---
title: "POST /verifyAssertion"
method: POST
path: "/verifyAssertion"
tags: ["relyingparty"]
---

# POST /verifyAssertion

`POST /verifyAssertion`

Verifies the assertion returned by the IdP.

## Request body

- IdentitytoolkitRelyingpartyVerifyAssertionRequest — Request to verify the IDP assertion.
  - `tenantProjectNumber` string, uint64 — Tenant project number to be used for idp discovery.
  - `postBody` string — The post body if the request is a HTTP POST.
  - `pendingIdToken` string — The GITKit token for the non-trusted IDP pending to be confirmed by the user.
  - `instanceId` string — Instance id token of the app.
  - `requestUri` string — The URI to which the IDP redirects the user back. It may contain federated login result params added by the IDP.
  - `delegatedProjectNumber` string, int64 — GCP project number of the requesting delegated app. Currently only intended for Firebase V1 migration.
  - `idToken` string — The GITKit token of the authenticated user.
  - `returnRefreshToken` boolean — Whether to return refresh tokens.
  - `sessionId` string — Session ID, which should match the one in previous createAuthUri request.
  - `returnSecureToken` boolean — Whether return sts id token and refresh token instead of gitkit token.
  - `returnIdpCredential` boolean — Whether return 200 and IDP credential rather than throw exception when federated id is already linked.
  - `autoCreate` boolean — When it's true, automatically creates a new account if the user doesn't exist. When it's false, allows existing user to sign in normally and throws exception if the user doesn't exist.
  - `tenantId` string — For multi-tenant use cases, in order to construct sign-in URL with the correct IDP parameters, Firebear needs to know which Tenant to retrieve IDP configs from.

## Response `200`

Successful response

---

[API](https://skmtc.net/google/apis/identitytoolkit.md) · [All operations](https://skmtc.net/google/apis/identitytoolkit/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/google/identitytoolkit/versions/9ea63f196a10/schema)