Get to Know the Salesforce Lightning Platform APIs
- Describe the benefits of the API-first approach to development.
- State use cases for REST API, SOAP API, Bulk API, and Streaming API.
- Name the two types of API limits and describe how they’re calculated.
API First at Salesforce
Salesforce Data APIs
REST API is a simple and powerful web service based on RESTful principles. It exposes all sorts of Salesforce functionality via REST resources and HTTP methods. For example, you can create, read, update, and delete (CRUD) records, search or query your data, retrieve object metadata, and access information about limits in your org. REST API supports both XML and JSON.
Because REST API has a lightweight request and response framework and is easy to use, it’s great for writing mobile and web apps.
SOAP API is a robust and powerful web service based on the industry-standard protocol of the same name. It uses a Web Services Description Language (WSDL) file to rigorously define the parameters for accessing data through the API. SOAP API supports XML only. Most of the SOAP API functionality is also available through REST API. It just depends on which standard better meets your needs.
Because SOAP API uses the WSDL file as a formal contract between the API and consumer, it’s great for writing server-to-server integrations.
Bulk API is a specialized RESTful API for loading and querying lots of data at once. By lots, we mean 50,000 records or more. Bulk API is asynchronous, meaning that you can submit a request and come back later for the results. This approach is the preferred one when dealing with large amounts of data. There are two versions of Bulk API (1.0 and 2.0). Both versions handle large amounts of data, but we use Bulk API 2.0 in this module because it’s a bit easier to use.
Bulk API is great for performing tasks that involve lots of records, such as loading data into your org for the first time.
Streaming API is a specialized API for setting up notifications that trigger when changes are made to your data. It uses a publish-subscribe, or pub/sub, model in which users can subscribe to channels that broadcast certain types of data changes.
The pub/sub model reduces the number of API requests by eliminating the need for polling. Streaming API is great for writing apps that would otherwise need to frequently poll for changes.
API Access and Authentication
All API calls, except for the SOAP API login() call, require authentication. You can either use one of the supported OAuth flows or authenticate with a session ID retrieved from the SOAP API login() call. Check the developer guide for your API of choice to get started.
There are two types of API limits. Concurrent limits cap the number of long-running calls (20 seconds or longer) that are running at one time. Total limits cap the number of calls made within a rolling 24-hour period.
Concurrent limits vary by org type. For a Trailhead Playground, the limit is five long-running calls at once. For a sandbox org, it’s 25 long-running calls.
Total limits vary by org edition, license type, and expansion packs that you purchase. For example, an Enterprise Edition org gets 1,000 calls per Salesforce license and 200 calls per Partner Community license. With an “Additional API Calls” pack, that same Enterprise Edition org gets an extra 4,000 calls. Total limits are also subject to minimums and maximums based on the org edition, but we won’t get into that here. If you want to know more, check out the Salesforce Developer Limits and Allocations Quick Reference link in the Resources section.
- The API Usage box on the System Overview page. (From Setup, enter System Overview in the Quick Find box, then select System Overview.)
- Information returned in the Sforce-Limit-Info response header for REST APIs.
- Information returned in the response body (in <type>API REQUESTS</type>) for SOAP APIs.
- The /limits call in the Lightning Platform REST API.
- The API Request Limit per Month usage-based entitlement, which shows you your org’s API calls aggregated over 30 days.
Which API Do I Use?
Choosing the right API for your integration needs is an important decision. Here’s some information on our most commonly used APIs, including supported protocols, data formats, communication paradigms, and use cases. Treat this section as a reference you can return to when you’re considering which API to use.
|API Name||Protocol||Data Format||Communication|
|REST API||REST||JSON, XML||Synchronous|
|SOAP API||SOAP (WSDL)||XML||Synchronous|
|Chatter REST API||REST||JSON, XML||Synchronous (photos are processed asynchronously)|
|User Interface API||REST||JSON||Synchronous|
|Analytics REST API||REST||JSON, XML||Synchronous|
|Bulk API||REST||CSV, JSON, XML||Asynchronous|
|Metadata API||SOAP (WSDL)||XML||Asynchronous|
|Streaming API||Bayeux||JSON||Asynchronous (stream of data)|
|Apex REST API||REST||JSON, XML, Custom||Synchronous|
|Apex SOAP API||SOAP (WSDL)||XML||Synchronous|
|Tooling API||REST or SOAP (WSDL)||JSON, XML, Custom||Synchronous|
When to Use REST API
REST API provides a powerful, convenient, and simple REST-based web services interface for interacting with Salesforce. Its advantages include ease of integration and development, and it’s an excellent choice of technology for use with mobile applications and web projects. For certain projects, you may want to use REST API with other Salesforce REST APIs. To build UI for creating, reading, updating, and deleting records, including building UI for list views, actions, and dependent picklists, use User Interface API. To build UI for Chatter, communities, or recommendations, use Chatter REST API. If you have many records to process, consider using Bulk API, which is based on REST principles and optimized for large sets of data.
