[Bccorb]

Closes #109.

Draft for maintainer sign-off. Vendor sources were checked on 2026-10-20 and must be re-checked on the publish day; pricing and plan contents in particular change often.

What this adds

• src/content/docs/compare/cognito.mdx (sidebar order 6): Seamless Auth vs Amazon Cognito. Links the existing Cognito migration guide.
• src/content/docs/compare/firebase-auth.mdx (sidebar order 7): Seamless Auth vs Firebase Authentication, with and without Identity Platform. States plainly that there is no Firebase migration guide yet, and only points at the generic CSV identity import as far as /operate/migrate-users supports it.

Both follow the Auth0 and Keycloak page structure: Choose them If, Choose Seamless Auth If, Feature Comparison, pricing Aside, Architecture Difference, When Not To Use Seamless Auth, migration section, Sources. The Compare sidebar is autogenerated and no page lists the compare pages, so no other files needed links.

Competitor claims and their sources (all checked 2026-10-20)

Cognito:

• Plans, free tiers, per-MAU prices, federated MAU price, M2M per-token billing, add-ons, SMS/email via SNS/SES, GovCloud exclusion: https://aws.amazon.com/cognito/pricing/
• Features by plan (passkeys and passwordless codes on Essentials and Plus, federation, authorization server, M2M, import, MFA, Lambda triggers, managed login, Plus logs): https://docs.aws.amazon.com/cognito/latest/developerguide/cognito-sign-in-feature-plans.html
• Passkeys not on Lite, WEB_AUTHN must accompany another option, user verification preferred by default, no attestation enforcement, 20 per user, OTP flows: https://docs.aws.amazon.com/cognito/latest/developerguide/amazon-cognito-user-pools-authentication-flow-methods.html
• Managed login and classic hosted UI, user pool domains, Amplify: https://docs.aws.amazon.com/cognito/latest/developerguide/cognito-user-pools-managed-login.html
• Social, SAML, OIDC federation: https://docs.aws.amazon.com/cognito/latest/developerguide/cognito-user-pools-identity-federation.html and https://docs.aws.amazon.com/cognito/latest/developerguide/cognito-user-pools-saml-idp.html
• Resource servers, scopes, client credentials, API Gateway authorizers: https://docs.aws.amazon.com/cognito/latest/developerguide/cognito-user-pools-define-resource-servers.html
• Lambda triggers: https://docs.aws.amazon.com/cognito/latest/developerguide/cognito-user-pools-working-with-lambda-triggers.html
• Identity pools and AWS credentials: https://docs.aws.amazon.com/cognito/latest/developerguide/cognito-identity.html
• CSV import with password hashes, 500,000 users per file: https://docs.aws.amazon.com/cognito/latest/developerguide/cognito-user-pools-using-import-tool.html
• Export limits (ListUsers 60 per call, no password field; export guidance does not carry passwords): https://docs.aws.amazon.com/cognito-user-identity-pools/latest/APIReference/API_ListUsers.html, https://docs.aws.amazon.com/cognito-user-identity-pools/latest/APIReference/API_UserType.html, https://docs.aws.amazon.com/solutions/latest/cognito-user-profiles-export-reference-architecture/guidance-components.html
• Region and encryption at rest: https://docs.aws.amazon.com/cognito/latest/developerguide/data-protection.html
• Compliance programs: https://docs.aws.amazon.com/cognito/latest/developerguide/compliance-validation.html

Firebase Authentication / Identity Platform:

• Spark vs Blaze allowances, phone auth on Blaze only: https://firebase.google.com/pricing
• Identity Platform per-MAU and per-SMS prices: https://cloud.google.com/identity-platform/pricing
• Sign-in methods, SDKs, FirebaseUI, Security Rules, upgrade features and post-upgrade limits: https://firebase.google.com/docs/auth
• Features only with Identity Platform, compliance table, SLA: https://cloud.google.com/identity-platform/docs/product-comparison
• Multi-tenancy: https://cloud.google.com/identity-platform/docs/multi-tenancy
• Blocking functions: https://firebase.google.com/docs/auth/extend-with-blocking-functions
• SAML (Identity Platform, SP-initiated only): https://firebase.google.com/docs/auth/web/saml
• MFA (SMS, TOTP): https://firebase.google.com/docs/auth/web/multi-factor and https://firebase.google.com/docs/auth/web/totp-mfa
• Email link sign-in: https://firebase.google.com/docs/auth/web/email-link-auth and limits at https://firebase.google.com/docs/auth/limits
• auth:export with hash parameters: https://firebase.google.com/docs/cli/auth
• Emulator (local testing, unsigned tokens): https://firebase.google.com/docs/emulator-suite/connect_auth
• Passkey status (no passkey sign-in method in the docs; mock passkey support in the Auth emulator, CLI v15.21.0): https://firebase.google.com/support/release-notes/cli
• US-only data processing, ISO and SOC: https://firebase.google.com/support/privacy

Seamless Auth claims were checked against origin/main of seamless-auth-api (v0.19.1), seamless-cli, seamless-auth-server, seamless-auth-react, seamless-auth-types, and the Go, Python, and Rust adapters.

Checks

• npm run lint: pass
• npm run typecheck: 0 errors, 0 warnings, 0 hints
• npm run build: 57 pages built, both new pages present (existing env highlighting and i18n warnings only)
• npx prettier --check on the new files: pass (src/content/docs is in .prettierignore)