Authentication

All API4Business APIs use OAuth2 Client Credentials authentication.

How it works

1. You send your client_id and client_secret to the token endpoint
2. You receive an access_token
3. You include the token in the Authorization header of every API request

Token endpoint

POST https://api.api4business.com/oauth/v1/token

Request

Parameter	Type	Required	Description
grant_type	string	Yes	Must be client_credentials
client_id	string	Yes	Your OAuth2 client ID
client_secret	string	Yes	Your OAuth2 client secret

Response

{
  "access_token": "eyJhbGciOiJSUzI1NiIsInR5cCI6...",
  "token_type": "Bearer",
  "expires_in": 3600
}

Using the token

Include the access token in the Authorization header:

Authorization: Bearer eyJhbGciOiJSUzI1NiIsInR5cCI6...

Token expiry

Access tokens expire. Check the expires_in field and refresh before expiry. Implement token caching in your application to avoid unnecessary token requests.

Getting credentials

Sign up at developers.api4business.com to get your client credentials.

Sandbox vs production

You will receive separate credentials for sandbox and production environments. See Environments for details.

What's next

• Environments — Sandbox vs production URLs
• Rate Limits — Throttling policy and retry logic