Having implemented all three approaches across different partner programs, here’s my comprehensive analysis:
OAuth2 Delegated Access:
This is the recommended approach for most partner portals. OAuth2 provides individual user authentication with proper audit trails - every API call is attributed to the specific partner user who initiated it. In AEC 2022, the OAuth implementation follows standard RFC 6749 with authorization code flow. Key benefits: granular permission scopes, automatic token expiration (enhances security), familiar authentication UX for partners. Implementation considerations: you need secure token storage (encrypted database or Redis), robust refresh token handling (tokens expire every 2 hours), and clear documentation for the consent flow. The delegated access model means partners authenticate with their actual AEC credentials, so you inherit AEC’s permission model - partners can only access data they’re entitled to in AEC itself. This is crucial for multi-tenant security. Gotcha: initial partner onboarding requires an admin to grant OAuth consent for your application, which adds a setup step but prevents unauthorized access.
API Key Simplicity:
API keys work well for small-scale integrations (under 10 partners) where your backend performs all API operations and partners never directly call AEC APIs. The simplicity is real - no token refresh logic, no consent flows, just include the key in request headers. However, this approach has significant security and compliance limitations. You’re creating a service account with broad access that represents all partners collectively, not individual users. Audit trails show generic “API integration” as the actor, not specific partner users. If a key is compromised, you must rotate it and update all integration points simultaneously - there’s no graceful key rotation in AEC 2022. API keys also never expire automatically, requiring manual rotation policies. Only use this approach if: (a) partners are highly trusted, (b) your backend is the only API consumer, (c) you don’t need user-level audit trails, and (d) compliance requirements are minimal.
SAML Enterprise SSO:
SAML is the enterprise-grade option for large partners (500+ users) who require federated identity management. It provides seamless SSO - partners authenticate once with their corporate IdP and gain access to both your portal and AEC without additional logins. AEC 2022’s SAML implementation supports both IdP-initiated and SP-initiated flows with standard SAML 2.0. Benefits: no password management, leverages existing enterprise identity infrastructure, meets compliance requirements for large enterprises. Complexity factors: you need to configure SAML service provider settings in AEC, manage X.509 certificate rotations (typically annual), implement SAML assertion parsing and validation, and coordinate with each partner’s IT team for IdP configuration. The setup can take 2-4 weeks per partner. SAML also requires technical expertise on both sides - not suitable for small partners without dedicated IT staff. Best used in a hybrid model: SAML for top enterprise partners who require it, OAuth2 for everyone else.
Recommendation for Your Use Case:
Given your partner mix (small agencies to large enterprises), implement OAuth2 as the primary authentication method with optional SAML for enterprise partners who require it. OAuth2 provides the right balance of security, usability, and audit compliance for most partners. For your top 5-10 enterprise partners, offer SAML as an optional upgrade path. Avoid API keys entirely for partner-facing integrations - the security and compliance risks outweigh the implementation simplicity. The token management overhead of OAuth2 is manageable with proper infrastructure (token refresh service, secure storage) and the security benefits are substantial.