earendil-works/pi · error · UnsupportedStrictJsonSchemaError

root schema must have type object

Error message

root schema must have type object

What it means

Error "root schema must have type object" thrown in earendil-works/pi.

Source

Thrown at packages/ai/src/api/constrained-sampling.ts:120

	const required = new Set(Array.isArray(schema.required) ? schema.required : []);
	if ([...required].some((key) => !propertyNames.includes(key))) {
		throw new UnsupportedStrictJsonSchemaError("required contains an unknown property");
	}
	for (const [key, property] of Object.entries(properties)) {
		makeJsonSchemaNodeStrict(property);
		if (!required.has(key) && !schemaAllowsNull(property)) {
			properties[key] = { anyOf: [property, { type: "null" }] };
		}
	}
	schema.required = propertyNames;
	schema.additionalProperties = false;
}

/** Convert a tool schema to the strict subset expected by provider constrained sampling. */
export function makeStrictJsonSchema(schema: Tool["parameters"]): Record<string, unknown> {
	const cloned: unknown = structuredClone(schema);
	if (!isJsonSchemaObject(cloned)) {
		throw new UnsupportedStrictJsonSchemaError("root schema must have type object");
	}
	makeJsonSchemaNodeStrict(cloned);
	if (cloned.type !== "object") {
		throw new UnsupportedStrictJsonSchemaError("root schema must have type object");
	}
	return cloned;
}

export function getJsonSchemaToolParameters(tool: Tool, strict: boolean | undefined): Tool["parameters"] {
	return (strict === true ? makeStrictJsonSchema(tool.parameters) : tool.parameters) as Tool["parameters"];
}

export interface GrammarConstrainedSampling {
	format: "lark" | "regex";
	definition: string;
	inputProperty: string;
}

View on GitHub (pinned to 4af9d21d3b)

Solutions

1. Use a root schema whose type is object.

When it happens

Trigger: Thrown at packages/ai/src/api/constrained-sampling.ts:120 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of earendil-works/pi@4af9d21d3b (2026-08-24). Data as JSON: /api/errors/77053aeaa8186dc2. Report an issue: GitHub.