As digital advertising grows in both complexity and importance, bi-directional APIs (Application Programming Interfaces) have become a crucial tool for automating campaigns and advertising workflows.
This article will:
- Define the difference between unidirectional and bi-directional APIs
- Outline specific bi-directional API use cases related to digital advertising workflows and strategies
- Examine common challenges and technical requirements for integrating bi-directional APIs
- Provide you with the most important questions to ask API providers when vetting partners for your agency or in-house advertising systems
What’s the difference between unidirectional APIs and bi-directional APIs?At its core, an API is a software connection between applications at the programmatic level—such as the connection between an e-commerce store and different payment processors. APIs make it possible for two applications or systems to share data with each other quickly and seamlessly, without manual intervention. There are two different kinds of APIs: unidirectional APIs and bi-directional APIs.
A unidirectional API (sometimes called a traditional API) is the most common type of API. With unidirectional APIs, data only flows in one direction: data can be read but you cannot write back to the server. Typically, data flows from the server to the client with unidirectional APIs. This basic data flow makes unidirectional APIs easy to implement, manage, and understand. However, they are also very limited in their functionality. You can’t use a unidirectional API to update data: you can only use the API to access or retrieve the data. That’s why they are best used in situations where you need information from a server but don’t need to send any information back. For example, when you look up the weather, you read data from the weather source. There’s no need to write back to NOAA about the weather, you just want to take the information in.
A bi-directional API is unique in that it enables a client to read data from the server and write data onto the server. Bi-directional APIs enable a seamless, two-way data exchange between systems. This means that communication takes place in both directions: a server can send data to a client without a direct request, and clients can overwrite server data with updates.
Bi-directional APIs enable real-time updates, notifications, and communication between two interconnected systems. Unlike unidirectional APIs, bi-directional APIs allow systems to dynamically exchange information: instant updates, personalized recommendations, live notifications, and real-time synchronizations across platforms. These flexibility and versatility features make bi-directional APIs ideal for applications (like digital advertising) that require continuous and responsive communication between two systems.
For example, bi-directional APIs enable you to leave comments, likes, and share posts within social platforms. You, as a user, are sending data to the system about what kind of content you want to engage with. In turn, the system finds and sends you new posts that it thinks you’ll like based on actions you’ve taken.
What are the benefits of using bi-directional APIs for ad agencies and enterprises?
Bi-directional APIs facilitate real-time communication between your agency and advertising publishers. This opens up a wide range of valuable opportunities for both ad strategies and AdOps workflows.
Here are three key benefits of using bi-directional APIs in digital advertising.
Enables real-time advertising at scale
Bi-directional APIs provide advertisers with a slew of benefits when it comes to real-time advertising. Real-time data is prominent—and critical—in digital advertising. A bi-directional API establishes a two-way data flow between publisher servers and your AdOps team. This real-time interaction between your data sets and publishers opens up opportunities for your team to build more strategic campaigns and manage campaigns more efficiently.
Since bi-directional APIs enable data to flow instantaneously between two systems, your teams can respond quickly (or instantly, with automation) to pivotal performance metrics. For example,
Advertising operations that rely heavily on manual updates or batch syncs (e.g. monthly budget updates) are both slow and prone to errors. Anytime there is a middle action or step between data and execution, you’re risking opportunities. Bi-directional APIs eliminate lag time so your teams can move faster and more efficiently for every customer in your portfolio.
Secure, controllable data transfers between internal systems and publishers
Security may be the biggest benefit of using bi-directional APIs—just ask your closest engineer. API integrations mean that you can safely retain control over critical processes while still integrating your internal systems with external publisher platforms.
These data exchanges can handle sensitive data securely because they typically use encryption when communicating between systems. By contrast, any sensitive customer information (like account details or budgets) that is entered manually increases the risk of data leaks of breaches.
