August 2026 Summaries

For B2B startups, authentication extends beyond basic login to include organization-based multi-tenancy, role management, invitations, self-service administration, enterprise SSO, SCIM provisioning, security controls, and machine-to-machine access. The comparison identifies PropelAuth as a B2B-focused option because it includes organizations, roles, invitations, hosted admin tools, SAML SSO, and predictable plan-based pricing, while noting that its advantages are less relevant to purely consumer applications. Auth0 offers a broad, established customer identity platform but may require teams to build more of the B2B management experience and can become costly under per-user pricing. AWS Cognito, Firebase Authentication, Microsoft Entra External ID, and Okta are presented as viable choices for teams committed to their respective cloud or enterprise ecosystems, though they generally lack packaged SaaS organization-management features. Keycloak provides a flexible open-source, self-hosted alternative but requires teams to operate, secure, and customize the identity infrastructure themselves. The selection guidance emphasizes evaluating whether organizational features are native, how SSO is priced and configured, how costs scale with users, and whether customer administrators can manage their own accounts.

Remote MCP servers require OAuth 2.1 authentication features including protected-resource and authorization-server discovery, dynamic client registration or Client ID Metadata Documents, PKCE, consent, scoped tokens, validation, and operational controls such as revocation and audit logs. The comparison evaluates PropelAuth, Auth0, WorkOS AuthKit, Clerk, and Descope as authorization servers for product teams building MCP integrations with clients such as Claude, ChatGPT, and Cursor. PropelAuth is generally available and emphasizes built-in organization-aware scopes, role restrictions, token introspection containing organization and permission data, client allowlists, audit logging, and session controls; Auth0 offers comparable MCP capabilities through an Early Access product but requires more tenant and API-audience configuration. WorkOS supports CIMD and DCR and can sit in front of an existing login system, though teams must implement organization-role-to-scope mapping, while Clerk provides MCP middleware and metadata support suited to existing Next.js or Express applications but offers more limited organization-aware scoping. Descope supports policy-based access decisions using scopes, roles, permissions, and custom attributes, along with downstream OAuth token storage. Selection depends primarily on organization and role requirements, control over OAuth client creation, product availability, and the need for future operational features such as audit trails and session management.

PropelAuth now allows a single organization to connect multiple identity providers, enabling groups such as employees, contractors, or acquired teams to access the same workspace through separate Okta, Entra ID, Google Workspace, SAML, OIDC, and SCIM configurations. The opt-in feature is enabled at both project and organization levels, with each connection assigned email domains that automatically route users to the appropriate provider without requiring them to select a connection. Separate setup links let different customer teams configure only their own identity provider, while eligible customer administrators can maintain configurations, certificates, nicknames, and SCIM settings for connections matching their email domain. Developers using Enterprise SSO APIs gain an endpoint for listing connections, must provide connection IDs for certain SCIM group requests, and may need to include a domain or email address in direct login redirects to avoid ambiguity. Existing authorization logic, organization-scoped queries, and role checks remain unchanged, while new connections in multi-connection organizations must be created through setup links.

A September 2026 comparison of managed authentication providers argues that provider selection should primarily reflect whether a startup serves individual users or business organizations, with core login, MFA, recovery, and attack-protection features largely common across vendors. It rates PropelAuth as most suitable for B2B SaaS because it treats organizations, per-organization roles, and multi-tenant authorization as native features and offers unlimited SAML/OIDC connections for $150 per month, though SCIM requires a higher plan and its ecosystem is smaller. Clerk is presented as the strongest option for consumer, prosumer, and Next.js applications due to polished React components and a large free tier, but B2B capabilities and multiple enterprise connections add costs. WorkOS is positioned for companies adding SSO and SCIM to an existing login system or selling to a small number of high-value enterprises, while its per-connection pricing can become costly for broader mid-market B2B adoption. Supabase Auth is recommended for teams already using Supabase because of its integration with PostgreSQL row-level security, although organizations and SCIM are not native; Auth0 is reserved for complex, regulated, or unusually diverse identity requirements despite heavier configuration and potentially escalating costs; and Kinde suits small teams seeking bundled authentication, feature flags, and billing. The comparison emphasizes that enterprise SSO connection counts, rather than active-user totals, often drive B2B authentication costs, and advises founders to assess organization models, SCIM needs, authorization requirements, and expected enterprise pipelines before committing to a provider.