// This instance does not require an Activity context.valfpnv=FirebasePhoneNumberVerification.getInstance()// Your request should include a nonce, which will propagate through the flow// and be present in the final response from FPNV. See the section "Verifying// theFirebase PNV token" for details on generating and verifying this.valnonce=fetchNonceFromYourServer()fpnv.getDigitalCredentialPayload(nonce,"https://example.com/privacy-policy").addOnSuccessListener{fpnvDigitalCredentialPayload->// Use the payload in the next step.// ...}.addOnFailureListener{e->/* Handle payload fetch failure */}

// This example uses string interpolation for clarity, but you should use some kind of type-safe// serialization method.funbuildDigitalCredentialRequestJson(nonce:String,fpnvDigitalCredentialPayload:String)="""    {      "requests": [        {          "protocol": "openid4vp-v1-unsigned",          "data": {            "response_type": "vp_token",            "response_mode": "dc_api",            "nonce": "$nonce",            "dcql_query": { "credentials": [$fpnvDigitalCredentialPayload] }          }        }      ]    }""".trimIndent()

suspendfunmakeFpnvRequest(context:Activity,nonce:String,fpnvDigitalCredentialPayload:String):GetCredentialResponse{// Helper function to build the digital credential request (defined above).// Pass the same nonce you passed to getDigitalCredentialPayload().valdigitalCredentialRequestJson=buildDigitalCredentialRequestJson(nonce,fpnvDigitalCredentialPayload)// CredentialManager requires an Activity context.valcredentialManager=CredentialManager.create(context)// Build a Credential Manager request that includes the Firebase PNV option. Note that// you can't combine the digital credential option with other options.valrequest=GetCredentialRequest.Builder().addCredentialOption(GetDigitalCredentialOption(digitalCredentialRequestJson)).build()// getCredential is a suspend function, so it must run in a coroutine scope,valcmResponse:GetCredentialResponse=try{credentialManager.getCredential(context,request)}catch(e:GetCredentialException){// If the user cancels the operation, the feature isn't available, or the// SIM doesn't support the feature, a GetCredentialCancellationException// will be returned. Otherwise, a GetCredentialUnsupportedException will// be returned with details in the exception message.throwe}returncmResponse}

valdcApiResponse=extractApiResponse(cmResponse)

funextractApiResponse(response:GetCredentialResponse):String{valcredential=response.credentialwhen(credential){isDigitalCredential->{valjson=JSONObject(credential.credentialJson)valfirebaseJwtArray=json.getJSONObject("data").getJSONObject("vp_token").getJSONArray("firebase")returnfirebaseJwtArray.getString(0)}else->{// Handle any unrecognized credential type here.Log.e(TAG,"Unexpected type of credential${credential.type}")}}}

fpnv.exchangeCredentialResponseForPhoneNumber(dcApiResponse).addOnSuccessListener{result->valphoneNumber=result.getPhoneNumber()// Verification successful}.addOnFailureListener{e->/* Handle exchange failure */}

app.get('/fpnvNonce',async(req,res)=>{constnonce=crypto.randomUUID();// TODO: Save the nonce to a database, key store, etc.// You should also assign the nonce an expiration time and periodically// clear expired nonces from your database.awaitpersistNonce({nonce,expiresAt:Date.now()+180000,// Give it a short duration.});// Return the nonce to the caller.res.send({nonce});});

import{JwtVerifier}from"aws-jwt-verify";// Find your Firebase project number in the Firebase console.constFIREBASE_PROJECT_NUMBER="123456789";// The issuer and audience claims of the FPNV token are specific to your// project.constissuer=`https://fpnv.googleapis.com/projects/${FIREBASE_PROJECT_NUMBER}`;constaudience=`https://fpnv.googleapis.com/projects/${FIREBASE_PROJECT_NUMBER}`;// The JWKS URL contains the current public signing keys for FPNV tokens.constjwksUri="https://fpnv.googleapis.com/v1beta/jwks";// Configure a JWT verifier to check the following:// - The token is signed by Google// - The issuer and audience claims match your project// - The token has not yet expired (default begavior)constfpnvVerifier=JwtVerifier.create({issuer,audience,jwksUri});app.post('/verifiedPhoneNumber',async(req,res)=>{if(!req.body)returnres.sendStatus(400);// Get the token from the body of the request.constfpnvToken=req.body;try{// Attempt to verify the token using the verifier configured above.constverifiedPayload=awaitfpnvVerifier.verify(fpnvToken);// Now that you've verified the signature and claims, verify the nonce.// TODO: Try to look up the nonce in your database and remove it if it's// found; if it's not found or it's expired, throw an error.awaittestAndRemoveNonce(verifiedPayload.nonce);// Only after verifying the JWT signature, claims, and nonce, get the// verified phone number from the subject claim.// You can use this value however it's needed by your app.constverifiedPhoneNumber=verifiedPayload.sub;// (Do something with it...)returnres.sendStatus(200);}catch{// If verification fails, reject the token.returnres.sendStatus(400);}});