Software developers that need to integrate Aspera high-speed transfer capabilities into their software or services typically use our file-based APIs to initiate, manage, and control high-speed transfers from one file system to another. To support the broader set of use cases where developers wish to bypass the file system and directly access the Aspera high-speed FASP “pipe” from their applications, we created the new Aspera FASPstream Binaries and API. Rather than starting a transfer by reading a file from disk and ending the transfer by writing to disk, the Aspera FASPStream binaries and the API support transfers to or from a custom process running in memory with another custom process running on a separate machine (Stream-to-Stream), or with a standard Aspera transfer server (Stream-to-File).
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The API uses the Aspera FASP protocol, so transfers achieve maximum speed over any distance, with security, efficiency, and bandwidth control. With the new API, transfers are no longer limited to a file or file set. The Aspera FASPStream API enables the transfer of any stream of bytes as they are being created or captured, and can allow access to portions of a file in memory during the transfer process rather than waiting for the entire file to be written to disk. Companies can easily access the FASP byte-stream with familiar file-I/O like API’s.

Use Cases

Media processing and distribution

  • Inline transcoding: the encoding process can begin while the transfer is still in progress, shortening the end-to-end processing time and accelerating the final delivery or play-out.
  • Inline file format validation: format validation engines can inspect portions of the file looking for anomalies while the transfer is still in progress, and abort the transfer if the file format does not conform to the standard.

Remote imaging or data capture

  • Capture and distribute content from remote locations to improve targeted data acquisition.
  • Initiate time-sensitive image processing analysis of large data files sooner to make faster business decisions.

Improve healthcare decisions

  • Medical imaging: Transfer high-resolution medical images, with speed, security and privacy, enabling diagnostic-quality viewing by healthcare practitioners in remote locations, to eliminate wait times and accelerate diagnosis.

Enhance legal discovery

  • eDiscovery: Accelerate the collection, indexing, processing, and analysis by embedding high-speed transfer into your e-Discovery platform.
  • Enable faster recovery and data analysis to view pertinent information relevant to a legal hold or case.

Enable In-Memory Access of Transfer Data

Rather than waiting for a file to be written to disk, Aspera offers access to byte-stream from the Aspera high-speed FASP “pipe” using the Aspera FASPstream.

  • Begin processing the incoming data as soon as the first bytes are transferred, rather than waiting for the entire transfer to complete.
  • Implement Senders to transfer data into the byte-stream or Receivers to read from the byte-stream using the Aspera FASPstream API.
  • Senders: use Aspera FASPstream to transfer data directly from memory rather than reading the source from disk.
  • Receivers: directly access data from the incoming Aspera FASPstream in memory instead of waiting for the transfer to complete and reading the file from disk.

Leverage Aspera FASP high-speed technology

Leverage Aspera FASP high-speed technology, which is efficient, stable, robust and predictable, even for the longest distances and networks with the worst conditions.

  • Transfer bulk data in the form of a byte-stream over wide area networks (WAN) at line speed, regardless of file size or distance, fully utilizing the available bandwidth using Aspera FASP.
  • Initiate high-speed transfers of bulk data from your application memory as the data is being captured or generated.
  • Enable organizations to reduce their process times by beginning process when the first byte is received.
  • Utilize Aspera security and management features when deployed in conjunction with an Aspera Server.

Seamlessly Integrate Technology into Application

The FASPstream API provides native language bindings to integrate into any existing and custom applications.

  • Create custom sender and receiver applications with or without an Aspera Transfer Server as one of the end points.
  • Flexible deployment models can be supported using the FASPstream API including FASPstream-to-FASPstream, File-to-FASPstream, and FASPstream-to-File.
  • Utilize familiar file-I/O like interface to access the FASP byte-stream to speed development.
  • Use the Aspera Developer Network to gain access to documentation, guides, tips, tricks, and sample code to help developers integrate the FASPstream technology.

Live Streaming Data Workflow

A complete end-to-end production system that enables near-live distribution of live content can be possible using Aspera FASPstream. This live content is ingested, transformed and delivered in near real time. Since the media delivery is distributed faster than the traditional workflow, this enables the delivery of additional streams besides the traditional single central live stream feed. 

  1. Live content is delivered to the Content Receiver as it is being captured using Aspera FASPstream
  2. The Content Receiver sends the byte-stream over to the transcoding service
  3. As bytes are transcoded, the transcoded bytes will be sent to an Origin Server
  4. Once inside a Content Delivery Network, the live content will be distributed to end users connected on device such as smartphones, tablets, and laptops. 


Content Delivery Networks (CDN) can use Aspera FASPstream for media ingest to speed the delivery of media content. FASPstream can be used throughout the entire process including into and out of the encoding process and to deliver media files to the Origin Servers and distribution nodes. Content is distributed faster than traditional transfer protocols, since FASPstream uses FASP, which overcomes packet loss and latency.

