Comparison
How SimpleQ compares to other queue and task-processing tools. SimpleQ is a managed queue built for AI-heavy backends and API-dependent workloads — it delivers jobs to your webhook with retries, rate limiting, a three-signal ack protocol, and backpressure handling that never wastes your retry budget.
Quick reference
| SimpleQ | Upstash QStash | AWS SQS | Cloud Tasks | BullMQ + Redis | Inngest | Trigger.dev | Apache Kafka | RabbitMQ | |
|---|---|---|---|---|---|---|---|---|---|
| Category | Managed queue | Managed queue | Managed queue | Managed queue | Self-hosted queue | Workflow engine | Task orchestration | Event streaming / log | Self-hosted broker |
| Delivery | Push (webhook) | Push (per-message URL) | Pull (polling) | Push (HTTP) | In-process worker | Serverless fn | Managed execution | Pull (consumer polls) | Push/pull (AMQP) |
| Retries | Configurable backoff | Configurable backoff (billed per attempt) | Visibility timeout | Configurable backoff | Configurable backoff | Per-step | Per-task | DIY (retry topics) | Requeue / DLX + TTL |
| Rate limiting | Per-queue fixed-window | Flow control (parallelism cap) | None built-in | Per-queue | Extension (extra Redis) | Per-function | Concurrency control | Client/broker quotas | Prefetch (QoS) |
| Ack mode | Three-signal: ack / nack / defer | No (HTTP response or callbacks) | Visibility timeout | No | No | N/A (durable exec) | N/A (managed exec) | Offset commit | Native (ack/nack/reject) |
| Backpressure | Defer (never burns attempts) | Retry (burns a billed attempt) | Manual | Retry (burns attempts) | Manual | Step retry | Task retry | Consumer pause/resume | Prefetch + nack/requeue |
| DLQ + replay | Built-in with API replay | Built-in DLQ + event logs | DLQ only (no replay API) | No | Failed job retention | Per-function | Per-task | Dead-letter topic + offset replay | Native DLX (manual replay) |
| Idempotency | Publish-boundary dedup (72h window) | Dedup ID / content-based (15-min window) | Content-based (FIFO only) | Task name dedup | Manual | Event key | Idempotency key | Idempotent producer / EOS | Manual (publisher confirms) |
| Per-job audit | Full attempt history | Event logs | CloudWatch aggregates | Cloud Monitoring | Bull Board (if set up) | Per-step logs | Per-task logs | Log offsets (no attempt history) | Mgmt UI stats (no attempt history) |
| Webhook signing | HMAC-SHA256, per-queue secret | JWT signing keys (Receiver.verify) | N/A (pull) | OIDC token | N/A (in-process) | Signing key (per-app) | N/A (managed) | N/A (pull, TLS+SASL) | N/A (AMQP, TLS+SASL) |
| AI features | Anthropic + OpenAI templates, seconds convention, ack-mode escape hatch | Direct LLM API calls with callbacks | None | None | None | None | OpenAI integration | None | None |
| Runs your code? | No | No | No | No | Yes (in-process) | Yes (serverless) | Yes (managed) | No | No |
| Workflow engine? | No | No (separate Upstash Workflow product) | No | No | Flows (basic) | Yes | Yes | No (streaming log) | No |
What SimpleQ is
A managed transport service built for backends that call LLM APIs, deliver webhooks, and sync to third-party APIs. You publish a job via REST API; SimpleQ queues it and POSTs it to your webhook with retries, backoff, rate limiting, and a dead-letter queue. You run the business logic — SimpleQ handles the delivery.
What SimpleQ is not
Not a workflow engine. No durable execution, no step functions, no event coordination. If you need multi-step orchestration, look at Inngest or Trigger.dev. SimpleQ solves the "queue a job and deliver it reliably" problem — and nothing beyond that.
Key differentiators
Three-signal ack protocol. Ack (success), nack (failure with a retryable flag), defer (backpressure). Three distinct outcome signals instead of the binary success/fail most queues offer. Once your /ack, /nack, or /defer callback returns 200, the outcome is guaranteed to be acted on. No other managed queue offers this.
Backpressure that never burns retries. When a downstream returns 429/503/529, the job is deferred and redelivered after the retryAfter delay — no attempt counted against maxAttempts. A job can be deferred 100 times during a sustained API outage and still complete when capacity returns. The retry budget is reserved for real failures only.
Push delivery. Unlike SQS (pull-based), SimpleQ POSTs jobs to your webhook. No polling infrastructure, no message-deletion API. Your worker is a plain HTTP endpoint — deploy it anywhere, in any framework, on any cloud.
Queue templates for AI workloads. template: "anthropic" or template: "openai" — one field in the create-queue POST configures ack mode, timeout, retry budget, and backoff tuned for each provider's API. Anthropic: 600s timeout for long Claude generations. OpenAI: 300s timeout for faster completions. Both handle rate-limit backpressure via defer.
Publish-boundary idempotency. Duplicate publish returns the existing job with its canonical ID. Safe-to-retry publishers without client-side dedup tracking.
