Module tool 

Tool handles: MCP sessions, HTTP/OpenAPI endpoints, local processes.

Tools are capabilities like everything else, which means a tool handle inherits the same guarantees: no ambient authority, attenuation-only narrowing, budget accounting and drop notification.

Adapter	What it talks to
McpSession	an MCP server, over an injected line transport (stdio or in-memory)
HttpTool	an HTTP endpoint restricted to an allowlist of METHOD path pairs
LocalProcess	a sandboxed child process: allowlisted program, no shell, scrubbed environment

Every adapter returns a Response::Value built from JSON, never a raw string dump, and every adapter refuses a call outside its policy with rpc/tool-policy.

Structs

HttpTool

An HTTP endpoint restricted to an allowlist.

LocalProcess

A sandboxed local process tool.

McpSession

A provider backed by an MCP session.

McpToolDef

One tool exposed by an MCP server.

MemoryTransport

An in-memory transport: requests are answered by a closure.

StdioTransport

A child-process MCP transport speaking JSON-RPC over stdin/stdout.

Traits

McpTransport

A line-oriented JSON-RPC transport used by McpSession.

Functions

json_to_value

Convert JSON into an RPC value.

value_to_json

Convert an RPC value into JSON.