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Automation Integration · head to head

Inngest vs Letta

Inngest logo

Inngest

Automation Integration

Unbreakable Agents. Invisible Infra.

From
Free
Rated
-
Full reviewWebsite
Letta logo

Letta

Automation Integration

Machines that learn

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Inngest hobby plans pause execution once free quota exhausted; upgrade required to continue; Letta free tier limited to 3 stateful agents
  • Prices and features above were last checked on 29 August 2026.

Where they differ

Only the attributes on which Inngest and Letta actually diverge.

Attributes where Inngest and Letta differ
AttributeInngestLetta

Identical on both: starting price (Free), pricing model (freemium), free tier (Yes), platforms (Web), user rating (Not yet rated), category (Automation Integration).

What people use each for

The jobs each tool is most often brought in to do.

Inngest

  • Handling unpredictable LLM behavior with fine-grained error controlnot Letta
  • Retrying failed workflow steps independently without restartingnot Letta
  • Rate limiting per-tenant usage on shared infrastructurenot Letta
  • Processing thousands of webhooks per event with replay capabilitynot Letta
  • Persisting state across serverless function invocationsnot Letta

Letta

  • Building agents with memory for continuous learningnot Inngest
  • Enabling reflection during idle periods via sleep-computenot Inngest
  • Managing agent context and extracting learningsnot Inngest

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Inngest

  • Hobby plans pause execution once free quota exhausted; upgrade required to continue
  • Pro plan overages carry tiered metering: additional concurrent steps at $25 per 25, span data at $3/GB, scores at $1.50 per 1K, events at $0.50 per 1M

Letta

  • Free tier limited to 3 stateful agents
  • Pro tier capped at 20 stateful agents
  • API Plan usage charges apply beyond base tier

Pricing, plan by plan

Inngest

Free
  • HobbyFree
    • 50k executions/month
    • 5 concurrent steps
    • 500 MB span data
  • Pro$99/month starting
    • 1M executions included, pay-as-you-go up to 20M
    • 100+ concurrent steps
    • 5 GB span data ingested
  • Enterprise$null/custom
    • customizable metrics
    • 90-day trace retention
    • SAML, RBAC, audit trails

Letta

Free
  • FreeFree
    • Limited agents
    • Limited Letta Auto usage
    • Bring your own API keys
  • Pro$20/month
    • Weekly and monthly Letta Auto quota
    • Pay-as-you-go overage
    • Up to 20 stateful agents
  • API Plan$20/month
    • Unlimited agents
    • $0.10/active agent/month
    • $0.00015/second for tool execution
  • Teams Pro$20/month
    • Per seat pricing
    • Add teammates
    • Letta Auto quota

Which should you pick?

Choose Inngest if

  • You want to start without paying.
Inngest review

Choose Letta if

  • You want to start without paying.
Letta review

Questions people ask

Is Inngest or Letta better?
Neither clearly leads. Inngest starts at Free and Letta at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Inngest or Letta?
Inngest starts at Free and Letta at Free.
Does Inngest or Letta run on more platforms?
Both run on Web, so platform support will not decide this one for you.
Can I use Inngest for free?
Both have a free tier, so you can try either at no cost before committing.
What is Inngest best used for?
Inngest is most often used for handling unpredictable llm behavior with fine-grained error control, retrying failed workflow steps independently without restarting, rate limiting per-tenant usage on shared infrastructure, processing thousands of webhooks per event with replay capability. Of those, handling unpredictable llm behavior with fine-grained error control and retrying failed workflow steps independently without restarting are not what Letta is typically brought in for.

Answered from the vendors’ own pages

Inngest: How much does Inngest cost?

Inngest offers a free Hobby plan with 50k executions per month and up to 3 users. Pro plans start at $99 per month with 1M executions included and support for up to 15 users. Additional Pro users cost $10 each. Enterprise plans require custom pricing.

Source
Letta: How much does Letta cost?

Letta offers a free tier, then Pro plan at $20/month with up to 20 stateful agents, API Plan at $20/month base plus usage charges ($0.10/active agent/month, $0.00015/second for tool execution), and Teams Pro at $20/seat/month.

Source
Inngest: Is there a free version of Inngest?

Yes, the Hobby plan is completely free and includes 50k executions per month, 5 concurrent steps, 500 MB span data ingested, 10K scores, 500k events ingested, and support for up to 3 users. Plan changes pause execution once the free quota is exhausted.

Source
Letta: How many agents can I create on the free plan?

The free tier is limited to 3 stateful agents. Pro plan allows up to 20 stateful agents, while API Plan offers unlimited agents.

Source
Inngest: What are the overage costs on Inngest Pro?

Inngest Pro includes 1M executions with additional executions at $0.50 per 1M up to 20M. Span data overages cost $3 per GB, scores at $1.50 per 1K, and events at $0.50 per 1M. Additional concurrent steps cost $25 per 25 steps beyond the included 100+.

Source
Letta: Does Letta charge for tool execution?

On the API Plan, Letta charges $0.00015 per second for tool execution. The Pro and Teams Pro plans include execution in their monthly fee.

Source
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