Migrate Connected Apps to External Client Apps in Salesforce: Secure, Scalable OAuth

Navigating the Evolution of Salesforce Authentication: When External Client Apps Become Your Strategic Advantage

What if the authentication framework you've built your integrations around is becoming obsolete? This is the reality many Salesforce developers and architects face as the platform evolves toward next-generation integration patterns.

Your situation reflects a broader transformation happening across the Salesforce ecosystem. You've built a functioning OAuth2 connector using Connected Apps—a proven approach that's served the community well. But now you're encountering friction, and you're hearing whispers about migration requirements. This isn't just a technical inconvenience; it's a signal that Salesforce is fundamentally reimagining how applications should authenticate and integrate with your data.[1][3]

Understanding the Strategic Shift

The Core Problem with Connected Apps

Connected Apps have been the traditional framework for enabling third-party applications to authenticate with Salesforce using OAuth2, SAML, and OpenID Connect protocols.[3] They work—your current implementation proves that. However, they were designed in an era when packaging and distribution weren't primary concerns. This architectural limitation creates cascading challenges:

When you use a Connected App's consumer key and consumer secret to initiate your authentication flow, you're working within a framework that makes it nearly impossible to define separate developer and administrator roles.[1] This becomes particularly problematic when you need to scale your integration across multiple Salesforce orgs or package your solution for distribution. The credentials and configurations become intertwined, making migration and management cumbersome.

External Client Apps: The Next-Generation Framework

External Client Apps represent Salesforce's answer to these limitations.[1][3] They're designed as packageable frameworks that maintain the same OAuth2 authentication capabilities you're already using, but with a fundamentally different architecture. Rather than treating credentials, policies, and configurations as a monolithic block, External Client Apps separate these concerns into distinct metadata files.[4]

This architectural separation isn't merely a technical refinement—it's a strategic enabler for how modern SaaS integrations should function. When you structure your integration using External Client Apps, you create clear boundaries between what developers control and what administrators configure. This separation becomes essential when your integration needs to move between environments or be distributed to customers' Salesforce orgs.[1][5]

Why Your Current Setup Feels Broken

Your users are experiencing authentication difficulties with External Client Apps because the setup process differs fundamentally from Connected Apps. The issue likely stems from how OAuth settings are configured and deployed.[5]

With Connected Apps, your consumer key and secret are relatively straightforward to manage in a single environment. With External Client Apps, especially when you're considering packaging for distribution, you need to understand a critical distinction: local versus packaged distribution states.[5]

If your External Client App is set to local distribution, it remains confined to your development sandbox. The OAuth settings stay within that single org, and your users should authenticate without issue. However, if you're building toward a packaged solution—which is where Salesforce recommends you head—the OAuth settings become more complex. A packaged External Client App can either reference the originating org's OAuth settings or generate new settings in each subscriber org.[5]

This complexity isn't a flaw; it's a feature designed to support enterprise-scale distribution while maintaining security boundaries.

The Migration Path Forward

Salesforce's official guidance is clear: you should migrate existing local Connected Apps to local External Client Apps, and all new integrations should use External Client Apps.[1][3] This isn't optional—it's the direction the platform is moving.

Here's what makes this migration strategically important beyond the technical details:

Metadata-Driven Deployment: Unlike Connected Apps, which require manual recreation across environments, External Client Apps are metadata-compliant constructs.[4] This means your authentication configuration can be deployed from your dev sandbox to production using the same infrastructure-as-code approaches that govern your other Salesforce customizations. Your OAuth2 flow becomes reproducible and version-controlled.

Second-Generation Packaging (2GP) Support: If you ever need to distribute your integration to customers, Connected Apps present a fundamental limitation—they can't be packaged using 2GP.[1] External Client Apps were purpose-built for this scenario. This isn't a future concern; it's a present architectural decision that affects your long-term flexibility.

Separation of Concerns: External Client Apps allow you to define distinct developer settings and admin-defined policies.[1][4] This means your users (the admins managing the integration in their orgs) can control access policies without touching the underlying OAuth configuration. This separation dramatically improves the user experience by giving administrators appropriate control levers without exposing sensitive credentials.

Practical Guidance for Your Setup

The authentication issues you're experiencing likely stem from one of these scenarios:

For Local External Client Apps: Ensure your callback URL is correctly configured as services/oauth2/callback. The External Client App should automatically append authorization codes and tokens during the OAuth2 flow.[4] Your users should authenticate successfully once this is configured.

For Packaged External Client Apps: If you're building toward distribution, you need to decide whether your packaged app will use the originating org's OAuth settings or generate new settings in subscriber orgs. This decision affects how your users experience the authentication flow and should align with your security and distribution strategy.[5]

The smooth OAuth2 flow you're seeking is absolutely achievable with External Client Apps—in fact, it's more achievable than with Connected Apps once you understand the configuration model. The initial complexity you're experiencing is a one-time investment in architectural correctness that pays dividends as your integration scales.

