# Fifth Third Bancorp Auth API

**Canonical:** https://apis.io/apis/fifth-third-bancorp/fifth-third-bancorp-auth-api/  
**Provider:** Fifth Third Bancorp — https://apis.io/providers/fifth-third-bancorp/  
**Base URL:** https://sandbox.newline53.com/api/v1  
**Documentation:** https://developers.newline53.com/reference/auth

Fifth Third Bancorp Auth API is one of 13 APIs that [Fifth Third Bancorp](https://apis.io/providers/fifth-third-bancorp/) publishes on the [APIs.io](https://apis.io/) network, described by a machine-readable OpenAPI specification. Tagged areas include Authentication. The published artifact set on APIs.io includes an OpenAPI specification, API documentation, and an API reference.

The Authentication section explains how to securely interact with Newline's API using access tokens and static IP addresses. Learn how to generate and refresh tokens to access protected resources. **Endpoints:** - POST [Generate an authentication token: POST /auth](https://developers.newline53.com/reference/post_auth) Newline requires access tokens and static IP addresses for authentication and authorization when requesting any resource endpoints. [POST /auth](https://developers.newline53.com/reference/post_auth) is used to obtain and refresh the required access tokens. Please work with your Relationship Team or the Newline Team in all environments to set up the IP Allowlist for your Program. To obtain an access token, you must submit a refresh token. After a program is set up, Newline will share your Program UID and HMAC key offline. These values are required for the refresh token and access token requests. ## Auth Flow The authentication flow is as follows: 1. Create a JWT using the following claim: ``` { "iat": <current Epoch time>, "sub": <Program UID> } ``` 1. Sign the JWT to create a JWS with the shared key using HS512 / SHA-512. 2. Exchange for an access token by sending a request to [POST /auth](https://developers.newline53.com/reference/post_auth), using the JWS in the `Authorization` header. 3. Access resources through other endpoints using the returned token in the `Authorization` header for up to 8 hours. 4. Repeat the process as needed to continue authenticating successfully. > **Note** > If a new access token is requested within the 8 hours of a previous token being successfully exchanged, the new token will still be generated. This does not expire the last token, and both tokens are usable simultaneously until their respective time is up. However, it is encouraged to use the new token and discard the old one if possible, as this behavior may change in the future.

## Operations (1)

| Method | Path | Summary |
|---|---|---|
| POST | `/auth` | Generate an authentication token |

## Machine-readable artifacts (24)

- **OpenAPI** — https://raw.githubusercontent.com/api-evangelist/fifth-third-bancorp/refs/heads/main/openapi/fifth-third-bancorp-auth-api-openapi.yml
- **Documentation** — https://developers.newline53.com/docs/api-authentication
- **APIReference** — https://developers.newline53.com/reference/post_auth
- **APIReference** — https://developers.newline53.com/reference/customers
- **Documentation** — https://developers.newline53.com/reference/overview-of-customer-types
- **APIReference** — https://developers.newline53.com/reference/customer-products
- **Documentation** — https://developers.newline53.com/reference/customer-product-statuses
- **APIReference** — https://developers.newline53.com/reference/products
- **APIReference** — https://developers.newline53.com/reference/pools
- **APIReference** — https://developers.newline53.com/reference/custodial-accounts
- **Documentation** — https://developers.newline53.com/reference/custodial-account-statuses
- **APIReference** — https://developers.newline53.com/reference/synthetic-accounts
- **Documentation** — https://developers.newline53.com/reference/synthetic-account-categories
- **APIReference** — https://developers.newline53.com/reference/transfers
- **Documentation** — https://developers.newline53.com/reference/transfer-statuses
- **APIReference** — https://developers.newline53.com/reference/combined-transfers
- **APIReference** — https://developers.newline53.com/reference/transactions
- **Documentation** — https://developers.newline53.com/reference/transaction-statuses-and-transaction-types
- **APIReference** — https://developers.newline53.com/reference/returns
- **APIReference** — https://developers.newline53.com/reference/virtual-reference-numbers
- **Documentation** — https://developers.newline53.com/reference/virtual-reference-number-statuses
- **APIReference** — https://developers.newline53.com/reference/sandbox
- **Documentation** — https://developers.newline53.com/docs/sandbox-walkthrough
- **APIsJSON** — https://raw.githubusercontent.com/api-evangelist/fifth-third-bancorp/refs/heads/main/apis.yml

## Other Fifth Third Bancorp APIs (12)

- [Fifth Third Bancorp Combined Transfers API](https://apis.io/apis/fifth-third-bancorp/fifth-third-bancorp-combined-transfers-api/)
- [Fifth Third Bancorp Custodial Accounts API](https://apis.io/apis/fifth-third-bancorp/fifth-third-bancorp-custodial-accounts-api/)
- [Fifth Third Bancorp Customer Products API](https://apis.io/apis/fifth-third-bancorp/fifth-third-bancorp-customer-products-api/)
- [Fifth Third Bancorp Customers API](https://apis.io/apis/fifth-third-bancorp/fifth-third-bancorp-customers-api/)
- [Fifth Third Bancorp Pools API](https://apis.io/apis/fifth-third-bancorp/fifth-third-bancorp-pools-api/)
- [Fifth Third Bancorp Products API](https://apis.io/apis/fifth-third-bancorp/fifth-third-bancorp-products-api/)
- [Fifth Third Bancorp Returns API](https://apis.io/apis/fifth-third-bancorp/fifth-third-bancorp-returns-api/)
- [Fifth Third Bancorp Sandbox API](https://apis.io/apis/fifth-third-bancorp/fifth-third-bancorp-sandbox-api/)
- [Fifth Third Bancorp Synthetic Accounts API](https://apis.io/apis/fifth-third-bancorp/fifth-third-bancorp-synthetic-accounts-api/)
- [Fifth Third Bancorp Transactions API](https://apis.io/apis/fifth-third-bancorp/fifth-third-bancorp-transactions-api/)
- [Fifth Third Bancorp Transfers API](https://apis.io/apis/fifth-third-bancorp/fifth-third-bancorp-transfers-api/)
- [Fifth Third Bancorp Virtual Reference Numbers API](https://apis.io/apis/fifth-third-bancorp/fifth-third-bancorp-virtual-reference-numbers-api/)

## Tags

Authentication

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/apis/fifth-third-bancorp/fifth-third-bancorp-auth-api/). The API's provider profile, Kin Score and agent-readiness rating are at https://apis.io/providers/fifth-third-bancorp/.