draf.ing runs a remote MCP server. Connect it once and Claude can build P&ID sheets in your account from a description of the process. The engine still chooses the symbols, the tag structure and the geometry.
https://draf.ing/mcphttps://draf.ing/mcp as the server URL.The handshake has to arrive at /mcp. A connector set up with https://draf.ing completes the sign-in and then reports that no MCP server was found at the URL.
One command, then authorise from inside the session.
claude mcp add --transport http draf-ing https://draf.ing/mcpRun /mcp, pick draf-ing, and finish the sign-in in the browser window it opens. Once the token is held, claude mcp list shows the connection.
Thirteen tools. A symbol's position can come from the client; its size, its nozzles, its tag number and the route of every line stay with the server.
| Tool | What it does |
|---|---|
| create_pid | Builds a sheet from process intent: streams, equipment, control loops. |
| list_diagrams | Lists your drawings with their ids, titles and current revisions. |
| get_diagram | Reads the drawing as a compact summary: every symbol's box, and for every line the faces it uses and how many bends its route has. |
| add_node | Adds one ISA symbol: equipment, instrument, final element, in-line device or off-page connector. Takes an optional x and y. |
| place_nodes | Moves symbols to given coordinates, re-routes every line that touches them, and nudges a symbol that came within about 30 px of lining up onto that axis. Reports the sheet size and any boxes that overlap. |
| add_edge | Connects two symbols through the port-aware orthogonal router, which picks the faces from where the two symbols stand. |
| set_flow | Shows, hides or reverses the flow arrowheads on a line. |
| delete_node | Deletes a symbol and every line attached to it. |
| delete_edge | Deletes one line. |
| relayout | Arranges symbols that have no position yet. Positions set by hand or by place_nodes, and locked symbols, stay where they are. |
| validate_diagram | Runs the engineering validation rules over the drawing. |
| export_png | Returns the sheet as an image, ruled with a labelled 100 px grid, so an assistant can see the drawing and read a correction straight off it. |
| export_svg | Exports the drawing as a self-contained SVG, for saving or handing to a person. |
The server also publishes two resources a client can read: draf://schema/intent, the process intent schema, and draf://catalog, the ISA symbol catalogue.
Say what the process is and you get a sheet back. Tag numbers, symbol shapes and line routes are the engine's to assign, so asking for a particular symbol file or a hand-drawn pipe route gets you nothing. Where the symbols sit is the one thing you can set yourself.
Draw the overhead system. A reflux drum fed by the condenser, a pump taking suction from the drum, level control on the drum acting on the pump discharge, and a pressure transmitter on the drum wired back to the control system.
Tag the drum D-102, use the vessel-drum symbol, and run its outlet pipe down the left edge of the sheet.
get_diagram returned. If you changed the sheet in the editor meanwhile, the write comes back 409 and the assistant reads the drawing again instead of overwriting you.validate_diagram applies the same rules the editor does.Reproducing a drawing means choosing the coordinates and leaving the drawing to the server. Six steps, and the last three can run as many times as the arrangement needs.
x and y. Coordinates are the top-left of the box in sheet pixels, x to the right and y down, snapped to a 10 px grid. Each call returns the box the engine built, so line symbols up by their centres (x + width/2) rather than their corners.add_edge and no port names. The router picks the faces the two symbols present each other, and picks them again whenever one of the symbols moves.place_nodes on what you placed. It re-routes the lines, lines up anything within a nudge of straight, and names the boxes that now overlap.get_diagram. Every line reports from_side, to_side and bends. A run with no bends is straight; two or more usually means the symbols are in the wrong place, so move a symbol instead of redrawing the line.export_png returns the sheet as an image, ruled with a labelled 100 px grid in sheet coordinates, so whatever stands in the wrong place can be read off the picture and moved with place_nodes. Reproducing a drawing means repeating this until the two match.A language model reads PNG, JPEG, GIF and WebP. An SVG reaches it as source text, which is both large and unreadable as a picture, so export_png is how an assistant checks its own work. A 900 px render of a normal sheet is about 25 KB and takes roughly 55 ms on the server; export_svg of the same sheet is 10 to 150 KB of markup nobody can look at.
Moving a symbol re-routes every line attached to it through the same port-aware router the editor uses, so runs keep their right angles, their nozzles and their crossing hops. There is no way to hand the server a pipe route, and that is deliberate: two sources of geometry would disagree.
/mcp, or you were signed in as a guest. Sign in to draf.ing in the same browser and connect again.Sheets the connector creates are ordinary draf.ing drawings. Same editor, same catalogue, same export.
Open the editor