OAuth flows setup

OAuth flows setup is a project: we connect the needed providers (Google, Yandex, VK, GitHub, Apple, etc.), implement a correct flow (for web — Authorization Code Flow with PKCE, without the outdated Implicit), secure token handling, state/nonce verification, linking with existing accounts, handling revocation/errors. Honestly about the nature, this is key: OAuth/OIDC is DELEGATING authentication to a third-party provider (you trust Google/Yandex's 'login', etc.) — convenient and frees you from storing passwords, but adds DEPENDENCY: if a user has issues with the provider or the provider is unavailable/changes rules — it affects login (so a fallback method is often needed). Honestly about security, important: OAuth is secure only with CORRECT implementation — errors (wrong flow, missing PKCE/state, insecure token storage, open redirect) create serious vulnerabilities (account takeover); 'sign in with Google' by itself does not guarantee security — correct implementation does, which is what we provide. Honestly about account linking: matching email and linking must be handled carefully, otherwise impersonation risks. Honestly about the boundary: this is login via a provider, not 2FA (746) and not your own passwordless system (747); they are often combined. Honestly about access: access to the code and app registration with providers is needed. Honestly about the effect: more convenient registration/login, but we do NOT guarantee sales growth by itself. If external login is not needed, the service is overkill. Picture this: instead of 'one more password for registration' — login via a familiar account, implemented securely. The base price starts from 18,000 ₽ per project; it depends on the number of providers.

• There is no convenient login via Google/Yandex/VK, etc.
• Password registration scares off some users.
• OAuth is implemented with errors (account-takeover risk).
• There is no correct linking of external and existing accounts.

• Connecting the needed providers (Google/Yandex/VK/GitHub/Apple, etc.)
• A correct flow (Authorization Code + PKCE, without Implicit)
• Secure token handling, state/nonce verification
• Linking with existing accounts
• Error/revocation handling and a fallback login method
• Indicating provider dependency
• Testing login scenarios
• Handover and review with you

• Convenient login via familiar accounts
• A correct and secure OAuth flow
• Correct account linking
• Fewer registration barriers (sales growth — not guaranteed)

• We clarify providers and scenarios; register apps, collect access
• We implement the correct flow, tokens, linking, a fallback method
• We test security and scenarios, review with you

• Is 'sign in with Google' secure by itself?

  Security comes from CORRECT implementation, not the fact of OAuth. Flow errors (no PKCE/state, insecure token storage, open redirect) create serious vulnerabilities up to account takeover. We implement a correct, secure flow.

• Does it create dependency on the provider?

  Yes. OAuth is delegating login to a third-party provider: provider unavailability/rule changes or user issues affect login. So we often add a fallback login method, so as not to fully depend on one provider.

• Does it replace 2FA?

  No. OAuth is a login method via a provider; 2FA (746) is an additional factor; passwordless (747) is a different system. They are often combined. We advise an appropriate combination for your case.