  1. The content provider uses FASPstream to deliver the media file to byte stream to the transcoding service.
  2. The transcoding process begins as soon as bytes are received and transcoded bytes are sent to an Origin Server.

  3. As the Origin Server receives bytes, it distributes the media content using FASPstream across the entire network.

  4. Since FASPstream uses FASP and overcomes packet loss and latency, the media content does not need to reside close to the end user.


Aspera FASPstream delivers the byte-stream of media content using the FASP protocol to enable end users to begin viewing content sooner. If the media content is not located in the closest Edge Server, Aspera FASPstream can be used to transfer the media content to the closest Edge Server and then forward it directly to the end user. This will bypass the time needed to completely copy over a file into the Edge Server before transferring it to the end user.

  1. An end user wants to view media on their device.
  2. The Edge Server checks for the media and delivers the media to the end user’s viewer using FASPstream if it is available.
  3. If the media was not available on the Edge Server:
  • An Origin Server or another distribution node can deliver the media file using Aspera FASPstream to the requesting Edge Server.
  • The Edge Server can then forward the byte-stream to the end user’s viewer as soon as it receives the first few bytes.


Aspera FASPstream is used to keep local and remote Git repositories in sync.

  1. FASPstream is used to deliver content into and out of the Git repository over the FASP protocol.
  2. When content is ready to be checked into the Remote Git repository, the Git Plugin can be used to initialize the FASPstream transfer to the repository.

  3. FASPstream is also used to deliver content to the Local Git repository, thereby delivering the most accurate version to the local repository.
  4. GASP, a protocol that uses FASPstream and designed for Git, was created to enable the delivery of content to and from the various Git repositories.


Aspera FASPstream can be used to deliver in flight entertainment quickly to aircrafts during layovers.

  1. FASPstream using the FASP protocol delivers updated in flight entertainment content to aircrafts.
  2. When an aircraft lands at the terminal, the FASPstream will begin delivering a byte-stream of in flight entertainment content to the aircraft while it is at the gate.
  3. The aircraft will receive the updated media content and be able to offer it to customers to view.

Deployment Models

Aspera FASPstream is integrated into existing or custom applications in one of three deployment models:

  • Custom Endpoints with FASPstream Embedded (Point-to-Point)
  • Custom Sender with Aspera Transfer Server (FASPstream-to-File)
  • Custom Receiver with Aspera Transfer Server (File-to-FASPstream)

Custom Endpoints with FASPStream Embedded (Point-to-Point)

  • Enable in-memory to in-memory data transfer using FASPstream via the FASP protocol
  • FASPstream sends byte-stream data as it is being captured or created
  • Developers have full control over the pre and post-processing from within both the sender and receiver endpoints

Custom Sender with Aspera Transfer Server (FASPStream-to-File)

  • Enable in-memory data to be transferred to an Aspera Server creating FASPstream-to-file transfer
  • Applications (programs, imaging equipment, and video equipment) can send data as it is being generated or captured
  • Enable data transfer immediately rather than waiting for a large file to be completely written to disk

Custom Receiver with Aspera Transfer Server (File-to-FASPStream)

  • Send byte-stream of data as a file is being read by the Aspera Transfer Server thereby creating a file-to-FASPstream transfer
  • Applications can access the data in memory as it is being received rather than waiting for the complete file
  • Act on content as soon as the first bytes arrive


Libraries Supported

  • Java
  • C++
  • .NET

Compatible Transfer Servers

  • Aspera Enterprise Server 3.4+
  • Aspera Connect Server 3.4+ 


Aspera FASPstream API can be used with any of Aspera transfer servers. The Aspera SDK is required to integrate into applications. 

Related Products

Enterprise Server

Aspera Enterprise Server is a versatile universal server application with a variety of client options (desktop, mobile, embedded), and with support for manual or automated transfers of files and directories. It enables seamless high-speed movement of files and directories across global enterprises, high-volume content ingest and distribution, and replaces FTP/SFTP servers for transfers of large, business-critical data.

Connect Server

Connect Server extends Enterprise Server functionality with web enablement technology, giving any web application the ability to facilitate high-speed FASP transfers. Users initiate transfers through Connect Server’s web-based directory, mobile devices, or custom web applications that use Aspera Connect API. A simple, self-installing browser plug-in performs the transfers from clients to the server, independent of the browser and without choking off other IP traffic.

Aspera SDK

The Aspera SDK offers a complete set of Application Program Interfaces (APIs) with supporting documentation and sample code to help developers integrate Aspera technology into applications as a replacement for traditional TCP-based protocols such as FTP or HTTP. The Aspera SDK includes web service APIs (REST and SOAP) as well as native libraries for Java, .NET, and C++.