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Service as Software: what it is and where the idea came from

Service as Software (SaS) is a service delivered by software. The client receives the work done instead of a tool to operate: AI agents carry out the steps, and what the client buys is the outcome.

By Sigil Labs · Published · Updated

Two readings of the term

The first reading comes from venture capital. For Foundation Capital, AI companies are leading “a transition from software as a service to service as software,” and in the services business “responsibility for achieving the desired outcome sits with the company selling the service” (source 7). In 2026, Julien Bek of Sequoia Capital summed up the difference: a copilot sells the tool, an autopilot sells the work (source 10). In Sigil Labs’ reading, both are investor theses about where new companies will come from.

The second reading comes from the services industry. HFS Research spells the term “Services-as-Software” and, in a November 2024 article on services and software blurring together, describes “one blended, scalable solution we are calling Services-as-Software” (source 11). In Sigil Labs’ reading, the ones changing here are the services firms themselves.

Timeline

  1. According to the company’s own history, salesforce.com launches in San Francisco at an event themed “The End of Software.” (source 1)

  2. The Software & Information Industry Association (SIIA) publishes “Software as a Service: Strategic Backgrounder,” which treats software as a service rather than a product and sets it apart from outsourcing whole business processes. (source 2)

  3. Marc Andreessen publishes “Why Software Is Eating the World” in The Wall Street Journal, arguing that software companies are set to take over large parts of the economy. (source 3)

  4. GitHub opens a technical preview of GitHub Copilot, an “AI pair programmer” built with OpenAI. It is an example of the copilot model: the tool helps the person who does the work. (source 4)

  5. Sarah Tavel of Benchmark publishes “AI startups: Sell work, not software”: instead of selling software that makes people more productive, sell the work itself, priced against what a person doing it would cost. (source 5)

  6. Dan Nguyen-Huu writes about an era of “Service-as-Software”: the service delivered in the form of software, powered by AI agents. It is the earliest dated use in this sense that Sigil Labs found; he does not claim to have coined the term. (source 6)

  7. Foundation Capital publishes “AI leads a service as software paradigm shift”: AI companies lead “a transition from software as a service to service as software,” in which the seller answers for the outcome. The essay credits no one with the term. (source 7)

  8. HFS Research (Phil Fersht and Saurabh Gupta) writes in its 2030 services vision that “The 2030 destination is Service-as-a-Software.” It is the earliest dated HFS use found. (source 8)

  9. In webinar slides, HFS Research lists “Services-as-Software (2024)” among the terms it says it coined, and the bio of Phil Fersht, HFS’s founder and CEO, says he “recently coined the term.” The claim is HFS’s own, and its earliest dated use found is from September 2024. (source 9)

  10. Julien Bek of Sequoia Capital publishes “Services: The New Software”: “A copilot sells the tool. An autopilot sells the work.” The essay does not use the phrase Service as Software. (source 10)

Copilot or Service as Software

What changes between a copilot and Service as Software
Aspect Copilot Service as Software
Who does the work The professional, with the tool alongside The system, with AI agents that carry out the steps
Who answers for the result The professional who uses the tool The company selling the service
Who buys The professional, to work faster Whoever needs the outcome
How it is priced, in Sigil Labs’ view Per seat or by consumption By the work delivered, such as each completed task
Where it fits, in Sigil Labs’ view Judgment work whose result is hard to check Work that follows rules and whose result can be checked

Where it fits, and where it does not

According to Sequoia, the place to start is work that is already outsourced: the company accepts that it can be done externally, a budget line for it already exists, and the buyer already purchases an outcome (source 10). The essay adds that the autopilot wins sooner where work follows rules, even complex ones, and, on consulting, that the work is mostly judgment, leaving open whether AI can split off a layer to automate. In Sigil Labs’ view, judgment work whose result is hard to check is where a copilot serves better.

Some actions also call for a person in the loop. Singapore’s agentic AI governance framework recommends checkpoints that require human approval for high-stakes or irreversible actions (source 14).

What changes in buying it

The buyer is no longer the professional who uses the tool but whoever needs the outcome (source 10). Pricing follows that shift. In 2024, Sierra described pricing in which it gets paid only when it completes a task, with criteria agreed upfront for each outcome (source 12). In 2026, the same company wrote that this pricing only works where the software is highly autonomous and the outcome can be attributed to it, and that it is more complex than seat-based or consumption pricing (source 13).

In Sigil Labs’ view, for the client the question stops being how many licenses to buy and becomes what counts as work delivered, and who checks it.

