How often should a developer request a new token when making multiple API calls in v1?

In Salesforce Marketing Cloud's legacy v1 (Legacy Package / REST API using the requestToken endpoint), the returned access token is valid for 60 minutes (one hour). The expiresIn value in the authentication response is 3600 seconds. A developer should reuse the same token for all API calls within that window and only request a new token once the current one is about to expire—i.e., approximately once an hour. Requesting a token before every call is unnecessary, adds latency, and can trigger rate-limiting. The token remains valid regardless of which routes or objects are accessed, and the lifetime is one hour, not 15 minutes.

A. Token validity is time-based, not scope/route-based; a single token works across routes and objects.

B. Requesting a token per call is inefficient and unnecessary since tokens persist for the full hour.

D. The v1 token lifetime is 3600 seconds (60 minutes), not 15 minutes.

1. Salesforce Marketing Cloud Developer Documentation — "Access Tokens for API Integrations" / Legacy Package Authentication (/v1/requestToken), section on token response fields (accessToken, expiresIn: 3600). developer.salesforce.com/docs/marketing/marketing-cloud/guide/access-token-s2s.html

2. Salesforce Marketing Cloud REST API Documentation — "Your First API Call," Authentication token lifetime (60 minutes), paragraph on reusing tokens.

3. Salesforce Marketing Cloud Developer Guide — "Legacy REST Authentication," expiresIn field definition (3600 seconds).

Note: The specific v1 requestToken documentation has been largely superseded by the enhanced (v2) OAuth package in current Salesforce documentation; the one-hour (3600-second) token lifetime for v1 is the officially documented behavior.