Ory

Ory is a modular open-source identity infrastructure stack that provides separate components for identity management (Kratos), OAuth2/OIDC (Hydra), and permissions (Keto). For agents that need to implement or integrate with identity systems — managing user identities, issuing OAuth tokens, enforcing fine-grained permissions — Ory provides a self-hostable alternative to commercial auth platforms with deep customization capability. The modular design means teams can adopt individual components rather than the full stack.

The API surface varies by component. Ory Kratos handles identity flows (registration, login, account recovery) with a browser-first and headless API model. Ory Hydra provides an OAuth2/OIDC server API. Ory Keto provides a permissions API based on Zanzibar (Google's permission system). Together they form a complete identity infrastructure that agents can build on or integrate with.

Authentication for Ory components themselves varies by deployment — self-hosted deployments manage their own credentials, while Ory Network (cloud) uses API keys. The self-hosting path requires more infrastructure investment but provides greater control. Teams choosing Ory should plan for the operational overhead of managing identity infrastructure rather than treating it as a simple API integration.

Reliability for self-hosted identity infrastructure is the team's responsibility. Identity systems are particularly sensitive to availability — an authentication service outage blocks user access to all dependent applications. Teams running Ory self-hosted need robust infrastructure, monitoring, and incident response for the identity layer. Ory Network provides managed reliability for teams that want it.

Documentation is comprehensive and technically precise. Each component has thorough documentation covering both the concepts and the implementation. Ory's documentation quality reflects the team's investment in developer experience, which is important given the complexity of identity systems. Teams new to OAuth2/OIDC concepts will find the conceptual guides valuable.