API terms of use: what developers should check

Rate limiting is a primary mechanism providers use to protect their infrastructure. Developers must identify the specific thresholds for calls per second, minute, or month. Exceeding these limits often results in temporary throttling or permanent suspension, which can break your application's functionality without warning.

Check if the limits are 'hard' or 'soft.' Hard limits stop service immediately, while soft limits might trigger overage fees. In jurisdictions like the EU or India, transparency regarding these technical constraints is increasingly viewed as a key component of fair commercial dealing between platforms.

• Maximum requests per time interval
• Consequences for exceeding quotas
• Process for requesting limit increases
• Caching rules for stored data
• Definitions of concurrent connections

The core value of an API is the data it provides. You must determine if you are granted a license to store that data or if you must delete it immediately after display. Some providers claim ownership over any 'derivative works' you create, which could legally jeopardize your own application's unique features.

Under US and UK law, the distinction between a 'license to use' and 'ownership' is critical. Ensure the terms do not force you to grant the provider a royalty-free license to your own proprietary code or user data in exchange for using their API.

• Persistence and storage limitations
• Attribution requirements for data display
• Ownership of derivative insights
• Prohibitions on data scraping
• Revocation of data licenses upon termination

Most free or low-tier APIs are provided 'as-is,' meaning the provider is not responsible if the service goes down. For mission-critical applications, look for a Service Level Agreement (SLA) that guarantees a certain percentage of uptime and provides credits for failures.

Limitation of liability clauses often cap the provider's financial responsibility to the amount you paid in the last few months. This is standard in SaaS agreements, but developers should be wary of clauses that exclude all liability even for gross negligence or intentional misconduct.

• Uptime percentage commitments
• Service credit policies
• Exclusion of indirect damages
• Maximum liability caps
• Force majeure event definitions

APIs evolve, and versioning is a constant challenge. Check the terms for a 'Deprecation Policy,' which outlines how much notice the provider must give before turning off an old version of the API. Without a clear policy, a provider could break your app overnight with an unannounced update.

In the EU, consumer protection and commercial fairness standards may offer slight protections against sudden changes, but in the US, 'at-will' modification is the industry standard. Always look for a guaranteed notice period of at least 30 to 90 days for breaking changes.

• Notice period for version changes
• Support duration for legacy versions
• Method of communication for updates
• Right to terminate upon material changes
• Auto-update requirements

When using an API that handles user data, you must comply with privacy laws like GDPR (EU), CCPA (US), or DPDP (India). The terms should clearly state who is the 'Data Controller' and who is the 'Data Processor.' This determines who is legally responsible for data breaches.

Security requirements often mandate that you use specific encryption standards or undergo periodic audits. Failing to meet these standards can lead to immediate termination of your API key and potential legal action from the provider if a breach occurs on your end.

• Encryption and hashing standards
• Data breach notification timelines
• Audit and inspection rights
• Jurisdictional data transfer rules
• Minimum security patch requirements