Upgrade to Zod 4, add 55 tests, bump to v0.8.0

- Replace hand-rolled zodToJsonSchema (94 lines) with Zod 4's built-in
  z.toJSONSchema() — covers all schema types, zero maintenance
- Peer dep bumped from zod@^3 to zod@^4 (breaking)
- 55 new unit tests across 6 files:
  - stream-edge-cases: abort, event ordering, usage accumulation
  - handoff-chains: A→B→C, system prompts, guardrail interactions
  - concurrent-tool-calls: parallel execution, failure isolation, ordering
  - tool-validation: malformed args, type mismatches, sync throws
  - model-errors: 429 retry, 401/503, content filter, exhausted retries
  - tracing-extended: multi-call spans, errors, concurrency, metadata

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: tylergibbs1

bun.lock

@@ -1,6 +1,6 @@
 {
   "name": "stratus-sdk",
-  "version": "0.7.6",
+  "version": "0.8.0",
   "type": "module",
   "main": "./dist/index.js",
   "types": "./dist/index.d.ts",
@@ -28,12 +28,12 @@
     "test": "bun test"
   },
   "peerDependencies": {
-    "zod": "^3.23.0"
+    "zod": "^4.0.0"
   },
   "devDependencies": {
     "@biomejs/biome": "^1.9.0",
     "@types/bun": "^1.3.9",
     "typescript": "^5.6.0",
-    "zod": "^3.23.0"
+    "zod": "^4.0.0"
   }
 }

package.json

@@ -1,93 +1,9 @@
-import type { z } from "zod";
+import { type ZodTypeAny, toJSONSchema } from "zod";
 
 type JsonSchema = Record<string, unknown>;
 
-export function zodToJsonSchema(schema: z.ZodTypeAny): JsonSchema {
-	return convertSchema(schema);
-}
-
-function convertSchema(schema: z.ZodTypeAny): JsonSchema {
-	const def = schema._def;
-	const typeName = def.typeName as string;
-
-	switch (typeName) {
-		case "ZodObject":
-			return convertObject(schema as z.ZodObject<z.ZodRawShape>);
-		case "ZodString":
-			return withDescription({ type: "string" }, def.description);
-		case "ZodNumber":
-			return withDescription({ type: "number" }, def.description);
-		case "ZodBoolean":
-			return withDescription({ type: "boolean" }, def.description);
-		case "ZodArray":
-			return withDescription(
-				{ type: "array", items: convertSchema(def.type) },
-				def.description,
-			);
-		case "ZodEnum":
-			return withDescription(
-				{ type: "string", enum: def.values as string[] },
-				def.description,
-			);
-		case "ZodNativeEnum":
-			return withDescription(
-				{ type: "string", enum: Object.values(def.values as Record<string, string>) },
-				def.description,
-			);
-		case "ZodOptional":
-			return convertSchema(def.innerType);
-		case "ZodNullable":
-			return { ...convertSchema(def.innerType), nullable: true };
-		case "ZodDefault":
-			return convertSchema(def.innerType);
-		case "ZodLiteral":
-			return withDescription({ type: typeof def.value, const: def.value }, def.description);
-		case "ZodUnion": {
-			const options = (def.options as z.ZodTypeAny[]).map(convertSchema);
-			return withDescription({ anyOf: options }, def.description);
-		}
-		default:
-			return {};
-	}
-}
-
-function convertObject(schema: z.ZodObject<z.ZodRawShape>): JsonSchema {
-	const shape = schema.shape;
-	const properties: Record<string, JsonSchema> = {};
-	const required: string[] = [];
-
-	for (const [key, value] of Object.entries(shape)) {
-		const fieldSchema = value as z.ZodTypeAny;
-		properties[key] = convertSchema(fieldSchema);
-
-		if (!isOptional(fieldSchema)) {
-			required.push(key);
-		}
-	}
-
-	const result: JsonSchema = {
-		type: "object",
-		properties,
-		additionalProperties: false,
-	};
-
-	if (required.length > 0) {
-		result.required = required;
-	}
-
-	return withDescription(result, schema._def.description);
-}
-
-function isOptional(schema: z.ZodTypeAny): boolean {
-	const typeName = schema._def.typeName as string;
-	if (typeName === "ZodOptional") return true;
-	if (typeName === "ZodDefault") return true;
-	return false;
-}
-
-function withDescription(schema: JsonSchema, description?: string): JsonSchema {
-	if (description) {
-		return { ...schema, description };
-	}
-	return schema;
+export function zodToJsonSchema(schema: ZodTypeAny): JsonSchema {
+	const result = toJSONSchema(schema) as JsonSchema;
+	delete result.$schema;
+	return result;
 }