diff --git a/packages/openai-agents/src/__tests__/native-graph.real-sdk.test.ts b/packages/openai-agents/src/__tests__/native-graph.real-sdk.test.ts
new file mode 100644
index 00000000..15e58b35
--- /dev/null
+++ b/packages/openai-agents/src/__tests__/native-graph.real-sdk.test.ts
@@ -0,0 +1,111 @@
+// The real `@openai/agents` package runs the graph; only the model is fake. native-graph.test.ts mocks
+// the whole package, which is how the Python twin of this adapter shipped a tool builder that crashed on
+// every node with a tool (AIC-3716). Kept in its own file because vi.mock applies per file.
+import type { GraphDefinition, GraphNode } from '@launchdarkly/ai-server';
+import {
+  type Model,
+  type ModelRequest,
+  type ModelResponse,
+  setDefaultModelProvider,
+  setTracingDisabled,
+  Usage,
+} from '@openai/agents';
+import { describe, expect, it } from 'vitest';
+import { toOpenAIAgents } from '../native-graph.js';
+
+// Not strict-mode shaped (`limit` optional, no additionalProperties), so a rewrite shows.
+const schema = {
+  type: 'object',
+  properties: { q: { type: 'string' }, limit: { type: 'integer' } },
+  required: ['q'],
+};
+
+const node: GraphNode = {
+  key: 'root',
+  config: {
+    model: { name: 'gpt-4o' },
+    provider: { name: 'OpenAI' },
+    instructions: 'help',
+    tools: { lookup: { name: 'lookup', type: 'function', description: 'Look up', parameters: schema } },
+  },
+  meta: { variationKey: 'v1', version: 1 },
+  edges: [],
+  isTerminal: true,
+} as unknown as GraphNode;
+
+const graphDef = {
+  key: 'test-graph',
+  enabled: true,
+  root: node,
+  getNode: (k: string) => (k === 'root' ? node : undefined),
+  reverseTraverse: async (fn: (n: GraphNode, ctx: Record<string, unknown>) => Promise<void>) => fn(node, {}),
+} as unknown as GraphDefinition;
+
+// Turn 1 calls the tool; turn 2 answers with the tool's result.
+class FakeModel implements Model {
+  requests: ModelRequest[] = [];
+
+  async getResponse(request: ModelRequest): Promise<ModelResponse> {
+    this.requests.push(request);
+    const results = (Array.isArray(request.input) ? request.input : []).filter(
+      (i) => i.type === 'function_call_result',
+    );
+    if (results.length === 0) {
+      return {
+        usage: new Usage(),
+        output: [
+          { type: 'function_call', callId: 'call1', name: 'lookup', arguments: '{"q":"hi"}', status: 'completed' },
+        ],
+      };
+    }
+    const last = results[results.length - 1] as { output: unknown };
+    const text = typeof last.output === 'string' ? last.output : (last.output as { text: string }).text;
+    return {
+      usage: new Usage(),
+      output: [
+        {
+          type: 'message',
+          role: 'assistant',
+          status: 'completed',
+          content: [{ type: 'output_text', text: `answer: ${text}` }],
+        },
+      ],
+    };
+  }
+
+  async *getStreamedResponse(): AsyncIterable<never> {
+    throw new Error('not streamed');
+  }
+}
+
+describe('toOpenAIAgents on the real @openai/agents', () => {
+  it('runs a node with a tool: the call reaches the handler and the run completes', async () => {
+    const model = new FakeModel();
+    // Module state, but vitest isolates each test file, so no other file sees it.
+    setDefaultModelProvider({ getModel: () => model });
+    // Never export this run's trace to OpenAI, whatever OPENAI_API_KEY is set.
+    setTracingDisabled(true);
+    const calls: unknown[] = [];
+
+    const result = await toOpenAIAgents(Promise.resolve(graphDef), {
+      toolHandlers: {
+        lookup: (args: unknown) => {
+          calls.push(args);
+          return `found ${(args as { q: string }).q}`;
+        },
+      },
+    }).invoke('q');
+
+    expect(calls).toEqual([{ q: 'hi' }]);
+    expect(result.response).toBe('answer: found hi');
+    expect(model.requests[0].tools).toEqual([
+      expect.objectContaining({
+        type: 'function',
+        name: 'lookup',
+        description: 'Look up',
+        parameters: schema,
+        strict: false,
+      }),
+    ]);
+  });
+});