REST API
Best for first-party backend integrations you directly control.
OAuth
Use OAuth when another application needs delegated access to HAL.
OAuth is the right fit for app-to-app authorization flows. Use it when bearer tokens or MCP keys are the wrong level of access for your integration.
Use cases
- Third-party products connecting user-owned HAL accounts
- Delegated access flows where a user explicitly authorizes the integration
- Apps that should not depend on personal session tokens
Choose the right integration surface
MCP
Best for external AI clients that should use HAL through tools.
OAuth
Best for delegated third-party app access.