Per-queue signing secrets. HMAC-SHA256 with a secret scoped to each queue, not the org. Different teams can own different queues without sharing credentials. If one secret leaks, only that queue is affected.
Per-job attempt history. Every attempt logged with status, error, webhookStatusCode, and timestamp. Debug attempt 3 of 5 without digging through aggregated metrics.
Seconds convention. All customer-facing durations are in seconds — matching what Anthropic, OpenAI, and Google return in their Retry-After headers. Zero conversion math when relaying backpressure from a downstream provider to SimpleQ's /defer endpoint.
DLQ with replay. Dead-letter queue with single and bulk replay via API. Inspect what failed, fix the root cause, replay — no manual re-publishing.
Detailed comparisons
Short, factual breakdowns of each alternative. Each links to a deeper feature-by-feature page with "when to choose" guidance.
SimpleQ vs Upstash QStash
QStash is the closest match to SimpleQ: both are managed queues that publish over HTTP and push to your endpoint with retries, backoff, and a dead-letter queue. The difference shows up under backpressure — SimpleQ treats a downstream 429/503/529 as a defer, holding the job and redelivering after Retry-After with no attempt burned, whereas QStash counts each retry as another billed message. SimpleQ also separates outcomes with a three-signal ack protocol (ack / nack / defer) instead of QStash's HTTP-response-or-callback model. QStash is the more mature, broader product, though: it has cron schedules, URL-group fan-out, strict FIFO, batch publish, a Python SDK, and GA compliance (SOC-2 / SLA) that SimpleQ does not offer yet. Deeper dive: SimpleQ vs Upstash QStash.
SimpleQ vs AWS SQS
SQS is pull-based: your workers poll for messages, manage visibility timeouts, and delete messages after processing. SimpleQ pushes jobs to a plain HTTP webhook, so there's no polling loop and no message-deletion step — deploy the worker anywhere. SimpleQ adds per-queue rate limiting (SQS has none built-in), a three-signal ack protocol in place of visibility timeouts, and DLQ replay via API. SQS wins on raw scale, maturity, deep IAM/AWS integration, and a native FIFO option. Deeper dive: SimpleQ vs AWS SQS.
SimpleQ vs Google Cloud Tasks
Both push over HTTP with configurable backoff, so the shapes are similar. Cloud Tasks can't tell backpressure from failure — a rate-limited downstream burns attempts — and has no dead-letter queue; SimpleQ adds defer for backpressure, ack mode, DLQ replay, and full per-job attempt history. Cloud Tasks is mature, inexpensive, and tightly integrated with GCP (OIDC-authenticated push to Cloud Run). Deeper dive: SimpleQ vs Google Cloud Tasks.
SimpleQ vs BullMQ
BullMQ runs in-process Node workers against a Redis instance you host and operate; SimpleQ is managed and pushes to a webhook in any language, which suits serverless deployments. SimpleQ brings built-in per-queue rate limiting, per-job attempt history, and HMAC-signed delivery without standing up Redis. BullMQ is open-source with no per-job cost beyond your Redis, offers lower-latency in-process execution, and has flows and repeatable jobs plus full operational control. Deeper dive: SimpleQ vs BullMQ.
SimpleQ vs Inngest
Inngest is a different category: a workflow engine with durable execution — multi-step functions, sleeps, event coordination — that runs your code on its platform. SimpleQ is transport only; it never executes your code, it delivers jobs and tracks the outcome. Choose Inngest when you need step orchestration and durable execution; choose SimpleQ when you need reliable delivery with explicit backpressure control and your code staying on your own runtime. Deeper dive: SimpleQ vs Inngest.
SimpleQ vs Trigger.dev
Trigger.dev is managed task execution: your tasks run on their infrastructure with per-task retries and concurrency control. With SimpleQ your code stays on your own runtime, and SimpleQ tracks the outcome through ack / nack / defer. Choose Trigger.dev to offload execution entirely; choose SimpleQ to keep your existing deployment and just add reliable delivery. Deeper dive: SimpleQ vs Trigger.dev.
SimpleQ vs Apache Kafka
Kafka is a streaming log, not a job queue: consumers poll partitions and you build your own retry and dead-letter machinery (retry topics, offset handling). SimpleQ pushes individual jobs with built-in backoff, defer, DLQ replay, and per-attempt history. Kafka is the right tool for high-throughput event streams, offset replay, and stream-processing ecosystems — SimpleQ is for delivering discrete background jobs reliably. Deeper dive: SimpleQ vs Apache Kafka.
SimpleQ vs RabbitMQ
RabbitMQ is a capable broker with native ack/nack/reject, rich exchange routing, and dead-letter exchanges — but you operate it (or pay for CloudAMQP), consumers speak AMQP, and there's no per-job attempt history. SimpleQ is managed, workers are plain HTTP endpoints, signing secrets are per-queue, backpressure never burns retries, and the DLQ has API replay. Reach for RabbitMQ when you need flexible routing topologies and are willing to run the broker. Deeper dive: SimpleQ vs RabbitMQ.