Omni.Schema (Omni v1.2.1)

Builders and validation for JSON Schema maps.

Each builder returns a plain map following JSON Schema conventions. Property keys are preserved as-is — use atoms for idiomatic Elixir, and JSON serialisation handles stringification on the wire.

Option keywords accept snake_case and are normalized to camelCase JSON Schema keywords automatically (e.g. min_length: becomes minLength). Keys without a known mapping pass through unchanged.

Example

iex> Omni.Schema.object(%{
...>   city: Omni.Schema.string(description: "City name"),
...>   temp: Omni.Schema.number()
...> }, required: [:city])
%{
  type: "object",
  properties: %{
    city: %{type: "string", description: "City name"},
    temp: %{type: "number"}
  },
  required: [:city]
}

Summary

Functions

any_of(schemas, opts \\ [])

Builds a JSON Schema anyOf — valid when at least one subschema matches.

array(opts)

Builds a JSON Schema array type.

array(items, opts \\ [])

Builds a JSON Schema array with the given items schema.

boolean(opts \\ [])

Builds a JSON Schema boolean type.

enum(values, opts \\ [])

Builds a JSON Schema enum — a list of allowed literal values.

integer(opts \\ [])

Builds a JSON Schema integer type.

number(opts \\ [])

Builds a JSON Schema number type.

object(opts)

Builds a JSON Schema object type.

object(properties, opts \\ [])

Builds a JSON Schema object with the given properties map.

string(opts \\ [])

Builds a JSON Schema string type.

update(schema, opts)

Merges additional options into an existing schema map.

validate(schema, input)

Validates input against a schema.

Functions

any_of(schemas, opts \\ [])

@spec any_of(
  [map()],
  keyword()
) :: map()

Builds a JSON Schema anyOf — valid when at least one subschema matches.

array(opts)

@spec array(keyword()) :: map()

Builds a JSON Schema array type.

array(items, opts \\ [])

@spec array(
  map(),
  keyword()
) :: map()

Builds a JSON Schema array with the given items schema.

boolean(opts \\ [])

@spec boolean(keyword()) :: map()

Builds a JSON Schema boolean type.

enum(values, opts \\ [])

@spec enum(
  list(),
  keyword()
) :: map()

Builds a JSON Schema enum — a list of allowed literal values.

integer(opts \\ [])

@spec integer(keyword()) :: map()

Builds a JSON Schema integer type.

number(opts \\ [])

@spec number(keyword()) :: map()

Builds a JSON Schema number type.

object(opts)

@spec object(keyword()) :: map()

Builds a JSON Schema object type.

object(properties, opts \\ [])

@spec object(
  map(),
  keyword()
) :: map()

Builds a JSON Schema object with the given properties map.

string(opts \\ [])

@spec string(keyword()) :: map()

Builds a JSON Schema string type.

update(schema, opts)

@spec update(
  map(),
  keyword()
) :: map()

Merges additional options into an existing schema map.

Schema.string() |> Schema.update(min_length: 1, max_length: 100)

validate(schema, input)

@spec validate(map(), term()) :: {:ok, term()} | {:error, term()}

Validates input against a schema.

Enforces types, required fields, string constraints (minLength, maxLength, pattern), numeric constraints (minimum, maximum, exclusiveMinimum, exclusiveMaximum), and anyOf unions. Array item types are validated, but array-level constraints (minItems, maxItems, uniqueItems) and multipleOf are not — these are still sent to the LLM in the schema but skipped during local validation.

Property key types are preserved: atom-keyed schemas validate and cast string-keyed JSON input back to atom keys, so validated output uses the same key types as the schema definition. Builder option keywords (e.g. min_length:) must be atoms.