Checked other resources

• This is a bug, not a usage question. For questions, please use the LangChain Forum (https://forum.langchain.com/).
• I added a very descriptive title to this issue.
• I searched the LangChain.js documentation with the integrated search.
• I used the GitHub search to find a similar question and didn't find it.
• I am sure that this is a bug in LangChain.js rather than my code.
• The bug is not resolved by updating to the latest stable version of LangChain (or the specific integration package).

Example Code

export const agent = createAgent({
    model,
    tools: [vectorizeSearch],
    middleware: [
      ...
    ],
    contextSchema: userContextSchema,  // ❌ Not recognized by LangSmith
    checkpointer: new MemorySaver(),
  });

Error Message and Stack Trace (if applicable)

In LangSmith Studio UI:
⚠️ No configuration schema or an empty schema found for assistant. Learn more: https://langchain-ai.github.io/langgraph/how-tos/configuration/

I also get this in my console Failed to obtain symbol "__langgraph__agent_graph__update": Unsupported type: never

Agent runs successfully when context is provided via:

  {
    "messages": [...],
}

{
      "context": { /* all required fields */ }
  }

Description

When using createAgent from langchain v1.0.0-alpha.9 with a contextSchema parameter, LangSmith Studio displays the error: "No configuration schema or an empty schema found for assistant" and links to configuration documentation.

The contextSchema is properly defined using Zod and validated at runtime (works correctly when passing context via configurable.context), but it's not exposed to LangSmith Studio's UI as a configurable schema.

System Info

Package Versions:

• langchain: 1.0.0-alpha.9
• @langchain/core: 1.0.0-alpha.7
• @langchain/langgraph: 0.4.9
• @langchain/langgraph-checkpoint: 0.1.1
• @langchain/google-genai: 0.2.18
• zod: 4.1.12

Environment:

• Node.js: v20.x
• OS: macOS (Darwin 25.0.0)
• TypeScript: 5.9.3
• Using LangGraph CLI dev server (port 2024)