# Authenticate Using User Credentials

**POST /auth/user**

Authenticates the partner application and a zipForm® user using username/password or user GUID, and returns a Context Id for use in subsequent requests.

Optionally supply `LinkExternalId` to link the user's account to a partner external ID.

**Returns 409** if account linking fails.


## Servers
- Production: https://ws.zipformplus.com/api (Production)
- Staging/QA: https://api.pre.zipformplus.com/api (Staging/QA)



## Parameters



### Body: application/json (object)

- **SharedKey** (string)
  Partner shared key

- **UserName** (string)
  zipForm® username (use with Password)

- **Password** (string)
  zipForm® password

- **UserId** (string)
  zipForm® user GUID (alternative to UserName/Password)

- **LinkExternalId** (string)
  Optional. Partner external ID to link to this zipForm® account.



## Responses
### 200
Authentication successful

#### Body: application/json (object)
- **contextId** (string)
  Session identifier to be used in subsequent requests


### 401
Unauthorized — invalid credentials

### 409
Account linking failed


[Powered by Bump.sh](https://bump.sh)