AI agents are the fastest-moving category in software right now: instead of returning a single answer, an agent takes a goal, breaks it into steps, and uses tools to get it done. This guide covers what separates a dependable agent from a demo, and how we evaluate them.
What is an AI agent?
An AI agent is a system that takes a goal, plans the steps to reach it, calls tools or APIs to act, and adjusts based on results — ideally with a human in the loop for oversight. That autonomy is the difference between an agent and a chatbot that only replies.
What to look for
- Reliable tool use — does it call the right tools and recover from errors?
- Autonomy vs. control — can you set guardrails and approve key steps?
- Integrations — the apps, APIs, and data it can actually reach.
- Memory & context — does it remember across steps and sessions?
- Oversight & safety — logs, permissions, and rollback.
- Transparent pricing — per-run, per-seat, or usage-based.
How we evaluate
Every tool in this category is scored the same way DigiJaws scores a site for AI search: can it be found, is it clearly understood, is it trusted, and does it deliver. We add hands-on testing and transparent, dated pricing — individual tool reviews are published to this category as we complete them.
We have reviewed 5 AI agent platforms in full, pricing each from the vendor’s own page rather than a third-party summary. LangChain rates highest at 4.0/5. The framework costs nothing. You can build and ship LangChain applications without paying anyone — LangSmith is the optional observability layer, not a licence. 2 of the 5 offer a free tier (LangChain and CrewAI).
One tool here publishes no price at all (Sierra), so any figure you find elsewhere is a third-party estimate rather than a vendor rate. We label those as reported.
The tools, compared
Every figure is taken from the vendor’s own pricing page and re-verified on the date shown in each review. Ratings are DigiJaws editorial ratings, not aggregated user scores.
| Tool | Rating | Entry price | Free tier | Best fit |
|---|---|---|---|---|
| LangChain | 4.0/5 | $39/seat/mo (LangSmith Plus) | Yes — framework free; LangSmith Developer free with 5,000 monthly traces | Engineering teams building LLM applications who need observability |
| CrewAI | 3.5/5 | $0 – Basic, 50 executions monthly | Yes – 50 executions monthly | Multi-agent orchestration |
| Sierra | 3.5/5 | ⚠️ Quote only – ~$1.50 per resolution reported | No | Outcome-priced customer service agents |
| Decagon | 3.0/5 | ⚠️ $50,000/yr platform fee reported | No | Per-conversation support agents |
| Beam AI | 3.0/5 | $50/mo (Pro) | Yes – 20 tasks/mo | Agentic process automation |
If you only read this far
LangChain
The framework costs nothing. You can build and ship LangChain applications without paying anyone — LangSmith is the optional observability layer, not a licence.
CrewAI
Rated 3.5/5. Execution-based billing. One execution is one complete crew kickoff regardless of internal complexity, token consumption or duration — a genuinely simple unit.
All 5 reviewed, in rating order
LangChain
The framework costs nothing. You can build and ship LangChain applications without paying anyone — LangSmith is the optional observability layer, not a licence.
Suits: Engineering teams building LLM applications who need observability. Not for: Teams wanting a no-code agent builder — CrewAI or Beam AI fit better.
Watch out: Trace overage at $2.50 per 1,000 is where production costs escalate.
Pricing: $39/seat/mo (LangSmith Plus)
Free tier: Yes — framework free; LangSmith Developer free with 5,000 monthly traces
Full review publishes 2026-09-29.
CrewAI
Execution-based billing. One execution is one complete crew kickoff regardless of internal complexity, token consumption or duration — a genuinely simple unit.
Suits: Teams whose usage genuinely fits within 50 monthly executions. Not for: Small and mid-sized teams outgrowing 50 executions — no tier exists.
Watch out: The $25 Professional tier was removed in spring 2026, so there is now nothing between a free 50-execution plan and an enterprise contract reported at $60,000 a year.
Pricing: $0 – Basic, 50 executions monthly · working tier ⚠️ Enterprise reported $60,000-$120,000/yr
Free tier: Yes – 50 executions monthly
Full review publishes 2026-09-29.
Sierra
Outcome-based pricing done properly. You pay when the agent resolves something, which aligns the vendor’s incentive with yours in a way seat licensing never does.
Suits: Enterprises with high customer service volume and measurable labour cost. Not for: Any organisation below enterprise customer service volume.
Watch out: The $1.50 headline is one component. Real contracts add a platform access fee, a per-conversation rate for routing, and implementation and optimisation services billed separately.
Pricing: ⚠️ Quote only – ~$1.50 per resolution reported · working tier $200,000-$350,000+/yr at 12,000 resolutions
Free tier: No
Full review publishes 2026-09-29.
Decagon
Genuine choice of pricing model. Being able to select per-conversation or per-resolution lets you match the contract to your expected resolution rate, which most vendors do not offer.
Suits: Enterprises with very high customer support volume. Not for: Any organisation below enterprise support volume.
Watch out: Per-conversation is the default and charges for interactions the AI fails to resolve — so a low resolution rate costs you twice, once in fees and once in escalations.
Pricing: ⚠️ $50,000/yr platform fee reported · working tier Median contracts $386,000-$400,000/yr reported
Free tier: No
Full review publishes 2026-09-29.
Beam AI
Beam prices on task volume and integrations rather than seats, so headcount does not drive the bill – but the allowance does: Pro covers 200 tasks a month, and the next tier up is $3,990.
Suits: Enterprise operations teams automating finance and back-office processes. Not for: Teams whose volume lands between the tiers – there is nothing between $50 and $3,990.
Watch out: the step from Pro to Scale is the whole decision: 200 tasks a month for $50, then a 79x jump with no tier in between.
Pricing: $50/mo (Pro, 200 tasks) · Scale $3,990/mo · Custom on quote
Free tier: Yes – 20 tasks/mo
Full review publishes 2026-10-06.
How to actually choose
The pricing page is rarely where these tools differ. What separates them is the limit you hit first — the metered unit, the seat policy, or the tier where the feature you actually came for finally appears. Here is the constraint that binds on each:
- LangChain: Trace overage at $2.50 per 1,000 is where production costs escalate.
- CrewAI: The $25 Professional tier was removed in spring 2026, so there is now nothing between a free 50-execution plan and an enterprise contract reported at $60,000 a year.
- Sierra: The $1.50 headline is one component. Real contracts add a platform access fee, a per-conversation rate for routing, and implementation and optimisation services billed separately.
- Decagon: Per-conversation is the default and charges for interactions the AI fails to resolve — so a low resolution rate costs you twice, once in fees and once in escalations.
- Beam AI: the task allowance decides the cost, not the seat count – and the only step above 200 tasks a month is $3,990.
Featured review
Start with our Manus AI review — a hands-on look at one of the leading options in this category.
Make sure AI can see you
Whichever tool you choose, buyers increasingly discover software through AI answers. See how ready your own site is to be cited with the free AI Visibility Checker, and learn the playbook in our guide to generative engine optimization.
Frequently asked questions
What is an AI agent?
An AI agent is software that takes a goal, plans steps, uses tools to act, and adapts to results — going beyond a chatbot that only responds.
How are AI agents different from chatbots?
A chatbot answers questions; an agent takes actions across multiple steps and tools to complete a task, often with limited human oversight.
Are AI agents safe to use for business?
They can be, when the tool offers permissions, approval steps, activity logs, and the ability to roll back actions. Prioritize agents with strong guardrails.
Best AI Agents (2026): The Complete Guide to Autonomous AI Tools. DigiJaws, 2026. https://digijaws.com/reviews/best-ai-agents/