What is apiaggregation?

API aggregation is the practice of combining data or functionality from multiple separate APIs into a single, unified response. Instead of a client having to call each API one by one, an aggregator service talks to all the needed APIs behind the scenes and returns one consolidated result.

Let's break it down

  • Multiple APIs: Think of several different services (weather, maps, payment) each with its own endpoint.
  • Aggregator layer: A middle‑man server that knows which APIs to call, in what order, and how to merge their answers.
  • Single request, single response: The client sends one request to the aggregator, which then fetches data from the various APIs, stitches the pieces together, and sends back one tidy package.

Why does it matter?

  • Simplifies client code - developers write less networking logic.
  • Reduces latency - the aggregator can run calls in parallel and send one response, saving round‑trip time.
  • Handles differences - it can translate mismatched data formats or authentication methods so the client sees a consistent shape.
  • Improves security - sensitive API keys stay on the server side, not exposed to browsers or mobile apps.

Where is it used?

  • Travel sites that show flight, hotel, and car‑rental options together.
  • Dashboard applications that pull metrics from several monitoring tools.
  • E‑commerce platforms that combine inventory, pricing, and shipping APIs.
  • Mobile apps that need weather, location, and social‑media data in one view.
  • Fintech services that merge bank account info, transaction history, and credit scores.

Good things about it

  • Cuts down the number of network calls a client must make.
  • Allows parallel fetching of data, often speeding up overall response time.
  • Provides a single place to enforce caching, rate‑limiting, and error handling.
  • Makes it easier to switch out or upgrade underlying APIs without changing the client.
  • Can normalize data structures, giving developers a predictable format to work with.

Not-so-good things

  • Adds an extra layer of complexity and another service to maintain.
  • Becomes a single point of failure if the aggregator goes down.
  • May introduce latency if the aggregator itself is slow or poorly optimized.
  • Requires careful handling of authentication and data privacy across multiple sources.
  • Can increase server costs because the aggregator does the work of many separate calls.