Transloadit

What is the Transloadit Rate Limiter?

A system protecting customers by limiting Assembly creation to 250 per minute and 2,500 concurrent Assemblies by default. By default, each Assembly can spend up to 8 hours uploading and then another 8 hours executing. Rejections use RATE_LIMIT_REACHED with an info.retryIn delay in seconds. Limits can be adjusted upon request.

Request + files
Processing platform
Results + status
A processing platform accepts an authenticated request, executes a workflow, and returns observable results. This diagram shows platform workflows broadly, not specifically the Rate Limiter.

How the Rate Limiter works

A rate limiter is the enforcing component behind one or more rate-limit policies. It observes work admitted under a chosen key, compares that work with independent budgets, and then accepts, delays, or rejects new work. Separating submission, concurrency, and phase-duration budgets prevents a client from satisfying one dimension while exhausting another. Integrations should treat the current product values and rejection shape in the API reference as the authoritative contract instead of copying them into local scheduling code.

Key facts

  1. A creation budget governs admission over time, while a concurrency budget governs work that remains active; a client scheduler must account for both independently.
  2. Upload and execution are distinct processing phases. Long work in either phase can retain concurrency capacity even when the recent submission rate is low.
  3. Retry behavior belongs to the service contract: clients should recognize the documented rejection signal and honor its supplied delay instead of retrying immediately.

When the Rate Limiter matters

Keep submission rate and concurrency within the documented limits, or arrange an adjustment before a predictable traffic surge. Treat a rejection as backpressure: stop new submissions, wait the number of seconds in the error’s info.retryIn field, and resume gradually. Uncontrolled immediate retries only add attempts without completing media work.

Common use cases for platform workflows

These examples cover platform workflows broadly, not specifically the Rate Limiter.

  • 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 the Rate Limiter.

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

  1. Define authentication, authorization, idempotency, retries, and terminal error behavior.
  2. Observe queue time, execution time, callbacks, and partial results with stable identifiers.
  3. Exercise malformed, duplicate, interrupted, and unauthorized requests before launch.

Turn media knowledge into a working pipeline

Connect uploads, processing, AI, storage, and delivery through one declarative API — with the encoding stack, scaling, and format churn handled for you.

Try Transloadit for free