schema

The schema block defines a custom type with named fields. Schemas are used for structured agent outputs, input types, and type-safe data passing between agents.

Syntax

schema <name> {
  field1 = <type>
  field2 = <type>
}

Field types

Each field is assigned a type. Use | nulltype to make a field optional — nulltype is the type whose only value is null:

schema report {
  title      = string                // required
  summary    = string                // required
  sources    = list[string]          // required
  word_count = number | nulltype     // optional
}

Field descriptions

Use the @desc annotation to document fields:

schema report {
  @desc("The report title")
  title = string

  @desc("Executive summary, max 200 words")
  summary = string

  @desc("List of source URLs")
  sources = list[string]
}

Examples

Structured output for an agent

schema analysis {
  sentiment  = string
  confidence = number
  keywords   = list[string]
}

agent analyst {
  model   = gpt4
  persona = "You analyze text sentiment."
  output  = analysis
}

Nested schemas

schema address {
  street = string
  city   = string
  zip    = string
}

schema customer {
  name    = string
  email   = string
  address = address
}

Schema with collections

schema search_results {
  query   = string
  results = list[string]
  metadata = map[string]
}