Let’s be honest. Today’s users don’t want to live inside Salesforce. They want clean dashboards, fast mobile apps, and simple portals that just work. That’s exactly where external client apps come in.

An external client app connects to Salesforce from the outside, pulling or pushing data securely using APIs. Think of it like a bridge between Salesforce and your customer-facing world.

An external client app is any application built outside Salesforce that interacts with Salesforce data using APIs. This could be a web app, mobile app, desktop tool, or even another SaaS platform.

In simple words, Salesforce stays the brain, and your external app becomes the face.

Because not everyone should log into Salesforce.

External apps help businesses:

• Share data with customers or partners

• Build custom user experiences

• Reduce Salesforce license costs

• Integrate Salesforce with other platforms

If Salesforce is the engine, your external app is the dashboard your users actually see.

Before building anything, you need to understand what you’re connecting to.

Salesforce is more than just a CRM. It’s a full platform with:

• Standard and custom objects

• Powerful APIs

• Security layers

• Automation tools

External apps tap into this ecosystem without living inside it.

Internal apps run inside Salesforce and use Lightning, Apex, and Visualforce.

External apps live outside Salesforce and use:

• REST or SOAP APIs

• OAuth authentication

• Connected Apps

Both are powerful. External apps just give you more freedom.

External client apps are everywhere. You just don’t always notice them.

Customers log in, check orders, raise tickets, or update profiles. No Salesforce UI. Just clean, branded experiences.

Partners need access to leads, opportunities, or deals without full CRM access. External apps solve this beautifully.

Mobile apps, websites, analytics tools, and payment systems often need Salesforce data in real time.

Skipping fundamentals is like building a house without a foundation.

You should always start in a Sandbox. Never build directly in production.

Use:

• Developer Sandbox for testing

• Full Sandbox for near-production testing

Know what data you need.

Standard Objects

Accounts, Contacts, Leads, Opportunities, Cases.

Custom Objects

Custom data built specifically for your business.

Understanding object relationships saves hours later.

Security is not optional. Salesforce takes this seriously, and so should you.

OAuth is how your external app proves it’s allowed to talk to Salesforce.

No username-password sharing. Just secure tokens.

A Connected App is Salesforce’s way of saying, “I trust this external app.”

You’ll create one before making any API calls.

Good planning saves bad rewrites.

Ask:

• Who will use this app?

• What data do they need?

• Read-only or write access?

Clarity here avoids scope creep.

Web apps are faster to build. Mobile apps feel more personal. Choose based on your audience, not trends.

Now let’s get practical.

Go to:
Setup → App Manager → New Connected App

Fill in:

• App name

• Contact email

This registers your app with Salesforce.

Enable OAuth and select required scopes like:

• Access and manage your data

• Perform requests on your behalf

Only choose what you actually need.

The callback URL is where Salesforce sends users after authentication.

For testing, a placeholder URL works.

Once saved, Salesforce gives you:

• Consumer Key

• Consumer Secret

These are the keys to your kingdom. Protect them.

Salesforce gives you multiple API options.

REST is lightweight, fast, and modern. Most external apps use REST APIs.

SOAP is more structured and enterprise-heavy. Useful for legacy systems.

REST vs SOAP Comparison

REST is flexible and simple. SOAP is rigid but powerful. Choose wisely.

This is where the magic happens.

Your app:

1. Requests authorization

2. Receives access token

3. Uses token to call APIs

No token, no data.

Once authenticated, you can:

• Query records

• Insert data

• Update objects

• Trigger automations

Salesforce becomes programmable.

Sometimes APIs aren’t enough.

Experience Cloud lets you create portals for customers and partners with controlled access.

Salesforce offers special licenses for external users at lower costs.

Perfect for scaling.

Security is not a checkbox. It’s a mindset.

Never hardcode tokens. Rotate them regularly.

Restrict access by IP where possible. Less exposure, more control.

Common Security Mistakes to Avoid

• Over-permissioning scopes

• Storing secrets in frontend code

• Ignoring token expiry

One mistake can expose everything.

Test like your business depends on it. Because it does.

Always test in sandbox first. Break things safely.

Use logs, error messages, and Salesforce debug tools to trace issues quickly.

Almost there.

Recreate Connected App settings carefully in production.

Track API usage, errors, and performance from day one.

Speed matters.

Salesforce has API limits. Use bulk queries and smart caching.

Cache frequently used data on your app side to reduce API calls.

Every build has bumps.

Usually caused by misconfigured OAuth settings or expired tokens.

Check object permissions, field-level security, and profiles.

The right tools make life easier.

• React

• Angular

• Node.js

• Python

• Java

Salesforce provides SDKs that simplify authentication and API calls.

Creating an external client app in Salesforce is not just a technical task. It’s a strategic move. You keep Salesforce powerful behind the scenes while delivering smooth, custom experiences to users.

Plan well, secure everything, test thoroughly, and build with scale in mind. When done right, your external app becomes an extension of Salesforce, not a limitation.

Not always. API-based apps can work without individual licenses.

REST API is the most commonly used and recommended.

Yes. OAuth is the standard and secure method.

Absolutely. Salesforce APIs work perfectly with mobile apps.

Very secure, if OAuth, scopes, and best practices are followed correctly.