# Anatomy of a Service

URL: /products/service/anatomy · Id: `page:products/service/anatomy`

> A Service sells a finished result under a written promise: its contract, coverage, steps and checkers, its supply, and the three Apps it compiles.

A [Service](/business/nouns/service) sells a finished result under a written promise. The [Startup](/business/nouns/startup) does the work and answers for it, and the [Customer](/business/nouns/customer) judges the result, not the effort.

## Who does the work
Every [Product](/business/nouns/product) answers one question: who does the work? With [Software](/business/nouns/software), the Customer does it with the Startup's tools. With a Service, the Startup does it and the Customer receives the result.

Take catalog cleanup. As Software, it is an [App](/business/nouns/app) where a store's merchandiser fixes listings by hand. As Catalogmend's Service, the store sends its catalog, and every listing error comes back fixed or explained within 48 hours.

The [Interface](/business/nouns/interface) does not decide the kind. An API that returns suggested fixes sells Software; an API that returns a corrected catalog the Startup stands behind sells a Service. The difference is who answers when a listing is wrong.

## The promise
A deadline and a price are not a promise. "Fixed in 48 hours" leaves open what fixed means, who checks it, and what happens when a listing cannot be fixed.

Every Service carries an [Outcome Contract](/business/nouns/outcome-contract) on its [Offer](/business/nouns/offer) that settles those questions as typed terms. They state done, who accepts by when, revisions, the deadline, the remedy and the [Event](/business/nouns/event) that earns, each covered in [outcome contracts](/products/service/outcome-contracts).

Beside the contract, `coverage` states what the Service delivers and for which inputs, before any charge: Catalogmend covers online catalogs up to 50,000 listings.

The contract binds the Startup, not any one worker. When an agent stalls on a catalog in a language it does not read and a person finishes it, the Customer's terms do not change.

## Steps, each with a checker
Each step is a [Verb](/business/nouns/verb) that runs as a [Function](/business/nouns/function): code, one model call, an agent with tools, or a [Human](/business/nouns/human). The caller sees the same [Action](/business/nouns/action) whichever kind runs it.

| Step | Function | Doer | Checker | Assurance |
| --- | --- | --- | --- | --- |
| Import the catalog | `code` | The import Function | A schema check | `measured` |
| Find each listing error | `agentic` | The audit agent | An [Evaluator](/business/nouns/evaluator) on another model | `graded` |
| Fix each listing | `agentic` | The fix agent | The same Evaluator, on every fix | `graded` |
| Check a sample | `human` | A reviewer | The step re-checks the whole batch | `attested` |

The doer is never the checker, and a Service's assurance is its weakest check on the way to done. A refund promise needs `graded` checks, and an outcome price needs `measured` ones. [`Offer.publish`](/business/nouns/offer/publish) refuses an Offer whose remedy or price basis its checks cannot back, with [`contract-unsupported`](/code/api/errors/contract-unsupported).

A step's Function is part of the definition. Moving the sample check from a person to an agent is a [Change](/business/nouns/change) like any other. The Offer's promise still passes the same publish check.

## Supply
Digital supply has no practical ceiling: each new [Order](/business/nouns/order) starts another agent. Human supply is finite, so a Service that needs people recruits, verifies and schedules them as [Suppliers](/business/nouns/supplier), and their booked hours cap its volume.

Some steps the law reserves to a credentialed person. Such a step declares its floor, `sign` or `practice`, with the [Credential](/business/nouns/credential) it needs and where. [Supply](/products/service/supply) and [human functions](/products/service/human-functions) cover both.

## Three Apps
| App | Who uses it | What it shows |
| --- | --- | --- |
| [Portal](/business/nouns/portal) | The buyer and the buyer's agent | Each Order and line, its state, its deadline, and the confirm, revise and dispute choices |
| Supplier app | Each recruited Supplier | Eligible [Tasks](/business/nouns/task), Credentials on file with their expiry, the terms of each Task, and earnings |
| [Review](/business/nouns/review) queue | The Startup's own people | The Tasks each `human` step and each flagged check sends them |

None is drawn by hand. Each compiles from the steps, the states and who may act on each one.

## Buyers that are agents
A Service sells to people and to their agents through the same Verbs. In the [b2a](/business/motions/b2a) [Motion](/business/nouns/motion), a store's buying agent places the Order over MCP, answers intake questions and reads the delivered report.

It confirms or disputes within the window, under a [Mandate](/business/nouns/mandate) its owner granted. Every step it took is on record, by the agent and for the store.

## Five shapes
A Startup picks its Service shape with a [Product Template](/business/nouns/product-template). Each answers who does the work and who answers for the result.

| Product Template | Who does the work | Who answers for the result |
| --- | --- | --- |
| [Services-as-Software](/products/templates/services-as-software) | [Agents](/business/nouns/agent), end to end | The Startup |
| [E2E managed service](/products/templates/managed-service) | Agents, with people in the loop, running a whole business function | The Startup |
| [Licensed-human marketplace](/products/templates/licensed-marketplace) | Credentialed professionals | Each professional, under their own [Agreement](/business/nouns/agreement) |
| [Marketplace](/products/templates/marketplace) | Suppliers who deal with buyers directly | Each Supplier |
| [Agent as a Service](/products/templates/agent-as-a-service) | An agent the Customer directs | The Customer, who directs the work |

The first two are Services. The marketplaces earn a take for matching and settling, while each Supplier answers for their own work. Agent as a Service hires out the worker, not the result: the [agent book](/products/agent) covers it.

## Next
[Life of an order](/products/service/life-of-an-order) follows one catalog audit through every part above.