APIs also utilize strict authentication standards, like OAuth or tokenized access. These features control which systems or users can access the data bridge. It also means you can maintain ownership of your valuable data instead of relying on a third-party platform to manage it.
Efficient and cost-saving advertising operations
Any time you can remove manual workflows or processes from your AdOps, you will gain unprecedented operational efficiencies. Simply put, utilizing bi-directional APIs drastically reduces your agency's reliance on manual copy-and-paste processes.
Bi-directional APIs guarantee that the most up-to-date and accurate data is in place. This cuts down on human error and gives your team the ability to act quickly as performance data comes in. Whether they are reallocating budgets to high-performing campaigns or tweaking keywords, these timely adjustments can be made fast and en masse.
Eliminating manual data processes has compounding benefits for your agency. You'll reduce errors, deploy campaigns faster, and stop paying strategists to perform mundane tasks. Simply put, offloading these manual tasks empowers teams to focus on high-impact tasks that deliver exceptional value to your customers.
The biggest challenge with bi-directional APIs: publisher API release upkeep
Upkeep is the biggest challenge with APIs, specifically in the fast-moving advertising domain. Advertising APIs evolve quickly and there are many of them to keep current.
For context, the Google Ads API typically has “three major releases and three major release sunsets per year,” according to their developer site. Meta has historically released updates for its Marketing API every 3-6 months.
Managing APIs for individual publishers can be a time-consuming and resource-intensive task for your agency. Yes, APIs will help your agency reduce manual labor for a variety of advertising operations and workflows. But if all you’re doing is exchanging manual campaign work for continual developer API upkeep, you’re still racking up hours of labor. In the long run, you’re still driving up labor costs with engineers instead of strategists.
The best solution is one that reduces this complexity: a stable, versioned API that sits in front of—and normalizes—the seemingly infinite number of channel partner APIs. Utilizing “one bi-directional API to rule them all,” so to speak, can greatly simplify your internal architecture.
Finding and implementing a stable, singular bi-directional API for all your digital advertising needs is a tremendous benefit, particularly as your company expands to new channels and publishers announce new features. Plus, using a well-engineered and well-maintained API for all your traditionally manual AdOps tasks can reduce labor demands to zero or near zero time.
How do digital advertisers use bi-directional APIs? Use cases and real life examples
Bi-directional APIs can be used across multiple advertising operational workflows to enhance precision and slash manual workloads. Here are ten ways (out of hundreds!) that ad agencies use Fluency’s bi-directional API to build, manage, and optimize multi-channel campaigns at scale.
1. Update budgets directly from a source of record
With bi-directional APIs, you can seamlessly sync budgets directly from sources (e.g. Salesforce) to publishers (e.g. Google). Fluency’s API enables you to both read budget records and modify budgets on publishers efficiently, eliminating costly manual errors while saving hours of tedious work.
2. Utilize dynamic, automatic campaign pacing
Bi-directional API capabilities, like those used by Fluency’s Digital Advertising Operating System (DAOS), can continuously monitor daily campaign spend and pacing for every customer in your portfolio. If an account or campaign is under-pacing, automation tools can adjust bids and spend targets in real time to prevent underspend.
3. Make multi-channel creative updates in bulk
Launching a time-sensitive promotion? With a bi-directional API integration, your team can push updated ad copy or creative assets to multiple publishers simultaneously. The API also confirms successful deployment by pulling real-time status data back into Fluency, making it possible to identify issues or errors instantly.
4. Automate keyword optimization in Google Ads
Fluency’s bi-directional API can analyze search query performance on key platforms like Google Ads. Underperforming keywords can be flagged, adjusted, or replaced with high-performing ones in real-time across all managed accounts, without logging into each account individually or making manual updates.
5. Make real-time budget adjustments across channels
Let’s say your Google campaigns are performing well but Facebook campaigns are under-delivering. With bi-directional APIs, these real-time performance metrics from both channels can trigger automation rules that reallocate budgets across channels. This ensures that cross-channel campaigns stay aligned with customer KPIs without manual intervention.
