Agent as a Service (AaaS) is being sold as an evolution of SaaS. In some ways it is. In others, it is a genuinely different category of software purchase — with different integration requirements, different pricing models, and different ways of measuring value.
How AaaS differs from SaaS
SaaS gives you a tool. You use the tool to do work. AaaS gives you a worker — one that takes goals as input and produces outcomes as output. The practical implication: with SaaS, you control every step of the process. With AaaS, you describe what you want and the agent decides how to get there.
That shift in control is the defining characteristic of AaaS — and it is also the source of most of the anxiety around it. Businesses that have been burned by software that did unexpected things are right to be cautious about software that makes decisions.
What to evaluate when buying AaaS
- Escalation visibility — Can you see when the agent escalated and why? What did it hand off?
- Audit trail — Is there a complete log of every action the agent took?
- Scope boundaries — What systems can the agent access? What can it not touch?
- Override mechanism — How do you stop the agent on a specific case? On all cases immediately?
- Error accountability — When the agent makes a mistake, who is responsible and what is the remediation process?
Pricing models and what they reveal
AaaS vendors price in one of three ways: per task completed, per hour of agent time, or flat monthly subscription. Per-task pricing aligns vendor incentives with your outcomes — they do better when the agent is useful. Flat subscription pricing is simpler to budget but does not align incentives the same way. Be sceptical of per-hour pricing for agents: it incentivises inefficiency.
The transition question
The right question for most businesses is not "should we switch from SaaS to AaaS" but "which of our existing SaaS workflows is a candidate for agent automation?" Start there — with a specific, well-defined workflow — before considering a broader transition.