Verb functions

A file named [Noun].[verb].ts in nouns/ holds the Function behind one Verb. The file name binds it; nothing registers it.

ReferenceCopy Anchor Link

TypeScript with one default export. .sb/types/ declares the Noun, each Verb's input type and $ globally, so the file needs no import.

The input type is named for the Noun and Verb: renew on Lease takes LeaseRenewInput, compiled from the Verb's entry in the Nouns file.

The kind is read from the code. $.Noun.verb() calls are code, $`…` is one model call, an Agent's tag such as rae`…` is agentic, and a person's tag is a human Task. The caller never sees which ran.

ExamplesCopy Anchor Link

MinimalCopy Anchor Link

export default async (lease: Lease, input: LeaseRenewInput, $: $) => {
  const end = new Date(lease.endsOn)
  end.setMonth(end.getMonth() + input.months)
  return $.Lease.update({ id: lease.$id, endsOn: end.toISOString().slice(0, 10) })
}

LeaselineCopy Anchor Link

Leaseline declares a Lease Noun whose renew Verb takes months and an optional increase (the Nouns file declares them). Renewal extends the end date by the term and raises the rent within the increase the manager allows.

export default async (lease: Lease, input: LeaseRenewInput, $: $) => {
  const end = new Date(lease.endsOn)
  end.setMonth(end.getMonth() + input.months)
  const rent = lease.rent && { ...lease.rent, amount: Math.round(lease.rent.amount * (1 + (input.increase ?? 0))) }
  return $.Lease.update({ id: lease.$id, endsOn: end.toISOString().slice(0, 10), rent })
}

The Function never sets status, and update takes no status input. When the Action succeeds, the Verb's Event, Lease.renewed, moves the record to renewed.

What it buildsCopy Anchor Link

The SoftwareBuilder compiles the file into one Function Version for the Verb.

• a Function with kind read from the code
• each call returns one Action pinned to that Function Version, with input, output and cost
• the Verb's Event, Lease.renewed, when the Action succeeds

Good to knowCopy Anchor Link

• Without the file, the Verb runs its inherited or default Function.
• A Verb has one body. This file and a Workflow on the same Verb fail the parse check together.
• Functions cover cascades, durable steps and agentic kinds.