curl --request POST \
  --url https://api.dfns.io/auth/action \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "challengeIdentifier": "eyJ0e...fQNA",
  "firstFactor": {
    "kind": "Fido2",
    "credentialAssertion": {
      "credId": "c1QEdgnPLJargwzy3cbYKny4Q18u0hr97unXsF3DiE8",
      "clientData": "eyJ0eXBlIjoid2ViYXV0aG4uZ2V0IiwiY2hhbGxlbmdlIjoiTVdNME1tWTVZVFEwTURSaU56ZGhOVEZoTnpZNU9EUXdOV0k1WlRRNFkyUmhPRFppTkRrM1pUWXpPVEU1T0dZeU1EY3haakJqWXprNE1tUTVZelkxTUEiLCJvcmlnaW4iOiJodHRwczovL2FwcC5kZm5zLm5pbmphIiwiY3Jvc3NPcmlnaW4iOmZhbHNlfQ",
      "authenticatorData": "WT-zFZUBbJHfBkmhzTlPf49LTn7asLeTQKhm_riCvFgFAAAAAA",
      "signature": "MEUCIQDJ8G9J1NTjdoKx0yloYw45bpn6fJhcqCoUGiZuOU1IAQIgAtPt7S8FHFYW9OMHh3S5FVAxk-lhli-2lX22bBNSDog",
      "userHandle": "dXMtMmJhMGgtbHZwMnEtOHYxODYwcGNqMWJoNWlyaQ"
    }
  }
}
'

{
  "userAction": "eyJ0eX...bzrQakA"
}

Create User Action Signature

Completes the user action signing process and provides a signing token that can be used to verify the user intended to perform the action.

This is the first step of the User Action Signing flow.

The type of credentials used to sign the action is determined by the kind field in the nested objects (firstFactor and secondFactor). Supported credential kinds are:

Fido2: User action is signed by a user’s signing device using WebAuthn.
Key: User action is signed by a user’s, or token’s, private key.
PasswordProtectedKey: Login challenge is signed by the decrypted user’s private key that was sent during Create User Action Signature Challenge step.

POST

auth

action

curl --request POST \
  --url https://api.dfns.io/auth/action \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "challengeIdentifier": "eyJ0e...fQNA",
  "firstFactor": {
    "kind": "Fido2",
    "credentialAssertion": {
      "credId": "c1QEdgnPLJargwzy3cbYKny4Q18u0hr97unXsF3DiE8",
      "clientData": "eyJ0eXBlIjoid2ViYXV0aG4uZ2V0IiwiY2hhbGxlbmdlIjoiTVdNME1tWTVZVFEwTURSaU56ZGhOVEZoTnpZNU9EUXdOV0k1WlRRNFkyUmhPRFppTkRrM1pUWXpPVEU1T0dZeU1EY3haakJqWXprNE1tUTVZelkxTUEiLCJvcmlnaW4iOiJodHRwczovL2FwcC5kZm5zLm5pbmphIiwiY3Jvc3NPcmlnaW4iOmZhbHNlfQ",
      "authenticatorData": "WT-zFZUBbJHfBkmhzTlPf49LTn7asLeTQKhm_riCvFgFAAAAAA",
      "signature": "MEUCIQDJ8G9J1NTjdoKx0yloYw45bpn6fJhcqCoUGiZuOU1IAQIgAtPt7S8FHFYW9OMHh3S5FVAxk-lhli-2lX22bBNSDog",
      "userHandle": "dXMtMmJhMGgtbHZwMnEtOHYxODYwcGNqMWJoNWlyaQ"
    }
  }
}
'

{
  "userAction": "eyJ0eX...bzrQakA"
}

Authorizations

Authorization

string

header

required

Bearer Token: Used to authenticate API requests. More details how to generate the token: Authentication flows

Body

application/json

challengeIdentifier

string

required

Temporary authentication token returned by the Create Challenge endpoint.

firstFactor

Fido2/Passkeys · object

required

First factor credential used to sign the challenge.

Fido2/Passkeys
Public/Private key pair
Password-protected Key
<Deprecated> Password

Show child attributes

secondFactor

Fido2/Passkeys · object

Second factor credential used to authenticate a user.

Fido2/Passkeys
Public/Private key pair
Password-protected Key
<Deprecated> TOTP

Show child attributes

Response

200 - application/json

Success

userAction

string

required

Signing token to use to verify the user intended to perform the action.

Last modified on July 20, 2026

Create User Action Challenge

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API Authorization

Identity & Access Management

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Management

Webhooks

Create User Action Signature

Authorizations

Body

Response