When to Use SOAP API
SOAP API provides a powerful, convenient, and simple SOAP-based web services interface for interacting with Salesforce. You can use SOAP API to create, retrieve, update, or delete records. You can also use SOAP API to perform searches and much more. Use SOAP API in any language that supports web services.
For example, you can use SOAP API to integrate Salesforce with your org’s ERP and finance systems. You can also deliver real-time sales and support information to company portals and populate critical business systems with customer information.
When to Use Chatter REST API
Use Chatter REST API to display Chatter feeds, users, groups, and followers, especially in mobile applications. Chatter REST API also provides programmatic access to files, recommendations, topics, notifications, Data.com purchasing, and more. Chatter REST API is similar to APIs offered by other companies with feeds, such as Facebook and Twitter, but it also exposes Salesforce features beyond Chatter.
When to Use User Interface API
When to Use the Analytics REST API
You can access Analytics assets—such as datasets, lenses, and dashboards—programmatically using the Analytics REST API. Send queries directly to the Analytics Platform. Access datasets that have been imported into the Analytics Platform. Create and retrieve lenses. Access XMD information. Retrieve a list of dataset versions. Create and retrieve Analytics applications. Create, update, and retrieve Analytics dashboards. Retrieve a list of dependencies for an application. Determine what features are available to the user. Work with snapshots. Manipulate replicated datasets.
When to Use Bulk API
Bulk API is based on REST principles and is optimized for loading or deleting large sets of data. You can use it to query, queryAll, insert, update, upsert, or delete many records asynchronously by submitting batches. Salesforce processes batches in the background.
SOAP API, in contrast, is optimized for real-time client applications that update a few records at a time. You can use SOAP API for processing many records, but when the data sets contain hundreds of thousands of records, SOAP API is less practical. Bulk API is designed to make it simple to process data from a few thousand to millions of records.
When to Use Metadata API
Use Metadata API to retrieve, deploy, create, update, or delete customizations for your org. The most common use is to migrate changes from a sandbox or testing org to your production environment. Metadata API is intended for managing customizations and for building tools that can manage the metadata model, not the data itself.
- The Salesforce Extensions for Visual Studio Code includes tools for developing on the Salesforce platform in the lightweight, extensible VS Code editor. These tools provide features for working with development orgs (scratch orgs, sandboxes, and DE orgs), Apex, Aura components, and Visualforce.
- The Ant Migration Tool is ideal if you use a script or the command line for moving metadata between a local directory and a Salesforce org.
When to Use Streaming API
Use Streaming API to receive near-real-time streams of data that are based on changes in Salesforce records or custom payloads. For Salesforce record changes, Salesforce publishes notifications when the changes occur. For custom notifications, you can publish event messages. Subscribers can receive notifications using CometD—an implementation of the Bayeux protocol that simulates push technology. Clients can also subscribe to some types of events with Apex triggers or declaratively with Process Builder and Flow Builder.
Use the type of streaming event that suits your needs.
When to Use Apex REST API
Use Apex REST API when you want to expose your Apex classes and methods so that external applications can access your code through REST architecture. Apex REST API supports both OAuth 2.0 and Session ID for authorization.
When to Use Apex SOAP API
Use Apex SOAP API when you want to expose Apex methods as SOAP web service APIs so that external applications can access your code through SOAP.
Apex SOAP API supports both OAuth 2.0 and Session ID for authorization.
When to Use Tooling API
Use Tooling API to build custom development tools or apps for Lightning Platform applications. For example, you can use Tooling API to add features and functionality to your existing Lightning Platform tools and build dynamic modules into your enterprise integration tools. You can also use Tooling API to build specialized development tools for a specific application or service.
Tooling API’s SOQL capabilities for many metadata types allow you to retrieve smaller pieces of metadata. Smaller retrieves improve performance, making Tooling API a good fit for developing interactive applications. Tooling API provides SOAP and REST interfaces.