6. Adjust and create inventory-based ads instantly
Whether you’re working with occupancy data, physical product inventory data, or SKUs, bi-directional APIs can sync live inventory data directly with publishers. For example, when inventory stock is low, the API can identify any ads featuring the low-stock product across multiple channels. Automated solutions can automatically pause the associated ads to avoid wasted spend and reactivate the ads when the product is back in stock—all without human intervention.
7. Write custom rule-based campaign adjustments to meet unique customer goals
Through API integrations, Fluency’s DAOS enables advertisers to create highly specific rules that cater to specific customer needs. For example, you can set up an automated rule that pauses or updates ads if a product’s price changes. Fluency’s API instantly syncs these updates from the company’s data source to all associated campaigns, saving you the hassle and headache of running outdated ads.
8. Build localized ads and targeting strategies at scale
Bi-directional APIs enable your team to automate multi-location geo-targeting updates across campaigns. For example, you can manage zip-code or radius targeting across multiple channels instead of on a per-platform basis. You can also automatically sync changes to business addresses, operating hours, specials, or brand colors in bulk, reducing manual workloads while making ads more relevant.
9. Reduce errors with improved compliance measures
Fluency’s DAOS uses bi-directional APIs to identify critical errors like disapproved ads or targeting issues across multiple platforms, delivered to your team in one place. Once identified, the system can even automatically fix compliance-related errors based on your agency’s preferred course of action and resubmit campaigns for approval.
10. Pull in real-time content and data for custom, targeted ads
Bi-directional APIs can connect customer CRMs directly to ad platforms. This makes it possible to dynamically adjust content based on user data. For instance, if a consumer interacts with a specific product on a website, the API can deliver tailored ads to the consumer that showcase complementary products instead of generic campaigns.
How to choose a bi-directional API provider for your enterprise advertising operations
When choosing the right bi-directional API solution for your advertising agency or enterprise, it’s important to think beyond channel-specific needs. The ideal bi-directional system will enable you to unlock efficiencies across multiple publishers, workflows, and customers. To ensure that a bi-directional API works with your agency’s needs and security protocols, here are some questions for vendors:
Functionality questions
- Can create and update campaign elements in bulk for multiple channels via a single system?
- Can I easily manage and move budgets across channels and publishers?
- Can I quickly create custom dashboards or cross-channel reports?
- Can this bi-directional API enable two-way data transfers between publishers and my CRM, analytics platform, or third-party tools?
Product questions
- How quickly are new publisher features and API updates supported?
- Does your company utilize a unified API interface, so my developers only need to learn and work with one set of conventions?
- Does the system include built-in error handling (e.g. mismatched campaign settings, budget overspend triggers, or failed audience imports)?
- How does your organization manage version controls and updated API requirements from publishers?
Security and governance questions
- What data security and governance measures are in place at your company?
- Does your system provide detailed data exchange logs?
- What authentication methods are supported (OAuth, API keys, etc.)?
- How is sensitive customer data encrypted both in transit and at rest?
- What compliance certifications does your system maintain (SOC 2, GDPR, etc.)?
Integration and support questions
- How does your company manage implementation and onboarding support?
- When critical issues arise, what is the average response time from your team?
- How does your company continue working with and supporting my team after implementation?
The future of digital advertising: bi-directional APIs for AdOps scalability
Whether you’re struggling to keep up with the accelerated volume of advertising API changes or having the age-old “build or buy” debate at your agency, utilizing a third-party bi-directional API offers the best of all worlds. You can get flexible reporting and management, external platform data engagement, and offload upkeep support to a dedicated team.
The time, cost, and resource savings generated by bi-directional APIs are unmatched, especially compared to manual processes. Two-way data synchronization via APIs makes it possible to automatically update hundreds or thousands of ad accounts based on data sources. Best of all, your agency can scale your efforts at lower labor costs while still providing unique value to your customers.
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