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Object Storage Service:Asynchronous processing

Last Updated:Mar 20, 2026

Use the x-oss-async-process header to submit a processing task in asynchronous mode. Unlike synchronous processing, asynchronous mode lets your application continue running other tasks without waiting for the current task to finish. This is well-suited for long-running operations such as document conversion, video transcoding, and video stitching.

When you submit an asynchronous task, the workflow is:

  1. Submit: Send the request with the x-oss-async-process header. OSS accepts the task and returns immediately — the processed output is not included in the response.

  2. Save: Use Save As to write the processed output to an OSS bucket.

  3. Get notified: Enable Message Notification to receive task completion status.

Supported operations

Replace the asterisk (*) in each operation with the actual processing parameter. For example, use x-oss-async-process=doc/convert to run document conversion.
FeatureOperationReferencesMethods
Document processingx-oss-async-process=doc/*Document conversionAlibaba Cloud SDK, RESTful APIs
Media processing (video)x-oss-async-process=video/*Video transcoding, Video-to-animated-image conversion, Generate CSS sprites from video snapshots, Frame capture, Video mergingAlibaba Cloud SDK, RESTful APIs
Media processing (audio)x-oss-async-process=audio/*Audio transcoding, Audio mergingAlibaba Cloud SDK, RESTful APIs

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