What is Sync Mode?
Sync Mode is a Transloadit operating mode in which the client waits for file transfer and processing to finish before receiving the final Assembly results. The request therefore remains open for the workflow’s duration.
How Sync Mode works
In Transloadit Sync Mode, submission and completed Assembly status share one blocking request-response exchange from the caller’s perspective. The connection stays occupied while uploads and processing steps execute, after which the final result can be consumed immediately. That coupling simplifies short, sequential integrations but transfers workflow duration into HTTP timeout and connection-capacity concerns. It belongs at the API orchestration edge, whereas asynchronous integrations persist an Assembly identifier and receive or retrieve completion later.
Key facts
- 1A processing job can continue beyond an intermediary’s request deadline even if the caller sees a timeout, so retry logic must avoid assuming that a missing synchronous response means no Assembly was created.
- 2Browser, reverse-proxy, load-balancer, and serverless time limits can differ; the shortest limit governs whether a synchronous call survives a long transcode or remote import.
- 3Sync Mode changes how completion is delivered, not the semantics of the Assembly steps themselves; dependency resolution and result structure remain properties of the configured workflow.
When Sync Mode matters
Choose Sync Mode when a caller can safely wait and needs completed results before continuing. Long or variable processing can exceed client, proxy, or server timeouts, making asynchronous handling more reliable.
Common use cases for platform workflows
These examples cover platform workflows broadly, not specifically Sync Mode.
- Running repeatable upload, import, processing, AI, storage, and notification pipelines.
- Tracking long-running media work independently from an application request.
- Referencing centrally stored credentials by name instead of sending storage secrets with each request.
Working with platform workflows
This guidance covers platform workflows broadly, not just Sync Mode.
A client authenticates and submits files or references together with workflow instructions. The platform validates the request, schedules dependent operations, records state transitions, and exposes results through a response, polling endpoint, or notification.
Platform concepts become reliable only when their lifecycle is explicit. Authentication, idempotency, retries, timeouts, observability, quotas, and terminal states should be designed together rather than added after failures occur.
What you gain
- Reusable workflows separate application intent from processing infrastructure.
- Stable job identifiers and lifecycle events improve observability and recovery.
- Managed queues and workers let products scale without embedding every media tool.
What it costs
- Synchronous responses are simple but keep connections open while long work executes.
- Aggressive retries improve recovery from transient faults but can duplicate work or overload a dependency.
- Higher concurrency reduces queue time until resource contention or a downstream limit becomes the bottleneck.
Before production
- 1Define authentication, authorization, idempotency, retries, and terminal error behavior.
- 2Observe queue time, execution time, callbacks, and partial results with stable identifiers.
- 3Exercise malformed, duplicate, interrupted, and unauthorized requests before launch.