Thingctx MCP server

thingctx

thingctx turns a description of any API, device, or local process into tools an AI agent can call: authorized per operation, over the system's own transport, and the agent never holds your keys. The description is a W3C Web of Things Thing Description (a TD), a plain JSON file naming what the system can do. Write one, or compile it from an OpenAPI spec. The described system is the server, so you run no server per integration.

A "Thing" is whatever you want to describe: a REST API, an app, a sensor, a media server, a local object, or one system that is several of those at once. A media server takes commands over HTTP and serves its stream over RTSP. The pump in examples/ reads over MQTT and acts through a local call. Each is one Thing and one description.

A description names actions, properties, and events, and gives each one a form: the entry that says where and how to reach it. The URL scheme in that address picks the transport per call, so however many protocols one Thing spans, the agent still sees one tool set.

docs/BINDINGS.md covers the transports and how to add your own. A subprocess transport, exec, also ships, and it ships locked: it refuses every command until you hand it an explicit allowlist.

Those three stay distinct all the way to the call. A read, a write, and a subscribe do not collapse into one undifferentiated function, which is why the gate can allow the read and refuse the write on the same system. A flat list of functions has no such handle.

Pick your path: use it as a library if you own the agent loop, the command line if you do not want to write code, the MCP bridge if your host only speaks MCP, or add a transport if thingctx does not speak your protocol yet.

Stuck, or wondering whether something is possible? Ask in Discussions. Want to build something small? The open issues say what would help.

First run: no keys, no network

One paste shows the whole idea. The description is inline and the handler ships with the package, so nothing here needs a key, a network, or a second file:

pip install thingctx

import asyncio

import thingctx
from thingctx.contrib.time import make_time_handler

TD = {
    "@context": "https://www.w3.org/2022/wot/td/v1.1",
    "id": "urn:thingctx:time",
    "title": "Time",
    "securityDefinitions": {"nosec_sc": {"scheme": "nosec"}},
    "security": ["nosec_sc"],
    "actions": {
        "getCurrentTime": {
            "description": "Current time in an IANA timezone (default UTC).",
            "input": {
                "type": "object",
                "properties": {"timezone": {"type": "string"}},
            },
            "safe": True,
            "idempotent": True,
            "forms": [{"href": "local://getCurrentTime"}],
        }
    },
}

Shortened. The full README is on GitHub.