How Sigil Labs builds it

Sigil Labs builds Service as Software systems from four parts: the process mapped with the client’s team, human approval points on the decisions that matter, limits for each agent, and an auditable record of what was done, by which agent and on what basis. Singapore’s framework points the same way: whoever deploys the agents remains accountable for their actions (source 14).

VoxxFlow, a Sigil Labs product in production, is one example: AI agents plan, create, review and publish marketing content, and nothing is published without human approval.

Empenho, a proof of concept, is the other: a platform for Portuguese accounting offices. Its supervised digital colleague leaves proposals in a “To review” queue and never sends anything, and the platform proposes extras to bill when it detects work outside the retainer, the contract with a monthly value, for someone in charge to approve.

Text written by the AI reaches the client only after someone in charge at the office approves it, and a number guard rejects notes containing figures that are not in the data given to the model. Beside the digital colleague, a copilot answers with sources, which puts both models on one platform.

Frequently asked questions

What is Service as Software?

Service as Software is the idea of selling finished work, done by software built on AI agents, instead of selling a tool the customer uses to do the work. In Foundation Capital’s April 2024 framing, responsibility for the outcome sits with the company selling the service. It reverses SaaS, where the customer buys the software and operates it.

What is the difference between a copilot and an autopilot?

A March 2026 essay by Julien Bek of Sequoia Capital sums up the distinction: a copilot sells the tool, an autopilot sells the work. With a copilot, the customer is the professional, who becomes more productive and takes responsibility for the output. With an autopilot, the vendor sells directly to whoever buys the outcome.

Who came up with the term Service as Software?

No source shows who coined the term. The earliest use found in its current sense is by Dan Nguyen-Huu, on November 7, 2023, and he does not claim to have invented it. Foundation Capital used it in April 2024 without crediting an origin. HFS Research, founded and led by Phil Fersht, says it coined the term, but its earliest dated use found is from September 2024.

How is Service as Software priced?

The pricing model associated with it is per outcome. In December 2024, Sierra said it gets paid only when it completes a task, with criteria agreed upfront for each outcome. In June 2026, the same company wrote that this pricing only works where the software is highly autonomous and the outcome can be attributed to it.

What kind of work does the model suit?

According to Sequoia, the place to start is work that is already outsourced, because the company accepts it can be done externally, already has a budget line for it and already buys an outcome. The essay adds that the autopilot advances sooner where work follows rules and, on consulting, that the work is mostly judgment, leaving open whether AI can split off a layer to automate.

Who is responsible if the agent gets it wrong?

Singapore’s agentic AI governance framework, published by IMDA in 2026, says that the organizations that deploy agents, and the people who oversee them, remain accountable for the agents’ actions. Sigil Labs, for its part, keeps human approval on the decisions that matter and a record of what each agent did.

Sources

  1. Salesforce. The History of Salesforce (opens in a new tab), .
  2. Software & Information Industry Association (SIIA). Software as a Service: Strategic Backgrounder (opens in a new tab), .
  3. Marc Andreessen, The Wall Street Journal (republished by Andreessen Horowitz). Why Software Is Eating the World (opens in a new tab), .
  4. Nat Friedman, GitHub. Introducing GitHub Copilot: your AI pair programmer (opens in a new tab), .
  5. Sarah Tavel, Benchmark. AI startups: Sell work, not software (opens in a new tab), .
  6. Dan Nguyen-Huu, Founder Catalyst. A New Frontier: Service-as-Software, powered by AI Agents (opens in a new tab), .
  7. Foundation Capital. AI leads a service as software paradigm shift (opens in a new tab), .
  8. Phil Fersht and Saurabh Gupta, HFS Research (Internet Archive copy). 2030 HFS Services Technology Vision: The Future of Services is No Services (opens in a new tab), .
  9. HFS Research. HFS Research webinar slides on Services-as-Software (opens in a new tab), .
  10. Julien Bek, Sequoia Capital. Services: The New Software (opens in a new tab), .
  11. Saurabh Gupta and Phil Fersht, HFS Research (Internet Archive copy). Welcome to the era of Services-as-Software... where the lines between services and software are blurring (opens in a new tab), .
  12. Elliot Greenwald, Sierra. Outcome-based pricing for AI agents (opens in a new tab), .
  13. Elliot Greenwald, Sierra. Outcomemaxxing (opens in a new tab), .
  14. Infocomm Media Development Authority (IMDA), Singapore. Model AI Governance Framework for Agentic AI, Version 1.5 (opens in a new tab), .