droid-mcp-core/io.droidmcp.core/OutputSchema

OutputSchema

Builds the JSON Schema a tool advertises as McpTool.outputSchema, and checks result maps against it.

override val outputSchema = OutputSchema.obj {
    integer("count")
    array("events") {
        integer("id")
        string("title", nullable = true)
        string("end", nullable = true)
    }
}

Every field is listed in required unless declared optional = true (for keys a tool only sometimes returns). nullable = true allows the key to hold JSON null. Objects stay open (no additionalProperties: false), so adding a result key later is not a breaking change.

Types

ObjectBuilder

class ObjectBuilder

Declares the properties of one object schema.

Functions

boolean

fun boolean(): Map<String, Any>

A boolean schema, for ObjectBuilder.array items.

integer

fun integer(): Map<String, Any>

An integer schema, for ObjectBuilder.array items.

number

fun number(): Map<String, Any>

A number schema, for ObjectBuilder.array items.

obj

fun obj(block: OutputSchema.ObjectBuilder.() -> Unit): Map<String, Any>

An object schema built by block. Use as the top-level McpTool.outputSchema.

string

fun string(): Map<String, Any>

A string schema, for ObjectBuilder.array items.

violations

fun violations(schema: Map<String, Any>, value: Any?): List<String>

Where value breaks schema, as path: problem strings; empty when it conforms. Covers the subset obj emits (type, properties, required, items). Meant for tests that pin a tool's real output to its declared schema.