earendil-works/pi · error · UnsupportedStrictJsonSchemaError

anyOf must contain at least one schema

Error message

anyOf must contain at least one schema

What it means

Error "anyOf must contain at least one schema" thrown in earendil-works/pi.

Source

Thrown at packages/ai/src/api/constrained-sampling.ts:65

	if (!isJsonSchemaObject(schema)) return false;
	if (schema.type === "null" || (Array.isArray(schema.type) && schema.type.includes("null"))) return true;
	if (schema.const === null || (Array.isArray(schema.enum) && schema.enum.includes(null))) return true;
	return Array.isArray(schema.anyOf) && schema.anyOf.some((variant) => schemaAllowsNull(variant));
}

function makeJsonSchemaNodeStrict(schema: unknown): void {
	if (!isJsonSchemaObject(schema)) {
		throw new UnsupportedStrictJsonSchemaError("boolean schemas are unsupported");
	}
	for (const key of UNSUPPORTED_STRICT_SCHEMA_KEYS) {
		if (schema[key] !== undefined) {
			throw new UnsupportedStrictJsonSchemaError(`${key} schemas are unsupported`);
		}
	}

	if (schema.anyOf !== undefined) {
		if (!Array.isArray(schema.anyOf) || schema.anyOf.length === 0) {
			throw new UnsupportedStrictJsonSchemaError("anyOf must contain at least one schema");
		}
		for (const variant of schema.anyOf) {
			if (isStructuredSchema(variant)) {
				throw new UnsupportedStrictJsonSchemaError("object and array unions are unsupported");
			}
			makeJsonSchemaNodeStrict(variant);
		}
	}

	if (schema.items !== undefined) {
		if (Array.isArray(schema.items)) {
			throw new UnsupportedStrictJsonSchemaError("tuple schemas are unsupported");
		}
		makeJsonSchemaNodeStrict(schema.items);
	}

	const isObjectSchema = schema.type === "object";
	if (schema.properties !== undefined && !isObjectSchema) {

View on GitHub (pinned to 4af9d21d3b)

Solutions

1. Provide at least one subschema in anyOf.

When it happens

Trigger: Thrown at packages/ai/src/api/constrained-sampling.ts:65 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/6173d873c9391ea7. Report an issue: GitHub.