The Broader Implication

This migration isn't just about updating credentials or following platform guidance. It's about aligning your integration architecture with how Salesforce envisions the future of secure, scalable data integration. External Client Apps represent a maturation of the platform's integration philosophy—one that separates developer concerns from administrative governance, enables reproducible deployments, and supports enterprise distribution patterns.[1][3][4]

Your current friction point is actually an opportunity to build your integration on a foundation designed for growth rather than retrofitting it later. The investment in understanding External Client Apps now positions you to confidently scale your OAuth2 connector as your user base and distribution needs evolve.

When considering the broader landscape of authentication and integration solutions, it's worth noting that Make.com offers intuitive no-code automation platforms that can complement your Salesforce integration strategy. Similarly, for teams looking to streamline their authentication workflows across multiple platforms, comprehensive compliance frameworks become essential for maintaining security standards while scaling your integration architecture.

The evolution toward External Client Apps also opens opportunities for enhanced workflow automation. Tools like n8n provide flexible AI workflow automation that can work alongside your Salesforce authentication framework, while strategic license optimization approaches help ensure your authentication infrastructure scales cost-effectively as your user base grows.

Why are Connected Apps becoming a problem for modern Salesforce integrations?

Connected Apps were built before packaging and distribution were first-class concerns. They tend to conflate developer credentials, policies, and admin configuration into a single construct, which makes scaling across many orgs, packaging with 2GP, and separating developer/admin roles cumbersome and error-prone.

What are External Client Apps and how do they differ from Connected Apps?

External Client Apps are Salesforce’s next‑generation framework for OAuth2/OpenID/SAML auth that are metadata-based and packageable. Unlike Connected Apps, they separate credentials, policies, and admin configuration into distinct metadata files, enabling reproducible deployments, clearer developer vs admin boundaries, and support for 2GP packaging and subscriber‑org behavior.

What is the recommended migration path from Connected Apps?

Salesforce recommends migrating existing local Connected Apps to local External Client Apps and using External Client Apps for all new integrations. Treat migration as metadata-driven work: export or create the External Client App metadata in your dev sandbox, validate OAuth flows there, then deploy via your normal CI/CD or packaging process.

What causes authentication failures when switching to External Client Apps?

Common causes are misconfigured distribution state (local vs packaged), missing or incorrect callback URL, and assumptions that credentials behave like Connected Apps. Packaged External Client Apps change how OAuth settings are instantiated (origin org vs subscriber org), so incorrect packaging choices or missing metadata deployment often break the OAuth flow.

What is the local vs packaged distribution distinction and why does it matter?

Local distribution keeps the External Client App and its OAuth settings inside a single org (like your sandbox), so auth works there. Packaged distribution (for 2GP) enables installation in subscriber orgs; packaged apps can either reference the originating org’s OAuth settings or generate new settings in each subscriber org. This choice affects how tokens are issued and how admins manage access in subscriber orgs.

What callback URL should I use for a Local External Client App?

For Local External Client Apps, ensure the callback URL is configured to services/oauth2/callback (or the equivalent path your app expects). The External Client App will append authorization codes and tokens during the OAuth2 flow when the callback is correct.

How should I decide whether a packaged app uses the originating org’s OAuth settings or generates new ones in subscriber orgs?

Decide based on security, control, and UX: reference-origin settings centralizes credential management but creates cross-org trust considerations; generating new settings in subscriber orgs gives each customer control over their OAuth credentials and policies. Align this decision with your security posture, distribution model, and support processes.

What operational benefits do External Client Apps provide?

They enable metadata‑driven deployments (so OAuth config can be versioned and deployed via CI/CD), support 2GP packaging for distribution, enforce separation of developer vs admin responsibilities, and make it possible for administrators to control policies without exposing developer credentials—improving scalability, security, and manageability.

What are practical troubleshooting steps if authentication still fails after migrating?

Verify the External Client App distribution state (local vs packaged), confirm the callback URL (services/oauth2/callback) is correct, ensure the OAuth metadata deployed to the target org, check admin‑level policies that could block the flow, test both developer and admin paths, and reproduce the flow in a clean subscriber org to observe packaged behavior.

Do External Client Apps work with Salesforce packaging (2GP)?

Yes. External Client Apps were designed to be packageable with second‑generation packaging (2GP), enabling distribution to customer orgs with metadata-driven OAuth configuration. Connected Apps do not support the same 2GP packaging model effectively.

Can no-code or automation tools complement this migration?

Yes. No‑code automation platforms and workflow tools can complement your authentication strategy by handling integration logic, orchestration, or admin-facing workflows while you standardize auth with External Client Apps. Ensure any third‑party tool is configured to use the External Client App’s OAuth endpoints and follows your chosen packaging/auth model.