  })
  .catch((err) => console.error(err));

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

See also

• {{domxref("AuthenticatorAttestationResponse")}}: the interface for the type of response given when creating a new credential

• {{domxref("AuthenticatorResponse")}}: the parent interface