# Product kinds URL: /products/four-kinds ยท Id: `page:products/four-kinds` > A Product is what a Customer gets from a Startup, with a promise; every Product is one of four kinds, supplied, bought, and earned in declared ways. A [Product](/business/nouns/product) is what a [Customer](/business/nouns/customer) gets from a [Startup](/business/nouns/startup), with a promise the Customer can rely on. Every Product is one of four kinds, and declares who supplies the work, who buys it, and how it earns. ## The promise comes first Three Customers can send the same request to the same API and expect different things. One buys facts, one buys a tool, and one buys a finished job. A Product's kind names which promise the Startup makes. | Kind | The promise | Built by | Example | | --- | --- | --- | --- | | Data, sold as a [Dataset](/business/nouns/dataset) | The records are true. | [SoftwareBuilder](/code/builders/software) | Verified building permits for roofing contractors. | | [Software](/business/nouns/software) | The tool works. | SoftwareBuilder | Lesson booking for independent music teachers. | | [Agent](/business/nouns/agent) | The task passes, or it is redone or free. | SoftwareBuilder | Month-end close for design studios, in their own accounting tool. | | [Service](/business/nouns/service) | The outcome arrives, or the remedy applies. | [ServiceBuilder](/code/builders/service) | Certified legal translation, redone free if review fails. | The line between an Agent and a Service is where done lives. An Agent is graded on the buyer's task, in the buyer's tools. A Service holds the work until it is done, under an [Outcome Contract](/business/nouns/outcome-contract) that names acceptance and the remedy for a miss. A Product can be several kinds at once. A Dataset served through an API is also Software, and it keeps the promises of both. ## Who supplies the work Supply is digital or human. Digital supply is infinite: code, models, and Agents do the work, so a digital Product needs only demand, while human supply is finite. Each [Human](/business/nouns/human) [Supplier](/business/nouns/supplier) is recruited, checked, credentialed, and paid out, and the Startup that sells their work runs supply acquisition beside demand. A notary marketplace cannot sell more sessions than it has commissioned notaries in a state. Where the law reserves an act to a license holder, the step is a [Reserved Act](/business/nouns/reserved-act) and its [Function](/business/nouns/function) is always human. A Product that needs one goes Live only once the [Credential](/business/nouns/credential) class is staffed. ## How a Product earns How a Product earns is a second axis, set on its [Offer](/business/nouns/offer). Any kind pairs with any earning model. | Earning model | The Customer pays | Example | | --- | --- | --- | | `subscription` | Each period, for access. | $29 a month per music teacher. | | `usage` | Per call, record, or task, counted by a [Meter](/business/nouns/meter). | Two cents per verified permit. | | `commerce` | Once per item, at checkout; an upstream supplier holds the stock and ships it. | A split ergonomic keyboard, dropshipped. | | `marketplace` | A Supplier directly, while the Startup takes a share. | Nonprofits hire grant writers; the Startup keeps 12 percent. | | `directory` | Nothing; listed Suppliers pay to appear. | Transcription vendors pay $99 a month for a verified listing. | Every Offer declares the [Event](/business/nouns/event) that earns its revenue: a Dataset or Software earns on `Action.done`. An Agent earns on the [Evaluator](/business/nouns/evaluator) verdict that its task passed. A Service earns when the Customer accepts the work, or when acceptance is deemed after its window. The warranty test separates a Service from a marketplace. If the Startup warrants the outcome, it sells a Service; if the Customer contracts with the Supplier directly, it runs a marketplace. ## Who buys The buyer is a person, a business, a developer, or an [Agent](/business/nouns/agent) buying for one of them. A [Motion](/business/nouns/motion) names the pair on each Offer: `b2b`, `b2c`, `b2d`, `b2a`, and the chains such as `b2a2c`, where an Agent buys for a consumer. The Motion changes who the Customer is, which [Interfaces](/business/nouns/interface) lead, and when a purchase needs an [Approval](/business/nouns/approval) or a [Mandate](/business/nouns/mandate). An Agent buyer reads the Offer's machine contract, asks for a quote, and checks out inside its own spending [Limits](/business/nouns/limit). It never needs the [Site](/business/nouns/site). ## Product Templates A [Product Template](/business/nouns/product-template) is a reusable definition of one kind of Product. It fixes the kind, the supply, who does the work, the Interfaces, the buyer, the earning model, and the assurance. | Product Template | Kind | Supply | Buyer | Earning model | | --- | --- | --- | --- | --- | | [Dataset API](/products/templates/dataset-api) | data | digital | human-or-agent | usage | | [Headless SaaS](/products/templates/headless-saas) | software | digital | human-or-agent | usage | | [SaaS](/products/templates/saas) | software | digital | human | subscription | | [Directory](/products/templates/directory) | data | digital | human-or-agent | directory | | [Marketplace](/products/templates/marketplace) | software | human | human-or-agent | marketplace | | [Licensed-human marketplace](/products/templates/licensed-marketplace) | service | human | human-or-agent | marketplace | | [Agent as a Service](/products/templates/agent-as-a-service) | agent | digital | human-or-agent | usage | | [Services-as-Software](/products/templates/services-as-software) | service | digital | human-or-agent | usage | | [E2E managed service](/products/templates/managed-service) | service | human | human | subscription | | [Dropship store](/products/templates/dropship-store) | software | digital | human-or-agent | commerce | A [Startup Template](/business/nouns/startup-template) combines Product Templates with an [operating model](/agents/operating-model) and the Motions they sell through. The [catalog](/start/templates) lists every combination, with what each adds to its base. ## Offers make Products available A Product is never sold bare. An Offer makes it available under a [Brand](/business/nouns/brand), at a [Price](/business/nouns/price), on terms, and one Product can carry several Offers for different buyers. Free is a Price: a $0 Offer still has terms. Accepting an Offer grants [Entitlements](/business/nouns/entitlement): a [Verb](/business/nouns/verb) on a [Noun](/business/nouns/noun) in the Customer's [Tenant](/business/nouns/tenant), bounded by a Limit. An [Order](/business/nouns/order) keeps the Offer [Version](/business/nouns/version) it bought, so a later price change never rewrites a past sale. ## Products compose A Service uses an Agent, the Agent uses Software, and the Software reads a Dataset. Each link is a `builtFrom` [Relationship](/business/nouns/relationship), shown on both Products. What a Product draws on but did not build is a [Source](/business/nouns/source): owned, wrapped, or recruited. Coverage, cost, and assurance roll up the chain. The translation Service's assurance is no stronger than its weakest step, and a remedy runs down the chain, so the upstream Agent's remedy settles first. ## Next [Operating models](/agents/operating-model): who runs the Startup, and what changes as humans join.