# Known Issues - AI SDK Demo
## Schema Serialization Issue with AI SDK v5
**Status**: 🔴 Active Issue - **CONFIRMED BUG**
**Priority**: High
**Affected**: All SkyFi MCP tools
**AI SDK Version**: v5.0.93
**Zod Version**: v3.25.76
### Problem
When attempting to use SkyFi MCP tools with AI SDK v5, we encounter the following error:
```
Invalid schema for function 'skyfi_search_data': schema must be a JSON Schema of 'type: "object"', got 'type: "None"'.
```
This error occurs **even when**:
- Using Zod schemas with required fields
- Using JSON schemas directly
- Using `.partial()` instead of `.optional()`
- Ensuring at least one required field exists
- Manually converting Zod to JSON schema
### Root Cause
**CONFIRMED**: This is a bug in AI SDK v5's internal schema serialization. The `tool()` function is incorrectly serializing Zod schemas (or JSON schemas) as `type: "None"` instead of `type: "object"`, regardless of the schema structure.
**Evidence**:
- Error persists with all schema variations
- Error occurs even with simple schemas that have required fields
- Error occurs with both Zod and JSON schemas
- Server-side logging shows correct schema structure before passing to `tool()`
### Attempted Solutions
We've tried multiple approaches:
1. ✅ Using `z.any()` for complex GeoJSON objects
2. ✅ Using `z.union([z.any(), z.undefined()])`
3. ✅ Using `z.object({}).passthrough()`
4. ✅ Removing `areaOfInterest` from schemas
5. ✅ Using JSON schema directly from `getSkyFiFunctions()`
6. ✅ Adding additional fields to schemas
None of these approaches have resolved the issue.
### Current Workaround
**Option 1: Tools Disabled (Current State)**
- Tools are currently disabled in `app/api/chat/route.ts`
- Basic chat functionality works without tools
- Users can still interact with the AI, but SkyFi MCP functions are not available
**Option 2: Use ADK or LangChain Demos**
- The ADK and LangChain integrations work correctly
- These frameworks don't have the same schema serialization issues
- See `demo/adk-demo/` and `demo/langchain-demo/` for working examples
### Recommended Solutions
1. **Wait for AI SDK v5 Fix**: This appears to be a bug in AI SDK v5's schema serialization. Monitor the [AI SDK GitHub repository](https://github.com/vercel/ai) for updates.
2. **Downgrade to AI SDK v3**: AI SDK v3 had different schema handling that might work better. However, this would require significant code changes.
3. **Use Function Calling Instead of Tools**: AI SDK v5 supports function calling with a different API that might not have this limitation.
4. **Create Minimal Schemas**: Ensure every schema has at least one required field, even if it's just a placeholder.
### Testing
To test if the issue is resolved:
1. Enable tools in `app/api/chat/route.ts` by uncommenting `const tools = createSkyFiTools();`
2. Restart the Next.js dev server
3. Try asking: "What tools do you have?"
4. Check the browser console and server logs for errors
### Related Issues
- [AI SDK v5 Tool Schema Serialization](https://github.com/vercel/ai/issues) - Search for similar issues
- [Zod Schema with All Optional Fields](https://github.com/colinhacks/zod/issues) - Related Zod serialization issues
### Next Steps
1. Monitor AI SDK v5 releases for schema serialization fixes
2. Consider creating a minimal reproduction case to report to the AI SDK team
3. Explore alternative approaches to tool definition in AI SDK v5
