LangChain AgentResolver Guard — Verify x402 Before Paying json_schema_validate
How to: LangChain AgentResolver Guard — Verify x402 Before Paying json_schema_validate
Add AgentResolver Guard — Verify x402 Before Paying to LangChain
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01
Open pip install langchain-mcp-adapters and merge this in. Keep any servers already there.
from langchain_mcp_adapters.client import MultiServerMCPClient
client = MultiServerMCPClient({
"agentresolver": {
"transport": "streamable_http",
"url": "https://agentresolver.vercel.app/mcp",
}
})
tools = await client.get_tools()
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02
Save the file and restart LangChain.
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03
Ask for something json_schema_validate does. LangChain lists the server's tools on connect and calls json_schema_validate itself — you do not invoke it by name.
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04
If nothing happens, check the server is running and that AgentResolver Guard — Verify x402 Before Paying's identifier in your config matches the one above exactly.
get_tools() returns the server's tools as LangChain tools, ready for an agent. LangChain docs
Same tool, other clients
This list was read from the server itself, by connecting to it and calling tools/list on 24 September 2026. It is what
the server actually exposes, not what its listing claims.
Mutating and Read-only are read off each tool's name, not its schema — a hint, not a guarantee. The registry stores tool names only; connect the server for its live schemas.